[2/2,ARM] Add support for -mpure-code in thumb-1 (v6m)

Hi,

This patch extends support for -mpure-code to all thumb-1 processors,
by removing the need for MOVT.

Symbol addresses are built using upper8_15, upper0_7, lower8_15 and
lower0_7 relocations, and constants are built using sequences of
movs/adds and lsls instructions.

The extension of the *thumb1_movhf pattern uses always the same size
(6) although it can emit a shorter sequence when possible. This is
similar to what *arm32_movhf already does.

CASE_VECTOR_PC_RELATIVE is now false with -mpure-code, to avoid
generating invalid assembly code with differences from symbols from
two different sections (the difference cannot be computed by the
assembler).

Tests pr45701-[12].c needed a small adjustment to avoid matching
upper8_15 when looking for the r8 register.

Test no-literal-pool.c is augmented with __fp16, so it now uses
-mfp16-format=ieee.

Test thumb1-Os-mult.c generates an inline code sequence with
-mpure-code and computes the multiplication by using a sequence of
add/shift rather than using the multiply instruction, so we skip it in
presence of -mpure-code.

With -mcpu=cortex-m0, the pure-code/no-literal-pool.c fails because
code like:
static char *p = "Hello World";
char *
testchar ()
{
  return p + 4;
}
generates 2 indirections (I removed non-essential directives/code)
        .section        .rodata
.LC0:
.ascii  "Hello World\000"
.data
p:
.word   .LC0
.section        .rodata
.LC2:
.word   p
.section .text,"0x20000006",%progbits
testchar:
push    {r7, lr}
add     r7, sp, #0
movs    r3, #:upper8_15:#.LC2
lsls    r3, #8
adds    r3, #:upper0_7:#.LC2
lsls    r3, #8
adds    r3, #:lower8_15:#.LC2
lsls    r3, #8
adds    r3, #:lower0_7:#.LC2
ldr     r3, [r3]
ldr     r3, [r3]
adds    r3, r3, #4
movs    r0, r3
mov     sp, r7
@ sp needed
pop     {r7, pc}

By contrast, when using -mcpu=cortex-m4, the code looks like:
        .section        .rodata
.LC0:
.ascii  "Hello World\000"
.data
p:
.word   .LC0
testchar:
push    {r7}
add     r7, sp, #0
movw    r3, #:lower16:p
movt    r3, #:upper16:p
ldr     r3, [r3]
adds    r3, r3, #4
mov     r0, r3
mov     sp, r7
pop     {r7}
bx      lr

I haven't found yet how to make code for cortex-m0 apply upper/lower
relocations to "p" instead of .LC2. The current code looks functional,
but could be improved.

OK as-is?

Thanks,

Christophe
From 8c57d721ee94d813553a203bcca5ee31b7ad1a31 Mon Sep 17 00:00:00 2001
From: Christophe Lyon <christophe.lyon@linaro.org>
Date: Fri, 18 Oct 2019 12:15:12 +0000
Subject: [PATCH 2/2] [ARM] Add support for -mpure-code in thumb-1 (v6m)

This patch extends support for -mpure-code to all thumb-1 processors,
by removing the need for MOVT.

Symbol addresses are built using upper8_15, upper0_7, lower8_15 and
lower0_7 relocations, and constants are built using sequences of
movs/adds and lsls instructions.

The extension of the *thumb1_movhf pattern uses always the same size
(6) although it can emit a shorter sequence when possible. This is
similar to what *arm32_movhf already does.

CASE_VECTOR_PC_RELATIVE is now false with -mpure-code, to avoid
generating invalid assembly code with differences from symbols from
two different sections (the difference cannot be computed by the
assembler).

Tests pr45701-[12].c needed a small adjustment to avoid matching
upper8_15 when looking for the r8 register.

Test no-literal-pool.c is augmented with __fp16, so it now uses
-mfp16-format=ieee.

Test thumb1-Os-mult.c generates an inline code sequence with
-mpure-code and computes the multiplication by using a sequence of
add/shift rather than using the multiply instruction, so we skip it in
presence of -mpure-code.

With -mcpu=cortex-m0, the pure-code/no-literal-pool.c fails because
code like:
static char *p = "Hello World";
char *
testchar ()
{
  return p + 4;
}
generates 2 indirections (I removed non-essential directives/code)
        .section        .rodata
.LC0:
	.ascii  "Hello World\000"
	.data
p:
	.word   .LC0
	.section        .rodata
.LC2:
	.word   p
	.section .text,"0x20000006",%progbits
testchar:
	push    {r7, lr}
	add     r7, sp, #0
	movs    r3, #:upper8_15:#.LC2
	lsls    r3, #8
	adds    r3, #:upper0_7:#.LC2
	lsls    r3, #8
	adds    r3, #:lower8_15:#.LC2
	lsls    r3, #8
	adds    r3, #:lower0_7:#.LC2
	ldr     r3, [r3]
	ldr     r3, [r3]
	adds    r3, r3, #4
	movs    r0, r3
	mov     sp, r7
	@ sp needed
	pop     {r7, pc}

By contrast, when using -mcpu=cortex-m4, the code looks like:
        .section        .rodata
.LC0:
	.ascii  "Hello World\000"
	.data
p:
	.word   .LC0
testchar:
	push    {r7}
	add     r7, sp, #0
	movw    r3, #:lower16:p
	movt    r3, #:upper16:p
	ldr     r3, [r3]
	adds    r3, r3, #4
	mov     r0, r3
	mov     sp, r7
	pop     {r7}
	bx      lr

I haven't found yet how to make code for cortex-m0 apply upper/lower
relocations to "p" instead of .LC2. The current code looks functional,
but could be improved.

2019-10-18  Christophe Lyon  <christophe.lyon@linaro.org>

	gcc/
	* config/arm/arm-protos.h (thumb1_gen_const_int): Add new prototype.
	* config/arm/arm.c (arm_option_check_internal): Remove restriction
	on MOVT for -mpure-code.
	(thumb1_gen_const_int): New function.
	(thumb1_legitimate_address_p): Support -mpure-code.
	(thumb1_rtx_costs): Likewise.
	(thumb1_size_rtx_costs): Likewise.
	(arm_thumb1_mi_thunk): Likewise.
	* config/arm/arm.h (CASE_VECTOR_PC_RELATIVE): Likewise.
	* config/arm/thumb1.md (thumb1_movsi_symbol_ref): New.
	(*thumb1_movhf): Support -mpure-code.

	gcc/tests/
	* gcc.target/arm/pr45701-1.c: Adjust for -mpure-code.
	* gcc.target/arm/pr45701-2.c: Likewise.
	* gcc.target/arm/pure-code/no-literal-pool.c: Add tests for
	__fp16.
	* gcc.target/arm/pure-code/pure-code.exp: Remove thumb2 and movt
	conditions.
	* gcc.target/arm/thumb1-Os-mult.c: Skip if -mpure-code is used.

Change-Id: I79c5a5043e7ffec084c38b59a44d69214c0834cf
---
 gcc/config/arm/arm-protos.h                        |  1 +
 gcc/config/arm/arm.c                               | 89 +++++++++++++++++++---
 gcc/config/arm/arm.h                               |  8 +-
 gcc/config/arm/thumb1.md                           | 69 +++++++++++++++--
 gcc/testsuite/gcc.target/arm/pr45701-1.c           |  2 +-
 gcc/testsuite/gcc.target/arm/pr45701-2.c           |  2 +-
 .../gcc.target/arm/pure-code/no-literal-pool.c     | 14 +++-
 .../gcc.target/arm/pure-code/pure-code.exp         |  9 +--
 gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c      |  1 +
 9 files changed, 167 insertions(+), 28 deletions(-)

Ping?

https://gcc.gnu.org/ml/gcc-patches/2019-10/msg01356.html

On Fri, 18 Oct 2019 at 15:18, Christophe Lyon
<christophe.lyon@linaro.org> wrote:
>
> Hi,
>
> This patch extends support for -mpure-code to all thumb-1 processors,
> by removing the need for MOVT.
>
> Symbol addresses are built using upper8_15, upper0_7, lower8_15 and
> lower0_7 relocations, and constants are built using sequences of
> movs/adds and lsls instructions.
>
> The extension of the *thumb1_movhf pattern uses always the same size
> (6) although it can emit a shorter sequence when possible. This is
> similar to what *arm32_movhf already does.
>
> CASE_VECTOR_PC_RELATIVE is now false with -mpure-code, to avoid
> generating invalid assembly code with differences from symbols from
> two different sections (the difference cannot be computed by the
> assembler).
>
> Tests pr45701-[12].c needed a small adjustment to avoid matching
> upper8_15 when looking for the r8 register.
>
> Test no-literal-pool.c is augmented with __fp16, so it now uses
> -mfp16-format=ieee.
>
> Test thumb1-Os-mult.c generates an inline code sequence with
> -mpure-code and computes the multiplication by using a sequence of
> add/shift rather than using the multiply instruction, so we skip it in
> presence of -mpure-code.
>
> With -mcpu=cortex-m0, the pure-code/no-literal-pool.c fails because
> code like:
> static char *p = "Hello World";
> char *
> testchar ()
> {
>   return p + 4;
> }
> generates 2 indirections (I removed non-essential directives/code)
>         .section        .rodata
> .LC0:
> .ascii  "Hello World\000"
> .data
> p:
> .word   .LC0
> .section        .rodata
> .LC2:
> .word   p
> .section .text,"0x20000006",%progbits
> testchar:
> push    {r7, lr}
> add     r7, sp, #0
> movs    r3, #:upper8_15:#.LC2
> lsls    r3, #8
> adds    r3, #:upper0_7:#.LC2
> lsls    r3, #8
> adds    r3, #:lower8_15:#.LC2
> lsls    r3, #8
> adds    r3, #:lower0_7:#.LC2
> ldr     r3, [r3]
> ldr     r3, [r3]
> adds    r3, r3, #4
> movs    r0, r3
> mov     sp, r7
> @ sp needed
> pop     {r7, pc}
>
> By contrast, when using -mcpu=cortex-m4, the code looks like:
>         .section        .rodata
> .LC0:
> .ascii  "Hello World\000"
> .data
> p:
> .word   .LC0
> testchar:
> push    {r7}
> add     r7, sp, #0
> movw    r3, #:lower16:p
> movt    r3, #:upper16:p
> ldr     r3, [r3]
> adds    r3, r3, #4
> mov     r0, r3
> mov     sp, r7
> pop     {r7}
> bx      lr
>
> I haven't found yet how to make code for cortex-m0 apply upper/lower
> relocations to "p" instead of .LC2. The current code looks functional,
> but could be improved.
>
> OK as-is?
>
> Thanks,
>
> Christophe

ping^2 ?

On Sun, 3 Nov 2019 at 16:07, Christophe Lyon <christophe.lyon@linaro.org> wrote:
>
> Ping?
>
> https://gcc.gnu.org/ml/gcc-patches/2019-10/msg01356.html
>
> On Fri, 18 Oct 2019 at 15:18, Christophe Lyon
> <christophe.lyon@linaro.org> wrote:
> >
> > Hi,
> >
> > This patch extends support for -mpure-code to all thumb-1 processors,
> > by removing the need for MOVT.
> >
> > Symbol addresses are built using upper8_15, upper0_7, lower8_15 and
> > lower0_7 relocations, and constants are built using sequences of
> > movs/adds and lsls instructions.
> >
> > The extension of the *thumb1_movhf pattern uses always the same size
> > (6) although it can emit a shorter sequence when possible. This is
> > similar to what *arm32_movhf already does.
> >
> > CASE_VECTOR_PC_RELATIVE is now false with -mpure-code, to avoid
> > generating invalid assembly code with differences from symbols from
> > two different sections (the difference cannot be computed by the
> > assembler).
> >
> > Tests pr45701-[12].c needed a small adjustment to avoid matching
> > upper8_15 when looking for the r8 register.
> >
> > Test no-literal-pool.c is augmented with __fp16, so it now uses
> > -mfp16-format=ieee.
> >
> > Test thumb1-Os-mult.c generates an inline code sequence with
> > -mpure-code and computes the multiplication by using a sequence of
> > add/shift rather than using the multiply instruction, so we skip it in
> > presence of -mpure-code.
> >
> > With -mcpu=cortex-m0, the pure-code/no-literal-pool.c fails because
> > code like:
> > static char *p = "Hello World";
> > char *
> > testchar ()
> > {
> >   return p + 4;
> > }
> > generates 2 indirections (I removed non-essential directives/code)
> >         .section        .rodata
> > .LC0:
> > .ascii  "Hello World\000"
> > .data
> > p:
> > .word   .LC0
> > .section        .rodata
> > .LC2:
> > .word   p
> > .section .text,"0x20000006",%progbits
> > testchar:
> > push    {r7, lr}
> > add     r7, sp, #0
> > movs    r3, #:upper8_15:#.LC2
> > lsls    r3, #8
> > adds    r3, #:upper0_7:#.LC2
> > lsls    r3, #8
> > adds    r3, #:lower8_15:#.LC2
> > lsls    r3, #8
> > adds    r3, #:lower0_7:#.LC2
> > ldr     r3, [r3]
> > ldr     r3, [r3]
> > adds    r3, r3, #4
> > movs    r0, r3
> > mov     sp, r7
> > @ sp needed
> > pop     {r7, pc}
> >
> > By contrast, when using -mcpu=cortex-m4, the code looks like:
> >         .section        .rodata
> > .LC0:
> > .ascii  "Hello World\000"
> > .data
> > p:
> > .word   .LC0
> > testchar:
> > push    {r7}
> > add     r7, sp, #0
> > movw    r3, #:lower16:p
> > movt    r3, #:upper16:p
> > ldr     r3, [r3]
> > adds    r3, r3, #4
> > mov     r0, r3
> > mov     sp, r7
> > pop     {r7}
> > bx      lr
> >
> > I haven't found yet how to make code for cortex-m0 apply upper/lower
> > relocations to "p" instead of .LC2. The current code looks functional,
> > but could be improved.
> >
> > OK as-is?
> >
> > Thanks,
> >
> > Christophe

Hi Christophe,

On 10/18/19 2:18 PM, Christophe Lyon wrote:
> Hi,
>
> This patch extends support for -mpure-code to all thumb-1 processors,
> by removing the need for MOVT.
>
> Symbol addresses are built using upper8_15, upper0_7, lower8_15 and
> lower0_7 relocations, and constants are built using sequences of
> movs/adds and lsls instructions.
>
> The extension of the *thumb1_movhf pattern uses always the same size
> (6) although it can emit a shorter sequence when possible. This is
> similar to what *arm32_movhf already does.
>
> CASE_VECTOR_PC_RELATIVE is now false with -mpure-code, to avoid
> generating invalid assembly code with differences from symbols from
> two different sections (the difference cannot be computed by the
> assembler).
>
> Tests pr45701-[12].c needed a small adjustment to avoid matching
> upper8_15 when looking for the r8 register.
>
> Test no-literal-pool.c is augmented with __fp16, so it now uses
> -mfp16-format=ieee.
>
> Test thumb1-Os-mult.c generates an inline code sequence with
> -mpure-code and computes the multiplication by using a sequence of
> add/shift rather than using the multiply instruction, so we skip it in
> presence of -mpure-code.
>
> With -mcpu=cortex-m0, the pure-code/no-literal-pool.c fails because
> code like:
> static char *p = "Hello World";
> char *
> testchar ()
> {
>   return p + 4;
> }
> generates 2 indirections (I removed non-essential directives/code)
>         .section        .rodata
> .LC0:
> .ascii  "Hello World\000"
> .data
> p:
> .word   .LC0
> .section        .rodata
> .LC2:
> .word   p
> .section .text,"0x20000006",%progbits
> testchar:
> push    {r7, lr}
> add     r7, sp, #0
> movs    r3, #:upper8_15:#.LC2
> lsls    r3, #8
> adds    r3, #:upper0_7:#.LC2
> lsls    r3, #8
> adds    r3, #:lower8_15:#.LC2
> lsls    r3, #8
> adds    r3, #:lower0_7:#.LC2
> ldr     r3, [r3]
> ldr     r3, [r3]
> adds    r3, r3, #4
> movs    r0, r3
> mov     sp, r7
> @ sp needed
> pop     {r7, pc}
>
> By contrast, when using -mcpu=cortex-m4, the code looks like:
>         .section        .rodata
> .LC0:
> .ascii  "Hello World\000"
> .data
> p:
> .word   .LC0
> testchar:
> push    {r7}
> add     r7, sp, #0
> movw    r3, #:lower16:p
> movt    r3, #:upper16:p
> ldr     r3, [r3]
> adds    r3, r3, #4
> mov     r0, r3
> mov     sp, r7
> pop     {r7}
> bx      lr
>
> I haven't found yet how to make code for cortex-m0 apply upper/lower
> relocations to "p" instead of .LC2. The current code looks functional,
> but could be improved.
>
> OK as-is?
>
> Thanks,
>
> Christophe


diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
index f995974..beb8411 100644
--- a/gcc/config/arm/arm-protos.h
+++ b/gcc/config/arm/arm-protos.h
@@ -66,6 +66,7 @@ extern bool arm_small_register_classes_for_mode_p (machine_mode);
  extern int const_ok_for_arm (HOST_WIDE_INT);
  extern int const_ok_for_op (HOST_WIDE_INT, enum rtx_code);
  extern int const_ok_for_dimode_op (HOST_WIDE_INT, enum rtx_code);
+extern void thumb1_gen_const_int (rtx, HOST_WIDE_INT);
  extern int arm_split_constant (RTX_CODE, machine_mode, rtx,
  			       HOST_WIDE_INT, rtx, rtx, int);
  extern int legitimate_pic_operand_p (rtx);
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 9f0975d..836f147 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -2882,13 +2882,19 @@ arm_option_check_internal (struct gcc_options *opts)
      {
        const char *flag = (target_pure_code ? "-mpure-code" :
  					     "-mslow-flash-data");
+      bool not_supported = arm_arch_notm || flag_pic || TARGET_NEON;
  
-      /* We only support -mpure-code and -mslow-flash-data on M-profile targets
-	 with MOVT.  */
-      if (!TARGET_HAVE_MOVT || arm_arch_notm || flag_pic || TARGET_NEON)
+      /* We only support -mslow-flash-data on M-profile targets with
+	 MOVT.  */
+      if (target_slow_flash_data && (!TARGET_HAVE_MOVT || not_supported))
  	error ("%s only supports non-pic code on M-profile targets with the "
  	       "MOVT instruction", flag);
  
+      /* We only support -mpure-code-flash-data on M-profile
+	 targets.  */


Typo in the option name.

+      if (target_pure_code && not_supported)
+	error ("%s only supports non-pic code on M-profile targets", flag);
+
        /* Cannot load addresses: -mslow-flash-data forbids literal pool and
  	 -mword-relocations forbids relocation of MOVT/MOVW.  */
        if (target_word_relocations)
@@ -4400,6 +4406,38 @@ const_ok_for_dimode_op (HOST_WIDE_INT i, enum rtx_code code)
      }
  }
  
+/* Emit a sequence of movs/adds/shift to produce a 32-bit constant.
+   Avoid generating useless code when one of the bytes is zero.  */
+void
+thumb1_gen_const_int (rtx op0, HOST_WIDE_INT op1)
+{
+  bool mov_done_p = false;
+  int i;
+
+  /* Emit upper 3 bytes if needed.  */
+  for (i = 0; i < 3; i++)
+    {
+      int byte = (op1 >> (8 * (3 - i))) & 0xff;
+
+      if (byte)
+	{
+	  emit_set_insn (op0, mov_done_p
+			 ? gen_rtx_PLUS (SImode,op0, GEN_INT (byte))
+			 : GEN_INT (byte));
+	  mov_done_p = true;
+	}
+
+      if (mov_done_p)
+	emit_set_insn (op0, gen_rtx_ASHIFT (SImode, op0, GEN_INT (8)));
+    }
+
+  /* Emit lower byte if needed.  */
+  if (!mov_done_p)
+    emit_set_insn (op0, GEN_INT (op1 & 0xff));
+  else if (op1 & 0xff)
+    emit_set_insn (op0, gen_rtx_PLUS (SImode, op0, GEN_INT (op1 & 0xff)));
+}

AFAIK we already have functions like arm_gen_constant that are supposed to generate optimal immediate sequences.
Do they not fit the usecase here?

Looks reasonable to me otherwise.
Thanks,
Kyrill


  +
  /* Emit a sequence of insns to handle a large constant.
     CODE is the code of the operation required, it can be any of SET, PLUS,
     IOR, AND, XOR, MINUS;
@@ -8530,7 +8568,8 @@ thumb1_legitimate_address_p (machine_mode mode, rtx x, int strict_p)
    /* This is PC relative data before arm_reorg runs.  */
    else if (GET_MODE_SIZE (mode) >= 4 && CONSTANT_P (x)
  	   && GET_CODE (x) == SYMBOL_REF
-           && CONSTANT_POOL_ADDRESS_P (x) && !flag_pic)
+	   && CONSTANT_POOL_ADDRESS_P (x) && !flag_pic
+	   && !arm_disable_literal_pool)
      return 1;
  
    /* This is PC relative data after arm_reorg runs.  */
@@ -8598,6 +8637,7 @@ thumb1_legitimate_address_p (machine_mode mode, rtx x, int strict_p)
  	   && GET_MODE_SIZE (mode) == 4
  	   && GET_CODE (x) == SYMBOL_REF
  	   && CONSTANT_POOL_ADDRESS_P (x)
+	   && !arm_disable_literal_pool
  	   && ! (flag_pic
  		 && symbol_mentioned_p (get_pool_constant (x))
  		 && ! pcrel_constant_p (get_pool_constant (x))))
@@ -9278,7 +9318,9 @@ thumb1_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer)
  	    return 0;
  	  if (thumb_shiftable_const (INTVAL (x)))
  	    return COSTS_N_INSNS (2);
-	  return COSTS_N_INSNS (3);
+	  return arm_disable_literal_pool
+	    ? COSTS_N_INSNS (8)
+	    : COSTS_N_INSNS (3);
  	}
        else if ((outer == PLUS || outer == COMPARE)
  	       && INTVAL (x) < 256 && INTVAL (x) > -256)
@@ -9435,7 +9477,9 @@ thumb1_size_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer)
  	  /* See split "TARGET_THUMB1 && satisfies_constraint_K".  */
            if (thumb_shiftable_const (INTVAL (x)))
              return COSTS_N_INSNS (2);
-          return COSTS_N_INSNS (3);
+	  return arm_disable_literal_pool
+	    ? COSTS_N_INSNS (8)
+	    : COSTS_N_INSNS (3);
          }
        else if ((outer == PLUS || outer == COMPARE)
                 && INTVAL (x) < 256 && INTVAL (x) > -256)
@@ -27073,14 +27117,41 @@ arm_thumb1_mi_thunk (FILE *file, tree, HOST_WIDE_INT delta,
  	  /* push r3 so we can use it as a temporary.  */
  	  /* TODO: Omit this save if r3 is not used.  */
  	  fputs ("\tpush {r3}\n", file);
-	  fputs ("\tldr\tr3, ", file);
+
+	  /* With -mpure-code, we cannot load the address from the
+	     constant pool: we build it explicitly.  */
+	  if (target_pure_code)
+	    {
+	      fputs ("\tmovs\tr3, #:upper8_15:#", file);
+	      assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
+	      fputc ('\n', file);
+	      fputs ("\tlsls r3, #8\n", file);
+	      fputs ("\tadds\tr3, #:upper0_7:#", file);
+	      assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
+	      fputc ('\n', file);
+	      fputs ("\tlsls r3, #8\n", file);
+	      fputs ("\tadds\tr3, #:lower8_15:#", file);
+	      assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
+	      fputc ('\n', file);
+	      fputs ("\tlsls r3, #8\n", file);
+	      fputs ("\tadds\tr3, #:lower0_7:#", file);
+	      assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
+	      fputc ('\n', file);
+	    }
+	  else
+	    fputs ("\tldr\tr3, ", file);
  	}
        else
  	{
  	  fputs ("\tldr\tr12, ", file);
  	}
-      assemble_name (file, label);
-      fputc ('\n', file);
+
+      if (!target_pure_code)
+	{
+	  assemble_name (file, label);
+	  fputc ('\n', file);
+	}
+
        if (flag_pic)
  	{
  	  /* If we are generating PIC, the ldr instruction below loads
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index 8b67c9c..d842448 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -1850,9 +1850,11 @@ enum arm_auto_incmodes
     for the index in the tablejump instruction.  */
  #define CASE_VECTOR_MODE Pmode
  
-#define CASE_VECTOR_PC_RELATIVE (TARGET_THUMB2				\
-				 || (TARGET_THUMB1			\
-				     && (optimize_size || flag_pic)))
+#define CASE_VECTOR_PC_RELATIVE ((TARGET_THUMB2				\
+				  || (TARGET_THUMB1			\
+				      && (optimize_size || flag_pic)))	\
+				 && (!target_pure_code))
+
  
  #define CASE_VECTOR_SHORTEN_MODE(min, max, body)			\
    (TARGET_THUMB1							\
diff --git a/gcc/config/arm/thumb1.md b/gcc/config/arm/thumb1.md
index 5c70200..dd758eb 100644
--- a/gcc/config/arm/thumb1.md
+++ b/gcc/config/arm/thumb1.md
@@ -43,6 +43,41 @@
  
  
  
+(define_insn "thumb1_movsi_symbol_ref"
+  [(set (match_operand:SI 0 "register_operand" "=l")
+	(match_operand:SI 1 "general_operand" ""))
+   ]
+  "TARGET_THUMB1
+   && arm_disable_literal_pool
+   && GET_CODE (operands[1]) == SYMBOL_REF"
+  "*
+  output_asm_insn (\"movs\\t%0, #:upper8_15:%1\", operands);
+  output_asm_insn (\"lsls\\t%0, #8\", operands);
+  output_asm_insn (\"adds\\t%0, #:upper0_7:%1\", operands);
+  output_asm_insn (\"lsls\\t%0, #8\", operands);
+  output_asm_insn (\"adds\\t%0, #:lower8_15:%1\", operands);
+  output_asm_insn (\"lsls\\t%0, #8\", operands);
+  output_asm_insn (\"adds\\t%0, #:lower0_7:%1\", operands);
+  return \"\";
+  "
+  [(set_attr "length" "14")
+   (set_attr "conds" "clob")]
+)
+
+(define_split
+  [(set (match_operand:SI 0 "register_operand" "")
+	(match_operand:SI 1 "immediate_operand" ""))]
+  "TARGET_THUMB1
+   && arm_disable_literal_pool
+   && GET_CODE (operands[1]) == CONST_INT
+   && !satisfies_constraint_I (operands[1])"
+  [(clobber (const_int 0))]
+  "
+    thumb1_gen_const_int (operands[0], INTVAL (operands[1]));
+    DONE;
+  "
+)
+
  (define_insn "*thumb1_adddi3"
    [(set (match_operand:DI          0 "register_operand" "=l")
  	(plus:DI (match_operand:DI 1 "register_operand" "%0")
@@ -829,8 +864,8 @@
     (set_attr "conds" "clob,nocond,nocond,nocond,nocond,clob")])
  
  (define_insn "*thumb1_movhf"
-  [(set (match_operand:HF     0 "nonimmediate_operand" "=l,l,m,*r,*h")
-	(match_operand:HF     1 "general_operand"      "l,mF,l,*h,*r"))]
+  [(set (match_operand:HF     0 "nonimmediate_operand" "=l,l,l,m,*r,*h")
+	(match_operand:HF     1 "general_operand"      "l, m,F,l,*h,*r"))]
    "TARGET_THUMB1
     && (	  s_register_operand (operands[0], HFmode)
         || s_register_operand (operands[1], HFmode))"
@@ -855,14 +890,34 @@
  	  }
  	return \"ldrh\\t%0, %1\";
        }
-    case 2: return \"strh\\t%1, %0\";
+    case 2:
+    {
+      int bits;
+      int high;
+      rtx ops[3];
+
+      bits = real_to_target (NULL, CONST_DOUBLE_REAL_VALUE (operands[1]),
+			     HFmode);
+      ops[0] = operands[0];
+      high = (bits >> 8) & 0xff;
+      ops[1] = GEN_INT (high);
+      ops[2] = GEN_INT (bits & 0xff);
+      if (high != 0)
+	output_asm_insn (\"movs\\t%0, %1\;lsls\\t%0, #8\;adds\\t%0, %2\", ops);
+      else
+	output_asm_insn (\"movs\\t%0, %2\", ops);
+
+      return \"\";
+    }
+    case 3: return \"strh\\t%1, %0\";
      default: return \"mov\\t%0, %1\";
      }
    "
-  [(set_attr "length" "2")
-   (set_attr "type" "mov_reg,load_4,store_4,mov_reg,mov_reg")
-   (set_attr "pool_range" "*,1018,*,*,*")
-   (set_attr "conds" "clob,nocond,nocond,nocond,nocond")])
+  [(set_attr "length" "2,2,6,2,2,2")
+   (set_attr "type" "mov_reg,load_4,mov_reg,store_4,mov_reg,mov_reg")
+   (set_attr "pool_range" "*,1018,*,*,*,*")
+   (set_attr "conds" "clob,nocond,nocond,nocond,nocond,nocond")])
+
  ;;; ??? This should have alternatives for constants.
  (define_insn "*thumb1_movsf_insn"
    [(set (match_operand:SF     0 "nonimmediate_operand" "=l,l,>,l, m,*r,*h")
diff --git a/gcc/testsuite/gcc.target/arm/pr45701-1.c b/gcc/testsuite/gcc.target/arm/pr45701-1.c
index b26011b..15913d8 100644
--- a/gcc/testsuite/gcc.target/arm/pr45701-1.c
+++ b/gcc/testsuite/gcc.target/arm/pr45701-1.c
@@ -2,7 +2,7 @@
  /* { dg-skip-if "" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */
  /* { dg-options "-mthumb -Os" }  */
  /* { dg-final { scan-assembler "push\t\{r3" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
-/* { dg-final { scan-assembler-not "\[^\-\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
+/* { dg-final { scan-assembler-not "\[^\-e\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
  
  extern int hist_verify;
  extern int a1;
diff --git a/gcc/testsuite/gcc.target/arm/pr45701-2.c b/gcc/testsuite/gcc.target/arm/pr45701-2.c
index 32eed4d..bb2d36e 100644
--- a/gcc/testsuite/gcc.target/arm/pr45701-2.c
+++ b/gcc/testsuite/gcc.target/arm/pr45701-2.c
@@ -2,7 +2,7 @@
  /* { dg-skip-if "" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */
  /* { dg-options "-mthumb -Os" }  */
  /* { dg-final { scan-assembler "push\t\{r3" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
-/* { dg-final { scan-assembler-not "\[^\-\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
+/* { dg-final { scan-assembler-not "\[^\-e\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
  
  extern int hist_verify;
  extern int a1;
diff --git a/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c b/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c
index 4b893fd..3de1620 100644
--- a/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c
+++ b/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c
@@ -1,12 +1,24 @@
  /* { dg-do compile } */
-/* { dg-options "-mpure-code" } */
+/* { dg-options "-mpure-code -mfp16-format=ieee" } */
  /* { dg-skip-if "" { *-*-* } { "-g" "-fpic" "-fPIC" } { "" } } */
  
+__fp16 hf;
  float sf;
  double df;
  long long l;
  static char *p = "Hello World";
  
+__fp16
+testsfp16 (__fp16 *p)
+{
+  hf = 1.3;
+  *p += hf;
+  if (*p > 1.1234f)
+    return 2.1234f;
+  else
+    return 3.1234f;
+}
+
  float
  testsf (float *p)
  {
diff --git a/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp b/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
index bf7e4ad..b05cfd6 100644
--- a/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
+++ b/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
@@ -25,11 +25,8 @@ if ![info exists DEFAULT_CFLAGS] then {
      set DEFAULT_CFLAGS " -ansi -pedantic-errors"
  }
  
-# The -mpure-code option is only available for M-profile targets that support
-# the MOVT instruction.
-if {([check_effective_target_arm_thumb2_ok]
-     || [check_effective_target_arm_thumb1_movt_ok])
-    && [check_effective_target_arm_cortex_m]} then {
+# The -mpure-code option is only available for M-profile targets.
+if {[check_effective_target_arm_cortex_m]} then {
  # Initialize `dg'.
  dg-init
  
@@ -56,4 +53,4 @@ set LTO_TORTURE_OPTIONS ${saved-lto_torture_options}
  
  # All done.
  dg-finish
-}
+#}
diff --git a/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c b/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c
index b989c42..92772d4 100644
--- a/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c
+++ b/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c
@@ -1,6 +1,7 @@
  /* { dg-do compile } */
  /* { dg-require-effective-target arm_thumb1_ok } */
  /* { dg-options "-Os" } */
+/* { dg-skip-if "-mpure-code generates an inline multiplication code sequence" { *-*-* } { "-mpure-code" } } */
  /* { dg-skip-if "" { ! { arm_thumb1 } } } */
  
  int

On 18/10/2019 14:18, Christophe Lyon wrote:
> +      bool not_supported = arm_arch_notm || flag_pic || TARGET_NEON;
>   

This is a poor name in the context of the function as a whole.  What's 
not supported.  Please think of a better name so that I have some idea 
what the intention is.

R.

On 18/10/2019 14:18, Christophe Lyon wrote:
> +thumb1_gen_const_int (rtx op0, HOST_WIDE_INT op1)
> +{
> +  bool mov_done_p = false;
> +  int i;
> +
> +  /* Emit upper 3 bytes if needed.  */
> +  for (i = 0; i < 3; i++)
> +    {
> +      int byte = (op1 >> (8 * (3 - i))) & 0xff;
> +
> +      if (byte)
> +	{
> +	  emit_set_insn (op0, mov_done_p
> +			 ? gen_rtx_PLUS (SImode,op0, GEN_INT (byte))
> +			 : GEN_INT (byte));
> +	  mov_done_p = true;
> +	}
> +
> +      if (mov_done_p)
> +	emit_set_insn (op0, gen_rtx_ASHIFT (SImode, op0, GEN_INT (8)));
> +    }
> +
> +  /* Emit lower byte if needed.  */
> +  if (!mov_done_p)
> +    emit_set_insn (op0, GEN_INT (op1 & 0xff));
> +  else if (op1 & 0xff)
> +    emit_set_insn (op0, gen_rtx_PLUS (SImode, op0, GEN_INT (op1 & 0xff)));
> +}
> +

What about Armv8-m.baseline, which has movw/movt?

R.

Hi Kyrill,


On Tue, 12 Nov 2019 at 11:34, Kyrill Tkachov
<kyrylo.tkachov@foss.arm.com> wrote:
>
> Hi Christophe,
>
> On 10/18/19 2:18 PM, Christophe Lyon wrote:
> > Hi,
> >
> > This patch extends support for -mpure-code to all thumb-1 processors,
> > by removing the need for MOVT.
> >
> > Symbol addresses are built using upper8_15, upper0_7, lower8_15 and
> > lower0_7 relocations, and constants are built using sequences of
> > movs/adds and lsls instructions.
> >
> > The extension of the *thumb1_movhf pattern uses always the same size
> > (6) although it can emit a shorter sequence when possible. This is
> > similar to what *arm32_movhf already does.
> >
> > CASE_VECTOR_PC_RELATIVE is now false with -mpure-code, to avoid
> > generating invalid assembly code with differences from symbols from
> > two different sections (the difference cannot be computed by the
> > assembler).
> >
> > Tests pr45701-[12].c needed a small adjustment to avoid matching
> > upper8_15 when looking for the r8 register.
> >
> > Test no-literal-pool.c is augmented with __fp16, so it now uses
> > -mfp16-format=ieee.
> >
> > Test thumb1-Os-mult.c generates an inline code sequence with
> > -mpure-code and computes the multiplication by using a sequence of
> > add/shift rather than using the multiply instruction, so we skip it in
> > presence of -mpure-code.
> >
> > With -mcpu=cortex-m0, the pure-code/no-literal-pool.c fails because
> > code like:
> > static char *p = "Hello World";
> > char *
> > testchar ()
> > {
> >   return p + 4;
> > }
> > generates 2 indirections (I removed non-essential directives/code)
> >         .section        .rodata
> > .LC0:
> > .ascii  "Hello World\000"
> > .data
> > p:
> > .word   .LC0
> > .section        .rodata
> > .LC2:
> > .word   p
> > .section .text,"0x20000006",%progbits
> > testchar:
> > push    {r7, lr}
> > add     r7, sp, #0
> > movs    r3, #:upper8_15:#.LC2
> > lsls    r3, #8
> > adds    r3, #:upper0_7:#.LC2
> > lsls    r3, #8
> > adds    r3, #:lower8_15:#.LC2
> > lsls    r3, #8
> > adds    r3, #:lower0_7:#.LC2
> > ldr     r3, [r3]
> > ldr     r3, [r3]
> > adds    r3, r3, #4
> > movs    r0, r3
> > mov     sp, r7
> > @ sp needed
> > pop     {r7, pc}
> >
> > By contrast, when using -mcpu=cortex-m4, the code looks like:
> >         .section        .rodata
> > .LC0:
> > .ascii  "Hello World\000"
> > .data
> > p:
> > .word   .LC0
> > testchar:
> > push    {r7}
> > add     r7, sp, #0
> > movw    r3, #:lower16:p
> > movt    r3, #:upper16:p
> > ldr     r3, [r3]
> > adds    r3, r3, #4
> > mov     r0, r3
> > mov     sp, r7
> > pop     {r7}
> > bx      lr
> >
> > I haven't found yet how to make code for cortex-m0 apply upper/lower
> > relocations to "p" instead of .LC2. The current code looks functional,
> > but could be improved.
> >
> > OK as-is?
> >
> > Thanks,
> >
> > Christophe
>
>
> diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
> index f995974..beb8411 100644
> --- a/gcc/config/arm/arm-protos.h
> +++ b/gcc/config/arm/arm-protos.h
> @@ -66,6 +66,7 @@ extern bool arm_small_register_classes_for_mode_p (machine_mode);
>   extern int const_ok_for_arm (HOST_WIDE_INT);
>   extern int const_ok_for_op (HOST_WIDE_INT, enum rtx_code);
>   extern int const_ok_for_dimode_op (HOST_WIDE_INT, enum rtx_code);
> +extern void thumb1_gen_const_int (rtx, HOST_WIDE_INT);
>   extern int arm_split_constant (RTX_CODE, machine_mode, rtx,
>                                HOST_WIDE_INT, rtx, rtx, int);
>   extern int legitimate_pic_operand_p (rtx);
> diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
> index 9f0975d..836f147 100644
> --- a/gcc/config/arm/arm.c
> +++ b/gcc/config/arm/arm.c
> @@ -2882,13 +2882,19 @@ arm_option_check_internal (struct gcc_options *opts)
>       {
>         const char *flag = (target_pure_code ? "-mpure-code" :
>                                              "-mslow-flash-data");
> +      bool not_supported = arm_arch_notm || flag_pic || TARGET_NEON;
>
> -      /* We only support -mpure-code and -mslow-flash-data on M-profile targets
> -        with MOVT.  */
> -      if (!TARGET_HAVE_MOVT || arm_arch_notm || flag_pic || TARGET_NEON)
> +      /* We only support -mslow-flash-data on M-profile targets with
> +        MOVT.  */
> +      if (target_slow_flash_data && (!TARGET_HAVE_MOVT || not_supported))
>         error ("%s only supports non-pic code on M-profile targets with the "
>                "MOVT instruction", flag);
>
> +      /* We only support -mpure-code-flash-data on M-profile
> +        targets.  */
>
>
> Typo in the option name.
>
Thanks for catching this.

> +      if (target_pure_code && not_supported)
> +       error ("%s only supports non-pic code on M-profile targets", flag);
> +
>         /* Cannot load addresses: -mslow-flash-data forbids literal pool and
>          -mword-relocations forbids relocation of MOVT/MOVW.  */
>         if (target_word_relocations)
> @@ -4400,6 +4406,38 @@ const_ok_for_dimode_op (HOST_WIDE_INT i, enum rtx_code code)
>       }
>   }
>
> +/* Emit a sequence of movs/adds/shift to produce a 32-bit constant.
> +   Avoid generating useless code when one of the bytes is zero.  */
> +void
> +thumb1_gen_const_int (rtx op0, HOST_WIDE_INT op1)
> +{
> +  bool mov_done_p = false;
> +  int i;
> +
> +  /* Emit upper 3 bytes if needed.  */
> +  for (i = 0; i < 3; i++)
> +    {
> +      int byte = (op1 >> (8 * (3 - i))) & 0xff;
> +
> +      if (byte)
> +       {
> +         emit_set_insn (op0, mov_done_p
> +                        ? gen_rtx_PLUS (SImode,op0, GEN_INT (byte))
> +                        : GEN_INT (byte));
> +         mov_done_p = true;
> +       }
> +
> +      if (mov_done_p)
> +       emit_set_insn (op0, gen_rtx_ASHIFT (SImode, op0, GEN_INT (8)));
> +    }
> +
> +  /* Emit lower byte if needed.  */
> +  if (!mov_done_p)
> +    emit_set_insn (op0, GEN_INT (op1 & 0xff));
> +  else if (op1 & 0xff)
> +    emit_set_insn (op0, gen_rtx_PLUS (SImode, op0, GEN_INT (op1 & 0xff)));
> +}
>
> AFAIK we already have functions like arm_gen_constant that are supposed to generate optimal immediate sequences.
> Do they not fit the usecase here?

I tried to replace
thumb1_gen_const_int (operands[0], INTVAL (operands[1]));
with
arm_gen_constant (SET, SImode, NULL_RTX, INTVAL (operands[1]),
operands[0], NULL_RTX, 1, 1);
in thumb1.md, but this does work.
One of the test cases (testsfp16 in no-literal-pool.c) tries to build
a floating-point constant 0x3f8fcb92,
and arm_gen_constant generates
(insn 66 34 72 (set (reg:SI 3 r3 [130])
        (const_int 1065353216 [0x3f800000]))
"/testsuite/gcc.target/arm/pure-code/no-literal-pool.c":16:6 818
{*thumb1_movsi_insn}
     (nil))
which leads to error: could not split insn

Christophe



>
> Looks reasonable to me otherwise.
> Thanks,
> Kyrill
>
>
>   +
>   /* Emit a sequence of insns to handle a large constant.
>      CODE is the code of the operation required, it can be any of SET, PLUS,
>      IOR, AND, XOR, MINUS;
> @@ -8530,7 +8568,8 @@ thumb1_legitimate_address_p (machine_mode mode, rtx x, int strict_p)
>     /* This is PC relative data before arm_reorg runs.  */
>     else if (GET_MODE_SIZE (mode) >= 4 && CONSTANT_P (x)
>            && GET_CODE (x) == SYMBOL_REF
> -           && CONSTANT_POOL_ADDRESS_P (x) && !flag_pic)
> +          && CONSTANT_POOL_ADDRESS_P (x) && !flag_pic
> +          && !arm_disable_literal_pool)
>       return 1;
>
>     /* This is PC relative data after arm_reorg runs.  */
> @@ -8598,6 +8637,7 @@ thumb1_legitimate_address_p (machine_mode mode, rtx x, int strict_p)
>            && GET_MODE_SIZE (mode) == 4
>            && GET_CODE (x) == SYMBOL_REF
>            && CONSTANT_POOL_ADDRESS_P (x)
> +          && !arm_disable_literal_pool
>            && ! (flag_pic
>                  && symbol_mentioned_p (get_pool_constant (x))
>                  && ! pcrel_constant_p (get_pool_constant (x))))
> @@ -9278,7 +9318,9 @@ thumb1_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer)
>             return 0;
>           if (thumb_shiftable_const (INTVAL (x)))
>             return COSTS_N_INSNS (2);
> -         return COSTS_N_INSNS (3);
> +         return arm_disable_literal_pool
> +           ? COSTS_N_INSNS (8)
> +           : COSTS_N_INSNS (3);
>         }
>         else if ((outer == PLUS || outer == COMPARE)
>                && INTVAL (x) < 256 && INTVAL (x) > -256)
> @@ -9435,7 +9477,9 @@ thumb1_size_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer)
>           /* See split "TARGET_THUMB1 && satisfies_constraint_K".  */
>             if (thumb_shiftable_const (INTVAL (x)))
>               return COSTS_N_INSNS (2);
> -          return COSTS_N_INSNS (3);
> +         return arm_disable_literal_pool
> +           ? COSTS_N_INSNS (8)
> +           : COSTS_N_INSNS (3);
>           }
>         else if ((outer == PLUS || outer == COMPARE)
>                  && INTVAL (x) < 256 && INTVAL (x) > -256)
> @@ -27073,14 +27117,41 @@ arm_thumb1_mi_thunk (FILE *file, tree, HOST_WIDE_INT delta,
>           /* push r3 so we can use it as a temporary.  */
>           /* TODO: Omit this save if r3 is not used.  */
>           fputs ("\tpush {r3}\n", file);
> -         fputs ("\tldr\tr3, ", file);
> +
> +         /* With -mpure-code, we cannot load the address from the
> +            constant pool: we build it explicitly.  */
> +         if (target_pure_code)
> +           {
> +             fputs ("\tmovs\tr3, #:upper8_15:#", file);
> +             assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
> +             fputc ('\n', file);
> +             fputs ("\tlsls r3, #8\n", file);
> +             fputs ("\tadds\tr3, #:upper0_7:#", file);
> +             assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
> +             fputc ('\n', file);
> +             fputs ("\tlsls r3, #8\n", file);
> +             fputs ("\tadds\tr3, #:lower8_15:#", file);
> +             assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
> +             fputc ('\n', file);
> +             fputs ("\tlsls r3, #8\n", file);
> +             fputs ("\tadds\tr3, #:lower0_7:#", file);
> +             assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
> +             fputc ('\n', file);
> +           }
> +         else
> +           fputs ("\tldr\tr3, ", file);
>         }
>         else
>         {
>           fputs ("\tldr\tr12, ", file);
>         }
> -      assemble_name (file, label);
> -      fputc ('\n', file);
> +
> +      if (!target_pure_code)
> +       {
> +         assemble_name (file, label);
> +         fputc ('\n', file);
> +       }
> +
>         if (flag_pic)
>         {
>           /* If we are generating PIC, the ldr instruction below loads
> diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
> index 8b67c9c..d842448 100644
> --- a/gcc/config/arm/arm.h
> +++ b/gcc/config/arm/arm.h
> @@ -1850,9 +1850,11 @@ enum arm_auto_incmodes
>      for the index in the tablejump instruction.  */
>   #define CASE_VECTOR_MODE Pmode
>
> -#define CASE_VECTOR_PC_RELATIVE (TARGET_THUMB2                         \
> -                                || (TARGET_THUMB1                      \
> -                                    && (optimize_size || flag_pic)))
> +#define CASE_VECTOR_PC_RELATIVE ((TARGET_THUMB2                                \
> +                                 || (TARGET_THUMB1                     \
> +                                     && (optimize_size || flag_pic)))  \
> +                                && (!target_pure_code))
> +
>
>   #define CASE_VECTOR_SHORTEN_MODE(min, max, body)                      \
>     (TARGET_THUMB1                                                      \
> diff --git a/gcc/config/arm/thumb1.md b/gcc/config/arm/thumb1.md
> index 5c70200..dd758eb 100644
> --- a/gcc/config/arm/thumb1.md
> +++ b/gcc/config/arm/thumb1.md
> @@ -43,6 +43,41 @@
>
>
>
> +(define_insn "thumb1_movsi_symbol_ref"
> +  [(set (match_operand:SI 0 "register_operand" "=l")
> +       (match_operand:SI 1 "general_operand" ""))
> +   ]
> +  "TARGET_THUMB1
> +   && arm_disable_literal_pool
> +   && GET_CODE (operands[1]) == SYMBOL_REF"
> +  "*
> +  output_asm_insn (\"movs\\t%0, #:upper8_15:%1\", operands);
> +  output_asm_insn (\"lsls\\t%0, #8\", operands);
> +  output_asm_insn (\"adds\\t%0, #:upper0_7:%1\", operands);
> +  output_asm_insn (\"lsls\\t%0, #8\", operands);
> +  output_asm_insn (\"adds\\t%0, #:lower8_15:%1\", operands);
> +  output_asm_insn (\"lsls\\t%0, #8\", operands);
> +  output_asm_insn (\"adds\\t%0, #:lower0_7:%1\", operands);
> +  return \"\";
> +  "
> +  [(set_attr "length" "14")
> +   (set_attr "conds" "clob")]
> +)
> +
> +(define_split
> +  [(set (match_operand:SI 0 "register_operand" "")
> +       (match_operand:SI 1 "immediate_operand" ""))]
> +  "TARGET_THUMB1
> +   && arm_disable_literal_pool
> +   && GET_CODE (operands[1]) == CONST_INT
> +   && !satisfies_constraint_I (operands[1])"
> +  [(clobber (const_int 0))]
> +  "
> +    thumb1_gen_const_int (operands[0], INTVAL (operands[1]));
> +    DONE;
> +  "
> +)
> +
>   (define_insn "*thumb1_adddi3"
>     [(set (match_operand:DI          0 "register_operand" "=l")
>         (plus:DI (match_operand:DI 1 "register_operand" "%0")
> @@ -829,8 +864,8 @@
>      (set_attr "conds" "clob,nocond,nocond,nocond,nocond,clob")])
>
>   (define_insn "*thumb1_movhf"
> -  [(set (match_operand:HF     0 "nonimmediate_operand" "=l,l,m,*r,*h")
> -       (match_operand:HF     1 "general_operand"      "l,mF,l,*h,*r"))]
> +  [(set (match_operand:HF     0 "nonimmediate_operand" "=l,l,l,m,*r,*h")
> +       (match_operand:HF     1 "general_operand"      "l, m,F,l,*h,*r"))]
>     "TARGET_THUMB1
>      && (         s_register_operand (operands[0], HFmode)
>          || s_register_operand (operands[1], HFmode))"
> @@ -855,14 +890,34 @@
>           }
>         return \"ldrh\\t%0, %1\";
>         }
> -    case 2: return \"strh\\t%1, %0\";
> +    case 2:
> +    {
> +      int bits;
> +      int high;
> +      rtx ops[3];
> +
> +      bits = real_to_target (NULL, CONST_DOUBLE_REAL_VALUE (operands[1]),
> +                            HFmode);
> +      ops[0] = operands[0];
> +      high = (bits >> 8) & 0xff;
> +      ops[1] = GEN_INT (high);
> +      ops[2] = GEN_INT (bits & 0xff);
> +      if (high != 0)
> +       output_asm_insn (\"movs\\t%0, %1\;lsls\\t%0, #8\;adds\\t%0, %2\", ops);
> +      else
> +       output_asm_insn (\"movs\\t%0, %2\", ops);
> +
> +      return \"\";
> +    }
> +    case 3: return \"strh\\t%1, %0\";
>       default: return \"mov\\t%0, %1\";
>       }
>     "
> -  [(set_attr "length" "2")
> -   (set_attr "type" "mov_reg,load_4,store_4,mov_reg,mov_reg")
> -   (set_attr "pool_range" "*,1018,*,*,*")
> -   (set_attr "conds" "clob,nocond,nocond,nocond,nocond")])
> +  [(set_attr "length" "2,2,6,2,2,2")
> +   (set_attr "type" "mov_reg,load_4,mov_reg,store_4,mov_reg,mov_reg")
> +   (set_attr "pool_range" "*,1018,*,*,*,*")
> +   (set_attr "conds" "clob,nocond,nocond,nocond,nocond,nocond")])
> +
>   ;;; ??? This should have alternatives for constants.
>   (define_insn "*thumb1_movsf_insn"
>     [(set (match_operand:SF     0 "nonimmediate_operand" "=l,l,>,l, m,*r,*h")
> diff --git a/gcc/testsuite/gcc.target/arm/pr45701-1.c b/gcc/testsuite/gcc.target/arm/pr45701-1.c
> index b26011b..15913d8 100644
> --- a/gcc/testsuite/gcc.target/arm/pr45701-1.c
> +++ b/gcc/testsuite/gcc.target/arm/pr45701-1.c
> @@ -2,7 +2,7 @@
>   /* { dg-skip-if "" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */
>   /* { dg-options "-mthumb -Os" }  */
>   /* { dg-final { scan-assembler "push\t\{r3" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
> -/* { dg-final { scan-assembler-not "\[^\-\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
> +/* { dg-final { scan-assembler-not "\[^\-e\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
>
>   extern int hist_verify;
>   extern int a1;
> diff --git a/gcc/testsuite/gcc.target/arm/pr45701-2.c b/gcc/testsuite/gcc.target/arm/pr45701-2.c
> index 32eed4d..bb2d36e 100644
> --- a/gcc/testsuite/gcc.target/arm/pr45701-2.c
> +++ b/gcc/testsuite/gcc.target/arm/pr45701-2.c
> @@ -2,7 +2,7 @@
>   /* { dg-skip-if "" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */
>   /* { dg-options "-mthumb -Os" }  */
>   /* { dg-final { scan-assembler "push\t\{r3" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
> -/* { dg-final { scan-assembler-not "\[^\-\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
> +/* { dg-final { scan-assembler-not "\[^\-e\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
>
>   extern int hist_verify;
>   extern int a1;
> diff --git a/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c b/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c
> index 4b893fd..3de1620 100644
> --- a/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c
> +++ b/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c
> @@ -1,12 +1,24 @@
>   /* { dg-do compile } */
> -/* { dg-options "-mpure-code" } */
> +/* { dg-options "-mpure-code -mfp16-format=ieee" } */
>   /* { dg-skip-if "" { *-*-* } { "-g" "-fpic" "-fPIC" } { "" } } */
>
> +__fp16 hf;
>   float sf;
>   double df;
>   long long l;
>   static char *p = "Hello World";
>
> +__fp16
> +testsfp16 (__fp16 *p)
> +{
> +  hf = 1.3;
> +  *p += hf;
> +  if (*p > 1.1234f)
> +    return 2.1234f;
> +  else
> +    return 3.1234f;
> +}
> +
>   float
>   testsf (float *p)
>   {
> diff --git a/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp b/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
> index bf7e4ad..b05cfd6 100644
> --- a/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
> +++ b/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
> @@ -25,11 +25,8 @@ if ![info exists DEFAULT_CFLAGS] then {
>       set DEFAULT_CFLAGS " -ansi -pedantic-errors"
>   }
>
> -# The -mpure-code option is only available for M-profile targets that support
> -# the MOVT instruction.
> -if {([check_effective_target_arm_thumb2_ok]
> -     || [check_effective_target_arm_thumb1_movt_ok])
> -    && [check_effective_target_arm_cortex_m]} then {
> +# The -mpure-code option is only available for M-profile targets.
> +if {[check_effective_target_arm_cortex_m]} then {
>   # Initialize `dg'.
>   dg-init
>
> @@ -56,4 +53,4 @@ set LTO_TORTURE_OPTIONS ${saved-lto_torture_options}
>
>   # All done.
>   dg-finish
> -}
> +#}
> diff --git a/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c b/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c
> index b989c42..92772d4 100644
> --- a/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c
> +++ b/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c
> @@ -1,6 +1,7 @@
>   /* { dg-do compile } */
>   /* { dg-require-effective-target arm_thumb1_ok } */
>   /* { dg-options "-Os" } */
> +/* { dg-skip-if "-mpure-code generates an inline multiplication code sequence" { *-*-* } { "-mpure-code" } } */
>   /* { dg-skip-if "" { ! { arm_thumb1 } } } */
>
>   int
>

On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
<Richard.Earnshaw@arm.com> wrote:
>
> On 18/10/2019 14:18, Christophe Lyon wrote:
> > +      bool not_supported = arm_arch_notm || flag_pic || TARGET_NEON;
> >
>
> This is a poor name in the context of the function as a whole.  What's
> not supported.  Please think of a better name so that I have some idea
> what the intention is.

That's to keep most of the code common when checking if -mpure-code
and -mslow-flash-data are supported.
These 3 cases are common to the two compilation flags, and
-mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.

Would "common_unsupported_modes" work better for you?
Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
the two tests.

Thanks,

Christophe

>
> R.

On Tue, 12 Nov 2019 at 12:17, Richard Earnshaw (lists)
<Richard.Earnshaw@arm.com> wrote:
>
> On 18/10/2019 14:18, Christophe Lyon wrote:
> > +thumb1_gen_const_int (rtx op0, HOST_WIDE_INT op1)
> > +{
> > +  bool mov_done_p = false;
> > +  int i;
> > +
> > +  /* Emit upper 3 bytes if needed.  */
> > +  for (i = 0; i < 3; i++)
> > +    {
> > +      int byte = (op1 >> (8 * (3 - i))) & 0xff;
> > +
> > +      if (byte)
> > +     {
> > +       emit_set_insn (op0, mov_done_p
> > +                      ? gen_rtx_PLUS (SImode,op0, GEN_INT (byte))
> > +                      : GEN_INT (byte));
> > +       mov_done_p = true;
> > +     }
> > +
> > +      if (mov_done_p)
> > +     emit_set_insn (op0, gen_rtx_ASHIFT (SImode, op0, GEN_INT (8)));
> > +    }
> > +
> > +  /* Emit lower byte if needed.  */
> > +  if (!mov_done_p)
> > +    emit_set_insn (op0, GEN_INT (op1 & 0xff));
> > +  else if (op1 & 0xff)
> > +    emit_set_insn (op0, gen_rtx_PLUS (SImode, op0, GEN_INT (op1 & 0xff)));
> > +}
> > +
>
> What about Armv8-m.baseline, which has movw/movt?
>
This is already supported since r247585 (May 2017) "[ARM] Enable
Purecode for ARMv8-M Baseline" AFAICT.

Thanks,

Christophe

> R.

On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
<christophe.lyon@linaro.org> wrote:
>
> On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
> <Richard.Earnshaw@arm.com> wrote:
> >
> > On 18/10/2019 14:18, Christophe Lyon wrote:
> > > +      bool not_supported = arm_arch_notm || flag_pic || TARGET_NEON;
> > >
> >
> > This is a poor name in the context of the function as a whole.  What's
> > not supported.  Please think of a better name so that I have some idea
> > what the intention is.
>
> That's to keep most of the code common when checking if -mpure-code
> and -mslow-flash-data are supported.
> These 3 cases are common to the two compilation flags, and
> -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
>
> Would "common_unsupported_modes" work better for you?
> Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
> the two tests.
>

Hi,

Here is an updated version, using "common_unsupported_modes" instead
of "not_supported", and fixing the typo reported by Kyrill.
The ChangeLog is still the same.

OK?

Thanks,

Christophe

> Thanks,
>
> Christophe
>
> >
> > R.
2019-10-18  Christophe Lyon  <christophe.lyon@linaro.org>

    	gcc/
    	* config/arm/arm-protos.h (thumb1_gen_const_int): Add new prototype.
    	* config/arm/arm.c (arm_option_check_internal): Remove restriction
    	on MOVT for -mpure-code.
    	(thumb1_gen_const_int): New function.
    	(thumb1_legitimate_address_p): Support -mpure-code.
    	(thumb1_rtx_costs): Likewise.
    	(thumb1_size_rtx_costs): Likewise.
    	(arm_thumb1_mi_thunk): Likewise.
    	* config/arm/arm.h (CASE_VECTOR_PC_RELATIVE): Likewise.
    	* config/arm/thumb1.md (thumb1_movsi_symbol_ref): New.
    	(*thumb1_movhf): Support -mpure-code.

    	gcc/tests/
    	* gcc.target/arm/pr45701-1.c: Adjust for -mpure-code.
    	* gcc.target/arm/pr45701-2.c: Likewise.
    	* gcc.target/arm/pure-code/no-literal-pool.c: Add tests for
    	__fp16.
    	* gcc.target/arm/pure-code/pure-code.exp: Remove thumb2 and movt
    	conditions.
    	* gcc.target/arm/thumb1-Os-mult.c: Skip if -mpure-code is used.
commit b96f1ce6d988db34557cbfe9cd414193cf3e95a6
Author: Christophe Lyon <christophe.lyon@linaro.org>
Date:   Fri Oct 18 12:15:12 2019 +0000

    [ARM] Add support for -mpure-code in thumb-1 (v6m)
    
    This patch extends support for -mpure-code to all thumb-1 processors,
    by removing the need for MOVT.
    
    Symbol addresses are built using upper8_15, upper0_7, lower8_15 and
    lower0_7 relocations, and constants are built using sequences of
    movs/adds and lsls instructions.
    
    The extension of the *thumb1_movhf pattern uses always the same size
    (6) although it can emit a shorter sequence when possible. This is
    similar to what *arm32_movhf already does.
    
    CASE_VECTOR_PC_RELATIVE is now false with -mpure-code, to avoid
    generating invalid assembly code with differences from symbols from
    two different sections (the difference cannot be computed by the
    assembler).
    
    Tests pr45701-[12].c needed a small adjustment to avoid matching
    upper8_15 when looking for the r8 register.
    
    Test no-literal-pool.c is augmented with __fp16, so it now uses
    -mfp16-format=ieee.
    
    Test thumb1-Os-mult.c generates an inline code sequence with
    -mpure-code and computes the multiplication by using a sequence of
    add/shift rather than using the multiply instruction, so we skip it in
    presence of -mpure-code.
    
    With -mcpu=cortex-m0, the pure-code/no-literal-pool.c fails because
    code like:
    static char *p = "Hello World";
    char *
    testchar ()
    {
      return p + 4;
    }
    generates 2 indirections (I removed non-essential directives/code)
            .section        .rodata
    .LC0:
    	.ascii  "Hello World\000"
    	.data
    p:
    	.word   .LC0
    	.section        .rodata
    .LC2:
    	.word   p
    	.section .text,"0x20000006",%progbits
    testchar:
    	push    {r7, lr}
    	add     r7, sp, #0
    	movs    r3, #:upper8_15:#.LC2
    	lsls    r3, #8
    	adds    r3, #:upper0_7:#.LC2
    	lsls    r3, #8
    	adds    r3, #:lower8_15:#.LC2
    	lsls    r3, #8
    	adds    r3, #:lower0_7:#.LC2
    	ldr     r3, [r3]
    	ldr     r3, [r3]
    	adds    r3, r3, #4
    	movs    r0, r3
    	mov     sp, r7
    	@ sp needed
    	pop     {r7, pc}
    
    By contrast, when using -mcpu=cortex-m4, the code looks like:
            .section        .rodata
    .LC0:
    	.ascii  "Hello World\000"
    	.data
    p:
    	.word   .LC0
    testchar:
    	push    {r7}
    	add     r7, sp, #0
    	movw    r3, #:lower16:p
    	movt    r3, #:upper16:p
    	ldr     r3, [r3]
    	adds    r3, r3, #4
    	mov     r0, r3
    	mov     sp, r7
    	pop     {r7}
    	bx      lr
    
    I haven't found yet how to make code for cortex-m0 apply upper/lower
    relocations to "p" instead of .LC2. The current code looks functional,
    but could be improved.
    
    2019-10-18  Christophe Lyon  <christophe.lyon@linaro.org>
    
    	gcc/
    	* config/arm/arm-protos.h (thumb1_gen_const_int): Add new prototype.
    	* config/arm/arm.c (arm_option_check_internal): Remove restriction
    	on MOVT for -mpure-code.
    	(thumb1_gen_const_int): New function.
    	(thumb1_legitimate_address_p): Support -mpure-code.
    	(thumb1_rtx_costs): Likewise.
    	(thumb1_size_rtx_costs): Likewise.
    	(arm_thumb1_mi_thunk): Likewise.
    	* config/arm/arm.h (CASE_VECTOR_PC_RELATIVE): Likewise.
    	* config/arm/thumb1.md (thumb1_movsi_symbol_ref): New.
    	(*thumb1_movhf): Support -mpure-code.
    
    	gcc/tests/
    	* gcc.target/arm/pr45701-1.c: Adjust for -mpure-code.
    	* gcc.target/arm/pr45701-2.c: Likewise.
    	* gcc.target/arm/pure-code/no-literal-pool.c: Add tests for
    	__fp16.
    	* gcc.target/arm/pure-code/pure-code.exp: Remove thumb2 and movt
    	conditions.
    	* gcc.target/arm/thumb1-Os-mult.c: Skip if -mpure-code is used.
    
    Change-Id: I79c5a5043e7ffec084c38b59a44d69214c0834cf

diff --git a/gcc/config/arm/arm-protos.h b/gcc/config/arm/arm-protos.h
index f995974..beb8411 100644
--- a/gcc/config/arm/arm-protos.h
+++ b/gcc/config/arm/arm-protos.h
@@ -66,6 +66,7 @@ extern bool arm_small_register_classes_for_mode_p (machine_mode);
 extern int const_ok_for_arm (HOST_WIDE_INT);
 extern int const_ok_for_op (HOST_WIDE_INT, enum rtx_code);
 extern int const_ok_for_dimode_op (HOST_WIDE_INT, enum rtx_code);
+extern void thumb1_gen_const_int (rtx, HOST_WIDE_INT);
 extern int arm_split_constant (RTX_CODE, machine_mode, rtx,
 			       HOST_WIDE_INT, rtx, rtx, int);
 extern int legitimate_pic_operand_p (rtx);
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 9f0975d..aa71020 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -2882,13 +2882,18 @@ arm_option_check_internal (struct gcc_options *opts)
     {
       const char *flag = (target_pure_code ? "-mpure-code" :
 					     "-mslow-flash-data");
+      bool common_unsupported_modes = arm_arch_notm || flag_pic || TARGET_NEON;
 
-      /* We only support -mpure-code and -mslow-flash-data on M-profile targets
-	 with MOVT.  */
-      if (!TARGET_HAVE_MOVT || arm_arch_notm || flag_pic || TARGET_NEON)
+      /* We only support -mslow-flash-data on M-profile targets with
+	 MOVT.  */
+      if (target_slow_flash_data && (!TARGET_HAVE_MOVT || common_unsupported_modes))
 	error ("%s only supports non-pic code on M-profile targets with the "
 	       "MOVT instruction", flag);
 
+      /* We only support -mpure-code on M-profile targets.  */
+      if (target_pure_code && common_unsupported_modes)
+	error ("%s only supports non-pic code on M-profile targets", flag);
+
       /* Cannot load addresses: -mslow-flash-data forbids literal pool and
 	 -mword-relocations forbids relocation of MOVT/MOVW.  */
       if (target_word_relocations)
@@ -4400,6 +4405,38 @@ const_ok_for_dimode_op (HOST_WIDE_INT i, enum rtx_code code)
     }
 }
 
+/* Emit a sequence of movs/adds/shift to produce a 32-bit constant.
+   Avoid generating useless code when one of the bytes is zero.  */
+void
+thumb1_gen_const_int (rtx op0, HOST_WIDE_INT op1)
+{
+  bool mov_done_p = false;
+  int i;
+
+  /* Emit upper 3 bytes if needed.  */
+  for (i = 0; i < 3; i++)
+    {
+      int byte = (op1 >> (8 * (3 - i))) & 0xff;
+
+      if (byte)
+	{
+	  emit_set_insn (op0, mov_done_p
+			 ? gen_rtx_PLUS (SImode,op0, GEN_INT (byte))
+			 : GEN_INT (byte));
+	  mov_done_p = true;
+	}
+
+      if (mov_done_p)
+	emit_set_insn (op0, gen_rtx_ASHIFT (SImode, op0, GEN_INT (8)));
+    }
+
+  /* Emit lower byte if needed.  */
+  if (!mov_done_p)
+    emit_set_insn (op0, GEN_INT (op1 & 0xff));
+  else if (op1 & 0xff)
+    emit_set_insn (op0, gen_rtx_PLUS (SImode, op0, GEN_INT (op1 & 0xff)));
+}
+
 /* Emit a sequence of insns to handle a large constant.
    CODE is the code of the operation required, it can be any of SET, PLUS,
    IOR, AND, XOR, MINUS;
@@ -8530,7 +8567,8 @@ thumb1_legitimate_address_p (machine_mode mode, rtx x, int strict_p)
   /* This is PC relative data before arm_reorg runs.  */
   else if (GET_MODE_SIZE (mode) >= 4 && CONSTANT_P (x)
 	   && GET_CODE (x) == SYMBOL_REF
-           && CONSTANT_POOL_ADDRESS_P (x) && !flag_pic)
+	   && CONSTANT_POOL_ADDRESS_P (x) && !flag_pic
+	   && !arm_disable_literal_pool)
     return 1;
 
   /* This is PC relative data after arm_reorg runs.  */
@@ -8598,6 +8636,7 @@ thumb1_legitimate_address_p (machine_mode mode, rtx x, int strict_p)
 	   && GET_MODE_SIZE (mode) == 4
 	   && GET_CODE (x) == SYMBOL_REF
 	   && CONSTANT_POOL_ADDRESS_P (x)
+	   && !arm_disable_literal_pool
 	   && ! (flag_pic
 		 && symbol_mentioned_p (get_pool_constant (x))
 		 && ! pcrel_constant_p (get_pool_constant (x))))
@@ -9278,7 +9317,9 @@ thumb1_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer)
 	    return 0;
 	  if (thumb_shiftable_const (INTVAL (x)))
 	    return COSTS_N_INSNS (2);
-	  return COSTS_N_INSNS (3);
+	  return arm_disable_literal_pool
+	    ? COSTS_N_INSNS (8)
+	    : COSTS_N_INSNS (3);
 	}
       else if ((outer == PLUS || outer == COMPARE)
 	       && INTVAL (x) < 256 && INTVAL (x) > -256)
@@ -9435,7 +9476,9 @@ thumb1_size_rtx_costs (rtx x, enum rtx_code code, enum rtx_code outer)
 	  /* See split "TARGET_THUMB1 && satisfies_constraint_K".  */
           if (thumb_shiftable_const (INTVAL (x)))
             return COSTS_N_INSNS (2);
-          return COSTS_N_INSNS (3);
+	  return arm_disable_literal_pool
+	    ? COSTS_N_INSNS (8)
+	    : COSTS_N_INSNS (3);
         }
       else if ((outer == PLUS || outer == COMPARE)
                && INTVAL (x) < 256 && INTVAL (x) > -256)
@@ -27073,14 +27116,41 @@ arm_thumb1_mi_thunk (FILE *file, tree, HOST_WIDE_INT delta,
 	  /* push r3 so we can use it as a temporary.  */
 	  /* TODO: Omit this save if r3 is not used.  */
 	  fputs ("\tpush {r3}\n", file);
-	  fputs ("\tldr\tr3, ", file);
+
+	  /* With -mpure-code, we cannot load the address from the
+	     constant pool: we build it explicitly.  */
+	  if (target_pure_code)
+	    {
+	      fputs ("\tmovs\tr3, #:upper8_15:#", file);
+	      assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
+	      fputc ('\n', file);
+	      fputs ("\tlsls r3, #8\n", file);
+	      fputs ("\tadds\tr3, #:upper0_7:#", file);
+	      assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
+	      fputc ('\n', file);
+	      fputs ("\tlsls r3, #8\n", file);
+	      fputs ("\tadds\tr3, #:lower8_15:#", file);
+	      assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
+	      fputc ('\n', file);
+	      fputs ("\tlsls r3, #8\n", file);
+	      fputs ("\tadds\tr3, #:lower0_7:#", file);
+	      assemble_name (file, XSTR (XEXP (DECL_RTL (function), 0), 0));
+	      fputc ('\n', file);
+	    }
+	  else
+	    fputs ("\tldr\tr3, ", file);
 	}
       else
 	{
 	  fputs ("\tldr\tr12, ", file);
 	}
-      assemble_name (file, label);
-      fputc ('\n', file);
+
+      if (!target_pure_code)
+	{
+	  assemble_name (file, label);
+	  fputc ('\n', file);
+	}
+
       if (flag_pic)
 	{
 	  /* If we are generating PIC, the ldr instruction below loads
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index 8b67c9c..d842448 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -1850,9 +1850,11 @@ enum arm_auto_incmodes
    for the index in the tablejump instruction.  */
 #define CASE_VECTOR_MODE Pmode
 
-#define CASE_VECTOR_PC_RELATIVE (TARGET_THUMB2				\
-				 || (TARGET_THUMB1			\
-				     && (optimize_size || flag_pic)))
+#define CASE_VECTOR_PC_RELATIVE ((TARGET_THUMB2				\
+				  || (TARGET_THUMB1			\
+				      && (optimize_size || flag_pic)))	\
+				 && (!target_pure_code))
+
 
 #define CASE_VECTOR_SHORTEN_MODE(min, max, body)			\
   (TARGET_THUMB1							\
diff --git a/gcc/config/arm/thumb1.md b/gcc/config/arm/thumb1.md
index 5c70200..dd758eb 100644
--- a/gcc/config/arm/thumb1.md
+++ b/gcc/config/arm/thumb1.md
@@ -43,6 +43,41 @@
 
 
 
+(define_insn "thumb1_movsi_symbol_ref"
+  [(set (match_operand:SI 0 "register_operand" "=l")
+	(match_operand:SI 1 "general_operand" ""))
+   ]
+  "TARGET_THUMB1
+   && arm_disable_literal_pool
+   && GET_CODE (operands[1]) == SYMBOL_REF"
+  "*
+  output_asm_insn (\"movs\\t%0, #:upper8_15:%1\", operands);
+  output_asm_insn (\"lsls\\t%0, #8\", operands);
+  output_asm_insn (\"adds\\t%0, #:upper0_7:%1\", operands);
+  output_asm_insn (\"lsls\\t%0, #8\", operands);
+  output_asm_insn (\"adds\\t%0, #:lower8_15:%1\", operands);
+  output_asm_insn (\"lsls\\t%0, #8\", operands);
+  output_asm_insn (\"adds\\t%0, #:lower0_7:%1\", operands);
+  return \"\";
+  "
+  [(set_attr "length" "14")
+   (set_attr "conds" "clob")]
+)
+
+(define_split
+  [(set (match_operand:SI 0 "register_operand" "")
+	(match_operand:SI 1 "immediate_operand" ""))]
+  "TARGET_THUMB1
+   && arm_disable_literal_pool
+   && GET_CODE (operands[1]) == CONST_INT
+   && !satisfies_constraint_I (operands[1])"
+  [(clobber (const_int 0))]
+  "
+    thumb1_gen_const_int (operands[0], INTVAL (operands[1]));
+    DONE;
+  "
+)
+
 (define_insn "*thumb1_adddi3"
   [(set (match_operand:DI          0 "register_operand" "=l")
 	(plus:DI (match_operand:DI 1 "register_operand" "%0")
@@ -829,8 +864,8 @@
    (set_attr "conds" "clob,nocond,nocond,nocond,nocond,clob")])
 
 (define_insn "*thumb1_movhf"
-  [(set (match_operand:HF     0 "nonimmediate_operand" "=l,l,m,*r,*h")
-	(match_operand:HF     1 "general_operand"      "l,mF,l,*h,*r"))]
+  [(set (match_operand:HF     0 "nonimmediate_operand" "=l,l,l,m,*r,*h")
+	(match_operand:HF     1 "general_operand"      "l, m,F,l,*h,*r"))]
   "TARGET_THUMB1
    && (	  s_register_operand (operands[0], HFmode)
        || s_register_operand (operands[1], HFmode))"
@@ -855,14 +890,34 @@
 	  }
 	return \"ldrh\\t%0, %1\";
       }
-    case 2: return \"strh\\t%1, %0\";
+    case 2:
+    {
+      int bits;
+      int high;
+      rtx ops[3];
+
+      bits = real_to_target (NULL, CONST_DOUBLE_REAL_VALUE (operands[1]),
+			     HFmode);
+      ops[0] = operands[0];
+      high = (bits >> 8) & 0xff;
+      ops[1] = GEN_INT (high);
+      ops[2] = GEN_INT (bits & 0xff);
+      if (high != 0)
+	output_asm_insn (\"movs\\t%0, %1\;lsls\\t%0, #8\;adds\\t%0, %2\", ops);
+      else
+	output_asm_insn (\"movs\\t%0, %2\", ops);
+
+      return \"\";
+    }
+    case 3: return \"strh\\t%1, %0\";
     default: return \"mov\\t%0, %1\";
     }
   "
-  [(set_attr "length" "2")
-   (set_attr "type" "mov_reg,load_4,store_4,mov_reg,mov_reg")
-   (set_attr "pool_range" "*,1018,*,*,*")
-   (set_attr "conds" "clob,nocond,nocond,nocond,nocond")])
+  [(set_attr "length" "2,2,6,2,2,2")
+   (set_attr "type" "mov_reg,load_4,mov_reg,store_4,mov_reg,mov_reg")
+   (set_attr "pool_range" "*,1018,*,*,*,*")
+   (set_attr "conds" "clob,nocond,nocond,nocond,nocond,nocond")])
+
 ;;; ??? This should have alternatives for constants.
 (define_insn "*thumb1_movsf_insn"
   [(set (match_operand:SF     0 "nonimmediate_operand" "=l,l,>,l, m,*r,*h")
diff --git a/gcc/testsuite/gcc.target/arm/pr45701-1.c b/gcc/testsuite/gcc.target/arm/pr45701-1.c
index b26011b..15913d8 100644
--- a/gcc/testsuite/gcc.target/arm/pr45701-1.c
+++ b/gcc/testsuite/gcc.target/arm/pr45701-1.c
@@ -2,7 +2,7 @@
 /* { dg-skip-if "" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */
 /* { dg-options "-mthumb -Os" }  */
 /* { dg-final { scan-assembler "push\t\{r3" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
-/* { dg-final { scan-assembler-not "\[^\-\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
+/* { dg-final { scan-assembler-not "\[^\-e\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
 
 extern int hist_verify;
 extern int a1;
diff --git a/gcc/testsuite/gcc.target/arm/pr45701-2.c b/gcc/testsuite/gcc.target/arm/pr45701-2.c
index 32eed4d..bb2d36e 100644
--- a/gcc/testsuite/gcc.target/arm/pr45701-2.c
+++ b/gcc/testsuite/gcc.target/arm/pr45701-2.c
@@ -2,7 +2,7 @@
 /* { dg-skip-if "" { ! { arm_thumb1_ok || arm_thumb2_ok } } } */
 /* { dg-options "-mthumb -Os" }  */
 /* { dg-final { scan-assembler "push\t\{r3" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
-/* { dg-final { scan-assembler-not "\[^\-\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
+/* { dg-final { scan-assembler-not "\[^\-e\]r8" { target { ! arm*-*-uclinuxfdpiceabi } } } } */
 
 extern int hist_verify;
 extern int a1;
diff --git a/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c b/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c
index 4b893fd..3de1620 100644
--- a/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c
+++ b/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c
@@ -1,12 +1,24 @@
 /* { dg-do compile } */
-/* { dg-options "-mpure-code" } */
+/* { dg-options "-mpure-code -mfp16-format=ieee" } */
 /* { dg-skip-if "" { *-*-* } { "-g" "-fpic" "-fPIC" } { "" } } */
 
+__fp16 hf;
 float sf;
 double df;
 long long l;
 static char *p = "Hello World";
 
+__fp16
+testsfp16 (__fp16 *p)
+{
+  hf = 1.3;
+  *p += hf;
+  if (*p > 1.1234f)
+    return 2.1234f;
+  else
+    return 3.1234f;
+}
+
 float
 testsf (float *p)
 {
diff --git a/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp b/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
index bf7e4ad..b05cfd6 100644
--- a/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
+++ b/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
@@ -25,11 +25,8 @@ if ![info exists DEFAULT_CFLAGS] then {
     set DEFAULT_CFLAGS " -ansi -pedantic-errors"
 }
 
-# The -mpure-code option is only available for M-profile targets that support
-# the MOVT instruction.
-if {([check_effective_target_arm_thumb2_ok]
-     || [check_effective_target_arm_thumb1_movt_ok])
-    && [check_effective_target_arm_cortex_m]} then {
+# The -mpure-code option is only available for M-profile targets.
+if {[check_effective_target_arm_cortex_m]} then {
 # Initialize `dg'.
 dg-init
 
@@ -56,4 +53,4 @@ set LTO_TORTURE_OPTIONS ${saved-lto_torture_options}
 
 # All done.
 dg-finish
-}
+#}
diff --git a/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c b/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c
index b989c42..92772d4 100644
--- a/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c
+++ b/gcc/testsuite/gcc.target/arm/thumb1-Os-mult.c
@@ -1,6 +1,7 @@
 /* { dg-do compile } */
 /* { dg-require-effective-target arm_thumb1_ok } */
 /* { dg-options "-Os" } */
+/* { dg-skip-if "-mpure-code generates an inline multiplication code sequence" { *-*-* } { "-mpure-code" } } */
 /* { dg-skip-if "" { ! { arm_thumb1 } } } */
 
 int

ping?

On Mon, 18 Nov 2019 at 10:00, Christophe Lyon
<christophe.lyon@linaro.org> wrote:
>
> On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
> <christophe.lyon@linaro.org> wrote:
> >
> > On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
> > <Richard.Earnshaw@arm.com> wrote:
> > >
> > > On 18/10/2019 14:18, Christophe Lyon wrote:
> > > > +      bool not_supported = arm_arch_notm || flag_pic || TARGET_NEON;
> > > >
> > >
> > > This is a poor name in the context of the function as a whole.  What's
> > > not supported.  Please think of a better name so that I have some idea
> > > what the intention is.
> >
> > That's to keep most of the code common when checking if -mpure-code
> > and -mslow-flash-data are supported.
> > These 3 cases are common to the two compilation flags, and
> > -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
> >
> > Would "common_unsupported_modes" work better for you?
> > Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
> > the two tests.
> >
>
> Hi,
>
> Here is an updated version, using "common_unsupported_modes" instead
> of "not_supported", and fixing the typo reported by Kyrill.
> The ChangeLog is still the same.
>
> OK?
>
> Thanks,
>
> Christophe
>
> > Thanks,
> >
> > Christophe
> >
> > >
> > > R.

ping?
https://gcc.gnu.org/ml/gcc-patches/2019-11/msg01667.html

Kyrill approved the previous version modulo a typo fix, but Richard
wanted a better name for a variable.
Is that version OK?

Thanks,

Christophe


On Tue, 26 Nov 2019 at 16:29, Christophe Lyon
<christophe.lyon@linaro.org> wrote:
>
> ping?
>
> On Mon, 18 Nov 2019 at 10:00, Christophe Lyon
> <christophe.lyon@linaro.org> wrote:
> >
> > On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
> > <christophe.lyon@linaro.org> wrote:
> > >
> > > On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
> > > <Richard.Earnshaw@arm.com> wrote:
> > > >
> > > > On 18/10/2019 14:18, Christophe Lyon wrote:
> > > > > +      bool not_supported = arm_arch_notm || flag_pic || TARGET_NEON;
> > > > >
> > > >
> > > > This is a poor name in the context of the function as a whole.  What's
> > > > not supported.  Please think of a better name so that I have some idea
> > > > what the intention is.
> > >
> > > That's to keep most of the code common when checking if -mpure-code
> > > and -mslow-flash-data are supported.
> > > These 3 cases are common to the two compilation flags, and
> > > -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
> > >
> > > Would "common_unsupported_modes" work better for you?
> > > Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
> > > the two tests.
> > >
> >
> > Hi,
> >
> > Here is an updated version, using "common_unsupported_modes" instead
> > of "not_supported", and fixing the typo reported by Kyrill.
> > The ChangeLog is still the same.
> >
> > OK?
> >
> > Thanks,
> >
> > Christophe
> >
> > > Thanks,
> > >
> > > Christophe
> > >
> > > >
> > > > R.

Ping?

Le jeu. 5 déc. 2019 à 11:13, Christophe Lyon <christophe.lyon@linaro.org> a
écrit :

> ping?
> https://gcc.gnu.org/ml/gcc-patches/2019-11/msg01667.html
>
> Kyrill approved the previous version modulo a typo fix, but Richard
> wanted a better name for a variable.
> Is that version OK?
>
> Thanks,
>
> Christophe
>
>
> On Tue, 26 Nov 2019 at 16:29, Christophe Lyon
> <christophe.lyon@linaro.org> wrote:
> >
> > ping?
> >
> > On Mon, 18 Nov 2019 at 10:00, Christophe Lyon
> > <christophe.lyon@linaro.org> wrote:
> > >
> > > On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
> > > <christophe.lyon@linaro.org> wrote:
> > > >
> > > > On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
> > > > <Richard.Earnshaw@arm.com> wrote:
> > > > >
> > > > > On 18/10/2019 14:18, Christophe Lyon wrote:
> > > > > > +      bool not_supported = arm_arch_notm || flag_pic ||
> TARGET_NEON;
> > > > > >
> > > > >
> > > > > This is a poor name in the context of the function as a whole.
> What's
> > > > > not supported.  Please think of a better name so that I have some
> idea
> > > > > what the intention is.
> > > >
> > > > That's to keep most of the code common when checking if -mpure-code
> > > > and -mslow-flash-data are supported.
> > > > These 3 cases are common to the two compilation flags, and
> > > > -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
> > > >
> > > > Would "common_unsupported_modes" work better for you?
> > > > Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
> > > > the two tests.
> > > >
> > >
> > > Hi,
> > >
> > > Here is an updated version, using "common_unsupported_modes" instead
> > > of "not_supported", and fixing the typo reported by Kyrill.
> > > The ChangeLog is still the same.
> > >
> > > OK?
> > >
> > > Thanks,
> > >
> > > Christophe
> > >
> > > > Thanks,
> > > >
> > > > Christophe
> > > >
> > > > >
> > > > > R.
>

Ping?

On Wed, 11 Dec 2019 at 18:19, Christophe Lyon
<christophe.lyon@linaro.org> wrote:
>
> Ping?
>
> Le jeu. 5 déc. 2019 à 11:13, Christophe Lyon <christophe.lyon@linaro.org> a écrit :
>>
>> ping?
>> https://gcc.gnu.org/ml/gcc-patches/2019-11/msg01667.html
>>
>> Kyrill approved the previous version modulo a typo fix, but Richard
>> wanted a better name for a variable.
>> Is that version OK?
>>
>> Thanks,
>>
>> Christophe
>>
>>
>> On Tue, 26 Nov 2019 at 16:29, Christophe Lyon
>> <christophe.lyon@linaro.org> wrote:
>> >
>> > ping?
>> >
>> > On Mon, 18 Nov 2019 at 10:00, Christophe Lyon
>> > <christophe.lyon@linaro.org> wrote:
>> > >
>> > > On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
>> > > <christophe.lyon@linaro.org> wrote:
>> > > >
>> > > > On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
>> > > > <Richard.Earnshaw@arm.com> wrote:
>> > > > >
>> > > > > On 18/10/2019 14:18, Christophe Lyon wrote:
>> > > > > > +      bool not_supported = arm_arch_notm || flag_pic || TARGET_NEON;
>> > > > > >
>> > > > >
>> > > > > This is a poor name in the context of the function as a whole.  What's
>> > > > > not supported.  Please think of a better name so that I have some idea
>> > > > > what the intention is.
>> > > >
>> > > > That's to keep most of the code common when checking if -mpure-code
>> > > > and -mslow-flash-data are supported.
>> > > > These 3 cases are common to the two compilation flags, and
>> > > > -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
>> > > >
>> > > > Would "common_unsupported_modes" work better for you?
>> > > > Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
>> > > > the two tests.
>> > > >
>> > >
>> > > Hi,
>> > >
>> > > Here is an updated version, using "common_unsupported_modes" instead
>> > > of "not_supported", and fixing the typo reported by Kyrill.
>> > > The ChangeLog is still the same.
>> > >
>> > > OK?
>> > >
>> > > Thanks,
>> > >
>> > > Christophe
>> > >
>> > > > Thanks,
>> > > >
>> > > > Christophe
>> > > >
>> > > > >
>> > > > > R.

Hi Christophe,

On 11/18/19 9:00 AM, Christophe Lyon wrote:
> On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
> <christophe.lyon@linaro.org> wrote:
> >
> > On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
> > <Richard.Earnshaw@arm.com> wrote:
> > >
> > > On 18/10/2019 14:18, Christophe Lyon wrote:
> > > > +      bool not_supported = arm_arch_notm || flag_pic || 
> TARGET_NEON;
> > > >
> > >
> > > This is a poor name in the context of the function as a whole.  What's
> > > not supported.  Please think of a better name so that I have some idea
> > > what the intention is.
> >
> > That's to keep most of the code common when checking if -mpure-code
> > and -mslow-flash-data are supported.
> > These 3 cases are common to the two compilation flags, and
> > -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
> >
> > Would "common_unsupported_modes" work better for you?
> > Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
> > the two tests.
> >
>
> Hi,
>
> Here is an updated version, using "common_unsupported_modes" instead
> of "not_supported", and fixing the typo reported by Kyrill.
> The ChangeLog is still the same.
>
> OK?


The name looks ok to me. Richard had a concern about Armv8-M Baseline, 
but I do see it being supported as you pointed out.

So I believe all the concerns are addressed.

Thus the code is ok. However, please also updated the documentation for 
-mpure-code in invoke.texi (it currently states that a MOVT instruction 
is needed).

Thanks,

Kyrill



>
> Thanks,
>
> Christophe
>
> > Thanks,
> >
> > Christophe
> >
> > >
> > > R.

On Tue, 17 Dec 2019 at 11:34, Kyrill Tkachov
<kyrylo.tkachov@foss.arm.com> wrote:
>
> Hi Christophe,
>
> On 11/18/19 9:00 AM, Christophe Lyon wrote:
> > On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
> > <christophe.lyon@linaro.org> wrote:
> > >
> > > On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
> > > <Richard.Earnshaw@arm.com> wrote:
> > > >
> > > > On 18/10/2019 14:18, Christophe Lyon wrote:
> > > > > +      bool not_supported = arm_arch_notm || flag_pic ||
> > TARGET_NEON;
> > > > >
> > > >
> > > > This is a poor name in the context of the function as a whole.  What's
> > > > not supported.  Please think of a better name so that I have some idea
> > > > what the intention is.
> > >
> > > That's to keep most of the code common when checking if -mpure-code
> > > and -mslow-flash-data are supported.
> > > These 3 cases are common to the two compilation flags, and
> > > -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
> > >
> > > Would "common_unsupported_modes" work better for you?
> > > Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
> > > the two tests.
> > >
> >
> > Hi,
> >
> > Here is an updated version, using "common_unsupported_modes" instead
> > of "not_supported", and fixing the typo reported by Kyrill.
> > The ChangeLog is still the same.
> >
> > OK?
>
>
> The name looks ok to me. Richard had a concern about Armv8-M Baseline,
> but I do see it being supported as you pointed out.
>
> So I believe all the concerns are addressed.
OK, thanks!

>
> Thus the code is ok. However, please also updated the documentation for
> -mpure-code in invoke.texi (it currently states that a MOVT instruction
> is needed).
>
I didn't think about this :(
It currently says: "This option is only available when generating
non-pic code for M-profile targets with the MOVT instruction."

I suggest to remove the "with the MOVT instruction" part. Is that OK
if I commit my patch and this doc change?

Christophe

> Thanks,
>
> Kyrill
>
>
>
> >
> > Thanks,
> >
> > Christophe
> >
> > > Thanks,
> > >
> > > Christophe
> > >
> > > >
> > > > R.

On 12/17/19 2:33 PM, Christophe Lyon wrote:
> On Tue, 17 Dec 2019 at 11:34, Kyrill Tkachov
> <kyrylo.tkachov@foss.arm.com> wrote:
>> Hi Christophe,
>>
>> On 11/18/19 9:00 AM, Christophe Lyon wrote:
>>> On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
>>> <christophe.lyon@linaro.org> wrote:
>>>> On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
>>>> <Richard.Earnshaw@arm.com> wrote:
>>>>> On 18/10/2019 14:18, Christophe Lyon wrote:
>>>>>> +      bool not_supported = arm_arch_notm || flag_pic ||
>>> TARGET_NEON;
>>>>> This is a poor name in the context of the function as a whole.  What's
>>>>> not supported.  Please think of a better name so that I have some idea
>>>>> what the intention is.
>>>> That's to keep most of the code common when checking if -mpure-code
>>>> and -mslow-flash-data are supported.
>>>> These 3 cases are common to the two compilation flags, and
>>>> -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
>>>>
>>>> Would "common_unsupported_modes" work better for you?
>>>> Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
>>>> the two tests.
>>>>
>>> Hi,
>>>
>>> Here is an updated version, using "common_unsupported_modes" instead
>>> of "not_supported", and fixing the typo reported by Kyrill.
>>> The ChangeLog is still the same.
>>>
>>> OK?
>>
>> The name looks ok to me. Richard had a concern about Armv8-M Baseline,
>> but I do see it being supported as you pointed out.
>>
>> So I believe all the concerns are addressed.
> OK, thanks!
>
>> Thus the code is ok. However, please also updated the documentation for
>> -mpure-code in invoke.texi (it currently states that a MOVT instruction
>> is needed).
>>
> I didn't think about this :(
> It currently says: "This option is only available when generating
> non-pic code for M-profile targets with the MOVT instruction."
>
> I suggest to remove the "with the MOVT instruction" part. Is that OK
> if I commit my patch and this doc change?

Yes, I think that is simplest correct change to make.

Thanks,

Kyrill


> Christophe
>
>> Thanks,
>>
>> Kyrill
>>
>>
>>
>>> Thanks,
>>>
>>> Christophe
>>>
>>>> Thanks,
>>>>
>>>> Christophe
>>>>
>>>>> R.

On Tue, 17 Dec 2019 at 16:31, Kyrill Tkachov
<kyrylo.tkachov@foss.arm.com> wrote:
>
>
> On 12/17/19 2:33 PM, Christophe Lyon wrote:
> > On Tue, 17 Dec 2019 at 11:34, Kyrill Tkachov
> > <kyrylo.tkachov@foss.arm.com> wrote:
> >> Hi Christophe,
> >>
> >> On 11/18/19 9:00 AM, Christophe Lyon wrote:
> >>> On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
> >>> <christophe.lyon@linaro.org> wrote:
> >>>> On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
> >>>> <Richard.Earnshaw@arm.com> wrote:
> >>>>> On 18/10/2019 14:18, Christophe Lyon wrote:
> >>>>>> +      bool not_supported = arm_arch_notm || flag_pic ||
> >>> TARGET_NEON;
> >>>>> This is a poor name in the context of the function as a whole.  What's
> >>>>> not supported.  Please think of a better name so that I have some idea
> >>>>> what the intention is.
> >>>> That's to keep most of the code common when checking if -mpure-code
> >>>> and -mslow-flash-data are supported.
> >>>> These 3 cases are common to the two compilation flags, and
> >>>> -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
> >>>>
> >>>> Would "common_unsupported_modes" work better for you?
> >>>> Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
> >>>> the two tests.
> >>>>
> >>> Hi,
> >>>
> >>> Here is an updated version, using "common_unsupported_modes" instead
> >>> of "not_supported", and fixing the typo reported by Kyrill.
> >>> The ChangeLog is still the same.
> >>>
> >>> OK?
> >>
> >> The name looks ok to me. Richard had a concern about Armv8-M Baseline,
> >> but I do see it being supported as you pointed out.
> >>
> >> So I believe all the concerns are addressed.
> > OK, thanks!
> >
> >> Thus the code is ok. However, please also updated the documentation for
> >> -mpure-code in invoke.texi (it currently states that a MOVT instruction
> >> is needed).
> >>
> > I didn't think about this :(
> > It currently says: "This option is only available when generating
> > non-pic code for M-profile targets with the MOVT instruction."
> >
> > I suggest to remove the "with the MOVT instruction" part. Is that OK
> > if I commit my patch and this doc change?
>
> Yes, I think that is simplest correct change to make.
>
> Thanks,
>
Thanks, committed as r279463.

> Kyrill
>
>
> > Christophe
> >
> >> Thanks,
> >>
> >> Kyrill
> >>
> >>
> >>
> >>> Thanks,
> >>>
> >>> Christophe
> >>>
> >>>> Thanks,
> >>>>
> >>>> Christophe
> >>>>
> >>>>> R.

Hi Christophe,

On 12/17/19 3:31 PM, Kyrill Tkachov wrote:
>
> On 12/17/19 2:33 PM, Christophe Lyon wrote:
>> On Tue, 17 Dec 2019 at 11:34, Kyrill Tkachov
>> <kyrylo.tkachov@foss.arm.com> wrote:
>>> Hi Christophe,
>>>
>>> On 11/18/19 9:00 AM, Christophe Lyon wrote:
>>>> On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
>>>> <christophe.lyon@linaro.org> wrote:
>>>>> On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
>>>>> <Richard.Earnshaw@arm.com> wrote:
>>>>>> On 18/10/2019 14:18, Christophe Lyon wrote:
>>>>>>> +      bool not_supported = arm_arch_notm || flag_pic ||
>>>> TARGET_NEON;
>>>>>> This is a poor name in the context of the function as a whole.  
>>>>>> What's
>>>>>> not supported.  Please think of a better name so that I have some 
>>>>>> idea
>>>>>> what the intention is.
>>>>> That's to keep most of the code common when checking if -mpure-code
>>>>> and -mslow-flash-data are supported.
>>>>> These 3 cases are common to the two compilation flags, and
>>>>> -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
>>>>>
>>>>> Would "common_unsupported_modes" work better for you?
>>>>> Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
>>>>> the two tests.
>>>>>
>>>> Hi,
>>>>
>>>> Here is an updated version, using "common_unsupported_modes" instead
>>>> of "not_supported", and fixing the typo reported by Kyrill.
>>>> The ChangeLog is still the same.
>>>>
>>>> OK?
>>>
>>> The name looks ok to me. Richard had a concern about Armv8-M Baseline,
>>> but I do see it being supported as you pointed out.
>>>
>>> So I believe all the concerns are addressed.
>> OK, thanks!
>>
>>> Thus the code is ok. However, please also updated the documentation for
>>> -mpure-code in invoke.texi (it currently states that a MOVT instruction
>>> is needed).
>>>
>> I didn't think about this :(
>> It currently says: "This option is only available when generating
>> non-pic code for M-profile targets with the MOVT instruction."
>>
>> I suggest to remove the "with the MOVT instruction" part. Is that OK
>> if I commit my patch and this doc change?
>
> Yes, I think that is simplest correct change to make.
>

Can you also send a patch to the changes.html page for GCC 10 making 
users aware that this restriction is now lifted?

Thanks,

Kyrill


> Thanks,
>
> Kyrill
>
>
>> Christophe
>>
>>> Thanks,
>>>
>>> Kyrill
>>>
>>>
>>>
>>>> Thanks,
>>>>
>>>> Christophe
>>>>
>>>>> Thanks,
>>>>>
>>>>> Christophe
>>>>>
>>>>>> R.

On Mon, 13 Jan 2020 at 14:49, Kyrill Tkachov
<kyrylo.tkachov@foss.arm.com> wrote:
>
> Hi Christophe,
>
> On 12/17/19 3:31 PM, Kyrill Tkachov wrote:
> >
> > On 12/17/19 2:33 PM, Christophe Lyon wrote:
> >> On Tue, 17 Dec 2019 at 11:34, Kyrill Tkachov
> >> <kyrylo.tkachov@foss.arm.com> wrote:
> >>> Hi Christophe,
> >>>
> >>> On 11/18/19 9:00 AM, Christophe Lyon wrote:
> >>>> On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
> >>>> <christophe.lyon@linaro.org> wrote:
> >>>>> On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
> >>>>> <Richard.Earnshaw@arm.com> wrote:
> >>>>>> On 18/10/2019 14:18, Christophe Lyon wrote:
> >>>>>>> +      bool not_supported = arm_arch_notm || flag_pic ||
> >>>> TARGET_NEON;
> >>>>>> This is a poor name in the context of the function as a whole.
> >>>>>> What's
> >>>>>> not supported.  Please think of a better name so that I have some
> >>>>>> idea
> >>>>>> what the intention is.
> >>>>> That's to keep most of the code common when checking if -mpure-code
> >>>>> and -mslow-flash-data are supported.
> >>>>> These 3 cases are common to the two compilation flags, and
> >>>>> -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
> >>>>>
> >>>>> Would "common_unsupported_modes" work better for you?
> >>>>> Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
> >>>>> the two tests.
> >>>>>
> >>>> Hi,
> >>>>
> >>>> Here is an updated version, using "common_unsupported_modes" instead
> >>>> of "not_supported", and fixing the typo reported by Kyrill.
> >>>> The ChangeLog is still the same.
> >>>>
> >>>> OK?
> >>>
> >>> The name looks ok to me. Richard had a concern about Armv8-M Baseline,
> >>> but I do see it being supported as you pointed out.
> >>>
> >>> So I believe all the concerns are addressed.
> >> OK, thanks!
> >>
> >>> Thus the code is ok. However, please also updated the documentation for
> >>> -mpure-code in invoke.texi (it currently states that a MOVT instruction
> >>> is needed).
> >>>
> >> I didn't think about this :(
> >> It currently says: "This option is only available when generating
> >> non-pic code for M-profile targets with the MOVT instruction."
> >>
> >> I suggest to remove the "with the MOVT instruction" part. Is that OK
> >> if I commit my patch and this doc change?
> >
> > Yes, I think that is simplest correct change to make.
> >
>
> Can you also send a patch to the changes.html page for GCC 10 making
> users aware that this restriction is now lifted?
>

Sure. I should have thought of it when I submitted the GCC patch...

How about the attached? I'm not sure about the right upper/lower case
and <code> markers....

Thanks,

Christophe

> Thanks,
>
> Kyrill
>
>
> > Thanks,
> >
> > Kyrill
> >
> >
> >> Christophe
> >>
> >>> Thanks,
> >>>
> >>> Kyrill
> >>>
> >>>
> >>>
> >>>> Thanks,
> >>>>
> >>>> Christophe
> >>>>
> >>>>> Thanks,
> >>>>>
> >>>>> Christophe
> >>>>>
> >>>>>> R.
commit ba2a354c9ed6c75ec00bf21dd6938b89a113a96e
Author: Christophe Lyon <christophe.lyon@linaro.org>
Date:   Tue Jan 14 13:48:19 2020 +0000

    [arm] Document -mpure-code support for v6m in gcc-10

diff --git a/htdocs/gcc-10/changes.html b/htdocs/gcc-10/changes.html
index caa9df7..26cdf66 100644
--- a/htdocs/gcc-10/changes.html
+++ b/htdocs/gcc-10/changes.html
@@ -417,7 +417,11 @@ a work-in-progress.</p>
   data-processing intrinsics</a> to include 32-bit SIMD, saturating arithmetic,
   16-bit multiplication and other related intrinsics aimed at DSP algorithm
   optimization.
-   </li>
+  </li>
+  <li>Support for <code>-mpure-code</code> in Thumb-1 (v6m) has been
+  added: this M-profile feature is no longer restricted to targets
+  with <code>MOTV</code>. For instance, Cortex-M0 is now
+  supported</li>
 </ul>
 
 <h3 id="avr">AVR</h3>

On 1/14/20 1:50 PM, Christophe Lyon wrote:
> On Mon, 13 Jan 2020 at 14:49, Kyrill Tkachov
> <kyrylo.tkachov@foss.arm.com> wrote:
>> Hi Christophe,
>>
>> On 12/17/19 3:31 PM, Kyrill Tkachov wrote:
>>> On 12/17/19 2:33 PM, Christophe Lyon wrote:
>>>> On Tue, 17 Dec 2019 at 11:34, Kyrill Tkachov
>>>> <kyrylo.tkachov@foss.arm.com> wrote:
>>>>> Hi Christophe,
>>>>>
>>>>> On 11/18/19 9:00 AM, Christophe Lyon wrote:
>>>>>> On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
>>>>>> <christophe.lyon@linaro.org> wrote:
>>>>>>> On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
>>>>>>> <Richard.Earnshaw@arm.com> wrote:
>>>>>>>> On 18/10/2019 14:18, Christophe Lyon wrote:
>>>>>>>>> +      bool not_supported = arm_arch_notm || flag_pic ||
>>>>>> TARGET_NEON;
>>>>>>>> This is a poor name in the context of the function as a whole.
>>>>>>>> What's
>>>>>>>> not supported.  Please think of a better name so that I have some
>>>>>>>> idea
>>>>>>>> what the intention is.
>>>>>>> That's to keep most of the code common when checking if -mpure-code
>>>>>>> and -mslow-flash-data are supported.
>>>>>>> These 3 cases are common to the two compilation flags, and
>>>>>>> -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
>>>>>>>
>>>>>>> Would "common_unsupported_modes" work better for you?
>>>>>>> Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
>>>>>>> the two tests.
>>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> Here is an updated version, using "common_unsupported_modes" instead
>>>>>> of "not_supported", and fixing the typo reported by Kyrill.
>>>>>> The ChangeLog is still the same.
>>>>>>
>>>>>> OK?
>>>>> The name looks ok to me. Richard had a concern about Armv8-M Baseline,
>>>>> but I do see it being supported as you pointed out.
>>>>>
>>>>> So I believe all the concerns are addressed.
>>>> OK, thanks!
>>>>
>>>>> Thus the code is ok. However, please also updated the documentation for
>>>>> -mpure-code in invoke.texi (it currently states that a MOVT instruction
>>>>> is needed).
>>>>>
>>>> I didn't think about this :(
>>>> It currently says: "This option is only available when generating
>>>> non-pic code for M-profile targets with the MOVT instruction."
>>>>
>>>> I suggest to remove the "with the MOVT instruction" part. Is that OK
>>>> if I commit my patch and this doc change?
>>> Yes, I think that is simplest correct change to make.
>>>
>> Can you also send a patch to the changes.html page for GCC 10 making
>> users aware that this restriction is now lifted?
>>
> Sure. I should have thought of it when I submitted the GCC patch...
>
> How about the attached? I'm not sure about the right upper/lower case
> and <code> markers....
>
> Thanks,
>
> Christophe

commit ba2a354c9ed6c75ec00bf21dd6938b89a113a96e
Author: Christophe Lyon<christophe.lyon@linaro.org>
Date:   Tue Jan 14 13:48:19 2020 +0000

     [arm] Document -mpure-code support for v6m in gcc-10

diff --git a/htdocs/gcc-10/changes.html b/htdocs/gcc-10/changes.html
index caa9df7..26cdf66 100644
--- a/htdocs/gcc-10/changes.html
+++ b/htdocs/gcc-10/changes.html
@@ -417,7 +417,11 @@ a work-in-progress.</p>
    data-processing intrinsics</a> to include 32-bit SIMD, saturating arithmetic,
    16-bit multiplication and other related intrinsics aimed at DSP algorithm
    optimization.
-   </li>
+  </li>
+  <li>Support for <code>-mpure-code</code> in Thumb-1 (v6m) has been
+  added: this M-profile feature is no longer restricted to targets
+  with <code>MOTV</code>. For instance, Cortex-M0 is now
+  supported</li>

Typo in MOVT.
Let's make the last sentence. "For example, <code>-mcpu=cortex-m0</code> now supports this option."

Ok with those changes.
Thanks,
Kyrill

  </ul>
  
  <h3 id="avr">AVR</h3>

On Tue, 14 Jan 2020 at 14:54, Kyrill Tkachov
<kyrylo.tkachov@foss.arm.com> wrote:
>
>
> On 1/14/20 1:50 PM, Christophe Lyon wrote:
> > On Mon, 13 Jan 2020 at 14:49, Kyrill Tkachov
> > <kyrylo.tkachov@foss.arm.com> wrote:
> >> Hi Christophe,
> >>
> >> On 12/17/19 3:31 PM, Kyrill Tkachov wrote:
> >>> On 12/17/19 2:33 PM, Christophe Lyon wrote:
> >>>> On Tue, 17 Dec 2019 at 11:34, Kyrill Tkachov
> >>>> <kyrylo.tkachov@foss.arm.com> wrote:
> >>>>> Hi Christophe,
> >>>>>
> >>>>> On 11/18/19 9:00 AM, Christophe Lyon wrote:
> >>>>>> On Wed, 13 Nov 2019 at 15:46, Christophe Lyon
> >>>>>> <christophe.lyon@linaro.org> wrote:
> >>>>>>> On Tue, 12 Nov 2019 at 12:13, Richard Earnshaw (lists)
> >>>>>>> <Richard.Earnshaw@arm.com> wrote:
> >>>>>>>> On 18/10/2019 14:18, Christophe Lyon wrote:
> >>>>>>>>> +      bool not_supported = arm_arch_notm || flag_pic ||
> >>>>>> TARGET_NEON;
> >>>>>>>> This is a poor name in the context of the function as a whole.
> >>>>>>>> What's
> >>>>>>>> not supported.  Please think of a better name so that I have some
> >>>>>>>> idea
> >>>>>>>> what the intention is.
> >>>>>>> That's to keep most of the code common when checking if -mpure-code
> >>>>>>> and -mslow-flash-data are supported.
> >>>>>>> These 3 cases are common to the two compilation flags, and
> >>>>>>> -mslow-flash-data still needs to check TARGET_HAVE_MOVT in addition.
> >>>>>>>
> >>>>>>> Would "common_unsupported_modes" work better for you?
> >>>>>>> Or I can duplicate the "arm_arch_notm || flag_pic || TARGET_NEON" in
> >>>>>>> the two tests.
> >>>>>>>
> >>>>>> Hi,
> >>>>>>
> >>>>>> Here is an updated version, using "common_unsupported_modes" instead
> >>>>>> of "not_supported", and fixing the typo reported by Kyrill.
> >>>>>> The ChangeLog is still the same.
> >>>>>>
> >>>>>> OK?
> >>>>> The name looks ok to me. Richard had a concern about Armv8-M Baseline,
> >>>>> but I do see it being supported as you pointed out.
> >>>>>
> >>>>> So I believe all the concerns are addressed.
> >>>> OK, thanks!
> >>>>
> >>>>> Thus the code is ok. However, please also updated the documentation for
> >>>>> -mpure-code in invoke.texi (it currently states that a MOVT instruction
> >>>>> is needed).
> >>>>>
> >>>> I didn't think about this :(
> >>>> It currently says: "This option is only available when generating
> >>>> non-pic code for M-profile targets with the MOVT instruction."
> >>>>
> >>>> I suggest to remove the "with the MOVT instruction" part. Is that OK
> >>>> if I commit my patch and this doc change?
> >>> Yes, I think that is simplest correct change to make.
> >>>
> >> Can you also send a patch to the changes.html page for GCC 10 making
> >> users aware that this restriction is now lifted?
> >>
> > Sure. I should have thought of it when I submitted the GCC patch...
> >
> > How about the attached? I'm not sure about the right upper/lower case
> > and <code> markers....
> >
> > Thanks,
> >
> > Christophe
>
> commit ba2a354c9ed6c75ec00bf21dd6938b89a113a96e
> Author: Christophe Lyon<christophe.lyon@linaro.org>
> Date:   Tue Jan 14 13:48:19 2020 +0000
>
>      [arm] Document -mpure-code support for v6m in gcc-10
>
> diff --git a/htdocs/gcc-10/changes.html b/htdocs/gcc-10/changes.html
> index caa9df7..26cdf66 100644
> --- a/htdocs/gcc-10/changes.html
> +++ b/htdocs/gcc-10/changes.html
> @@ -417,7 +417,11 @@ a work-in-progress.</p>
>     data-processing intrinsics</a> to include 32-bit SIMD, saturating arithmetic,
>     16-bit multiplication and other related intrinsics aimed at DSP algorithm
>     optimization.
> -   </li>
> +  </li>
> +  <li>Support for <code>-mpure-code</code> in Thumb-1 (v6m) has been
> +  added: this M-profile feature is no longer restricted to targets
> +  with <code>MOTV</code>. For instance, Cortex-M0 is now
> +  supported</li>
>
> Typo in MOVT.

sigh, I did read my text several times :(

> Let's make the last sentence. "For example, <code>-mcpu=cortex-m0</code> now supports this option."
>
OK, thanks

> Ok with those changes.
> Thanks,
> Kyrill
>
>   </ul>
>
>   <h3 id="avr">AVR</h3>
>