diff mbox

[arm-embedded,committed] Add support for -mpure-code option

Message ID 5821E32B.8070501@arm.com
State New
Headers show

Commit Message

Andre Vieira (lists) Nov. 8, 2016, 2:37 p.m. UTC
Hi,

Backported the support for the ARM -mpure-code option, including the
follow-up fixes to the embedded-6-branch. Tested for arm-none-eabi.

Committed in revision r241970.

Cheers,
Andre

gcc/ChangeLog.arm:
2016-11-08  Andre Vieira  <andre.simoesdiasvieira@arm.com>

       Backport from mainline
       2016-09-23  Uros Bizjak  <ubizjak@gmail.com>
                   Jakub Jelinek  <jakub@redhat.com>

       * hooks.h (hook_uint_uintp_false): Rename to...
       (hook_bool_uint_uintp_false): ... this.
       * hooks.c (hook_uint_uintp_false): Rename to...
       (hook_bool_uint_uintp_false): ... this.
       * target.def (elf_flags_numeric): Use hook_bool_uint_uintp_false
       instead of hook_uint_uintp_false.

       2016-09-23  Richard Biener  <rguenther@suse.de>

       * hooks.h (hook_uint_uintp_false): Declare.

       2016-09-22  Andre Vieira  <andre.simoesdiasvieira@arm.com>
                   Terry Guo  <terry.guo@arm.com>

       * target.def (elf_flags_numeric): New target hook.
       * targhooks.h (default_asm_elf_flags_numeric): New.
       * varasm.c (default_asm_elf_flags_numeric): New.
       (default_elf_asm_named_section): Use new target hook.
       * config/arm/arm.opt (mpure-code): New.
       * config/arm/arm.h (SECTION_ARM_PURECODE): New.
       * config/arm/arm.c (arm_asm_init_sections): Add section
       attribute to default text section if -mpure-code.
       (arm_option_check_internal): Diagnose use of option with
       non supported targets and/or options.
       (arm_asm_elf_flags_numeric): New.
       (arm_function_section): New.
       (arm_elf_section_type_flags): New.
       * config/arm/elf.h (JUMP_TABLES_IN_TEXT_SECTION): Disable
       for -mpure-code.
       * gcc/doc/texi (TARGET_ASM_ELF_FLAGS_NUMERIC): New.
       * gcc/doc/texi.in (TARGET_ASM_ELF_FLAGS_NUMERIC): Likewise.

gcc/testsuite/ChangeLog.arm:
2016-11-08  Andre Vieira  <andre.simoesdiasvieira@arm.com>

       Backport from mainline
       2016-10-21  Andre Vieira  <andre.simoesdiasvieira@arm.com>

       * gcc.target/arm/pure-code/pure-code.exp: Require arm_cortex_m
       effective target.

       2016-09-22  Andre Vieira  <andre.simoesdiasvieira@arm.com>
                   Terry Guo  <terry.guo@arm.com>

       * gcc.target/arm/pure-code/ffunction-sections.c: New.
       * gcc.target/arm/pure-code/no-literal-pool.c: New.
       * gcc.target/arm/pure-code/pure-code.exp: New.
diff mbox

Patch

diff --git a/gcc/ChangeLog.arm b/gcc/ChangeLog.arm
index f45bd18e94e597208132b067607bf186d2e30f09..b048981d664a952135ff942fe298cce32bbc52a9 100644
--- a/gcc/ChangeLog.arm
+++ b/gcc/ChangeLog.arm
@@ -1,6 +1,44 @@ 
 2016-11-08  Andre Vieira  <andre.simoesdiasvieira@arm.com>
 
 	Backport from mainline
+	2016-09-23  Uros Bizjak  <ubizjak@gmail.com>
+		    Jakub Jelinek  <jakub@redhat.com>
+
+	* hooks.h (hook_uint_uintp_false): Rename to...
+	(hook_bool_uint_uintp_false): ... this.
+	* hooks.c (hook_uint_uintp_false): Rename to...
+	(hook_bool_uint_uintp_false): ... this.
+	* target.def (elf_flags_numeric): Use hook_bool_uint_uintp_false
+	instead of hook_uint_uintp_false.
+
+	2016-09-23  Richard Biener  <rguenther@suse.de>
+
+	* hooks.h (hook_uint_uintp_false): Declare.
+
+	2016-09-22  Andre Vieira  <andre.simoesdiasvieira@arm.com>
+		    Terry Guo  <terry.guo@arm.com>
+
+	* target.def (elf_flags_numeric): New target hook.
+	* targhooks.h (default_asm_elf_flags_numeric): New.
+	* varasm.c (default_asm_elf_flags_numeric): New.
+	(default_elf_asm_named_section): Use new target hook.
+	* config/arm/arm.opt (mpure-code): New.
+	* config/arm/arm.h (SECTION_ARM_PURECODE): New.
+	* config/arm/arm.c (arm_asm_init_sections): Add section
+	attribute to default text section if -mpure-code.
+	(arm_option_check_internal): Diagnose use of option with
+	non supported targets and/or options.
+	(arm_asm_elf_flags_numeric): New.
+	(arm_function_section): New.
+	(arm_elf_section_type_flags): New.
+	* config/arm/elf.h (JUMP_TABLES_IN_TEXT_SECTION): Disable
+	for -mpure-code.
+	* gcc/doc/texi (TARGET_ASM_ELF_FLAGS_NUMERIC): New.
+	* gcc/doc/texi.in (TARGET_ASM_ELF_FLAGS_NUMERIC): Likewise.
+
+2016-11-08  Andre Vieira  <andre.simoesdiasvieira@arm.com>
+
+	Backport from mainline
 	2016-05-27  Ulrich Weigand  <uweigand@de.ibm.com>
 
 	* configure.ac: Treat a --with-headers option without argument
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index 77f2e102fe55246676598b8f93ea6737dcc2abbb..93f5e25099501c2b475eb1801dfc7228ced3f839 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -2285,4 +2285,8 @@  extern const char *host_detect_local_cpu (int argc, const char **argv);
 /* For switching between functions with different target attributes.  */
 #define SWITCHABLE_TARGET 1
 
+/* Define SECTION_ARM_PURECODE as the ARM specific section attribute
+   representation for SHF_ARM_PURECODE in GCC.  */
+#define SECTION_ARM_PURECODE SECTION_MACH_DEP
+
 #endif /* ! GCC_ARM_H */
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index d0f5c733ff822eb0e09649f0c5ed8890cc03d0c8..707e52d77e483563e0217a9a87aa5d655a79e29f 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -216,8 +216,8 @@  static bool arm_return_in_memory (const_tree, const_tree);
 static void arm_unwind_emit (FILE *, rtx_insn *);
 static bool arm_output_ttype (rtx);
 static void arm_asm_emit_except_personality (rtx);
-static void arm_asm_init_sections (void);
 #endif
+static void arm_asm_init_sections (void);
 static rtx arm_dwarf_register_span (rtx);
 
 static tree arm_cxx_guard_type (void);
@@ -301,6 +301,10 @@  static void arm_canonicalize_comparison (int *code, rtx *op0, rtx *op1,
 static unsigned HOST_WIDE_INT arm_asan_shadow_offset (void);
 
 static void arm_sched_fusion_priority (rtx_insn *, int, int *, int*);
+static section *arm_function_section (tree, enum node_frequency, bool, bool);
+static bool arm_asm_elf_flags_numeric (unsigned int flags, unsigned int *num);
+static unsigned int arm_elf_section_type_flags (tree decl, const char *name,
+						int reloc);
 
 /* Table of machine attributes.  */
 static const struct attribute_spec arm_attribute_table[] =
@@ -588,8 +592,8 @@  static const struct attribute_spec arm_attribute_table[] =
 #define TARGET_ASM_EMIT_EXCEPT_PERSONALITY arm_asm_emit_except_personality
 
 #undef TARGET_ASM_INIT_SECTIONS
-#define TARGET_ASM_INIT_SECTIONS arm_asm_init_sections
 #endif /* ARM_UNWIND_INFO */
+#define TARGET_ASM_INIT_SECTIONS arm_asm_init_sections
 
 #undef TARGET_DWARF_REGISTER_SPAN
 #define TARGET_DWARF_REGISTER_SPAN arm_dwarf_register_span
@@ -736,6 +740,15 @@  static const struct attribute_spec arm_attribute_table[] =
 #undef TARGET_SCHED_FUSION_PRIORITY
 #define TARGET_SCHED_FUSION_PRIORITY arm_sched_fusion_priority
 
+#undef  TARGET_ASM_FUNCTION_SECTION
+#define TARGET_ASM_FUNCTION_SECTION arm_function_section
+
+#undef TARGET_ASM_ELF_FLAGS_NUMERIC
+#define TARGET_ASM_ELF_FLAGS_NUMERIC arm_asm_elf_flags_numeric
+
+#undef TARGET_SECTION_TYPE_FLAGS
+#define TARGET_SECTION_TYPE_FLAGS arm_elf_section_type_flags
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 /* Obstack for minipool constant handling.  */
@@ -2798,6 +2811,12 @@  arm_option_check_internal (struct gcc_options *opts)
       && ((!(arm_arch7 && !arm_arch_notm) && !arm_arch7em)
 	  || (TARGET_THUMB1_P (flags) || flag_pic || TARGET_NEON)))
     error ("-mslow-flash-data only supports non-pic code on armv7-m targets");
+
+  /* We only support pure-code on Thumb-2 M-profile targets.  */
+  if (target_pure_code
+      && (!arm_arch_thumb2 || arm_arch_notm || flag_pic || TARGET_NEON))
+    error ("-mpure-code only supports non-pic code on armv7-m targets");
+
 }
 
 /* Recompute the global settings depending on target attribute options.  */
@@ -3437,8 +3456,9 @@  arm_option_override (void)
 			 global_options.x_param_values,
 			 global_options_set.x_param_values);
 
-  /* Currently, for slow flash data, we just disable literal pools.  */
-  if (target_slow_flash_data)
+  /* Currently, for slow flash data, we just disable literal pools.  We also
+     disable it for pure-code.  */
+  if (target_slow_flash_data || target_pure_code)
     arm_disable_literal_pool = true;
 
   /* Disable scheduling fusion by default if it's not armv7 processor
@@ -27163,17 +27183,24 @@  arm_asm_emit_except_personality (rtx personality)
   output_addr_const (asm_out_file, personality);
   fputc ('\n', asm_out_file);
 }
+#endif /* ARM_UNWIND_INFO */
 
 /* Implement TARGET_ASM_INITIALIZE_SECTIONS.  */
 
 static void
 arm_asm_init_sections (void)
 {
+#if ARM_UNWIND_INFO
   exception_section = get_unnamed_section (0, output_section_asm_op,
 					   "\t.handlerdata");
-}
 #endif /* ARM_UNWIND_INFO */
 
+#ifdef OBJECT_FORMAT_ELF
+  if (target_pure_code)
+    text_section->unnamed.data = "\t.section .text,\"0x20000006\",%progbits";
+#endif
+}
+
 /* Output unwind directives for the start/end of a function.  */
 
 void
@@ -30389,4 +30416,111 @@  arm_sched_fusion_priority (rtx_insn *insn, int max_pri,
   return;
 }
 
+/* Implement the TARGET_ASM_ELF_FLAGS_NUMERIC hook.
+
+   For pure-code sections there is no letter code for this attribute, so
+   output all the section flags numerically when this is needed.  */
+
+static bool
+arm_asm_elf_flags_numeric (unsigned int flags, unsigned int *num)
+{
+
+  if (flags & SECTION_ARM_PURECODE)
+    {
+      *num = 0x20000000;
+
+      if (!(flags & SECTION_DEBUG))
+	*num |= 0x2;
+      if (flags & SECTION_EXCLUDE)
+	*num |= 0x80000000;
+      if (flags & SECTION_WRITE)
+	*num |= 0x1;
+      if (flags & SECTION_CODE)
+	*num |= 0x4;
+      if (flags & SECTION_MERGE)
+	*num |= 0x10;
+      if (flags & SECTION_STRINGS)
+	*num |= 0x20;
+      if (flags & SECTION_TLS)
+	*num |= 0x400;
+      if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
+	*num |= 0x200;
+
+	return true;
+    }
+
+  return false;
+}
+
+/* Implement the TARGET_ASM_FUNCTION_SECTION hook.
+
+   If pure-code is passed as an option, make sure all functions are in
+   sections that have the SHF_ARM_PURECODE attribute.  */
+
+static section *
+arm_function_section (tree decl, enum node_frequency freq,
+		      bool startup, bool exit)
+{
+  const char * section_name;
+  section * sec;
+
+  if (!decl || TREE_CODE (decl) != FUNCTION_DECL)
+    return default_function_section (decl, freq, startup, exit);
+
+  if (!target_pure_code)
+    return default_function_section (decl, freq, startup, exit);
+
+
+  section_name = DECL_SECTION_NAME (decl);
+
+  /* If a function is not in a named section then it falls under the 'default'
+     text section, also known as '.text'.  We can preserve previous behavior as
+     the default text section already has the SHF_ARM_PURECODE section
+     attribute.  */
+  if (!section_name)
+    {
+      section *default_sec = default_function_section (decl, freq, startup,
+						       exit);
+
+      /* If default_sec is not null, then it must be a special section like for
+	 example .text.startup.  We set the pure-code attribute and return the
+	 same section to preserve existing behavior.  */
+      if (default_sec)
+	  default_sec->common.flags |= SECTION_ARM_PURECODE;
+      return default_sec;
+    }
+
+  /* Otherwise look whether a section has already been created with
+     'section_name'.  */
+  sec = get_named_section (decl, section_name, 0);
+  if (!sec)
+    /* If that is not the case passing NULL as the section's name to
+       'get_named_section' will create a section with the declaration's
+       section name.  */
+    sec = get_named_section (decl, NULL, 0);
+
+  /* Set the SHF_ARM_PURECODE attribute.  */
+  sec->common.flags |= SECTION_ARM_PURECODE;
+
+  return sec;
+}
+
+/* Implements the TARGET_SECTION_FLAGS hook.
+
+   If DECL is a function declaration and pure-code is passed as an option
+   then add the SFH_ARM_PURECODE attribute to the section flags.  NAME is the
+   section's name and RELOC indicates whether the declarations initializer may
+   contain runtime relocations.  */
+
+static unsigned int
+arm_elf_section_type_flags (tree decl, const char *name, int reloc)
+{
+  unsigned int flags = default_section_type_flags (decl, name, reloc);
+
+  if (decl && TREE_CODE (decl) == FUNCTION_DECL && target_pure_code)
+    flags |= SECTION_ARM_PURECODE;
+
+  return flags;
+}
+
 #include "gt-arm.h"
diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md
index 2c76708a9fb2d99515cfb2f8dd19dd4b31dd9a9b..d77ac7ab62573e6e65629e90697ef0b932973548 100644
--- a/gcc/config/arm/arm.md
+++ b/gcc/config/arm/arm.md
@@ -8192,7 +8192,7 @@ 
    (match_operand:SI 2 "const_int_operand" "")	; total range
    (match_operand:SI 3 "" "")			; table label
    (match_operand:SI 4 "" "")]			; Out of range label
-  "TARGET_32BIT || optimize_size || flag_pic"
+  "(TARGET_32BIT || optimize_size || flag_pic) && !target_pure_code"
   "
   {
     enum insn_code code;
diff --git a/gcc/config/arm/arm.opt b/gcc/config/arm/arm.opt
index 0ebe0174390167b79a64583c35a3f8fb018f6538..35f047e2de1659c2b426cf42dbbdae5be62cbfef 100644
--- a/gcc/config/arm/arm.opt
+++ b/gcc/config/arm/arm.opt
@@ -281,3 +281,7 @@  Assume loading data from flash is slower than fetching instructions.
 masm-syntax-unified
 Target Report Var(inline_asm_unified) Init(0) Save
 Assume unified syntax for inline assembly code.
+
+mpure-code
+Target Report Var(target_pure_code) Init(0)
+Do not allow constant data to be placed in code sections.
diff --git a/gcc/config/arm/elf.h b/gcc/config/arm/elf.h
index 246de5492665ba2a0292736a9c53fbaaef184d72..bc4eb86f1da5beabf32647637eb87a3fc17a6c6a 100644
--- a/gcc/config/arm/elf.h
+++ b/gcc/config/arm/elf.h
@@ -104,7 +104,8 @@ 
    the code more efficient, but for Thumb-1 it's better to put them out of
    band unless we are generating compressed tables.  */
 #define JUMP_TABLES_IN_TEXT_SECTION					\
-   (TARGET_32BIT || (TARGET_THUMB && (optimize_size || flag_pic)))
+   ((TARGET_32BIT || (TARGET_THUMB && (optimize_size || flag_pic))) \
+    && !target_pure_code)
 
 #ifndef LINK_SPEC
 #define LINK_SPEC "%{mbig-endian:-EB} %{mlittle-endian:-EL} -X"
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index bc8a1c230087a5c023926cf3a9771000bf6a5463..905af69c0895c390da408c40f8b1eaa986d7f8d3 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -632,7 +632,8 @@  Objective-C and Objective-C++ Dialects}.
 -mneon-for-64bits @gol
 -mslow-flash-data @gol
 -masm-syntax-unified @gol
--mrestrict-it}
+-mrestrict-it @gol
+-mpure-code}
 
 @emph{AVR Options}
 @gccoptlist{-mmcu=@var{mcu} -maccumulate-args -mbranch-cost=@var{cost} @gol
@@ -14321,6 +14322,14 @@  Print CPU tuning information as comment in assembler file.  This is
 an option used only for regression testing of the compiler and not
 intended for ordinary use in compiling code.  This option is disabled
 by default.
+
+@item -mpure-code
+@opindex mpure-code
+Do not allow constant data to be placed in code sections.
+Additionally, when compiling for ELF object format give all text sections the
+ELF processor-specific section attribute @code{SHF_ARM_PURECODE}.  This option
+is only available when generating non-pic code for ARMv7-M targets.
+
 @end table
 
 @node AVR Options
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 745910f9a33134eaac75afd676c73e2a0f9dcfe0..1feb631628960cf1242032bd5a8e20ae6fe9253d 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -7510,6 +7510,18 @@  is non-NULL, it is the @code{VAR_DECL} or @code{FUNCTION_DECL} with which
 this section is associated.
 @end deftypefn
 
+@deftypefn {Target Hook} bool TARGET_ASM_ELF_FLAGS_NUMERIC (unsigned int @var{flags}, unsigned int *@var{num})
+This hook can be used to encode ELF section flags for which no letter
+code has been defined in the assembler.  It is called by
+@code{default_asm_named_section} whenever the section flags need to be
+emitted in the assembler output.  If the hook returns true, then the
+numerical value for ELF section flags should be calculated from
+@var{flags} and saved in @var{*num}; the value will be printed out
+instead of the normal sequence of letter codes.  If the hook is not
+defined, or if it returns false, then @var{num} will be ignored and the
+traditional letter sequence will be emitted.
+@end deftypefn
+
 @deftypefn {Target Hook} {section *} TARGET_ASM_FUNCTION_SECTION (tree @var{decl}, enum node_frequency @var{freq}, bool @var{startup}, bool @var{exit})
 Return preferred text (sub)section for function @var{decl}.
 Main purpose of this function is to separate cold, normal and hot
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index f31c763991c595db02b2b1ef2939a05becb58a70..db0d75fbe8940c94dd87fc7114804cf31f877ec2 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -5209,6 +5209,8 @@  of the filename using this macro.
 
 @hook TARGET_ASM_NAMED_SECTION
 
+@hook TARGET_ASM_ELF_FLAGS_NUMERIC
+
 @hook TARGET_ASM_FUNCTION_SECTION
 
 @hook TARGET_ASM_FUNCTION_SWITCHED_TEXT_SECTIONS
diff --git a/gcc/hooks.h b/gcc/hooks.h
index 2dc59baeadde877577026fd9f0aefd8bc9e51c36..0cdfc81ca42e4aa713c518b556eee18334bdb568 100644
--- a/gcc/hooks.h
+++ b/gcc/hooks.h
@@ -76,6 +76,7 @@  extern void hook_void_tree (tree);
 extern void hook_void_tree_treeptr (tree, tree *);
 extern void hook_void_int_int (int, int);
 extern void hook_void_gcc_optionsp (struct gcc_options *);
+extern bool hook_bool_uint_uintp_false (unsigned int, unsigned int *);
 
 extern int hook_int_uint_mode_1 (unsigned int, machine_mode);
 extern int hook_int_const_tree_0 (const_tree);
diff --git a/gcc/hooks.c b/gcc/hooks.c
index 99ec4014adb6fcbb073bf538dd00fe8695ee6cb2..0d18ef699dccaa83bcf170f9e440219cd9a93a2b 100644
--- a/gcc/hooks.c
+++ b/gcc/hooks.c
@@ -481,3 +481,12 @@  void
 hook_void_gcc_optionsp (struct gcc_options *opts ATTRIBUTE_UNUSED)
 {
 }
+
+/* Generic hook that takes an unsigned int, an unsigned int pointer and
+   returns false.  */
+
+bool
+hook_bool_uint_uintp_false (unsigned int, unsigned int *)
+{
+  return false;
+}
diff --git a/gcc/target.def b/gcc/target.def
index 20f2b32da1e902a8f799f0ef4a5d53650e8fa91c..33a671af95b5aac4e077b7c75474efcd3f66ac48 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -432,6 +432,22 @@  this section is associated.",
  void, (const char *name, unsigned int flags, tree decl),
  default_no_named_section)
 
+/* Tell assembler what section attributes to assign this elf section
+   declaration, using their numerical value.  */
+DEFHOOK
+(elf_flags_numeric,
+ "This hook can be used to encode ELF section flags for which no letter\n\
+code has been defined in the assembler.  It is called by\n\
+@code{default_asm_named_section} whenever the section flags need to be\n\
+emitted in the assembler output.  If the hook returns true, then the\n\
+numerical value for ELF section flags should be calculated from\n\
+@var{flags} and saved in @var{*num}; the value will be printed out\n\
+instead of the normal sequence of letter codes.  If the hook is not\n\
+defined, or if it returns false, then @var{num} will be ignored and the\n\
+traditional letter sequence will be emitted.",
+ bool, (unsigned int flags, unsigned int *num),
+ hook_bool_uint_uintp_false)
+
 /* Return preferred text (sub)section for function DECL.
    Main purpose of this function is to separate cold, normal and hot
    functions. STARTUP is true when function is known to be used only 
diff --git a/gcc/testsuite/ChangeLog.arm b/gcc/testsuite/ChangeLog.arm
index 4f847db707687e64d9a52d0672ee59b75938f7e5..90911ada82c7c3a00c91ac1fa48a2ca660047700 100644
--- a/gcc/testsuite/ChangeLog.arm
+++ b/gcc/testsuite/ChangeLog.arm
@@ -1,3 +1,18 @@ 
+2016-11-08  Andre Vieira  <andre.simoesdiasvieira@arm.com>
+
+	Backport from mainline
+	2016-10-21  Andre Vieira  <andre.simoesdiasvieira@arm.com>
+
+	* gcc.target/arm/pure-code/pure-code.exp: Require arm_cortex_m
+	effective target.
+
+	2016-09-22  Andre Vieira  <andre.simoesdiasvieira@arm.com>
+		    Terry Guo  <terry.guo@arm.com>
+
+	* gcc.target/arm/pure-code/ffunction-sections.c: New.
+	* gcc.target/arm/pure-code/no-literal-pool.c: New.
+	* gcc.target/arm/pure-code/pure-code.exp: New.
+
 2016-10-27  Thomas Preud'homme  <thomas.preudhomme@arm.com>
 
 	Backport from mainline
diff --git a/gcc/testsuite/gcc.target/arm/pure-code/ffunction-sections.c b/gcc/testsuite/gcc.target/arm/pure-code/ffunction-sections.c
new file mode 100644
index 0000000000000000000000000000000000000000..26fe38c05295b70ccc35ed900d41b34aae2c87a8
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pure-code/ffunction-sections.c
@@ -0,0 +1,17 @@ 
+/* { dg-do compile } */
+/* { dg-skip-if "" { *-*-* } { "-fpic" "-fPIC" } { "" } } */
+/* { dg-options "-ffunction-sections -mpure-code" } */
+#include <limits.h>
+
+char * foo (void)
+{
+  return "foo";
+}
+
+unsigned int bar (unsigned int b)
+{
+  return UINT_MAX - b;
+}
+
+/* { dg-final { scan-assembler {\.section\t\.text\.foo[^\n]*\"0x20000006\"} } } */
+/* { dg-final { scan-assembler {\.section\t\.text\.bar[^\n]*\"0x20000006\"} } } */
diff --git a/gcc/testsuite/gcc.target/arm/pure-code/no-casesi.c b/gcc/testsuite/gcc.target/arm/pure-code/no-casesi.c
new file mode 100644
index 0000000000000000000000000000000000000000..ba116a8261b16610e6af47d26a6e1a07b0127561
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pure-code/no-casesi.c
@@ -0,0 +1,29 @@ 
+/* { dg-do compile } */
+/* { dg-options "-mpure-code" } */
+/* { dg-skip-if "" { *-*-* } { "-g" "-fpic" "-fPIC" } { "" } } */
+
+extern int foo (void);
+extern int bar (void);
+extern int baz (void);
+extern int fooz (void);
+
+int caller (unsigned int reg_type)
+{
+  switch (reg_type)
+    {
+    case 0x80000000:
+      return (int) foo ();
+
+    case 0x80000003:
+      return (int) bar ();
+
+    case 0x80000001:
+      return (int) baz ();
+
+    case 0x80000004:
+      return (int) fooz ();
+    }
+}
+
+/* { dg-final { scan-assembler-not "\\.(float|l\\?double|\d?byte|short|int|long|quad|word)\\s+\[^.\]" } } */
+/* { dg-final { scan-assembler "text,\"0x20000006\"" } } */
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
new file mode 100644
index 0000000000000000000000000000000000000000..4b893fd32f722e6cd7dfde5c8542ab98327ba375
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pure-code/no-literal-pool.c
@@ -0,0 +1,68 @@ 
+/* { dg-do compile } */
+/* { dg-options "-mpure-code" } */
+/* { dg-skip-if "" { *-*-* } { "-g" "-fpic" "-fPIC" } { "" } } */
+
+float sf;
+double df;
+long long l;
+static char *p = "Hello World";
+
+float
+testsf (float *p)
+{
+  if (*p > 1.1234f)
+    return 2.1234f;
+  else
+    return 3.1234f;
+}
+
+double
+testdf (double *p)
+{
+  if (*p > 4.1234)
+    return 2.1234;
+  else
+    return 3.1234;
+}
+
+long long
+testll (long long *p)
+{
+  if (*p > 0x123456789ABCDEFll)
+    return 0x111111111ll;
+  else
+    return 0x222222222ll;
+}
+
+char *
+testchar ()
+{
+  return p + 4;
+}
+
+int
+foo (int a, int b)
+{
+  int i;
+  volatile int *labelref = &&label1;
+
+  if (a > b)
+    {
+      while (i < b)
+	{
+	  a += *labelref;
+	  i += 1;
+	}
+      goto *labelref;
+    }
+  else
+    b = b + 3;
+
+  a = a * b;
+
+label1:
+  return a + b;
+}
+
+/* { dg-final { scan-assembler-not "\\.(float|l\\?double|\d?byte|short|int|long|quad|word)\\s+\[^.\]" } } */
+/* { dg-final { scan-assembler "text,\"0x20000006\"" } } */
diff --git a/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp b/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
new file mode 100644
index 0000000000000000000000000000000000000000..418946009646eba31496f85914314de2acdac352
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pure-code/pure-code.exp
@@ -0,0 +1,58 @@ 
+#   Copyright (C) 1997-2016 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.
+
+# GCC testsuite for ARM's -mpure-code option, using the `dg.exp' driver.
+
+# Load support procs.
+load_lib gcc-dg.exp
+
+# If a testcase doesn't have special options, use these.
+global DEFAULT_CFLAGS
+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
+# thumb2.
+if {[check_effective_target_arm_thumb2_ok]
+    && [check_effective_target_arm_cortex_m]} then {
+# Initialize `dg'.
+dg-init
+
+set saved-dg-do-what-default ${dg-do-what-default}
+set dg-do-what-default "assemble"
+
+set saved-lto_torture_options ${LTO_TORTURE_OPTIONS}
+
+# Add -ffat-lto-objects option to all LTO options such that we can do assembly
+# scans.
+proc add_fat_objects { list } {
+    set res {}
+    foreach el $list {set res [lappend res [concat $el " -ffat-lto-objects"]]}
+    return $res
+};
+set LTO_TORTURE_OPTIONS [add_fat_objects ${LTO_TORTURE_OPTIONS}]
+
+gcc-dg-runtest [lsort [glob $srcdir/$subdir/*.c]] \
+	"" $DEFAULT_CFLAGS
+
+# Restore global values
+set dg-do-what-default ${saved-dg-do-what-default}
+set LTO_TORTURE_OPTIONS ${saved-lto_torture_options}
+
+# All done.
+dg-finish
+}
diff --git a/gcc/varasm.c b/gcc/varasm.c
index b0f2af03de492b1499ab52a73a49d2ec33920045..72a178d13f3d6a62ce0560e759c663b7c78f381d 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -6238,7 +6238,8 @@  void
 default_elf_asm_named_section (const char *name, unsigned int flags,
 			       tree decl)
 {
-  char flagchars[10], *f = flagchars;
+  char flagchars[11], *f = flagchars;
+  unsigned int numeric_value = 0;
 
   /* If we have already declared this section, we can use an
      abbreviated form to switch back to it -- unless this section is
@@ -6251,27 +6252,34 @@  default_elf_asm_named_section (const char *name, unsigned int flags,
       return;
     }
 
-  if (!(flags & SECTION_DEBUG))
-    *f++ = 'a';
+  /* If we have a machine specific flag, then use the numeric value to pass
+     this on to GAS.  */
+  if (targetm.asm_out.elf_flags_numeric (flags, &numeric_value))
+      snprintf (f, sizeof (flagchars), "0x%08x", numeric_value);
+  else
+    {
+      if (!(flags & SECTION_DEBUG))
+	*f++ = 'a';
 #if defined (HAVE_GAS_SECTION_EXCLUDE) && HAVE_GAS_SECTION_EXCLUDE == 1
-  if (flags & SECTION_EXCLUDE)
-    *f++ = 'e';
+      if (flags & SECTION_EXCLUDE)
+	*f++ = 'e';
 #endif
-  if (flags & SECTION_WRITE)
-    *f++ = 'w';
-  if (flags & SECTION_CODE)
-    *f++ = 'x';
-  if (flags & SECTION_SMALL)
-    *f++ = 's';
-  if (flags & SECTION_MERGE)
-    *f++ = 'M';
-  if (flags & SECTION_STRINGS)
-    *f++ = 'S';
-  if (flags & SECTION_TLS)
-    *f++ = TLS_SECTION_ASM_FLAG;
-  if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
-    *f++ = 'G';
-  *f = '\0';
+      if (flags & SECTION_WRITE)
+	*f++ = 'w';
+      if (flags & SECTION_CODE)
+	*f++ = 'x';
+      if (flags & SECTION_SMALL)
+	*f++ = 's';
+      if (flags & SECTION_MERGE)
+	*f++ = 'M';
+      if (flags & SECTION_STRINGS)
+	*f++ = 'S';
+      if (flags & SECTION_TLS)
+	*f++ = TLS_SECTION_ASM_FLAG;
+      if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
+	*f++ = 'G';
+      *f = '\0';
+    }
 
   fprintf (asm_out_file, "\t.section\t%s,\"%s\"", name, flagchars);