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[PING,^,3,AArch64] Add doloop_end pattern for -fmodulo-sched

Message ID DA41BE1DDCA941489001C7FBD7A8820E555589A3@szxema507-mbx.china.huawei.com
State New
Headers show

Commit Message

Yangfei (Felix) Nov. 18, 2014, 10:48 a.m. UTC 
Yes, major code is borrowed from ARM port with the expected mode of loop pseudo changed to DImode. 
The function loop_canon_p called in sms_schedule can make sure that SMS is only performed for innermost loops. 
But I think it's a good idea to implement the TARGET_CAN_USE_DOLOOP_P hook here. 
See my updated patch below.  How about this one? 




> 

> On 17 November 2014 07:59, Yangfei (Felix) <felix.yang@huawei.com> wrote:

> 

> >> +2014-11-13  Felix Yang  <felix.yang@huawei.com>

> >> +

> >> +     * config/aarch64/aarch64.md (doloop_end): New pattern.

> >> +

> 

> This looks like a straight copy of the ARM code, but without the

> TARGET_CAN_USE_DOLOOP_P definition.  If the reason for including this code

> is for the benefit of module-sched then should the hook be defined to limit the

> use of this pattern to inner most loops only?

> 

> Cheers

> /Marcus

Comments

Richard Henderson Nov. 18, 2014, 10:56 a.m. UTC | #1 
On 11/18/2014 11:48 AM, Yangfei (Felix) wrote:
> +(define_expand "doloop_end"
> +  [(use (match_operand 0 "" ""))      ; loop pseudo
> +   (use (match_operand 1 "" ""))]     ; label
> +  ""
> +{
> +  /* Currently SMS relies on the do-loop pattern to recognize loops
> +     where (1) the control part consists of all insns defining and/or
> +     using a certain 'count' register and (2) the loop count can be
> +     adjusted by modifying this register prior to the loop.
> +     ??? The possible introduction of a new block to initialize the
> +     new IV can potentially affect branch optimizations.  */
> +  if (optimize > 0 && flag_modulo_sched)

You'd be better off moving this condition into the expansion predicate (which
is currently "").

This short-circuits a lot of unnecessary work.  See  pass_rtl_doloop::gate.


r~
diff mbox

Patch

Index: gcc/ChangeLog
===================================================================
--- gcc/ChangeLog	(revision 217394)
+++ gcc/ChangeLog	(working copy)
@@ -1,3 +1,8 @@ 
+2014-11-13  Felix Yang  <felix.yang@huawei.com>
+
+	* config/aarch64/aarch64.c (doloop_end): New pattern.
+	* config/aarch64/aarch64.md (TARGET_CAN_USE_DOLOOP_P): Implement.
+
 2014-11-11  Andrew Pinski  <apinski@cavium.com>
 
 	Bug target/61997
Index: gcc/config/aarch64/aarch64.md
===================================================================
--- gcc/config/aarch64/aarch64.md	(revision 217394)
+++ gcc/config/aarch64/aarch64.md	(working copy)
@@ -4087,6 +4087,47 @@ 
   [(set_attr "type" "mrs")])
 
 
+;; Define the subtract-one-and-jump insns so loop.c
+;; knows what to generate.
+(define_expand "doloop_end"
+  [(use (match_operand 0 "" ""))      ; loop pseudo
+   (use (match_operand 1 "" ""))]     ; label
+  ""
+{
+  /* Currently SMS relies on the do-loop pattern to recognize loops
+     where (1) the control part consists of all insns defining and/or
+     using a certain 'count' register and (2) the loop count can be
+     adjusted by modifying this register prior to the loop.
+     ??? The possible introduction of a new block to initialize the
+     new IV can potentially affect branch optimizations.  */
+  if (optimize > 0 && flag_modulo_sched)
+    {
+      rtx s0;
+      rtx bcomp;
+      rtx loc_ref;
+      rtx cc_reg;
+      rtx insn;
+      rtx cmp;
+
+      if (GET_MODE (operands[0]) != DImode)
+	FAIL;
+
+      s0 = operands [0];
+      insn = emit_insn (gen_adddi3_compare0 (s0, s0, GEN_INT (-1)));
+
+      cmp = XVECEXP (PATTERN (insn), 0, 0);
+      cc_reg = SET_DEST (cmp);
+      bcomp = gen_rtx_NE (VOIDmode, cc_reg, const0_rtx);
+      loc_ref = gen_rtx_LABEL_REF (VOIDmode, operands [1]);
+      emit_jump_insn (gen_rtx_SET (VOIDmode, pc_rtx,
+				   gen_rtx_IF_THEN_ELSE (VOIDmode, bcomp,
+							 loc_ref, pc_rtx)));
+      DONE;
+    }
+  else
+    FAIL;
+})
+
 ;; AdvSIMD Stuff
 (include "aarch64-simd.md")
 
Index: gcc/config/aarch64/aarch64.c
===================================================================
--- gcc/config/aarch64/aarch64.c	(revision 217394)
+++ gcc/config/aarch64/aarch64.c	(working copy)
@@ -10224,6 +10224,9 @@  aarch64_use_by_pieces_infrastructure_p (unsigned i
 #define TARGET_USE_BY_PIECES_INFRASTRUCTURE_P \
   aarch64_use_by_pieces_infrastructure_p
 
+#undef TARGET_CAN_USE_DOLOOP_P
+#define TARGET_CAN_USE_DOLOOP_P can_use_doloop_if_innermost
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 #include "gt-aarch64.h"