From: H.J. Lu <hongjiu.lu@intel.com>
Date: Mon, 18 May 2009 17:21:13 +0000 (+0000)
Subject: re PR target/39942 (Nonoptimal code - leaveq; xchg   %ax,%ax; retq)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6a90d232abb6815994146ecc0ebbfc83d37f6d8a;p=gcc.git

re PR target/39942 (Nonoptimal code - leaveq; xchg   %ax,%ax; retq)

2009-05-18  H.J. Lu  <hongjiu.lu@intel.com>

	PR target/39942
	* config/i386/i386.c (ix86_avoid_jump_misspredicts): Replace
	gen_align with gen_pad.
	(ix86_reorg): Check ASM_OUTPUT_MAX_SKIP_PAD instead of
	#ifdef ASM_OUTPUT_MAX_SKIP_ALIGN.

	* config/i386/i386.h (ASM_OUTPUT_MAX_SKIP_PAD): New.
	* config/i386/x86-64.h (ASM_OUTPUT_MAX_SKIP_PAD): Likewise.

	* config/i386/i386.md (align): Renamed to ...
	(pad): This.  Replace ASM_OUTPUT_MAX_SKIP_ALIGN with
	ASM_OUTPUT_MAX_SKIP_PAD.

From-SVN: r147671
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 68b34198c90..8260f928946 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2009-05-18  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/39942
+	* config/i386/i386.c (ix86_avoid_jump_misspredicts): Replace
+	gen_align with gen_pad.
+	(ix86_reorg): Check ASM_OUTPUT_MAX_SKIP_PAD instead of
+	#ifdef ASM_OUTPUT_MAX_SKIP_ALIGN.
+
+	* config/i386/i386.h (ASM_OUTPUT_MAX_SKIP_PAD): New.
+	* config/i386/x86-64.h (ASM_OUTPUT_MAX_SKIP_PAD): Likewise.
+
+	* config/i386/i386.md (align): Renamed to ...
+	(pad): This.  Replace ASM_OUTPUT_MAX_SKIP_ALIGN with
+	ASM_OUTPUT_MAX_SKIP_PAD.
+
 2009-05-18  Andreas Schwab  <schwab@linux-m68k.org>
 
 	* config.gcc: Fix variable syntax.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index acd3069c7fc..e9f8b9566a0 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -27334,7 +27334,7 @@ ix86_avoid_jump_mispredicts (void)
 	  if (dump_file)
 	    fprintf (dump_file, "Padding insn %i by %i bytes!\n",
 		     INSN_UID (insn), padsize);
-          emit_insn_before (gen_align (GEN_INT (padsize)), insn);
+          emit_insn_before (gen_pad (GEN_INT (padsize)), insn);
 	}
     }
 }
@@ -27402,7 +27402,7 @@ ix86_reorg (void)
     {
       if (TARGET_PAD_RETURNS)
 	ix86_pad_returns ();
-#ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
+#ifdef ASM_OUTPUT_MAX_SKIP_PAD
       if (TARGET_FOUR_JUMP_LIMIT)
 	ix86_avoid_jump_mispredicts ();
 #endif
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index f41ed7db665..e42686b4809 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -2175,6 +2175,22 @@ do {									\
 #define ASM_OUTPUT_OPCODE(STREAM, PTR) \
   ASM_OUTPUT_AVX_PREFIX ((STREAM), (PTR))
 
+/* A C statement to output to the stdio stream FILE an assembler
+   command to pad the location counter to a multiple of 1<<LOG
+   bytes if it is within MAX_SKIP bytes.  */
+
+#ifdef HAVE_GAS_MAX_SKIP_P2ALIGN
+#undef  ASM_OUTPUT_MAX_SKIP_PAD
+#define ASM_OUTPUT_MAX_SKIP_PAD(FILE, LOG, MAX_SKIP)			\
+  if ((LOG) != 0)							\
+    {									\
+      if ((MAX_SKIP) == 0)						\
+        fprintf ((FILE), "\t.p2align %d\n", (LOG));			\
+      else								\
+        fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP));	\
+    }
+#endif
+
 /* Under some conditions we need jump tables in the text section,
    because the assembler cannot handle label differences between
    sections.  This is the case for x86_64 on Mach-O for example.  */
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 198b59d2e47..2e2880220b8 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -15519,16 +15519,16 @@
    (set_attr "length_immediate" "0")
    (set_attr "modrm" "0")])
 
-;; Align to 16-byte boundary, max skip in op0.  Used to avoid
+;; Pad to 16-byte boundary, max skip in op0.  Used to avoid
 ;; branch prediction penalty for the third jump in a 16-byte
 ;; block on K8.
 
-(define_insn "align"
+(define_insn "pad"
   [(unspec_volatile [(match_operand 0 "" "")] UNSPECV_ALIGN)]
   ""
 {
-#ifdef ASM_OUTPUT_MAX_SKIP_ALIGN
-  ASM_OUTPUT_MAX_SKIP_ALIGN (asm_out_file, 4, (int)INTVAL (operands[0]));
+#ifdef ASM_OUTPUT_MAX_SKIP_PAD
+  ASM_OUTPUT_MAX_SKIP_PAD (asm_out_file, 4, (int)INTVAL (operands[0]));
 #else
   /* It is tempting to use ASM_OUTPUT_ALIGN here, but we don't want to do that.
      The align insn is used to avoid 3 jump instructions in the row to improve
diff --git a/gcc/config/i386/x86-64.h b/gcc/config/i386/x86-64.h
index 96649af7d0e..5d6958cc4ad 100644
--- a/gcc/config/i386/x86-64.h
+++ b/gcc/config/i386/x86-64.h
@@ -81,6 +81,15 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
       }									\
     }									\
   } while (0)
+#undef  ASM_OUTPUT_MAX_SKIP_PAD
+#define ASM_OUTPUT_MAX_SKIP_PAD(FILE, LOG, MAX_SKIP)			\
+  if ((LOG) != 0)							\
+    {									\
+      if ((MAX_SKIP) == 0)						\
+        fprintf ((FILE), "\t.p2align %d\n", (LOG));			\
+      else								\
+        fprintf ((FILE), "\t.p2align %d,,%d\n", (LOG), (MAX_SKIP));	\
+    }
 #endif