From 0c5faf294f9329ea1d10c3424f82339cf30d893a Mon Sep 17 00:00:00 2001
From: Roger Sayle <roger@eyesopen.com>
Date: Wed, 24 Mar 2004 02:28:41 +0000
Subject: [PATCH] reg-stack.c (get_true_reg): Handle FLOAT_TRUNCATE like
 FLOAT_EXTEND if flag_unsafe_math_optimizations.

	* reg-stack.c (get_true_reg): Handle FLOAT_TRUNCATE like FLOAT_EXTEND
	if flag_unsafe_math_optimizations.
	* config/i386/i386.md (truncdfsf2): If flag_unsafe_math_optimizations
	and TARGET_80387 expand using truncdfsf2_noop pattern.
	(truncxfsf2): Likewise using truncxfsf2_noop.
	(truncxfdf2): Likewise using truncxfdf2_noop.
	(truncdfsf2_noop, truncxfsf2_noop, truncxfdf2_noop): New patterns.

From-SVN: r79893
---
 gcc/ChangeLog           | 10 +++++++
 gcc/config/i386/i386.md | 58 +++++++++++++++++++++++++++++++++++++----
 gcc/reg-stack.c         |  7 +++++
 3 files changed, 70 insertions(+), 5 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e38cf9c0e4a3..924c0fa7f0f5 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2004-03-23  Roger Sayle  <roger@eyesopen.com>
+
+	* reg-stack.c (get_true_reg): Handle FLOAT_TRUNCATE like FLOAT_EXTEND
+	if flag_unsafe_math_optimizations.
+	* config/i386/i386.md (truncdfsf2): If flag_unsafe_math_optimizations
+	and TARGET_80387 expand using truncdfsf2_noop pattern.
+	(truncxfsf2): Likewise using truncxfsf2_noop.
+	(truncxfdf2): Likewise using truncxfdf2_noop.
+	(truncdfsf2_noop, truncxfsf2_noop, truncxfdf2_noop): New patterns.
+
 2004-03-23  Ziemowit Laski  <zlaski@apple.com>
 
 	* hooks.c (hook_constcharptr_tree_null): New hook.
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 781b0cad07df..4906d35b7d02 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -3653,15 +3653,29 @@
 	      (clobber (match_dup 2))])]
   "TARGET_80387 || TARGET_SSE2"
   "
-   if (TARGET_80387)
-     operands[2] = assign_386_stack_local (SFmode, 0);
-   else
+   if (!TARGET_80387)
      {
 	emit_insn (gen_truncdfsf2_sse_only (operands[0], operands[1]));
 	DONE;
      }
+   else if (flag_unsafe_math_optimizations)
+     {
+	rtx reg = REG_P (operands[0]) ? operands[0] : gen_reg_rtx (SFmode);
+	emit_insn (gen_truncdfsf2_noop (reg, operands[1]));
+	if (reg != operands[0])
+	  emit_move_insn (operands[0], reg);
+	DONE;
+     }
+   else
+     operands[2] = assign_386_stack_local (SFmode, 0);
 ")
 
+(define_insn "truncdfsf2_noop"
+  [(set (match_operand:SF 0 "register_operand" "=f")
+	(float_truncate:SF (match_operand:DF 1 "register_operand" "f")))]
+  "TARGET_80387 && flag_unsafe_math_optimizations"
+  "#")
+
 (define_insn "*truncdfsf2_1"
   [(set (match_operand:SF 0 "nonimmediate_operand" "=m,?f#rx,?r#fx,?x#rf")
 	(float_truncate:SF
@@ -3886,7 +3900,24 @@
 		    (match_operand:XF 1 "register_operand" "")))
 	      (clobber (match_dup 2))])]
   "TARGET_80387"
-  "operands[2] = assign_386_stack_local (SFmode, 0);")
+  "
+  if (flag_unsafe_math_optimizations)
+    {
+      rtx reg = REG_P (operands[0]) ? operands[0] : gen_reg_rtx (SFmode);
+      emit_insn (gen_truncxfsf2_noop (reg, operands[1]));
+      if (reg != operands[0])
+	emit_move_insn (operands[0], reg);
+      DONE;
+    }
+  else
+    operands[2] = assign_386_stack_local (SFmode, 0);
+  ")
+
+(define_insn "truncxfsf2_noop"
+  [(set (match_operand:SF 0 "register_operand" "=f")
+	(float_truncate:SF (match_operand:XF 1 "register_operand" "f")))]
+  "TARGET_80387 && flag_unsafe_math_optimizations"
+  "#")
 
 (define_insn "*truncxfsf2_1"
   [(set (match_operand:SF 0 "nonimmediate_operand" "=m,?f#rx,?r#fx,?x#rf")
@@ -3948,7 +3979,24 @@
 		    (match_operand:XF 1 "register_operand" "")))
 	      (clobber (match_dup 2))])]
   "TARGET_80387"
-  "operands[2] = assign_386_stack_local (DFmode, 0);")
+  "
+  if (flag_unsafe_math_optimizations)
+    {
+      rtx reg = REG_P (operands[0]) ? operands[0] : gen_reg_rtx (DFmode);
+      emit_insn (gen_truncxfdf2_noop (reg, operands[1]));
+      if (reg != operands[0])
+	emit_move_insn (operands[0], reg);
+      DONE;
+    }
+  else
+    operands[2] = assign_386_stack_local (DFmode, 0);
+  ")
+
+(define_insn "truncxfdf2_noop"
+  [(set (match_operand:DF 0 "register_operand" "=f")
+	(float_truncate:DF (match_operand:XF 1 "register_operand" "f")))]
+  "TARGET_80387 && flag_unsafe_math_optimizations"
+  "#")
 
 (define_insn "*truncxfdf2_1"
   [(set (match_operand:DF 0 "nonimmediate_operand" "=m,?f#rY,?r#fY,?Y#rf")
diff --git a/gcc/reg-stack.c b/gcc/reg-stack.c
index 22b290fd5cbd..31ebddb46401 100644
--- a/gcc/reg-stack.c
+++ b/gcc/reg-stack.c
@@ -574,6 +574,13 @@ get_true_reg (rtx *pat)
       case FIX:
       case FLOAT_EXTEND:
 	pat = & XEXP (*pat, 0);
+	break;
+
+      case FLOAT_TRUNCATE:
+	if (!flag_unsafe_math_optimizations)
+	  return pat;
+	pat = & XEXP (*pat, 0);
+	break;
       }
 }