From: Jakub Jelinek <jakub@redhat.com>
Date: Thu, 10 Feb 2005 17:11:11 +0000 (+0100)
Subject: re PR rtl-optimization/19579 (-march=i686 generates a bogus program for x86*)
X-Git-Tag: releases/gcc-3.4.4~237
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c465b9e6c00602b49d31cef4865e3a41193e1349;p=thirdparty%2Fgcc.git

re PR rtl-optimization/19579 (-march=i686 generates a bogus program for x86*)

	PR rtl-optimization/19579
	* ifcvt.c (noce_try_cmove_arith): If emitting instructions to set up
	both A and B, see if they don't clobber registers the other expr uses.

	* gcc.c-torture/execute/20050124-1.c: New test.

From-SVN: r94835
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index eb394b821812..19e4d7bd956b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2005-02-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/19579
+	* ifcvt.c (noce_try_cmove_arith): If emitting instructions to set up
+	both A and B, see if they don't clobber registers the other expr uses.
+
 2005-02-08  Alan Modra  <amodra@bigpond.net.au>
 
 	PR target/19803
diff --git a/gcc/ifcvt.c b/gcc/ifcvt.c
index 640ab2cf2f9c..b9a50387dc82 100644
--- a/gcc/ifcvt.c
+++ b/gcc/ifcvt.c
@@ -1193,6 +1193,7 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
   rtx a = if_info->a;
   rtx b = if_info->b;
   rtx x = if_info->x;
+  rtx orig_a, orig_b;
   rtx insn_a, insn_b;
   rtx tmp, target;
   int is_mem = 0;
@@ -1248,6 +1249,9 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
 
   start_sequence ();
 
+  orig_a = a;
+  orig_b = b;
+
   /* If either operand is complex, load it into a register first.
      The best way to do this is to copy the original insn.  In this
      way we preserve any clobbers etc that the insn may have had.
@@ -1279,7 +1283,7 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
     }
   if (! general_operand (b, GET_MODE (b)))
     {
-      rtx set;
+      rtx set, last;
 
       if (no_new_pseudos)
 	goto end_seq_and_fail;
@@ -1287,9 +1291,7 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
       if (is_mem)
 	{
           tmp = gen_reg_rtx (GET_MODE (b));
-	  tmp = emit_insn (gen_rtx_SET (VOIDmode,
-				  	tmp,
-					b));
+	  tmp = gen_rtx_SET (VOIDmode, tmp, b);
 	}
       else if (! insn_b)
 	goto end_seq_and_fail;
@@ -1299,8 +1301,22 @@ noce_try_cmove_arith (struct noce_if_info *if_info)
 	  tmp = copy_rtx (insn_b);
 	  set = single_set (tmp);
 	  SET_DEST (set) = b;
-	  tmp = emit_insn (PATTERN (tmp));
+	  tmp = PATTERN (tmp);
+	}
+
+      /* If insn to set up A clobbers any registers B depends on, try to
+	 swap insn that sets up A with the one that sets up B.  If even
+	 that doesn't help, punt.  */
+      last = get_last_insn ();
+      if (last && modified_in_p (orig_b, last))
+	{
+	  tmp = emit_insn_before (tmp, get_insns ());
+	  if (modified_in_p (orig_a, tmp))
+	    goto end_seq_and_fail;
 	}
+      else
+	tmp = emit_insn (tmp);
+
       if (recog_memoized (tmp) < 0)
 	goto end_seq_and_fail;
     }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d13ae5c69674..3f14579324c4 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2005-02-10  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/19579
+	* gcc.c-torture/execute/20050124-1.c: New test.
+
 2005-02-09  Mark Mitchell  <mark@codesourcery.com>
 
 	PR c++/19787