loop-invariant.c (invariant_for_use, [...]): Fail for read-write uses.

	* loop-invariant.c (invariant_for_use, check_dependencies): Fail for
	read-write uses.

From-SVN: r111141

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d01a0490d8d52f939d6a0cb38852b410dd6208f0..953abf6cadd5bb89805f8f0ed34f0a1ee8431cfb 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2006-02-16  Zdenek Dvorak <dvorakz@suse.cz>
+
+       * loop-invariant.c (invariant_for_use, check_dependencies): Fail for
+       read-write uses.
+
 2006-02-16  Zdenek Dvorak <dvorakz@suse.cz>
 
        PR rtl-optimization/26296

diff --git a/gcc/loop-invariant.c b/gcc/loop-invariant.c
index 03a0c34e6cba93f54cb35e9da445e63559889e4f..04531a0e05fcc95afe97ac646d66aed7e059a76e 100644 (file)
--- a/gcc/loop-invariant.c
+++ b/gcc/loop-invariant.c
@@ -233,6 +233,9 @@ invariant_for_use (struct df_ref *use)
   struct df_ref *def;
   basic_block bb = BLOCK_FOR_INSN (use->insn), def_bb;
 
+  if (use->flags & DF_REF_READ_WRITE)
+    return NULL;
+
   defs = DF_REF_CHAIN (use);
   if (!defs || defs->next)
     return NULL;
@@ -682,7 +685,8 @@ record_use (struct def *def, rtx *use, rtx insn)
 }
 
 /* Finds the invariants INSN depends on and store them to the DEPENDS_ON
-   bitmap.  */
+   bitmap.  Returns true if all dependencies of INSN are known to be
+   loop invariants, false otherwise.  */
 
 static bool
 check_dependencies (rtx insn, bitmap depends_on)
@@ -695,6 +699,9 @@ check_dependencies (rtx insn, bitmap depends_on)
 
   for (use = DF_INSN_GET (df, insn)->uses; use; use = use->next_ref)
     {
+      if (use->flags & DF_REF_READ_WRITE)
+       return false;
+
       defs = DF_REF_CHAIN (use);
       if (!defs)
        continue;