2006-01-24 Dirk Mueller <dmueller@suse.de>

[pf3gnuchains/gcc-fork.git] / gcc / cse.c

diff --git a/gcc/cse.c b/gcc/cse.c
index 8ec610f..ce6edcd 100644 (file)
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -2538,16 +2538,26 @@ exp_equiv_p (rtx x, rtx y, int validate, bool for_gcse)
     case MEM:
       if (for_gcse)
        {
-         /* Can't merge two expressions in different alias sets, since we
-            can decide that the expression is transparent in a block when
-            it isn't, due to it being set with the different alias set.  */
-         if (MEM_ALIAS_SET (x) != MEM_ALIAS_SET (y))
-           return 0;
-
          /* A volatile mem should not be considered equivalent to any
             other.  */
          if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y))
            return 0;
+
+         /* Can't merge two expressions in different alias sets, since we
+            can decide that the expression is transparent in a block when
+            it isn't, due to it being set with the different alias set.
+
+            Also, can't merge two expressions with different MEM_ATTRS.
+            They could e.g. be two different entities allocated into the
+            same space on the stack (see e.g. PR25130).  In that case, the
+            MEM addresses can be the same, even though the two MEMs are
+            absolutely not equivalent.  
+   
+            But because really all MEM attributes should be the same for
+            equivalent MEMs, we just use the invariant that MEMs that have
+            the same attributes share the same mem_attrs data structure.  */
+         if (MEM_ATTRS (x) != MEM_ATTRS (y))
+           return 0;
        }
       break;
 
@@ -3088,7 +3098,7 @@ find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2,
              || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT
                  && code == LT && STORE_FLAG_VALUE == -1)
 #ifdef FLOAT_STORE_FLAG_VALUE
-             || (SCALAR_FLOAT_MODE_P (arg1)
+             || (SCALAR_FLOAT_MODE_P (GET_MODE (arg1))
                  && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)),
                      REAL_VALUE_NEGATIVE (fsfv)))
 #endif
@@ -3098,7 +3108,7 @@ find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2,
                   || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT
                       && code == GE && STORE_FLAG_VALUE == -1)
 #ifdef FLOAT_STORE_FLAG_VALUE
-                  || (SCALAR_FLOAT_MODE_P (arg1)
+                  || (SCALAR_FLOAT_MODE_P (GET_MODE (arg1))
                       && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)),
                           REAL_VALUE_NEGATIVE (fsfv)))
 #endif
@@ -3946,7 +3956,7 @@ fold_rtx (rtx x, rtx insn)
          enum machine_mode mode_arg1;
 
 #ifdef FLOAT_STORE_FLAG_VALUE
-         if (SCALAR_FLOAT_MODE (mode))
+         if (SCALAR_FLOAT_MODE_P (mode))
            {
              true_rtx = (CONST_DOUBLE_FROM_REAL_VALUE
                          (FLOAT_STORE_FLAG_VALUE (mode), mode));
@@ -7666,7 +7676,7 @@ cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode)
 /* If we have a fixed condition code register (or two), walk through
    the instructions and try to eliminate duplicate assignments.  */
 
-void
+static void
 cse_condition_code_reg (void)
 {
   unsigned int cc_regno_1;