Backported from mainline

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

diff --git a/gcc/postreload.c b/gcc/postreload.c
index 8994366..5c18912 100644 (file)
--- a/gcc/postreload.c
+++ b/gcc/postreload.c
@@ -112,8 +112,8 @@ reload_cse_simplify (rtx insn, rtx testreg)
          if (REG_P (value)
              && ! REG_FUNCTION_VALUE_P (value))
            value = 0;
-         check_for_inc_dec (insn);
-         delete_insn_and_edges (insn);
+         if (check_for_inc_dec (insn))
+           delete_insn_and_edges (insn);
          return;
        }
 
@@ -164,8 +164,8 @@ reload_cse_simplify (rtx insn, rtx testreg)
 
       if (i < 0)
        {
-         check_for_inc_dec (insn);
-         delete_insn_and_edges (insn);
+         if (check_for_inc_dec (insn))
+           delete_insn_and_edges (insn);
          /* We're done with this insn.  */
          return;
        }
@@ -1312,11 +1312,21 @@ reload_combine (void)
         is and then later disable any optimization that would cross it.  */
       if (LABEL_P (insn))
        last_label_ruid = reload_combine_ruid;
-      else if (BARRIER_P (insn)
-              || (INSN_P (insn) && volatile_insn_p (PATTERN (insn))))
-       for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
-         if (! fixed_regs[r])
+      else if (BARRIER_P (insn))
+       {
+         /* Crossing a barrier resets all the use information.  */
+         for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
+           if (! fixed_regs[r])
              reg_state[r].use_index = RELOAD_COMBINE_MAX_USES;
+       }
+      else if (INSN_P (insn) && volatile_insn_p (PATTERN (insn)))
+       /* Optimizations across insns being marked as volatile must be
+          prevented.  All the usage information is invalidated
+          here.  */
+       for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
+         if (! fixed_regs[r]
+             && reg_state[r].use_index != RELOAD_COMBINE_MAX_USES)
+           reg_state[r].use_index = -1;
 
       if (! NONDEBUG_INSN_P (insn))
        continue;