compare-elim.c (equivalent_reg_at_start): Return NULL_RTX when returned register...

	* compare-elim.c (equivalent_reg_at_start): Return NULL_RTX
	when returned register mode doesn't match original mode.

From-SVN: r248009

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b144a53..9ec0a53 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,7 +1,12 @@
+2017-05-13  Uros Bizjak  <ubizjak@gmail.com>
+
+       * compare-elim.c (equivalent_reg_at_start): Return NULL_RTX
+       when returned register mode doesn't match original mode.
+
 2017-05-12  Jeff Law  <law@redhat.com>
            Jakub Jelinek  <jakub@redhat.com>
 
-       * config/mn10300/mn10300.c (mn10300_match_ccmode): Fix where    
+       * config/mn10300/mn10300.c (mn10300_match_ccmode): Fix where
        we look for cc setter after the compare-elim changes.
        * config/mn10300/mn10300.md (addsi3_flags): Fix order of patterns
        within the vector to match what compare-elim now expects.

diff --git a/gcc/compare-elim.c b/gcc/compare-elim.c
index 69b1de7..b5ce993 100644 (file)
--- a/gcc/compare-elim.c
+++ b/gcc/compare-elim.c
@@ -526,6 +526,7 @@ maybe_select_cc_mode (struct comparison *cmp, rtx a ATTRIBUTE_UNUSED,
 static rtx
 equivalent_reg_at_start (rtx reg, rtx_insn *end, rtx_insn *start)
 {
+  machine_mode orig_mode = GET_MODE (reg);
   rtx_insn *bb_head = BB_HEAD (BLOCK_FOR_INSN (end));
 
   for (rtx_insn *insn = PREV_INSN (end);
@@ -572,6 +573,9 @@ equivalent_reg_at_start (rtx reg, rtx_insn *end, rtx_insn *start)
        return NULL_RTX;
     }
 
+  if (GET_MODE (reg) != orig_mode)
+    return NULL_RTX;
+
   return reg;
 }