re PR rtl-optimization/12845 (missed jump optimization)

	PR optimization/12845
	* pa.c (output_cbranch): Use cmpb for DImode comparisons with 0.

From-SVN: r73205

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3f2dfc3..e279678 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2003-11-02  John David Anglin  <dave.anglin@nrc-cnrc.gc.ca>
+
+       PR optimization/12845
+       * pa.c (output_cbranch): Use cmpb for DImode comparisons with 0.
+
 2003-11-02  Zack Weinberg  <zack@codesourcery.com>
 
        * print-rtl.c (print_rtx): Call PRINT_REG with second argument -1.

diff --git a/gcc/config/pa/pa.c b/gcc/config/pa/pa.c
index 89bcd66..856e301 100644 (file)
--- a/gcc/config/pa/pa.c
+++ b/gcc/config/pa/pa.c
@@ -5579,6 +5579,12 @@ output_cbranch (rtx *operands, int nullify, int length, int negated, rtx insn)
   if (next_real_insn (JUMP_LABEL (insn)) == next_real_insn (insn))
     return "nop";
 
+  /* The doubleword form of the cmpib instruction doesn't have the LEU
+     and GTU conditions while the cmpb instruction does.  Since we accept
+     zero for cmpb, we must ensure that we use cmpb for the comparison.  */
+  if (GET_MODE (operands[1]) == DImode && operands[2] == const0_rtx)
+    operands[2] = gen_rtx_REG (DImode, 0);
+
   /* If this is a long branch with its delay slot unfilled, set `nullify'
      as it can nullify the delay slot and save a nop.  */
   if (length == 8 && dbr_sequence_length () == 0)