rs6000: Workaround for new ifcvt behavior [PR104335].

Since r12-6747-gaa8cfe785953a0 ifcvt passes a "cc comparison"
i.e. the representation of the result of a comparison to the
backend.  rs6000_emit_int_cmove () is not prepared to handle this.
Therefore, this patch makes it return false in such a case.

	PR target/104335

gcc/ChangeLog:

	* config/rs6000/rs6000.cc (rs6000_emit_int_cmove): Return false
	if the expected comparison's first operand is of mode MODE_CC.

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index e76c017..32a13cd 100644 (file)
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -16215,6 +16215,12 @@ rs6000_emit_int_cmove (rtx dest, rtx op, rtx true_cond, rtx false_cond)
   if (mode != SImode && (!TARGET_POWERPC64 || mode != DImode))
     return false;
 
+  /* PR104335: We now need to expect CC-mode "comparisons"
+     coming from ifcvt.  The following code expects proper
+     comparisons so better abort here.  */
+  if (GET_MODE_CLASS (GET_MODE (XEXP (op, 0))) == MODE_CC)
+    return false;
+
   /* We still have to do the compare, because isel doesn't do a
      compare, it just looks at the CRx bits set by a previous compare
      instruction.  */