visium.c (visium_select_cc_mode): Return CCmode for any RTX present on the RHS of a SET.

	* config/visium/visium.c (visium_select_cc_mode): Return CCmode
	for any RTX present on the RHS of a SET.
	* compare-elim.c (try_eliminate_compare): Restore comment.

From-SVN: r253830

gcc/ChangeLog

+2017-10-17  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* config/visium/visium.c (visium_select_cc_mode): Return CCmode for
+	any RTX present on the RHS of a SET.
+	* compare-elim.c (try_eliminate_compare): Restore comment.
+
 2017-10-17  Jakub Jelinek  <jakub@redhat.com>
 
 	* langhooks.h (struct lang_hooks): Document that tree_size langhook

gcc/compare-elim.c

@@ -729,6 +729,7 @@ try_eliminate_compare (struct comparison *cmp)
   if (try_merge_compare (cmp))
     return true;
 
+  /* We must have found an interesting "clobber" preceding the compare.  */
   if (cmp->prev_clobber == NULL)
     return false;
 

gcc/config/visium/visium.c

@@ -2938,12 +2938,6 @@ visium_select_cc_mode (enum rtx_code code, rtx op0, rtx op1)
       /* This is a btst, the result is in C instead of Z.  */
       return CCCmode;
 
-    case CONST_INT:
-      /* This is a degenerate case, typically an uninitialized variable.  */
-      gcc_assert (op0 == constm1_rtx);
-
-      /* ... fall through ... */
-
     case REG:
     case AND:
     case IOR:
@@ -2960,6 +2954,17 @@ visium_select_cc_mode (enum rtx_code code, rtx op0, rtx op1)
 	 when applied to a comparison with zero.  */
       return CCmode;
 
+    /* ??? Cater to the junk RTXes sent by try_merge_compare.  */
+    case ASM_OPERANDS:
+    case CALL:
+    case CONST_INT:
+    case LO_SUM:
+    case HIGH:
+    case MEM:
+    case UNSPEC:
+    case ZERO_EXTEND:
+      return CCmode;
+
     default:
       gcc_unreachable ();
     }