[patch] Fix failure of ACATS c45503c at -O2

[Eric Botcazou]

Hi,

this test started to fail recently as the result of the work of Richard S., 
but the underlying issue had been latent for a long time.  It boils down to 
this excerpt from the VRP1 dump file:

Found new range for _9: [0, 12]
marking stmt to be not simulated again

Visiting statement:
_3 = _9 %[fl] _11;
Found new range for _3: [0, +INF]

which is plain wrong since the sign of FLOOR_MOD_EXPR is the sign of the 
divisor and not that of the dividend (the latter is for TRUNC_MOD_EXPR).

I have attached a fix for mainline and another one for the 4.9/5 branches.

Tested on x86_64-suse-linux, OK for all active branches?


2015-10-20  Eric Botcazou  <ebotca...@adacore.com>

        * fold-const.c (tree_binary_nonnegative_warnv_p) <FLOOR_MOD_EXPR>:
        Recurse on operand #1 instead of operand #0.
        <CEIL_MOD_EXPR>: Do not recurse.
        <ROUND_MOD_EXPR>: Likewise.

-- 
Eric Botcazou
Index: fold-const.c
===================================================================
--- fold-const.c	(revision 229022)
+++ fold-const.c	(working copy)
@@ -12982,11 +12982,15 @@ tree_binary_nonnegative_warnv_p (enum tr
       return RECURSE (op0) && RECURSE (op1);
 
     case TRUNC_MOD_EXPR:
-    case CEIL_MOD_EXPR:
-    case FLOOR_MOD_EXPR:
-    case ROUND_MOD_EXPR:
+      /* The sign of the remainder is that of the dividend.  */
       return RECURSE (op0);
 
+    case FLOOR_MOD_EXPR:
+      /* The sign of the remainder is that of the divisor.  */
+      return RECURSE (op1);
+
+    case CEIL_MOD_EXPR:
+    case ROUND_MOD_EXPR:
     default:
       return tree_simple_nonnegative_warnv_p (code, type);
     }

Index: fold-const.c
===================================================================
--- fold-const.c	(revision 228932)
+++ fold-const.c	(working copy)
@@ -14853,11 +14853,17 @@ tree_binary_nonnegative_warnv_p (enum tr
 						strict_overflow_p));
 
     case TRUNC_MOD_EXPR:
-    case CEIL_MOD_EXPR:
-    case FLOOR_MOD_EXPR:
-    case ROUND_MOD_EXPR:
+      /* The sign of the remainder is that of the dividend.  */
       return tree_expr_nonnegative_warnv_p (op0,
 					    strict_overflow_p);
+
+    case FLOOR_MOD_EXPR:
+      /* The sign of the remainder is that of the divisor.  */
+      return tree_expr_nonnegative_warnv_p (op1,
+					    strict_overflow_p);
+
+    case CEIL_MOD_EXPR:
+    case ROUND_MOD_EXPR:
     default:
       return tree_simple_nonnegative_warnv_p (code, type);
     }