fold-const.c (const_binop): Don't constant fold the operation if the result has overflowed and...

	* fold-const.c (const_binop): Don't constant fold the operation
	if the result has overflowed and flag_trapping_math.
	* simplify-rtx.c (simplify_const_binary_operation): Likewise.

From-SVN: r107092

gcc/ChangeLog

+2005-11-16  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* fold-const.c (const_binop): Don't constant fold the operation
+	if the result has overflowed and flag_trapping_math.
+	* simplify-rtx.c (simplify_const_binary_operation): Likewise.
+
 2005-11-16  Daniel Jacobowitz  <dan@codesourcery.com>
 
 	* config/arm/unwind-arm.c (abort): Add prototype here.

gcc/fold-const.c

@@ -1537,6 +1537,16 @@ const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
       inexact = real_arithmetic (&value, code, &d1, &d2);
       real_convert (&result, mode, &value);
 
+      /* Don't constant fold this floating point operation if
+	 the result has overflowed and flag_trapping_math.  */
+
+      if (flag_trapping_math
+	  && MODE_HAS_INFINITIES (mode)
+	  && REAL_VALUE_ISINF (result)
+	  && !REAL_VALUE_ISINF (d1)
+	  && !REAL_VALUE_ISINF (d2))
+	return NULL_TREE;
+
       /* Don't constant fold this floating point operation if the
 	 result may dependent upon the run-time rounding mode and
 	 flag_rounding_math is set, or if GCC's software emulation

gcc/simplify-rtx.c

@@ -2242,6 +2242,17 @@ simplify_const_binary_operation (enum rtx_code code, enum machine_mode mode,
 				     &f0, &f1);
 	  real_convert (&result, mode, &value);
 
+	  /* Don't constant fold this floating point operation if
+	     the result has overflowed and flag_trapping_math.  */
+
+	  if (flag_trapping_math
+	      && MODE_HAS_INFINITIES (mode)
+	      && REAL_VALUE_ISINF (result)
+	      && !REAL_VALUE_ISINF (f0)
+	      && !REAL_VALUE_ISINF (f1))
+	    /* Overflow plus exception.  */
+	    return 0;
+
 	  /* Don't constant fold this floating point operation if the
 	     result may dependent upon the run-time rounding mode and
 	     flag_rounding_math is set, or if GCC's software emulation

gcc/testsuite/ChangeLog

+2005-11-16  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.dg/fold-overflow-1.c: New test.
+
 2005-11-16  Daniel Jacobowitz  <dan@codesourcery.com>
 
 	* gcc.dg/cleanup-5.c, gcc.dg/cleanup-8.c, gcc.dg/cleanup-9.c,

gcc/testsuite/gcc.dg/fold-overflow-1.c

+/* { dg-compile } */
+/* { dg-options "-O -ftrapping-math" } */
+
+float f1 =  __FLT_MAX__ + __FLT_MAX__;
+
+float foo1(void)
+{
+  return  __FLT_MAX__ + __FLT_MAX__;
+}
+
+float f2 = 1.0f/0.0f;
+
+float foo2(void)
+{
+  return 1.0f/0.0f;
+}
+
+/* { dg-final { scan-assembler-times "2139095040" 2 } } */