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Fix PR c/45969 (excess precision regression)
- From: "Joseph S. Myers" <joseph at codesourcery dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Thu, 14 Oct 2010 15:51:05 +0000 (UTC)
- Subject: Fix PR c/45969 (excess precision regression)
This patch fixes PR 45969, a regression caused by the C excess
precision changes where build_binary_op tried to compute a semantic
type for a boolean operation on floating-point values when it should
just have let the semantic type be the same type, int, as that used
for computing the result. I think boolean operations are the only
case where this can occur; I've added an appropriate check to avoid
computing a semantic type in this case.
Bootstrapped with no regressions on i686-pc-linux-gnu. Applied to
mainline. Will apply to 4.5 branch subject to testing there.
2010-10-14 Joseph Myers <joseph@codesourcery.com>
PR c/45969
* c-typeck.c (build_binary_op): Don't try to compute a semantic
type with excess precision for boolean operations.
testsuite:
2010-10-14 Joseph Myers <joseph@codesourcery.com>
PR c/45969
* gcc.c-torture/compile/pr45969-1.c: New test.
Index: gcc/c-typeck.c
===================================================================
--- gcc/c-typeck.c (revision 165418)
+++ gcc/c-typeck.c (working copy)
@@ -9423,6 +9423,10 @@ build_binary_op (location_t location, en
precision. */
bool may_need_excess_precision;
+ /* True means this is a boolean operation that converts both its
+ operands to truth-values. */
+ bool boolean_op = false;
+
if (location == UNKNOWN_LOCATION)
location = input_location;
@@ -9650,6 +9654,7 @@ build_binary_op (location_t location, en
op0 = c_common_truthvalue_conversion (location, op0);
op1 = c_common_truthvalue_conversion (location, op1);
converted = 1;
+ boolean_op = true;
}
if (code == TRUTH_ANDIF_EXPR)
{
@@ -10192,7 +10197,8 @@ build_binary_op (location_t location, en
if (build_type == NULL_TREE)
{
build_type = result_type;
- if (type0 != orig_type0 || type1 != orig_type1)
+ if ((type0 != orig_type0 || type1 != orig_type1)
+ && !boolean_op)
{
gcc_assert (may_need_excess_precision && common);
semantic_result_type = c_common_type (orig_type0, orig_type1);
Index: gcc/testsuite/gcc.c-torture/compile/pr45969-1.c
===================================================================
--- gcc/testsuite/gcc.c-torture/compile/pr45969-1.c (revision 0)
+++ gcc/testsuite/gcc.c-torture/compile/pr45969-1.c (revision 0)
@@ -0,0 +1,6 @@
+/* { dg-options "-std=c89" } */
+void crash() {
+ double l[4];
+ if((l[0]+l[2]) && (l[1]+l[3])){
+ }
+}
--
Joseph S. Myers
joseph@codesourcery.com