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Fix ICE with -Wduplicated-branches (PR c/79199)
- From: Marek Polacek <polacek at redhat dot com>
- To: GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 26 Jan 2017 12:21:02 +0100
- Subject: Fix ICE with -Wduplicated-branches (PR c/79199)
- Authentication-results: sourceware.org; auth=none
This testcase was breaking because we found ourselves in operand_equal_p
with a COND_EXPR whose operand 2 was null -- i.e., missing else branch,
which won't happen for ? : but can happen here via -Wduplicated-branches.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2017-01-26 Marek Polacek <polacek@redhat.com>
PR c/79199
* fold-const.c (operand_equal_p) [COND_EXPR]: Use OP_SAME_WITH_NULL
for the third operand.
* c-c++-common/Wduplicated-branches-13.c: New test.
diff --git gcc/fold-const.c gcc/fold-const.c
index 5576d59..a8bb8af 100644
--- gcc/fold-const.c
+++ gcc/fold-const.c
@@ -3147,7 +3147,7 @@ operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
TREE_OPERAND (arg1, 0), flags));
case COND_EXPR:
- if (! OP_SAME (1) || ! OP_SAME (2))
+ if (! OP_SAME (1) || ! OP_SAME_WITH_NULL (2))
return 0;
flags &= ~OEP_ADDRESS_OF;
return OP_SAME (0);
diff --git gcc/testsuite/c-c++-common/Wduplicated-branches-13.c gcc/testsuite/c-c++-common/Wduplicated-branches-13.c
index e69de29..7aa5b37 100644
--- gcc/testsuite/c-c++-common/Wduplicated-branches-13.c
+++ gcc/testsuite/c-c++-common/Wduplicated-branches-13.c
@@ -0,0 +1,23 @@
+/* PR c/79199 */
+/* { dg-do compile } */
+/* { dg-options "-Wduplicated-branches" } */
+
+unsigned int a, b, c, d, e;
+void
+fn1 (void)
+{
+ if (0) /* { dg-warning "this condition has identical branches" } */
+ {
+ if (d > 4294967293)
+ (void) 5;
+ c = d;
+ b = e | a;
+ }
+ else
+ {
+ if (d > 4294967293)
+ (void) 5;
+ c = d;
+ b = e | a;
+ }
+}
Marek