The problem is `!a?b:c` pattern will create a COND_EXPR with an 1bit signed
integer
which breaks patterns like `a?~t:t`. This rejects when we have a signed operand
for
both patterns.
Note for GCC 15, I am going to look at the canonicalization of `a?~t:t` where t
was a constant since I think keeping it a COND_EXPR might be more canonical and
is what VPR produces from the same IR; if anything expand should handle which
one
is better.
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/114666
gcc/ChangeLog:
* match.pd (`!a?b:c`): Reject signed types for the condition.
(`a?~t:t`): Likewise.
gcc/testsuite/ChangeLog:
* gcc.c-torture/execute/bitfld-signed1-1.c: New test.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
---
gcc/match.pd | 6 +++++-
.../gcc.c-torture/execute/bitfld-signed1-1.c | 13 +++++++++++++
2 files changed, 18 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.c-torture/execute/bitfld-signed1-1.c
diff --git a/gcc/match.pd b/gcc/match.pd
index 15a1e7350d4..d401e7503e6 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -5895,7 +5895,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
/* !A ? B : C -> A ? C : B. */
(simplify
(cnd (logical_inverted_value truth_valued_p@0) @1 @2)
- (cnd @0 @2 @1)))
+ /* For CONDs, don't handle signed values here. */
+ (if (cnd == VEC_COND_EXPR
+ || TYPE_UNSIGNED (TREE_TYPE (@0)))
+ (cnd @0 @2 @1))))
/* abs/negative simplifications moved from fold_cond_expr_with_comparison.
@@ -7095,6 +7098,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(cond @0 @1 @2)
(with { bool wascmp; }
(if (INTEGRAL_TYPE_P (type)
+ && TYPE_UNSIGNED (TREE_TYPE (@0))
&& bitwise_inverted_equal_p (@1, @2, wascmp)
&& (!wascmp || TYPE_PRECISION (type) == 1))
(if ((!TYPE_UNSIGNED (type) && TREE_CODE (type) == BOOLEAN_TYPE)
diff --git a/gcc/testsuite/gcc.c-torture/execute/bitfld-signed1-1.c
b/gcc/testsuite/gcc.c-torture/execute/bitfld-signed1-1.c
new file mode 100644
index 00000000000..b0ff120ea51
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/bitfld-signed1-1.c
@@ -0,0 +1,13 @@
+/* PR tree-optimization/114666 */
+/* We used to miscompile this to be always aborting
+ due to the use of the signed 1bit into the COND_EXPR. */
+
+struct {
+ signed a : 1;
+} b = {-1};
+char c;
+int main()
+{
+ if ((b.a ^ 1UL) < 3)
+ __builtin_abort();
+}
--
2.43.0
