https://gcc.gnu.org/g:e17e3de4bbb1848ce1ce7d69d7786b92f1969b11
commit r16-2039-ge17e3de4bbb1848ce1ce7d69d7786b92f1969b11
Author: Andrew Pinski <quic_apin...@quicinc.com>
Date: Sat Jul 5 08:40:45 2025 -0700
cdce: Fix non-call exceptions with signaling nans [PR120951]
The cdce code introduces a test for a NaN using the EQ_EXPR code.
The problem is EQ_EXPR can cause an exception with non-call exceptions
and signaling nans turned on. This is now correctly rejected by the verfier
since r16-241-g4c40e3d7b9152f.
The fix is seperate out the comparison into its own statement from the
GIMPLE_COND.
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/120951
gcc/ChangeLog:
* tree-call-cdce.cc (use_internal_fn): For non-call exceptions
with EQ_EXPR can throw for floating point types, then create
the EQ_EXPR seperately.
gcc/testsuite/ChangeLog:
* gcc.dg/torture/pr120951-1.c: New test.
Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
Diff:
---
gcc/testsuite/gcc.dg/torture/pr120951-1.c | 12 ++++++++++++
gcc/tree-call-cdce.cc | 17 +++++++++++++++--
2 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/gcc/testsuite/gcc.dg/torture/pr120951-1.c
b/gcc/testsuite/gcc.dg/torture/pr120951-1.c
new file mode 100644
index 000000000000..4e2b41deb52b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr120951-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-fnon-call-exceptions -fsignaling-nans" } */
+
+/* PR tree-optimization/120951 */
+
+/* cdce would create a trapping comparison inside a condition.
+ tests to make sure that does not happen. */
+
+double f(double r, double i) {
+ return __builtin_fmod(r, i);
+}
+
diff --git a/gcc/tree-call-cdce.cc b/gcc/tree-call-cdce.cc
index 649c1e2b9f99..3edea754ee4d 100644
--- a/gcc/tree-call-cdce.cc
+++ b/gcc/tree-call-cdce.cc
@@ -36,6 +36,7 @@ along with GCC; see the file COPYING3. If not see
#include "builtins.h"
#include "internal-fn.h"
#include "tree-dfa.h"
+#include "tree-eh.h"
/* This pass serves two closely-related purposes:
@@ -1222,8 +1223,20 @@ use_internal_fn (gcall *call)
{
/* Skip the call if LHS == LHS. If we reach here, EDOM is the only
valid errno value and it is used iff the result is NaN. */
- conds.quick_push (gimple_build_cond (EQ_EXPR, lhs, lhs,
- NULL_TREE, NULL_TREE));
+ /* In the case of non call exceptions, with signaling NaNs, EQ_EXPR
+ can throw an exception and that can't be part of the GIMPLE_COND. */
+ if (flag_exceptions
+ && cfun->can_throw_non_call_exceptions
+ && operation_could_trap_p (EQ_EXPR, true, false, NULL_TREE))
+ {
+ tree b = make_ssa_name (boolean_type_node);
+ conds.quick_push (gimple_build_assign (b, EQ_EXPR, lhs, lhs));
+ conds.quick_push (gimple_build_cond (NE_EXPR, b, boolean_false_node,
+ NULL_TREE, NULL_TREE));
+ }
+ else
+ conds.quick_push (gimple_build_cond (EQ_EXPR, lhs, lhs,
+ NULL_TREE, NULL_TREE));
nconds++;
/* Try replacing the original call with a direct assignment to
