https://gcc.gnu.org/g:8c0458505a9b1b276fbad81d20849b88eda12d24
commit r16-7113-g8c0458505a9b1b276fbad81d20849b88eda12d24 Author: Richard Biener <[email protected]> Date: Wed Jan 28 10:55:56 2026 +0100 ipa/111036 - strip nop conversions around __builtin_constant_p arguments The PR is about inconsistent behavior wrt inline predicate analysis and later folding of __builtin_constant_p which ultimatively results from fold_builtin_constant_p stripping nops off its argument but this not being done on GIMPLE. The following adds a match.pd pattern for this. PR ipa/111036 * match.pd (__builtin_constant_p ((T)x)): Strip nop-conversions from __builtin_constant_p arguments. * gcc.dg/torture/pr111036.c: New testcase. Diff: --- gcc/match.pd | 5 +++++ gcc/testsuite/gcc.dg/torture/pr111036.c | 24 ++++++++++++++++++++++++ 2 files changed, 29 insertions(+) diff --git a/gcc/match.pd b/gcc/match.pd index 01b95ec07553..d86429f5dd8f 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -12236,3 +12236,8 @@ and, long as the requested element is within range. */ (simplify (IFN_VEC_EXTRACT (vec_duplicate @0) INTEGER_CST@1) @0) + +/* Strip nop-conversions __builtin_constant_p arguments. */ +(simplify + (BUILT_IN_CONSTANT_P (nop_convert@1 @0)) + (BUILT_IN_CONSTANT_P @0)) diff --git a/gcc/testsuite/gcc.dg/torture/pr111036.c b/gcc/testsuite/gcc.dg/torture/pr111036.c new file mode 100644 index 000000000000..f3a0e61705d2 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr111036.c @@ -0,0 +1,24 @@ +/* { dg-do run } */ + +#include <stdlib.h> + +__attribute__((aligned(32))) static struct +{ + unsigned long long available_cmd_ids_per_core[2]; +} _rl2c_cmd_id_data; + +static inline void __attribute__((always_inline)) +foo (void *base, size_t length) +{ + unsigned long int p = (unsigned long int) base; + if (__builtin_constant_p(p) && (p & 31) == 0) { exit (0); } + else if (__builtin_constant_p(length)) { exit (0); } + else { exit (0); } +} + +int main(int argc, char **argv) +{ + foo(&_rl2c_cmd_id_data, sizeof(*(&_rl2c_cmd_id_data))); + return 0; +} +
