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math: guard __builtin_roundeven against non-glibc platforms #1398

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Merged
mr-c merged 2 commits into from
Mar 27, 2026
+34 −4
Merged

math: guard __builtin_roundeven against non-glibc platforms #1398

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fd3d458
math: restrict __builtin_roundeven to glibc >= 2.25 on GCC 10+
jkkim0724 Mar 27, 2026
4e0a8fc
ci: add Alpine (musl + GCC + SIMDE_NO_NATIVE) to Cirrus CI
jkkim0724 Mar 27, 2026
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17 changes: 17 additions & 0 deletions .cirrus.yml
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Original file line number Diff line number Diff line change
@@ -1,6 +1,23 @@
container:
image: debian:trixie-slim

task:
name: Alpine (musl + GCC + SIMDE_NO_NATIVE)
skip: $BRANCH == "master" || ($BRANCH != 'ci/cirrus' && $BRANCH =~ '^ci/.+')
container:
image: alpine:latest
env:
CC: gcc
CXX: g++
install_dependencies_script:
- apk add --no-cache build-base meson ninja python3
configure_script:
- meson setup build -Dc_args="-DSIMDE_NO_NATIVE -Wextra -Werror" -Dcpp_args="-DSIMDE_NO_NATIVE -Wextra -Werror"
build_script:
- ninja -C build -v -j 3
test_script:
- ninja -C build -v test

task:
name: Sanitizers
skip: $BRANCH == "master" || ($BRANCH != 'ci/cirrus' && $BRANCH =~ '^ci/.+')
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21 changes: 17 additions & 4 deletions simde/simde-math.h
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Expand Up @@ -1266,9 +1266,17 @@ simde_math_fpclass(double v, const int imm8) {
#endif

#if !defined(simde_math_roundeven)
/* GCC 10+ lowers __builtin_roundeven to a libm roundeven() call when
* the target has no native instruction. roundeven() is C23 and only
* available in glibc >= 2.25; other platforms (musl, OpenBSD, MinGW,
* etc.) lack the symbol and produce a link error. Clang lowers the
* builtin to an llvm.roundeven.* intrinsic which is always emitted
* inline (no libm dependency), so the GCC guard is not needed there. */
#if \
((!defined(HEDLEY_EMSCRIPTEN_VERSION) || HEDLEY_EMSCRIPTEN_VERSION_CHECK(3, 1, 43)) && HEDLEY_HAS_BUILTIN(__builtin_roundeven)) || \
HEDLEY_GCC_VERSION_CHECK(10,0,0)
((!defined(HEDLEY_EMSCRIPTEN_VERSION) || HEDLEY_EMSCRIPTEN_VERSION_CHECK(3, 1, 43)) && \
HEDLEY_HAS_BUILTIN(__builtin_roundeven) && \
(!HEDLEY_GCC_VERSION_CHECK(10,0,0) || \
(defined(__GLIBC__) && ((__GLIBC__ > 2) || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 25)))))
#define simde_math_roundeven(v) __builtin_roundeven(v)
#elif defined(simde_math_round) && defined(simde_math_fabs)
static HEDLEY_INLINE
Expand All @@ -1286,9 +1294,14 @@ simde_math_fpclass(double v, const int imm8) {
#endif

#if !defined(simde_math_roundevenf)
/* Same rationale as simde_math_roundeven above; applies to the float
* variant. GCC 10+ requires glibc >= 2.25 for roundevenf(); Clang
* is always safe via llvm.roundeven.f32 inline expansion. */
#if \
((!defined(HEDLEY_EMSCRIPTEN_VERSION) || HEDLEY_EMSCRIPTEN_VERSION_CHECK(3, 1, 43)) && HEDLEY_HAS_BUILTIN(__builtin_roundevenf)) || \
HEDLEY_GCC_VERSION_CHECK(10,0,0)
((!defined(HEDLEY_EMSCRIPTEN_VERSION) || HEDLEY_EMSCRIPTEN_VERSION_CHECK(3, 1, 43)) && \
HEDLEY_HAS_BUILTIN(__builtin_roundevenf) && \
(!HEDLEY_GCC_VERSION_CHECK(10,0,0) || \
(defined(__GLIBC__) && ((__GLIBC__ > 2) || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 25)))))
#define simde_math_roundevenf(v) __builtin_roundevenf(v)
#elif defined(simde_math_roundf) && defined(simde_math_fabsf)
static HEDLEY_INLINE
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