From 4fb8320a2efb2216c7ddcc929ad0362f4e285681 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Fri, 10 Jun 2016 12:16:18 +0100 Subject: [PATCH] avx2 configure: Use primitives in test Use the avx2 primitives during the test, thus making sure that the compiler and assembler could actually use avx2. This also detects the failure case on gcc 4.8.x with -save-temps and avoids the need for the gcc version check in cutils. Signed-off-by: Dr. David Alan Gilbert Message-Id: <1465557378-24105-3-git-send-email-dgilbert@redhat.com> Signed-off-by: Paolo Bonzini --- configure | 17 ++++++++++++----- util/cutils.c | 8 +------- 2 files changed, 13 insertions(+), 12 deletions(-) diff --git a/configure b/configure index 3c0e279762..c57d6a7a6d 100755 --- a/configure +++ b/configure @@ -1779,13 +1779,20 @@ fi # avx2 optimization requirement check cat > $TMPC << EOF -static void bar(void) {} +#pragma GCC push_options +#pragma GCC target("avx2") +#include +#include + +static int bar(void *a) { + return _mm256_movemask_epi8(_mm256_cmpeq_epi8(*(__m256i *)a, (__m256i){0})); +} static void *bar_ifunc(void) {return (void*) bar;} -void foo(void) __attribute__((ifunc("bar_ifunc"))); -int main(void) { foo(); return 0; } +int foo(void *a) __attribute__((ifunc("bar_ifunc"))); +int main(int argc, char *argv[]) { return foo(argv[0]);} EOF -if compile_prog "-mavx2" "" ; then - if readelf --syms $TMPE |grep "IFUNC.*foo" >/dev/null 2>&1; then +if compile_object "" ; then + if readelf --syms $TMPO |grep "IFUNC.*foo" >/dev/null 2>&1; then avx2_opt="yes" fi fi diff --git a/util/cutils.c b/util/cutils.c index 43d1afbbec..5830a688dc 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -256,13 +256,7 @@ static size_t buffer_find_nonzero_offset_inner(const void *buf, size_t len) return i * sizeof(VECTYPE); } -/* - * GCC before version 4.9 has a bug which will cause the target - * attribute work incorrectly and failed to compile in some case, - * restrict the gcc version to 4.9+ to prevent the failure. - */ - -#if defined CONFIG_AVX2_OPT && QEMU_GNUC_PREREQ(4, 9) +#if defined CONFIG_AVX2_OPT #pragma GCC push_options #pragma GCC target("avx2") #include