| Message ID | 1466287502-18730-3-git-send-email-pmaydell@chiark.greenend.org.uk |
|---|---|
| State | New |
| Headers | show |
Am 19.06.2016 um 00:05 schrieb Peter Maydell: > From: Peter Maydell <peter.maydell@linaro.org> > > The AVX2 optimization test assumes that the object format > is ELF and the system has the readelf utility. If this isn't > true then configure might fail or emit a warning (since in > a pipe "foo | bar >/dev/null 2>&1" does not redirect the > stderr of foo, only of bar). Adjust the check so that if > we don't have readelf or don't have an ELF object then we > just don't enable the AVX2 optimization. > > Reported-by: Stefan Weil <sw@weilnetz.de> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > configure | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/configure b/configure > index 7beefcd..30bca55 100755 > --- a/configure > +++ b/configure > @@ -1792,8 +1792,10 @@ int foo(void *a) __attribute__((ifunc("bar_ifunc"))); > int main(int argc, char *argv[]) { return foo(argv[0]);} > EOF > if compile_object "" ; then > - if readelf --syms $TMPO |grep "IFUNC.*foo" >/dev/null 2>&1; then > - avx2_opt="yes" > + if has readelf; then > + if readelf --syms $TMPO 2>/dev/null |grep -q "IFUNC.*foo"; then > + avx2_opt="yes" > + fi > fi > fi > > You could check "has readelf" earlier and avoid the compile test if there is no readelf (saves a little time). The final I/O redirection is still needed (otherwise Linux users will see the grep output). Regards Stefan
On 19 June 2016 at 06:53, Stefan Weil <sw@weilnetz.de> wrote: > Am 19.06.2016 um 00:05 schrieb Peter Maydell: >> From: Peter Maydell <peter.maydell@linaro.org> >> >> The AVX2 optimization test assumes that the object format >> is ELF and the system has the readelf utility. If this isn't >> true then configure might fail or emit a warning (since in >> a pipe "foo | bar >/dev/null 2>&1" does not redirect the >> stderr of foo, only of bar). Adjust the check so that if >> we don't have readelf or don't have an ELF object then we >> just don't enable the AVX2 optimization. >> >> Reported-by: Stefan Weil <sw@weilnetz.de> >> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> >> --- >> configure | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/configure b/configure >> index 7beefcd..30bca55 100755 >> --- a/configure >> +++ b/configure >> @@ -1792,8 +1792,10 @@ int foo(void *a) __attribute__((ifunc("bar_ifunc"))); >> int main(int argc, char *argv[]) { return foo(argv[0]);} >> EOF >> if compile_object "" ; then >> - if readelf --syms $TMPO |grep "IFUNC.*foo" >/dev/null 2>&1; then >> - avx2_opt="yes" >> + if has readelf; then >> + if readelf --syms $TMPO 2>/dev/null |grep -q "IFUNC.*foo"; then >> + avx2_opt="yes" >> + fi >> fi >> fi >> >> > > You could check "has readelf" earlier and avoid the compile test > if there is no readelf (saves a little time). I guess so, though there's not much in it. > The final I/O redirection is still needed (otherwise Linux users will > see the grep output). I added -q which should suppress that, no ? thanks -- PMM
Am 19.06.2016 um 11:41 schrieb Peter Maydell: > On 19 June 2016 at 06:53, Stefan Weil <sw@weilnetz.de> wrote: >> Am 19.06.2016 um 00:05 schrieb Peter Maydell: >>> From: Peter Maydell <peter.maydell@linaro.org> >>> >>> The AVX2 optimization test assumes that the object format >>> is ELF and the system has the readelf utility. If this isn't >>> true then configure might fail or emit a warning (since in >>> a pipe "foo | bar >/dev/null 2>&1" does not redirect the >>> stderr of foo, only of bar). Adjust the check so that if >>> we don't have readelf or don't have an ELF object then we >>> just don't enable the AVX2 optimization. >>> >>> Reported-by: Stefan Weil <sw@weilnetz.de> >>> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> >>> --- >>> configure | 6 ++++-- >>> 1 file changed, 4 insertions(+), 2 deletions(-) >>> >>> diff --git a/configure b/configure >>> index 7beefcd..30bca55 100755 >>> --- a/configure >>> +++ b/configure >>> @@ -1792,8 +1792,10 @@ int foo(void *a) __attribute__((ifunc("bar_ifunc"))); >>> int main(int argc, char *argv[]) { return foo(argv[0]);} >>> EOF >>> if compile_object "" ; then >>> - if readelf --syms $TMPO |grep "IFUNC.*foo" >/dev/null 2>&1; then >>> - avx2_opt="yes" >>> + if has readelf; then >>> + if readelf --syms $TMPO 2>/dev/null |grep -q "IFUNC.*foo"; then >>> + avx2_opt="yes" >>> + fi >>> fi >>> fi >>> >>> >> >> You could check "has readelf" earlier and avoid the compile test >> if there is no readelf (saves a little time). > > I guess so, though there's not much in it. > >> The final I/O redirection is still needed (otherwise Linux users will >> see the grep output). > > I added -q which should suppress that, no ? > > thanks > -- PMM > Sorry, I missed that detail. Reviewed-by: Stefan Weil <sw@weilnetz.de>
diff --git a/configure b/configure index 7beefcd..30bca55 100755 --- a/configure +++ b/configure @@ -1792,8 +1792,10 @@ int foo(void *a) __attribute__((ifunc("bar_ifunc"))); int main(int argc, char *argv[]) { return foo(argv[0]);} EOF if compile_object "" ; then - if readelf --syms $TMPO |grep "IFUNC.*foo" >/dev/null 2>&1; then - avx2_opt="yes" + if has readelf; then + if readelf --syms $TMPO 2>/dev/null |grep -q "IFUNC.*foo"; then + avx2_opt="yes" + fi fi fi