Message ID | 20180331175420.19860-1-thomas.petazzoni@bootlin.com |
---|---|
State | Accepted |
Headers | show |
Series | toolchain-wrapper: use -ffp-contract=off on MIPS Xburst for gcc >= 4.6 | expand |
On 31 March 2018 at 14:54, Thomas Petazzoni <thomas.petazzoni@bootlin.com> wrote: > From: Waldemar Brodkorb <wbx@openadk.org> > > Since gcc 4.6, GCC deprecated -mfused-madd, -ffp-contract=off should > be used for the Xburst workaround. > > Tested with the MIPS Sourcery 2011.03 toolchain (based on gcc 4.5), > the toolchain wrapper uses -mno-fused-madd, as expected: > > $ BR2_DEBUG_WRAPPER=2 ./output/host/bin/mips-linux-gnu-gcc -o toto toto.c > Toolchain wrapper executing: > '/home/thomas/toolchains/mips-2011.03/bin/mips-linux-gnu-gcc' > '--sysroot' > '/home/thomas/projets/buildroot/output/host/mipsel-buildroot-linux-gnu/sysroot' > '-mabi=32' > '-msoft-float' > '-mno-fused-madd' > '-EL' > '-march=mips32r2' > '-o' > 'toto' > 'toto.c' > > And with the MIPS Sourcery 2012.09 toolchain (based on gcc 4.7), the > toolchain wrapper uses -ffp-contract=off, as expected: > > $ BR2_DEBUG_WRAPPER=2 ./output/host/bin/mips-linux-gnu-gcc -o toto toto.c > Toolchain wrapper executing: > '/home/thomas/toolchains/mips-2012.09/bin/mips-linux-gnu-gcc' > '--sysroot' > '/home/thomas/projets/buildroot/output/host/mipsel-buildroot-linux-gnu/sysroot' > '-mabi=32' > '-msoft-float' > '-ffp-contract=off' > '-EL' > '-march=mips32r2' > '-o' > 'toto' > 'toto.c' > > Fixes the ci20_defconfig build: > > https://gitlab.com/buildroot.org/buildroot/-/jobs/60303132 > Fixed that one, but U-Boot fails to build here. I'll submit a patch. > Signed-off-by: Waldemar Brodkorb <wbx@openadk.org> > [Thomas: rework to continue supporting pre-gcc-4.6 toolchains, extend > the commit log after doing more testing.] > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar> Thanks, Eze
Hello, On Sat, 31 Mar 2018 19:54:20 +0200, Thomas Petazzoni wrote: > From: Waldemar Brodkorb <wbx@openadk.org> > > Since gcc 4.6, GCC deprecated -mfused-madd, -ffp-contract=off should > be used for the Xburst workaround. > > Tested with the MIPS Sourcery 2011.03 toolchain (based on gcc 4.5), > the toolchain wrapper uses -mno-fused-madd, as expected: > > $ BR2_DEBUG_WRAPPER=2 ./output/host/bin/mips-linux-gnu-gcc -o toto toto.c > Toolchain wrapper executing: > '/home/thomas/toolchains/mips-2011.03/bin/mips-linux-gnu-gcc' > '--sysroot' > '/home/thomas/projets/buildroot/output/host/mipsel-buildroot-linux-gnu/sysroot' > '-mabi=32' > '-msoft-float' > '-mno-fused-madd' > '-EL' > '-march=mips32r2' > '-o' > 'toto' > 'toto.c' > > And with the MIPS Sourcery 2012.09 toolchain (based on gcc 4.7), the > toolchain wrapper uses -ffp-contract=off, as expected: > > $ BR2_DEBUG_WRAPPER=2 ./output/host/bin/mips-linux-gnu-gcc -o toto toto.c > Toolchain wrapper executing: > '/home/thomas/toolchains/mips-2012.09/bin/mips-linux-gnu-gcc' > '--sysroot' > '/home/thomas/projets/buildroot/output/host/mipsel-buildroot-linux-gnu/sysroot' > '-mabi=32' > '-msoft-float' > '-ffp-contract=off' > '-EL' > '-march=mips32r2' > '-o' > 'toto' > 'toto.c' > > Fixes the ci20_defconfig build: > > https://gitlab.com/buildroot.org/buildroot/-/jobs/60303132 > > Signed-off-by: Waldemar Brodkorb <wbx@openadk.org> > [Thomas: rework to continue supporting pre-gcc-4.6 toolchains, extend > the commit log after doing more testing.] > Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com> > --- > toolchain/toolchain-wrapper.c | 3 +++ > toolchain/toolchain-wrapper.mk | 6 ++++++ > 2 files changed, 9 insertions(+) Applied to master, thanks. Thomas
diff --git a/toolchain/toolchain-wrapper.c b/toolchain/toolchain-wrapper.c index 2928ea42d0..c5eb813dd0 100644 --- a/toolchain/toolchain-wrapper.c +++ b/toolchain/toolchain-wrapper.c @@ -82,6 +82,9 @@ static char *predef_args[] = { #ifdef BR_NO_FUSED_MADD "-mno-fused-madd", #endif +#ifdef BR_FP_CONTRACT_OFF + "-ffp-contract=off", +#endif #ifdef BR_BINFMT_FLAT "-Wl,-elf2flt", #endif diff --git a/toolchain/toolchain-wrapper.mk b/toolchain/toolchain-wrapper.mk index 7f72a0cade..6e95545ebf 100644 --- a/toolchain/toolchain-wrapper.mk +++ b/toolchain/toolchain-wrapper.mk @@ -28,8 +28,14 @@ endif # Avoid FPU bug on XBurst CPUs ifeq ($(BR2_mips_xburst),y) +# Before gcc 4.6, -mno-fused-madd was needed, after -ffp-contract is +# needed +ifeq ($(BR2_TOOLCHAIN_GCC_AT_LEAST_4_6),y) +TOOLCHAIN_WRAPPER_ARGS += -DBR_FP_CONTRACT_OFF +else TOOLCHAIN_WRAPPER_ARGS += -DBR_NO_FUSED_MADD endif +endif ifeq ($(BR2_CCACHE_USE_BASEDIR),y) TOOLCHAIN_WRAPPER_ARGS += -DBR_CCACHE_BASEDIR='"$(BASE_DIR)"'