[Buildroot] [git commit] toolchain-wrapper: use -ffp-contract=off on MIPS Xburst for gcc >= 4.6

[Peter Korsgaard]

>>>>> "Thomas" == Thomas Petazzoni <thomas.petazzoni at bootlin.com> writes:

 > commit: https://git.buildroot.net/buildroot/commit/?id=5e58509bfe497c5e85db58f8213b0a44ac79dd3f
 > branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/master

 > 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 at 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 at bootlin.com>
 > Reviewed-by: Ezequiel Garcia <ezequiel at vanguardiasur.com.ar>
 > Signed-off-by: Thomas Petazzoni <thomas.petazzoni at bootlin.com>

Committed to 2018.02.x, thanks.

-- 
Bye, Peter Korsgaard