kumquat-buildroot/toolchain/toolchain-wrapper.mk
Waldemar Brodkorb 5e58509bfe toolchain-wrapper: use -ffp-contract=off on MIPS Xburst for gcc >= 4.6
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>
Reviewed-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
2018-04-01 16:23:33 +02:00

59 lines
1.8 KiB
Makefile

################################################################################
#
# definition of the toolchain wrapper build commands
#
################################################################################
# We use --hash-style=both to increase the compatibility of the generated
# binary with older platforms, except for MIPS, where the only acceptable
# hash style is 'sysv'
ifeq ($(findstring mips,$(HOSTARCH)),mips)
TOOLCHAIN_WRAPPER_HASH_STYLE = sysv
else
TOOLCHAIN_WRAPPER_HASH_STYLE = both
endif
TOOLCHAIN_WRAPPER_ARGS = $($(PKG)_TOOLCHAIN_WRAPPER_ARGS)
TOOLCHAIN_WRAPPER_ARGS += -DBR_SYSROOT='"$(STAGING_SUBDIR)"'
# We create a list like '"-mfoo", "-mbar", "-mbarfoo"' so that each flag is a
# separate argument when used in execv() by the toolchain wrapper.
TOOLCHAIN_WRAPPER_OPTS = \
$(foreach f,$(call qstrip,$(BR2_TARGET_OPTIMIZATION)),"$(f)"$(comma))
TOOLCHAIN_WRAPPER_ARGS += -DBR_ADDITIONAL_CFLAGS='$(TOOLCHAIN_WRAPPER_OPTS)'
ifeq ($(BR2_CCACHE),y)
TOOLCHAIN_WRAPPER_ARGS += -DBR_CCACHE
endif
ifeq ($(BR2_x86_x1000),y)
TOOLCHAIN_WRAPPER_ARGS += -DBR_OMIT_LOCK_PREFIX
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)"'
endif
define TOOLCHAIN_WRAPPER_BUILD
$(HOSTCC) $(HOST_CFLAGS) $(TOOLCHAIN_WRAPPER_ARGS) \
-s -Wl,--hash-style=$(TOOLCHAIN_WRAPPER_HASH_STYLE) \
toolchain/toolchain-wrapper.c \
-o $(@D)/toolchain-wrapper
endef
define TOOLCHAIN_WRAPPER_INSTALL
$(INSTALL) -D -m 0755 $(@D)/toolchain-wrapper \
$(HOST_DIR)/bin/toolchain-wrapper
endef