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| author | Ralf Baechle <ralf@linux-mips.org> | 2015-02-19 12:47:20 (GMT) |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2015-02-19 12:47:20 (GMT) |
| commit | a8140f36af2a8b63fd507bd8c1fa00df7819e0de (patch) | |
| tree | 4fb445ab51030bae2fefb4529538e2899fa03146 | |
| parent | ed4cbc81addbc076b016c5b979fd1a02f0897f0a (diff) | |
| download | linux-a8140f36af2a8b63fd507bd8c1fa00df7819e0de.tar.xz | |
MIPS: Makefile: Pass -march option on Loongson3A cores
The loongson 3A cores do not select a suitable -march option so the build
system uses the default one from the toolchain. This may or may not be
suitable for a loongson 3A build. In order to avoid that, we explicitly set
a suitable -march option for that core. Furthermore, some very old
compilers don't support -march= at all and there is the possibility of
toolchain combinations such as GCC 4.9 and binutils 2.24 for which
-march=loongson3a will result in MIPS64 R2 code being generated but then
rejected by GAS. So treat the Longsoon 3A as an R2 CPU.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| -rw-r--r-- | arch/mips/Makefile | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/mips/Makefile b/arch/mips/Makefile index 2563a08..4547719 100644 --- a/arch/mips/Makefile +++ b/arch/mips/Makefile @@ -182,6 +182,16 @@ cflags-$(CONFIG_CPU_CAVIUM_OCTEON) += -Wa,-march=octeon endif cflags-$(CONFIG_CAVIUM_CN63XXP1) += -Wa,-mfix-cn63xxp1 cflags-$(CONFIG_CPU_BMIPS) += -march=mips32 -Wa,-mips32 -Wa,--trap +# +# binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a +# as MIPS64 R1; older versions as just R1. This leaves the possibility open +# that GCC might generate R2 code for -march=loongson3a which then is rejected +# by GAS. The cc-option can't probe for this behaviour so -march=loongson3a +# can't easily be used safely within the kbuild framework. +# +cflags-$(CONFIG_CPU_LOONGSON3) += \ + $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) \ + -Wa,-mips64r2 -Wa,--trap cflags-$(CONFIG_CPU_R4000_WORKAROUNDS) += $(call cc-option,-mfix-r4000,) cflags-$(CONFIG_CPU_R4400_WORKAROUNDS) += $(call cc-option,-mfix-r4400,) |