diff options
| author | Huacai Chen <chenhc@lemote.com> | 2016-01-21 21:09:48 +0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2016-01-22 01:59:18 +0100 |
| commit | 5188129b8c9f58ba089bfd3809a163a8c087c797 (patch) | |
| tree | 6b06698b8e1152bb86382bef377a684ffee002e3 /arch/mips/loongson64 | |
| parent | 6e52684467b2c135e07e638469cd1d78bd8286ac (diff) | |
| download | linux-stable-5188129b8c9f58ba089bfd3809a163a8c087c797.tar.gz linux-stable-5188129b8c9f58ba089bfd3809a163a8c087c797.tar.bz2 linux-stable-5188129b8c9f58ba089bfd3809a163a8c087c797.zip | |
MIPS: Loongson-3: Improve -march option and move it to Platform
If GCC >= 4.9 and Binutils >=2.25, we use -march=loongson3a, otherwise
we use -march=mips64r2, this can slightly improve performance. Besides,
arch/mips/loongson64/Platform is a better location rather than arch/
mips/Makefile.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12161/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/loongson64')
| -rw-r--r-- | arch/mips/loongson64/Platform | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/mips/loongson64/Platform b/arch/mips/loongson64/Platform index 2e48e83d5524..85d808924c94 100644 --- a/arch/mips/loongson64/Platform +++ b/arch/mips/loongson64/Platform @@ -22,6 +22,27 @@ ifdef CONFIG_CPU_LOONGSON2F_WORKAROUNDS endif endif +cflags-$(CONFIG_CPU_LOONGSON3) += -Wa,--trap +# +# binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a +# as MIPS64 R2; older versions as just R1. This leaves the possibility open +# that GCC might generate R2 code for -march=loongson3a which then is rejected +# by GAS. The cc-option can't probe for this behaviour so -march=loongson3a +# can't easily be used safely within the kbuild framework. +# +ifeq ($(call cc-ifversion, -ge, 0409, y), y) + ifeq ($(call ld-ifversion, -ge, 22500000, y), y) + cflags-$(CONFIG_CPU_LOONGSON3) += \ + $(call cc-option,-march=loongson3a -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) + else + cflags-$(CONFIG_CPU_LOONGSON3) += \ + $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) + endif +else + cflags-$(CONFIG_CPU_LOONGSON3) += \ + $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64) +endif + # # Loongson Machines' Support # |