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| author | Yousong Zhou <yszhou4tech@gmail.com> | 2015-09-26 13:41:43 +0800 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2015-10-05 11:30:23 +0200 |
| commit | 71a0a72456b48de972d7ed613b06a22a3aa9057f (patch) | |
| tree | af08c45e6fef47fa99e0a8a022cd1dc52d5ee1ff | |
| parent | 1bb3bf6226eedee453902e5cf8899ee548f43840 (diff) | |
| download | linux-71a0a72456b48de972d7ed613b06a22a3aa9057f.tar.bz2 | |
MIPS: UAPI: Ignore __arch_swab{16,32,64} when using MIPS16
Some GCC versions (e.g. 4.8.3) can incorrectly inline a function with
MIPS32 instructions into another function with MIPS16 code [1], causing
the assembler to genereate incorrect binary code or fail right away
complaining about unrecognized opcode.
In the case of __arch_swab{16,32}, when inlined by the compiler with
flags `-mips32r2 -mips16 -Os', the assembler can fail with the following
error.
{standard input}:79: Error: unrecognized opcode `wsbh $2,$2'
For performance concerns and to workaround the issue already existing in
older compilers, just ignore these 2 functions when compiling with
mips16 enabled.
[1] Inlining nomips16 function into mips16 function can result in
undefined builtins, https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55777
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11241/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| -rw-r--r-- | arch/mips/include/uapi/asm/swab.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/mips/include/uapi/asm/swab.h b/arch/mips/include/uapi/asm/swab.h index 8f2d184dbe9f..23cd9b118c9e 100644 --- a/arch/mips/include/uapi/asm/swab.h +++ b/arch/mips/include/uapi/asm/swab.h @@ -13,8 +13,9 @@ #define __SWAB_64_THRU_32__ -#if (defined(__mips_isa_rev) && (__mips_isa_rev >= 2)) || \ - defined(_MIPS_ARCH_LOONGSON3A) +#if !defined(__mips16) && \ + ((defined(__mips_isa_rev) && (__mips_isa_rev >= 2)) || \ + defined(_MIPS_ARCH_LOONGSON3A)) static inline __attribute_const__ __u16 __arch_swab16(__u16 x) { @@ -65,5 +66,5 @@ static inline __attribute_const__ __u64 __arch_swab64(__u64 x) } #define __arch_swab64 __arch_swab64 #endif /* __mips64 */ -#endif /* MIPS R2 or newer or Loongson 3A */ +#endif /* (not __mips16) and (MIPS R2 or newer or Loongson 3A) */ #endif /* _ASM_SWAB_H */ |