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authorYousong Zhou <yszhou4tech@gmail.com>2015-09-26 13:41:43 +0800
committerRalf Baechle <ralf@linux-mips.org>2015-10-05 11:30:23 +0200
commit71a0a72456b48de972d7ed613b06a22a3aa9057f (patch)
treeaf08c45e6fef47fa99e0a8a022cd1dc52d5ee1ff
parent1bb3bf6226eedee453902e5cf8899ee548f43840 (diff)
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.h7
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 */