53 lines
2 KiB
Diff
53 lines
2 KiB
Diff
From 71a0a72456b48de972d7ed613b06a22a3aa9057f Mon Sep 17 00:00:00 2001
|
|
From: Yousong Zhou <yszhou4tech@gmail.com>
|
|
Date: Sat, 26 Sep 2015 13:41:43 +0800
|
|
Subject: [PATCH] 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>
|
|
---
|
|
arch/mips/include/uapi/asm/swab.h | 7 ++++---
|
|
1 file changed, 4 insertions(+), 3 deletions(-)
|
|
|
|
--- 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
|
|
}
|
|
#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 */
|