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| author | H. Peter Anvin <hpa@zytor.com> | 2016-06-08 22:38:40 +0300 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2016-06-08 22:41:20 +0300 |
| commit | ff3554b409b82d349f71e9d7082648b7b0a1a5bb (patch) | |
| tree | bf0166f5e2be0455efb82ba62c1532baa6e41555 /arch/x86/include/asm/asm.h | |
| parent | 18fe58229d80c7f4f138a07e84ba608e1ebd232b (diff) | |
| download | linux-ff3554b409b82d349f71e9d7082648b7b0a1a5bb.tar.xz | |
x86, asm: define CC_SET() and CC_OUT() macros
The CC_SET() and CC_OUT() macros can be used together to take
advantage of the new __GCC_ASM_FLAG_OUTPUTS__ feature in gcc 6+ while
remaining backwards compatible. CC_SET() generates a SET instruction
on older compilers; CC_OUT() makes sure the output is received in the
correct variable.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/1465414726-197858-5-git-send-email-hpa@linux.intel.com
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Diffstat (limited to 'arch/x86/include/asm/asm.h')
| -rw-r--r-- | arch/x86/include/asm/asm.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h index f5063b6659eb..7acb51c49fec 100644 --- a/arch/x86/include/asm/asm.h +++ b/arch/x86/include/asm/asm.h @@ -42,6 +42,18 @@ #define _ASM_SI __ASM_REG(si) #define _ASM_DI __ASM_REG(di) +/* + * Macros to generate condition code outputs from inline assembly, + * The output operand must be type "bool". + */ +#ifdef __GCC_ASM_FLAG_OUTPUTS__ +# define CC_SET(c) "\n\t/* output condition code " #c "*/\n" +# define CC_OUT(c) "=@cc" #c +#else +# define CC_SET(c) "\n\tset" #c " %[_cc_" #c "]\n" +# define CC_OUT(c) [_cc_ ## c] "=qm" +#endif + /* Exception table entry */ #ifdef __ASSEMBLY__ # define _ASM_EXTABLE_HANDLE(from, to, handler) \ |