Commit-ID: ff3554b409b82d349f71e9d7082648b7b0a1a5bb Gitweb: http://git.kernel.org/tip/ff3554b409b82d349f71e9d7082648b7b0a1a5bb Author: H. Peter Anvin <h...@zytor.com> AuthorDate: Wed, 8 Jun 2016 12:38:40 -0700 Committer: H. Peter Anvin <h...@linux.intel.com> CommitDate: Wed, 8 Jun 2016 12:41:20 -0700
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 <h...@zytor.com> Link: http://lkml.kernel.org/r/1465414726-197858-5-git-send-email-...@linux.intel.com Reviewed-by: Andy Lutomirski <l...@kernel.org> Reviewed-by: Borislav Petkov <b...@suse.de> Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org> --- arch/x86/include/asm/asm.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h index f5063b6..7acb51c 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) \
