Commit ff3554b4 authored Jun 08, 2016 by H. Peter Anvin Committed by H. Peter Anvin Jun 08, 2016

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>

parent 18fe5822

arch/x86/include/asm/asm.h

+12 −0

Original line number	Diff line number	Diff line
		@@ -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) \