diff options
Diffstat (limited to 'arch/x86/include/asm/msr.h')
| -rw-r--r-- | arch/x86/include/asm/msr.h | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h index af5f9a11980..39dc7b33aa0 100644 --- a/arch/x86/include/asm/msr.h +++ b/arch/x86/include/asm/msr.h @@ -59,15 +59,14 @@ static inline unsigned long long native_read_tscp(unsigned int *aux) * edx:eax, while for x86_64 it doesn't mean rdx:rax or edx:eax. Instead, * it means rax *or* rdx. */ -#ifdef CONFIG_X86_64 -#define DECLARE_ARGS(val, low, high) unsigned low, high -#define EAX_EDX_VAL(val, low, high) ((low) | ((u64)(high) << 32)) -#define EAX_EDX_ARGS(val, low, high) "a" (low), "d" (high) +#if CONFIG_IS_ENABLED(X86_64) +/* Using 64-bit values saves one instruction clearing the high half of low */ +#define DECLARE_ARGS(val, low, high) unsigned long low, high +#define EAX_EDX_VAL(val, low, high) ((low) | (high) << 32) #define EAX_EDX_RET(val, low, high) "=a" (low), "=d" (high) #else #define DECLARE_ARGS(val, low, high) unsigned long long val #define EAX_EDX_VAL(val, low, high) (val) -#define EAX_EDX_ARGS(val, low, high) "A" (val) #define EAX_EDX_RET(val, low, high) "=A" (val) #endif |