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Diffstat (limited to 'arch/x86/include/asm/arch_hweight.h')
-rw-r--r--arch/x86/include/asm/arch_hweight.h26
1 files changed, 12 insertions, 14 deletions
diff --git a/arch/x86/include/asm/arch_hweight.h b/arch/x86/include/asm/arch_hweight.h
index 259a7c1ef709..e7cd63175de4 100644
--- a/arch/x86/include/asm/arch_hweight.h
+++ b/arch/x86/include/asm/arch_hweight.h
@@ -1,9 +1,11 @@
#ifndef _ASM_X86_HWEIGHT_H
#define _ASM_X86_HWEIGHT_H
+#include <asm/cpufeatures.h>
+
#ifdef CONFIG_64BIT
-/* popcnt %edi, %eax -- redundant REX prefix for alignment */
-#define POPCNT32 ".byte 0xf3,0x40,0x0f,0xb8,0xc7"
+/* popcnt %edi, %eax */
+#define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc7"
/* popcnt %rdi, %rax */
#define POPCNT64 ".byte 0xf3,0x48,0x0f,0xb8,0xc7"
#define REG_IN "D"
@@ -15,19 +17,15 @@
#define REG_OUT "a"
#endif
-/*
- * __sw_hweightXX are called from within the alternatives below
- * and callee-clobbered registers need to be taken care of. See
- * ARCH_HWEIGHT_CFLAGS in <arch/x86/Kconfig> for the respective
- * compiler switches.
- */
+#define __HAVE_ARCH_SW_HWEIGHT
+
static __always_inline unsigned int __arch_hweight32(unsigned int w)
{
- unsigned int res = 0;
+ unsigned int res;
asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT)
- : "="REG_OUT (res)
- : REG_IN (w));
+ : "="REG_OUT (res)
+ : REG_IN (w));
return res;
}
@@ -51,11 +49,11 @@ static inline unsigned long __arch_hweight64(__u64 w)
#else
static __always_inline unsigned long __arch_hweight64(__u64 w)
{
- unsigned long res = 0;
+ unsigned long res;
asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT)
- : "="REG_OUT (res)
- : REG_IN (w));
+ : "="REG_OUT (res)
+ : REG_IN (w));
return res;
}