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x86: Use POPCNT mnemonics in arch_hweight.h 

Recently, the minimum required version of binutils was changed to
2.20, which supports POPCNT instruction mnemonics.

Replace the byte-wise specification of POPCNT with those proper
mnemonics.

 [ bp: massage commit message and remove line breaks. ]

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
CC: "H. Peter Anvin" <hpa@zytor.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20181014202354.21281-1-ubizjak@gmail.com
This commit is contained in:
Uros Bizjak 2018-10-14 22:23:54 +02:00 committed by Borislav Petkov
parent 651022382c
commit 566b62a367
1 changed files with 2 additions and 8 deletions
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10
arch/x86/include/asm/arch_hweight.h
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@ -5,15 +5,9 @@
#include <asm/cpufeatures.h>
#ifdef CONFIG_64BIT
/* 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"
#define REG_OUT "a"
#else
/* popcnt %eax, %eax */
#define POPCNT32 ".byte 0xf3,0x0f,0xb8,0xc0"
#define REG_IN "a"
#define REG_OUT "a"
#endif
@ -24,7 +18,7 @@ static __always_inline unsigned int __arch_hweight32(unsigned int w)
{
unsigned int res;
asm (ALTERNATIVE("call __sw_hweight32", POPCNT32, X86_FEATURE_POPCNT)
asm (ALTERNATIVE("call __sw_hweight32", "popcntl %1, %0", X86_FEATURE_POPCNT)
: "="REG_OUT (res)
: REG_IN (w));
@ -52,7 +46,7 @@ static __always_inline unsigned long __arch_hweight64(__u64 w)
{
unsigned long res;
asm (ALTERNATIVE("call __sw_hweight64", POPCNT64, X86_FEATURE_POPCNT)
asm (ALTERNATIVE("call __sw_hweight64", "popcntq %1, %0", X86_FEATURE_POPCNT)
: "="REG_OUT (res)
: REG_IN (w));