x86: Use POPCNT mnemonics in arch_hweight.h (566b62a3) · Commits · 戴 / test

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

arch/x86/include/asm/arch_hweight.h

+2 −8

Original line number	Diff line number	Diff line
		@@ -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));

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