linux-kernel - [tip:x86/asm] x86: Use POPCNT mnemonics in arch

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Message-ID: <tip-566b62a3676caed1f8c626e26066ff3ae3a38918@git.kernel.org>
Date:   Mon, 5 Nov 2018 01:54:55 -0800
From:   tip-bot for Uros Bizjak <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     hpa@...or.com, bp@...e.de, linux-kernel@...r.kernel.org,
        mingo@...nel.org, mingo@...hat.com, tglx@...utronix.de,
        ubizjak@...il.com
Subject: [tip:x86/asm] x86: Use POPCNT mnemonics in arch_hweight.h

Commit-ID:  566b62a3676caed1f8c626e26066ff3ae3a38918
Gitweb:     https://git.kernel.org/tip/566b62a3676caed1f8c626e26066ff3ae3a38918
Author:     Uros Bizjak <ubizjak@...il.com>
AuthorDate: Sun, 14 Oct 2018 22:23:54 +0200
Committer:  Borislav Petkov <bp@...e.de>
CommitDate: Mon, 5 Nov 2018 10:42:32 +0100

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@...il.com>
Signed-off-by: Borislav Petkov <bp@...e.de>
CC: "H. Peter Anvin" <hpa@...or.com>
CC: Ingo Molnar <mingo@...hat.com>
CC: Thomas Gleixner <tglx@...utronix.de>
Link: http://lkml.kernel.org/r/20181014202354.21281-1-ubizjak@gmail.com
---
 arch/x86/include/asm/arch_hweight.h | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/arch_hweight.h b/arch/x86/include/asm/arch_hweight.h
index 34a10b2d5b73..fc0693569f7a 100644
--- a/arch/x86/include/asm/arch_hweight.h
+++ b/arch/x86/include/asm/arch_hweight.h
@@ -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));