From: tip-bot for Denys Vlasenko <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de,
rostedt@goodmis.org, ast@plumgrid.com, keescook@chromium.org,
wad@chromium.org, oleg@redhat.com, hpa@zytor.com,
mingo@kernel.org, luto@amacapital.net,
torvalds@linux-foundation.org, fweisbec@gmail.com,
dvlasenk@redhat.com, bp@alien8.de
Subject: [tip:x86/asm] x86/asm: Replace "MOVQ $imm, %reg" with MOVL
Date: Thu, 2 Apr 2015 05:26:28 -0700 [thread overview]
Message-ID: <tip-a734b4a23e4b5a5bba577d11b6e2ff21f6ca4fce@git.kernel.org> (raw)
In-Reply-To: <1427821211-25099-8-git-send-email-dvlasenk@redhat.com>
Commit-ID: a734b4a23e4b5a5bba577d11b6e2ff21f6ca4fce
Gitweb: http://git.kernel.org/tip/a734b4a23e4b5a5bba577d11b6e2ff21f6ca4fce
Author: Denys Vlasenko <dvlasenk@redhat.com>
AuthorDate: Tue, 31 Mar 2015 19:00:10 +0200
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 1 Apr 2015 13:17:39 +0200
x86/asm: Replace "MOVQ $imm, %reg" with MOVL
There is no reason to use MOVQ to load a non-negative immediate
constant value into a 64-bit register. MOVL does the same, since
the upper 32 bits are zero-extended by the CPU.
This makes the code a bit smaller, while leaving functionality
unchanged.
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427821211-25099-8-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/crypto/crc32c-pcl-intel-asm_64.S | 2 +-
arch/x86/crypto/twofish-x86_64-asm_64.S | 4 ++--
arch/x86/kernel/relocate_kernel_64.S | 8 ++++----
3 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/x86/crypto/crc32c-pcl-intel-asm_64.S b/arch/x86/crypto/crc32c-pcl-intel-asm_64.S
index 26d49eb..225be06 100644
--- a/arch/x86/crypto/crc32c-pcl-intel-asm_64.S
+++ b/arch/x86/crypto/crc32c-pcl-intel-asm_64.S
@@ -178,7 +178,7 @@ continue_block:
## 2a) PROCESS FULL BLOCKS:
################################################################
full_block:
- movq $128,%rax
+ movl $128,%eax
lea 128*8*2(block_0), block_1
lea 128*8*3(block_0), block_2
add $128*8*1, block_0
diff --git a/arch/x86/crypto/twofish-x86_64-asm_64.S b/arch/x86/crypto/twofish-x86_64-asm_64.S
index a039d21..a350c99 100644
--- a/arch/x86/crypto/twofish-x86_64-asm_64.S
+++ b/arch/x86/crypto/twofish-x86_64-asm_64.S
@@ -264,7 +264,7 @@ ENTRY(twofish_enc_blk)
movq R1, 8(%rsi)
popq R1
- movq $1,%rax
+ movl $1,%eax
ret
ENDPROC(twofish_enc_blk)
@@ -316,6 +316,6 @@ ENTRY(twofish_dec_blk)
movq R1, 8(%rsi)
popq R1
- movq $1,%rax
+ movl $1,%eax
ret
ENDPROC(twofish_dec_blk)
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index 04cb179..98111b3 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -123,7 +123,7 @@ identity_mapped:
* Set cr4 to a known state:
* - physical address extension enabled
*/
- movq $X86_CR4_PAE, %rax
+ movl $X86_CR4_PAE, %eax
movq %rax, %cr4
jmp 1f
@@ -246,17 +246,17 @@ swap_pages:
movq %rsi, %rax
movq %r10, %rdi
- movq $512, %rcx
+ movl $512, %ecx
rep ; movsq
movq %rax, %rdi
movq %rdx, %rsi
- movq $512, %rcx
+ movl $512, %ecx
rep ; movsq
movq %rdx, %rdi
movq %r10, %rsi
- movq $512, %rcx
+ movl $512, %ecx
rep ; movsq
lea PAGE_SIZE(%rax), %rsi
next prev parent reply other threads:[~2015-04-02 12:27 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-31 17:00 [PATCH 1/9] x86/asm/entry/64: do not TRACE_IRQS fast SYSRET64 path Denys Vlasenko
2015-03-31 17:00 ` [PATCH 2/9] x86/asm/entry/32: Use PUSH instructions to build pt_regs on stack Denys Vlasenko
2015-04-01 8:51 ` Ingo Molnar
2015-04-01 13:12 ` Denys Vlasenko
2015-04-01 13:21 ` Ingo Molnar
2015-04-01 13:53 ` Borislav Petkov
2015-04-02 12:25 ` [tip:x86/asm] x86/asm/entry/32: Use smaller PUSH instructions instead of MOV, to build 'pt_regs' " tip-bot for Denys Vlasenko
2015-03-31 17:00 ` [PATCH 3/9] x86/asm/entry/64: simplify retint_kernel label usage, make retint_restore_args label local Denys Vlasenko
2015-04-02 12:25 ` [tip:x86/asm] x86/asm/entry/64: Simplify " tip-bot for Denys Vlasenko
2015-03-31 17:00 ` [PATCH 4/9] x86/asm/entry/64: remove redundant DISABLE_INTERRUPTS Denys Vlasenko
2015-04-02 12:25 ` [tip:x86/asm] x86/asm/entry/64: Remove redundant DISABLE_INTERRUPTS() tip-bot for Denys Vlasenko
2015-03-31 17:00 ` [PATCH 5/9] x86/asm/entry/64: simplify looping around preempt_schedule_irq Denys Vlasenko
2015-04-02 12:26 ` [tip:x86/asm] x86/asm/entry/64: Simplify looping around preempt_schedule_irq() tip-bot for Denys Vlasenko
2015-03-31 17:00 ` [PATCH 6/9] x86/asm/entry/64: tidy up some instructions Denys Vlasenko
2015-03-31 17:00 ` [PATCH 7/9] x86/asm/entry/32: " Denys Vlasenko
2015-03-31 22:21 ` Brian Gerst
2015-03-31 23:09 ` Linus Torvalds
2015-04-01 11:10 ` Denys Vlasenko
2015-04-01 15:50 ` Linus Torvalds
2015-04-01 20:52 ` Denys Vlasenko
2015-04-01 20:57 ` H. Peter Anvin
2015-04-01 22:14 ` Linus Torvalds
2015-04-02 0:32 ` Brian Gerst
2015-04-01 8:29 ` Ingo Molnar
2015-03-31 17:00 ` [PATCH 8/9] x86/asm: replace MOVQ $imm,%reg with MOVL Denys Vlasenko
2015-04-02 12:26 ` tip-bot for Denys Vlasenko [this message]
2015-03-31 17:00 ` [PATCH 9/9] x86/asm/entry/64: use local label to skip around sycall dispatch Denys Vlasenko
2015-04-02 12:26 ` [tip:x86/asm] x86/asm/entry/64: Use " tip-bot for Denys Vlasenko
2015-04-02 12:25 ` [tip:x86/asm] x86/asm/entry/64: Do not TRACE_IRQS fast SYSRET64 path tip-bot for Denys Vlasenko
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