From a734b4a23e4b5a5bba577d11b6e2ff21f6ca4fce Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 31 Mar 2015 19:00:10 +0200 Subject: [PATCH] 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 Cc: Alexei Starovoitov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Frederic Weisbecker Cc: H. Peter Anvin Cc: Kees Cook Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Steven Rostedt Cc: Will Drewry Link: http://lkml.kernel.org/r/1427821211-25099-8-git-send-email-dvlasenk@redhat.com Signed-off-by: Ingo Molnar --- 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 26d49ebae040..225be06edc80 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 a039d21986a2..a350c990dc86 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 04cb1790a596..98111b38ebfd 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 -- 2.20.1