提交 96958231 编写于 作者: I Ingo Molnar 提交者: Linus Torvalds

[PATCH] kvm: optimize inline assembly

Forms like "0(%rsp)" generate an instruction with an unnecessary one byte
displacement under certain circumstances.  replace with the equivalent
"(%rsp)".
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 54fb996a
......@@ -1786,10 +1786,10 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
"kvm_vmx_return: "
/* Save guest registers, load host registers, keep flags */
#ifdef CONFIG_X86_64
"xchg %3, 0(%%rsp) \n\t"
"xchg %3, (%%rsp) \n\t"
"mov %%rax, %c[rax](%3) \n\t"
"mov %%rbx, %c[rbx](%3) \n\t"
"pushq 0(%%rsp); popq %c[rcx](%3) \n\t"
"pushq (%%rsp); popq %c[rcx](%3) \n\t"
"mov %%rdx, %c[rdx](%3) \n\t"
"mov %%rsi, %c[rsi](%3) \n\t"
"mov %%rdi, %c[rdi](%3) \n\t"
......@@ -1804,24 +1804,24 @@ static int vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
"mov %%r15, %c[r15](%3) \n\t"
"mov %%cr2, %%rax \n\t"
"mov %%rax, %c[cr2](%3) \n\t"
"mov 0(%%rsp), %3 \n\t"
"mov (%%rsp), %3 \n\t"
"pop %%rcx; pop %%r15; pop %%r14; pop %%r13; pop %%r12;"
"pop %%r11; pop %%r10; pop %%r9; pop %%r8;"
"pop %%rbp; pop %%rdi; pop %%rsi;"
"pop %%rdx; pop %%rbx; pop %%rax \n\t"
#else
"xchg %3, 0(%%esp) \n\t"
"xchg %3, (%%esp) \n\t"
"mov %%eax, %c[rax](%3) \n\t"
"mov %%ebx, %c[rbx](%3) \n\t"
"pushl 0(%%esp); popl %c[rcx](%3) \n\t"
"pushl (%%esp); popl %c[rcx](%3) \n\t"
"mov %%edx, %c[rdx](%3) \n\t"
"mov %%esi, %c[rsi](%3) \n\t"
"mov %%edi, %c[rdi](%3) \n\t"
"mov %%ebp, %c[rbp](%3) \n\t"
"mov %%cr2, %%eax \n\t"
"mov %%eax, %c[cr2](%3) \n\t"
"mov 0(%%esp), %3 \n\t"
"mov (%%esp), %3 \n\t"
"pop %%ecx; popa \n\t"
#endif
......
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