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Avoid an unnecessary mov on syscalls with < 4 arguments.

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This commit is contained in:
Alex Smith 2012-07-23 14:18:54 +01:00
parent fd9f32c0db
commit fe2e732721
1 changed files with 39 additions and 30 deletions
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69
src/system/libroot/os/arch/x86_64/syscalls.inc
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@ -8,39 +8,48 @@
// The kernel follows the AMD64 ABI for parameter passing (first 6 arguments in
// registers and the remaining ones in on the stack), except that RCX is used
// by SYSCALL so it is moved to R10. Syscall number goes in RAX.
// registers and the remaining ones in on the stack), except that RCX (argument
// 4) is overwritten by the SYSCALL instruction, so it is moved to R10. Syscall
// number goes in RAX.
#define _SYSCALL(name, n) \
.align 8; \
FUNCTION(name): \
movq %rcx, %r10; \
movq $n, %rax; \
syscall; \
ret; \
#define _SYSCALL_NO_RCX(name, n) \
.align 8; \
FUNCTION(name): \
movq $n, %rax; \
syscall; \
ret; \
FUNCTION_END(name)
#define _SYSCALL_RCX(name, n) \
.align 8; \
FUNCTION(name): \
movq %rcx, %r10; \
movq $n, %rax; \
syscall; \
ret; \
FUNCTION_END(name)
#define SYSCALL0(name, n) _SYSCALL(name, n)
#define SYSCALL1(name, n) _SYSCALL(name, n)
#define SYSCALL2(name, n) _SYSCALL(name, n)
#define SYSCALL3(name, n) _SYSCALL(name, n)
#define SYSCALL4(name, n) _SYSCALL(name, n)
#define SYSCALL5(name, n) _SYSCALL(name, n)
#define SYSCALL6(name, n) _SYSCALL(name, n)
#define SYSCALL7(name, n) _SYSCALL(name, n)
#define SYSCALL8(name, n) _SYSCALL(name, n)
#define SYSCALL9(name, n) _SYSCALL(name, n)
#define SYSCALL10(name, n) _SYSCALL(name, n)
#define SYSCALL11(name, n) _SYSCALL(name, n)
#define SYSCALL12(name, n) _SYSCALL(name, n)
#define SYSCALL13(name, n) _SYSCALL(name, n)
#define SYSCALL14(name, n) _SYSCALL(name, n)
#define SYSCALL15(name, n) _SYSCALL(name, n)
#define SYSCALL16(name, n) _SYSCALL(name, n)
#define SYSCALL17(name, n) _SYSCALL(name, n)
#define SYSCALL18(name, n) _SYSCALL(name, n)
#define SYSCALL19(name, n) _SYSCALL(name, n)
#define SYSCALL20(name, n) _SYSCALL(name, n)
#define SYSCALL0(name, n) _SYSCALL_NO_RCX(name, n)
#define SYSCALL1(name, n) _SYSCALL_NO_RCX(name, n)
#define SYSCALL2(name, n) _SYSCALL_NO_RCX(name, n)
#define SYSCALL3(name, n) _SYSCALL_NO_RCX(name, n)
#define SYSCALL4(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL5(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL6(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL7(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL8(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL9(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL10(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL11(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL12(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL13(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL14(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL15(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL16(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL17(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL18(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL19(name, n) _SYSCALL_RCX(name, n)
#define SYSCALL20(name, n) _SYSCALL_RCX(name, n)