syscall: avoid zeroing unused syscall arguments
Zeroing unused registers is not required. Removing it makes the code
very slightly smaller and very slightly faster.
Change-Id: I1ec17b497db971ca8a3641e3e94c063571419f27
GitHub-Last-Rev: f721bb263637717e8ff9fd2c34148b5b2762e8c4
GitHub-Pull-Request: golang/go#31596
Reviewed-on: https://go-review.googlesource.com/c/go/+/173160
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/src/syscall/asm_darwin_amd64.s b/src/syscall/asm_darwin_amd64.s
index eab4fcd..c863889 100644
--- a/src/syscall/asm_darwin_amd64.s
+++ b/src/syscall/asm_darwin_amd64.s
@@ -17,9 +17,6 @@
MOVQ a1+8(FP), DI
MOVQ a2+16(FP), SI
MOVQ a3+24(FP), DX
- MOVQ $0, R10
- MOVQ $0, R8
- MOVQ $0, R9
MOVQ trap+0(FP), AX // syscall entry
ADDQ $0x2000000, AX
SYSCALL
@@ -100,9 +97,6 @@
MOVQ a1+8(FP), DI
MOVQ a2+16(FP), SI
MOVQ a3+24(FP), DX
- MOVQ $0, R10
- MOVQ $0, R8
- MOVQ $0, R9
MOVQ trap+0(FP), AX // syscall entry
ADDQ $0x2000000, AX
SYSCALL
diff --git a/src/syscall/asm_linux_amd64.s b/src/syscall/asm_linux_amd64.s
index 364815d..2c337433 100644
--- a/src/syscall/asm_linux_amd64.s
+++ b/src/syscall/asm_linux_amd64.s
@@ -19,9 +19,6 @@
MOVQ a1+8(FP), DI
MOVQ a2+16(FP), SI
MOVQ a3+24(FP), DX
- MOVQ $0, R10
- MOVQ $0, R8
- MOVQ $0, R9
MOVQ trap+0(FP), AX // syscall entry
SYSCALL
CMPQ AX, $0xfffffffffffff001
@@ -70,9 +67,6 @@
MOVQ a1+8(FP), DI
MOVQ a2+16(FP), SI
MOVQ a3+24(FP), DX
- MOVQ $0, R10
- MOVQ $0, R8
- MOVQ $0, R9
MOVQ trap+0(FP), AX // syscall entry
SYSCALL
CMPQ AX, $0xfffffffffffff001
@@ -139,9 +133,6 @@
MOVQ a1+8(FP), DI
MOVQ a2+16(FP), SI
MOVQ a3+24(FP), DX
- MOVQ $0, R10
- MOVQ $0, R8
- MOVQ $0, R9
MOVQ trap+0(FP), AX // syscall entry
SYSCALL
MOVQ AX, r1+32(FP)
diff --git a/src/syscall/asm_unix_amd64.s b/src/syscall/asm_unix_amd64.s
index 025408f..9cf3fe0 100644
--- a/src/syscall/asm_unix_amd64.s
+++ b/src/syscall/asm_unix_amd64.s
@@ -21,9 +21,6 @@
MOVQ a1+8(FP), DI
MOVQ a2+16(FP), SI
MOVQ a3+24(FP), DX
- MOVQ $0, R10
- MOVQ $0, R8
- MOVQ $0, R9
SYSCALL
JCC ok
MOVQ $-1, r1+32(FP) // r1
@@ -65,9 +62,6 @@
MOVQ a1+8(FP), DI
MOVQ a2+16(FP), SI
MOVQ a3+24(FP), DX
- MOVQ $0, R10
- MOVQ $0, R8
- MOVQ $0, R9
MOVQ trap+0(FP), AX // syscall entry
SYSCALL
JCC ok1
