code review 124390043: go.sys/unix: just jump to syscall.Syscall etc.

unix/asm_dragonfly_386.s

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 #include "textflag.h"
 
 //
 // System call support for 386, FreeBSD
 //
 
-// func Syscall(trap int32, a1, a2, a3 int32) (r1, r2, err int32);
-// func Syscall6(trap int32, a1, a2, a3, a4, a5, a6 int32) (r1, r2, err int32);
-// Trap # in AX, args on stack above caller pc.
+// Just jump to package syscall's implementation for all these functions.
+// The runtime may know about them.
 
 TEXT    ·Syscall(SB),NOSPLIT,$0-32
-        CALL    runtime·entersyscall(SB)
-        MOVL    4(SP), AX       // syscall entry
-        // slide args down on top of system call number
-        LEAL            8(SP), SI
-        LEAL            4(SP), DI
-        CLD
-        MOVSL
-        MOVSL
-        MOVSL
-        INT     $0x80
-        JAE     ok
-        MOVL    $-1, 20(SP)     // r1
-        MOVL    $-1, 24(SP)     // r2
-        MOVL    AX, 28(SP)              // errno
-        CALL    runtime·exitsyscall(SB)
-        RET
-ok:
-        MOVL    AX, 20(SP)      // r1
-        MOVL    DX, 24(SP)      // r2
-        MOVL    $0, 28(SP)      // errno
-        CALL    runtime·exitsyscall(SB)
-        RET
+        JMP     syscall·Syscall(SB)
 
 TEXT    ·Syscall6(SB),NOSPLIT,$0-44
-        CALL    runtime·entersyscall(SB)
-        MOVL    4(SP), AX       // syscall entry
-        // slide args down on top of system call number
-        LEAL            8(SP), SI
-        LEAL            4(SP), DI
-        CLD
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        INT     $0x80
-        JAE     ok6
-        MOVL    $-1, 32(SP)     // r1
-        MOVL    $-1, 36(SP)     // r2
-        MOVL    AX, 40(SP)              // errno
-        CALL    runtime·exitsyscall(SB)
-        RET
-ok6:
-        MOVL    AX, 32(SP)      // r1
-        MOVL    DX, 36(SP)      // r2
-        MOVL    $0, 40(SP)      // errno
-        CALL    runtime·exitsyscall(SB)
-        RET
+        JMP     syscall·Syscall6(SB)
 
 TEXT    ·Syscall9(SB),NOSPLIT,$0-56
-        CALL    runtime·entersyscall(SB)
-        MOVL    4(SP), AX       // syscall entry
-        // slide args down on top of system call number
-        LEAL            8(SP), SI
-        LEAL            4(SP), DI
-        CLD
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        INT     $0x80
-        JAE     ok9
-        MOVL    $-1, 44(SP)     // r1
-        MOVL    $-1, 48(SP)     // r2
-        MOVL    AX, 52(SP)              // errno
-        CALL    runtime·exitsyscall(SB)
-        RET
-ok9:
-        MOVL    AX, 44(SP)      // r1
-        MOVL    DX, 48(SP)      // r2
-        MOVL    $0, 52(SP)      // errno
-        CALL    runtime·exitsyscall(SB)
-        RET
+        JMP     syscall·Syscall9(SB)
 
 TEXT ·RawSyscall(SB),NOSPLIT,$0-32
-        MOVL    4(SP), AX       // syscall entry
-        // slide args down on top of system call number
-        LEAL            8(SP), SI
-        LEAL            4(SP), DI
-        CLD
-        MOVSL
-        MOVSL
-        MOVSL
-        INT     $0x80
-        JAE     ok1
-        MOVL    $-1, 20(SP)     // r1
-        MOVL    $-1, 24(SP)     // r2
-        MOVL    AX, 28(SP)              // errno
-        RET
-ok1:
-        MOVL    AX, 20(SP)      // r1
-        MOVL    DX, 24(SP)      // r2
-        MOVL    $0, 28(SP)      // errno
-        RET
+        JMP     syscall·RawSyscall(SB)
 
 TEXT    ·RawSyscall6(SB),NOSPLIT,$0-44
-        MOVL    4(SP), AX       // syscall entry
-        // slide args down on top of system call number
-        LEAL            8(SP), SI
-        LEAL            4(SP), DI
-        CLD
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        MOVSL
-        INT     $0x80
-        JAE     ok2
-        MOVL    $-1, 32(SP)     // r1
-        MOVL    $-1, 36(SP)     // r2
-        MOVL    AX, 40(SP)              // errno
-        RET
-ok2:
-        MOVL    AX, 32(SP)      // r1
-        MOVL    DX, 36(SP)      // r2
-        MOVL    $0, 40(SP)      // errno
-        RET
+        JMP     syscall·RawSyscall6(SB)