syscall: mksyscall_mingw.sh emitting shorter calls (to Syscall or Syscall6)...

syscall: mksyscall_mingw.sh emitting shorter calls (to Syscall or Syscall6) when there are fewer arguments

R=rsc
CC=golang-dev
https://golang.org/cl/622041

src/pkg/runtime/mingw/syscall.cgo

@@ -6,18 +6,6 @@ package syscall
 #include "runtime.h"
 #include "os.h"
 
-static uintptr
-stdcallerr(uintptr *lasterr, uintptr trap, uintptr a1, uintptr a2, uintptr a3, uintptr a4, uintptr a5, uintptr a6, uintptr a7, uintptr a8, uintptr a9)
-{
-	uintptr r;
-
-	·entersyscall();
-	r = (uintptr)stdcall_raw((void*)trap, a1, a2, a3, a4, a5, a6, a7, a8, a9);
-	*lasterr = (uintptr)stdcall_raw(GetLastError);
-	·exitsyscall();
-	return r;
-}
-
 func loadlibraryex(filename uintptr) (handle uint32) {
 	handle = (uint32)stdcall(LoadLibraryEx, filename, 0, 0);
 }
@@ -27,18 +15,27 @@ func getprocaddress(handle uint32, procname uintptr) (proc uintptr) {
 }
 
 func Syscall(trap uintptr, a1 uintptr, a2 uintptr, a3 uintptr) (r1 uintptr, r2 uintptr, err uintptr) {
-	r1 = stdcallerr(&err, trap, a1, a2, a3, 0, 0, 0, 0, 0, 0);
+	·entersyscall();
+	r1 = (uintptr)stdcall_raw((void*)trap, a1, a2, a3);
 	r2 = 0;
+	err = (uintptr)stdcall_raw(GetLastError);
+	·exitsyscall();
 }
 
 func Syscall6(trap uintptr, a1 uintptr, a2 uintptr, a3 uintptr, a4 uintptr, a5 uintptr, a6 uintptr) (r1 uintptr, r2 uintptr, err uintptr) {
-	r1 = stdcallerr(&err, trap, a1, a2, a3, a4, a5, a6, 0, 0, 0);
+	·entersyscall();
+	r1 = (uintptr)stdcall_raw((void*)trap, a1, a2, a3, a4, a5, a6);
 	r2 = 0;
+	err = (uintptr)stdcall_raw(GetLastError);
+	·exitsyscall();
 }
 
 func Syscall9(trap uintptr, a1 uintptr, a2 uintptr, a3 uintptr, a4 uintptr, a5 uintptr, a6 uintptr, a7 uintptr, a8 uintptr, a9 uintptr) (r1 uintptr, r2 uintptr, lasterr uintptr) {
-	r1 = stdcallerr(&lasterr, trap, a1, a2, a3, a4, a5, a6, a7, a8, a9);
+	·entersyscall();
+	r1 = (uintptr)stdcall_raw((void*)trap, a1, a2, a3, a4, a5, a6, a7, a8, a9);
 	r2 = 0;
+	lasterr = (uintptr)stdcall_raw(GetLastError);
+	·exitsyscall();
 }
 
 func RawSyscall(trap uintptr, a1 uintptr, a2 uintptr, a3 uintptr) (r1 uintptr, r2 uintptr, err uintptr) {

src/pkg/syscall/mksyscall_mingw.sh

@@ -109,7 +109,7 @@ while(<>) {
 	# Go function header.
 	$text .= sprintf "func %s(%s) (%s) {\n", $func, join(', ', @in), join(', ', @out);
 
-	# Prepare arguments to Syscall9.
+	# Prepare arguments to Syscall.
 	my @args = ();
 	my $n = 0;
 	foreach my $p (@in) {
@@ -138,8 +138,18 @@ while(<>) {
 	}
 
 	# Determine which form to use; pad args with zeros.
-	my $asm = "Syscall9";
-	if(@args <= 9) {
+	my $asm = "Syscall";
+	if(@args <= 3) {
+		while(@args < 3) {
+			push @args, "0";
+		}
+	} elsif(@args <= 6) {
+		$asm = "Syscall6";
+		while(@args < 6) {
+			push @args, "0";
+		}
+	} elsif(@args <= 9) {
+		$asm = "Syscall9";
 		while(@args < 9) {
 			push @args, "0";
 		}

src/pkg/syscall/zsyscall_mingw_386.go

@@ -16,13 +16,13 @@ var (
 )
 
 func GetLastError() (lasterrno int) {
-	r0, _, _ := Syscall9(procGetLastError, 0, 0, 0, 0, 0, 0, 0, 0, 0)
+	r0, _, _ := Syscall(procGetLastError, 0, 0, 0)
 	lasterrno = int(r0)
 	return
 }
 
 func LoadLibrary(libname string) (handle uint32, errno int) {
-	r0, _, e1 := Syscall9(procLoadLibraryW, uintptr(unsafe.Pointer(StringToUTF16Ptr(libname))), 0, 0, 0, 0, 0, 0, 0, 0)
+	r0, _, e1 := Syscall(procLoadLibraryW, uintptr(unsafe.Pointer(StringToUTF16Ptr(libname))), 0, 0)
 	handle = uint32(r0)
 	if uint32(r0) == 0 {
 		errno = int(e1)
@@ -33,7 +33,7 @@ func LoadLibrary(libname string) (handle uint32, errno int) {
 }
 
 func FreeLibrary(handle uint32) (ok bool, errno int) {
-	r0, _, e1 := Syscall9(procFreeLibrary, uintptr(handle), 0, 0, 0, 0, 0, 0, 0, 0)
+	r0, _, e1 := Syscall(procFreeLibrary, uintptr(handle), 0, 0)
 	ok = bool(r0 != 0)
 	if uint32(r0) == 0 {
 		errno = int(e1)
@@ -44,7 +44,7 @@ func FreeLibrary(handle uint32) (ok bool, errno int) {
 }
 
 func GetProcAddress(module uint32, procname string) (proc uint32, errno int) {
-	r0, _, e1 := Syscall9(procGetProcAddress, uintptr(module), uintptr(unsafe.Pointer(StringBytePtr(procname))), 0, 0, 0, 0, 0, 0, 0)
+	r0, _, e1 := Syscall(procGetProcAddress, uintptr(module), uintptr(unsafe.Pointer(StringBytePtr(procname))), 0)
 	proc = uint32(r0)
 	if uint32(r0) == 0 {
 		errno = int(e1)
@@ -55,7 +55,7 @@ func GetProcAddress(module uint32, procname string) (proc uint32, errno int) {
 }
 
 func GetVersion() (ver uint32, errno int) {
-	r0, _, e1 := Syscall9(procGetVersion, 0, 0, 0, 0, 0, 0, 0, 0, 0)
+	r0, _, e1 := Syscall(procGetVersion, 0, 0, 0)
 	ver = uint32(r0)
 	if uint32(r0) == 0 {
 		errno = int(e1)