remove unused registers for x86_64 linux syscalls

Signed-off-by: leongross <leon.gross@9elements.com>
This commit is contained in:
leongross
2024-06-21 13:40:02 +02:00
committed by Ron Evans
parent dd6fa89aa6
commit d33ace7b59
+6 -3
View File
@@ -33,18 +33,17 @@ func (b *builder) createRawSyscall(call *ssa.CallCommon) (llvm.Value, error) {
"{r10}",
"{r8}",
"{r9}",
"{r11}",
"{r12}",
"{r13}",
}[i]
llvmValue := b.getValue(arg, getPos(call))
args = append(args, llvmValue)
argTypes = append(argTypes, llvmValue.Type())
}
// rcx and r11 are clobbered by the syscall, so make sure they are not used
constraints += ",~{rcx},~{r11}"
fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
target := llvm.InlineAsm(fnType, "syscall", constraints, true, false, llvm.InlineAsmDialectIntel, false)
return b.CreateCall(fnType, target, args, ""), nil
case b.GOARCH == "386" && b.GOOS == "linux":
// Sources:
// syscall(2) man page
@@ -71,6 +70,7 @@ func (b *builder) createRawSyscall(call *ssa.CallCommon) (llvm.Value, error) {
fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
target := llvm.InlineAsm(fnType, "int 0x80", constraints, true, false, llvm.InlineAsmDialectIntel, false)
return b.CreateCall(fnType, target, args, ""), nil
case b.GOARCH == "arm" && b.GOOS == "linux":
// Implement the EABI system call convention for Linux.
// Source: syscall(2) man page.
@@ -103,6 +103,7 @@ func (b *builder) createRawSyscall(call *ssa.CallCommon) (llvm.Value, error) {
fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
target := llvm.InlineAsm(fnType, "svc #0", constraints, true, false, 0, false)
return b.CreateCall(fnType, target, args, ""), nil
case b.GOARCH == "arm64" && b.GOOS == "linux":
// Source: syscall(2) man page.
args := []llvm.Value{}
@@ -135,6 +136,7 @@ func (b *builder) createRawSyscall(call *ssa.CallCommon) (llvm.Value, error) {
fnType := llvm.FunctionType(b.uintptrType, argTypes, false)
target := llvm.InlineAsm(fnType, "svc #0", constraints, true, false, 0, false)
return b.CreateCall(fnType, target, args, ""), nil
default:
return llvm.Value{}, b.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+b.GOOS+"/"+b.GOARCH)
}
@@ -217,6 +219,7 @@ func (b *builder) createSyscall(call *ssa.CallCommon) (llvm.Value, error) {
retval = b.CreateInsertValue(retval, syscallResult, 0, "")
retval = b.CreateInsertValue(retval, errResult, 2, "")
return retval, nil
default:
return llvm.Value{}, b.makeError(call.Pos(), "unknown GOOS/GOARCH for syscall: "+b.GOOS+"/"+b.GOARCH)
}