Improved Windows x86-64 ABI support

src/asm/Instruction.go

@@ -25,6 +25,9 @@ type CallExtern struct {
 	Function string
 }
 
+type CallExternStart struct{}
+type CallExternEnd struct{}
+
 type FunctionStart struct{}
 type FunctionEnd struct{}
 
@@ -51,6 +54,10 @@ type MoveRegisterRegister struct {
 	Source      cpu.Register
 }
 
+type PushRegister struct {
+	Register cpu.Register
+}
+
 type Return struct{}
 
 type SubRegisterNumber struct {

src/asm/compilerARM.go

@@ -32,6 +32,12 @@ func (c *compilerARM) Compile(instr Instruction) {
 			offset := (address - start) / 4
 			binary.LittleEndian.PutUint32(c.code[start:start+4], arm.Call(offset))
 		})
+	case *CallExtern:
+		panic("not implemented")
+	case *CallExternStart:
+		panic("not implemented")
+	case *CallExternEnd:
+		panic("not implemented")
 	case *Jump:
 		start := len(c.code)
 		c.append(arm.Jump(0))
@@ -76,6 +82,8 @@ func (c *compilerARM) Compile(instr Instruction) {
 		c.code = arm.MoveRegisterNumber(c.code, instr.Destination, instr.Number)
 	case *MoveRegisterRegister:
 		c.append(arm.MoveRegisterRegister(instr.Destination, instr.Source))
+	case *PushRegister:
+		panic("not implemented")
 	case *Return:
 		c.append(arm.Return())
 	case *Syscall:

src/asm/compilerX86.go

@@ -41,12 +41,8 @@ func (c *compilerX86) Compile(instr Instruction) {
 			binary.LittleEndian.PutUint32(c.code[end-4:end], uint32(offset))
 		})
 	case *CallExtern:
-		c.code = x86.MoveRegisterRegister(c.code, x86.R5, x86.SP)
-		c.code = x86.AndRegisterNumber(c.code, x86.SP, -16)
-		c.code = x86.SubRegisterNumber(c.code, x86.SP, 32)
 		c.code = x86.CallAt(c.code, 0)
 		end := len(c.code)
-		c.code = x86.MoveRegisterRegister(c.code, x86.SP, x86.R5)
 
 		c.Defer(func() {
 			index := c.libraries.Index(instr.Library, instr.Function)
@@ -59,6 +55,12 @@ func (c *compilerX86) Compile(instr Instruction) {
 			offset := address - end
 			binary.LittleEndian.PutUint32(c.code[end-4:end], uint32(offset))
 		})
+	case *CallExternStart:
+		c.code = x86.MoveRegisterRegister(c.code, x86.R5, x86.SP)
+		c.code = x86.AndRegisterNumber(c.code, x86.SP, -16)
+		c.code = x86.SubRegisterNumber(c.code, x86.SP, 32)
+	case *CallExternEnd:
+		c.code = x86.MoveRegisterRegister(c.code, x86.SP, x86.R5)
 	case *FunctionStart:
 	case *FunctionEnd:
 	case *Jump:
@@ -100,6 +102,8 @@ func (c *compilerX86) Compile(instr Instruction) {
 		c.code = x86.MoveRegisterNumber(c.code, instr.Destination, instr.Number)
 	case *MoveRegisterRegister:
 		c.code = x86.MoveRegisterRegister(c.code, instr.Destination, instr.Source)
+	case *PushRegister:
+		c.code = x86.PushRegister(c.code, instr.Register)
 	case *Return:
 		c.code = x86.Return(c.code)
 	case *SubRegisterNumber:

src/ssa2asm/CreateSteps.go

@@ -41,6 +41,12 @@ func (f *Compiler) CreateSteps(ir ssa.IR) []Step {
 
 		case *ssa.CallExtern:
 			for r, param := range instr.Arguments[1:] {
+				if r >= len(f.CPU.ExternCall.In) {
+					// Temporary hack to allow arguments 5 and 6 to be hinted as r10 and r11, then pushed later.
+					f.ValueToStep[param].Hint(f.CPU.ExternCall.Volatile[1+r])
+					continue
+				}
+
 				f.ValueToStep[param].Hint(f.CPU.ExternCall.In[r])
 			}
 

src/ssa2asm/Exec.go

@@ -69,10 +69,15 @@ func (f *Compiler) Exec(step *Step) {
 		})
 
 	case *ssa.CallExtern:
+		f.Assembler.Append(&asm.CallExternStart{})
 		args := instr.Arguments[1:]
 
 		for i, arg := range args {
-			if f.ValueToStep[arg].Register != f.CPU.ExternCall.In[i] {
+			if i >= len(f.CPU.ExternCall.In) {
+				f.Assembler.Append(&asm.PushRegister{
+					Register: f.ValueToStep[arg].Register,
+				})
+			} else if f.ValueToStep[arg].Register != f.CPU.ExternCall.In[i] {
 				f.Assembler.Append(&asm.MoveRegisterRegister{
 					Destination: f.CPU.ExternCall.In[i],
 					Source:      f.ValueToStep[arg].Register,
@@ -85,6 +90,7 @@ func (f *Compiler) Exec(step *Step) {
 		library := fn.UniqueName[:dot]
 		function := fn.UniqueName[dot+1:]
 		f.Assembler.Append(&asm.CallExtern{Library: library, Function: function})
+		f.Assembler.Append(&asm.CallExternEnd{})
 
 		if step.Register == -1 || step.Register == f.CPU.ExternCall.Out[0] {
 			return