Browse Source

compiler: extract inline asm builtins into separate file

This commit refactors the compiler a bit to have all inline assembly in
a separate file.
pull/289/head
Ayke van Laethem 6 years ago
committed by Ron Evans
parent
commit
0739775719
  1. 122
      compiler/compiler.go
  2. 162
      compiler/inlineasm.go

122
compiler/compiler.go

@ -9,7 +9,6 @@ import (
"go/types"
"os"
"path/filepath"
"regexp"
"runtime"
"strconv"
"strings"
@ -1342,120 +1341,15 @@ func (c *Compiler) parseCall(frame *Frame, instr *ssa.CallCommon) (llvm.Value, e
// Try to call the function directly for trivially static calls.
if fn := instr.StaticCallee(); fn != nil {
if fn.RelString(nil) == "device/arm.Asm" || fn.RelString(nil) == "device/avr.Asm" {
// Magic function: insert inline assembly instead of calling it.
fnType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{}, false)
asm := constant.StringVal(instr.Args[0].(*ssa.Const).Value)
target := llvm.InlineAsm(fnType, asm, "", true, false, 0)
return c.builder.CreateCall(target, nil, ""), nil
}
if fn.RelString(nil) == "device/arm.ReadRegister" {
// Magic function: return the given register.
fnType := llvm.FunctionType(c.uintptrType, []llvm.Type{}, false)
regname := constant.StringVal(instr.Args[0].(*ssa.Const).Value)
target := llvm.InlineAsm(fnType, "mov $0, "+regname, "=r", false, false, 0)
return c.builder.CreateCall(target, nil, ""), nil
}
if strings.HasPrefix(fn.RelString(nil), "device/arm.SVCall") {
// Magic function: inline this call as a SVC instruction.
num, _ := constant.Uint64Val(instr.Args[0].(*ssa.Const).Value)
args := []llvm.Value{}
argTypes := []llvm.Type{}
asm := "svc #" + strconv.FormatUint(num, 10)
constraints := "={r0}"
for i, arg := range instr.Args[1:] {
arg = arg.(*ssa.MakeInterface).X
if i == 0 {
constraints += ",0"
} else {
constraints += ",{r" + strconv.Itoa(i) + "}"
}
llvmValue, err := c.parseExpr(frame, arg)
if err != nil {
return llvm.Value{}, err
}
args = append(args, llvmValue)
argTypes = append(argTypes, llvmValue.Type())
}
// Implement the ARM calling convention by marking r1-r3 as
// clobbered. r0 is used as an output register so doesn't have to be
// marked as clobbered.
constraints += ",~{r1},~{r2},~{r3}"
fnType := llvm.FunctionType(c.uintptrType, argTypes, false)
target := llvm.InlineAsm(fnType, asm, constraints, true, false, 0)
return c.builder.CreateCall(target, args, ""), nil
}
if fn.RelString(nil) == "device/arm.AsmFull" || fn.RelString(nil) == "device/avr.AsmFull" {
asmString := constant.StringVal(instr.Args[0].(*ssa.Const).Value)
registers := map[string]llvm.Value{}
registerMap := instr.Args[1].(*ssa.MakeMap)
for _, r := range *registerMap.Referrers() {
switch r := r.(type) {
case *ssa.DebugRef:
// ignore
case *ssa.MapUpdate:
if r.Block() != registerMap.Block() {
return llvm.Value{}, c.makeError(instr.Pos(), "register value map must be created in the same basic block")
}
key := constant.StringVal(r.Key.(*ssa.Const).Value)
//println("value:", r.Value.(*ssa.MakeInterface).X.String())
value, err := c.parseExpr(frame, r.Value.(*ssa.MakeInterface).X)
if err != nil {
return llvm.Value{}, err
}
registers[key] = value
case *ssa.Call:
if r.Common() == instr {
break
}
default:
return llvm.Value{}, c.makeError(instr.Pos(), "don't know how to handle argument to inline assembly: "+r.String())
}
}
// TODO: handle dollar signs in asm string
registerNumbers := map[string]int{}
var err error
argTypes := []llvm.Type{}
args := []llvm.Value{}
constraints := []string{}
asmString = regexp.MustCompile("\\{[a-zA-Z]+\\}").ReplaceAllStringFunc(asmString, func(s string) string {
// TODO: skip strings like {r4} etc. that look like ARM push/pop
// instructions.
name := s[1 : len(s)-1]
if _, ok := registers[name]; !ok {
if err == nil {
err = c.makeError(instr.Pos(), "unknown register name: "+name)
}
return s
}
if _, ok := registerNumbers[name]; !ok {
registerNumbers[name] = len(registerNumbers)
argTypes = append(argTypes, registers[name].Type())
args = append(args, registers[name])
switch registers[name].Type().TypeKind() {
case llvm.IntegerTypeKind:
constraints = append(constraints, "r")
case llvm.PointerTypeKind:
constraints = append(constraints, "*m")
default:
err = c.makeError(instr.Pos(), "unknown type in inline assembly for value: "+name)
return s
}
}
return fmt.Sprintf("${%v}", registerNumbers[name])
})
if err != nil {
return llvm.Value{}, err
}
fnType := llvm.FunctionType(c.ctx.VoidType(), argTypes, false)
target := llvm.InlineAsm(fnType, asmString, strings.Join(constraints, ","), true, false, 0)
return c.builder.CreateCall(target, args, ""), nil
}
switch fn.RelString(nil) {
case "device/arm.ReadRegister":
return c.emitReadRegister(instr.Args)
case "device/arm.Asm", "device/avr.Asm":
return c.emitAsm(instr.Args)
case "device/arm.AsmFull", "device/avr.AsmFull":
return c.emitAsmFull(frame, instr)
case "device/arm.SVCall0", "device/arm.SVCall1", "device/arm.SVCall2", "device/arm.SVCall3", "device/arm.SVCall4":
return c.emitSVCall(frame, instr.Args)
case "syscall.Syscall", "syscall.Syscall6", "syscall.Syscall9":
return c.emitSyscall(frame, instr)
}

162
compiler/inlineasm.go

@ -0,0 +1,162 @@
package compiler
// This file implements inline asm support by calling special functions.
import (
"fmt"
"go/constant"
"regexp"
"strconv"
"strings"
"golang.org/x/tools/go/ssa"
"tinygo.org/x/go-llvm"
)
// This is a compiler builtin, which reads the given register by name:
//
// func ReadRegister(name string) uintptr
//
// The register name must be a constant, for example "sp".
func (c *Compiler) emitReadRegister(args []ssa.Value) (llvm.Value, error) {
fnType := llvm.FunctionType(c.uintptrType, []llvm.Type{}, false)
regname := constant.StringVal(args[0].(*ssa.Const).Value)
target := llvm.InlineAsm(fnType, "mov $0, "+regname, "=r", false, false, 0)
return c.builder.CreateCall(target, nil, ""), nil
}
// This is a compiler builtin, which emits a piece of inline assembly with no
// operands or return values. It is useful for trivial instructions, like wfi in
// ARM or sleep in AVR.
//
// func Asm(asm string)
//
// The provided assembly must be a constant.
func (c *Compiler) emitAsm(args []ssa.Value) (llvm.Value, error) {
// Magic function: insert inline assembly instead of calling it.
fnType := llvm.FunctionType(c.ctx.VoidType(), []llvm.Type{}, false)
asm := constant.StringVal(args[0].(*ssa.Const).Value)
target := llvm.InlineAsm(fnType, asm, "", true, false, 0)
return c.builder.CreateCall(target, nil, ""), nil
}
// This is a compiler builtin, which allows assembly to be called in a flexible
// way.
//
// func AsmFull(asm string, regs map[string]interface{})
//
// The asm parameter must be a constant string. The regs parameter must be
// provided immediately. For example:
//
// arm.AsmFull(
// "str {value}, {result}",
// map[string]interface{}{
// "value": 1
// "result": &dest,
// })
func (c *Compiler) emitAsmFull(frame *Frame, instr *ssa.CallCommon) (llvm.Value, error) {
asmString := constant.StringVal(instr.Args[0].(*ssa.Const).Value)
registers := map[string]llvm.Value{}
registerMap := instr.Args[1].(*ssa.MakeMap)
for _, r := range *registerMap.Referrers() {
switch r := r.(type) {
case *ssa.DebugRef:
// ignore
case *ssa.MapUpdate:
if r.Block() != registerMap.Block() {
return llvm.Value{}, c.makeError(instr.Pos(), "register value map must be created in the same basic block")
}
key := constant.StringVal(r.Key.(*ssa.Const).Value)
//println("value:", r.Value.(*ssa.MakeInterface).X.String())
value, err := c.parseExpr(frame, r.Value.(*ssa.MakeInterface).X)
if err != nil {
return llvm.Value{}, err
}
registers[key] = value
case *ssa.Call:
if r.Common() == instr {
break
}
default:
return llvm.Value{}, c.makeError(instr.Pos(), "don't know how to handle argument to inline assembly: "+r.String())
}
}
// TODO: handle dollar signs in asm string
registerNumbers := map[string]int{}
var err error
argTypes := []llvm.Type{}
args := []llvm.Value{}
constraints := []string{}
asmString = regexp.MustCompile("\\{[a-zA-Z]+\\}").ReplaceAllStringFunc(asmString, func(s string) string {
// TODO: skip strings like {r4} etc. that look like ARM push/pop
// instructions.
name := s[1 : len(s)-1]
if _, ok := registers[name]; !ok {
if err == nil {
err = c.makeError(instr.Pos(), "unknown register name: "+name)
}
return s
}
if _, ok := registerNumbers[name]; !ok {
registerNumbers[name] = len(registerNumbers)
argTypes = append(argTypes, registers[name].Type())
args = append(args, registers[name])
switch registers[name].Type().TypeKind() {
case llvm.IntegerTypeKind:
constraints = append(constraints, "r")
case llvm.PointerTypeKind:
constraints = append(constraints, "*m")
default:
err = c.makeError(instr.Pos(), "unknown type in inline assembly for value: "+name)
return s
}
}
return fmt.Sprintf("${%v}", registerNumbers[name])
})
if err != nil {
return llvm.Value{}, err
}
fnType := llvm.FunctionType(c.ctx.VoidType(), argTypes, false)
target := llvm.InlineAsm(fnType, asmString, strings.Join(constraints, ","), true, false, 0)
return c.builder.CreateCall(target, args, ""), nil
}
// This is a compiler builtin which emits an inline SVCall instruction. It can
// be one of:
//
// func SVCall0(num uintptr) uintptr
// func SVCall1(num uintptr, a1 interface{}) uintptr
// func SVCall2(num uintptr, a1, a2 interface{}) uintptr
// func SVCall3(num uintptr, a1, a2, a3 interface{}) uintptr
// func SVCall4(num uintptr, a1, a2, a3, a4 interface{}) uintptr
//
// The num parameter must be a constant. All other parameters may be any scalar
// value supported by LLVM inline assembly.
func (c *Compiler) emitSVCall(frame *Frame, args []ssa.Value) (llvm.Value, error) {
num, _ := constant.Uint64Val(args[0].(*ssa.Const).Value)
llvmArgs := []llvm.Value{}
argTypes := []llvm.Type{}
asm := "svc #" + strconv.FormatUint(num, 10)
constraints := "={r0}"
for i, arg := range args[1:] {
arg = arg.(*ssa.MakeInterface).X
if i == 0 {
constraints += ",0"
} else {
constraints += ",{r" + strconv.Itoa(i) + "}"
}
llvmValue, err := c.parseExpr(frame, arg)
if err != nil {
return llvm.Value{}, err
}
llvmArgs = append(llvmArgs, llvmValue)
argTypes = append(argTypes, llvmValue.Type())
}
// Implement the ARM calling convention by marking r1-r3 as
// clobbered. r0 is used as an output register so doesn't have to be
// marked as clobbered.
constraints += ",~{r1},~{r2},~{r3}"
fnType := llvm.FunctionType(c.uintptrType, argTypes, false)
target := llvm.InlineAsm(fnType, asm, constraints, true, false, 0)
return c.builder.CreateCall(target, llvmArgs, ""), nil
}
Loading…
Cancel
Save