compiler: really define runtime/volatile.* functions

This makes them available to deferred calls, among others.

Author: aykevl

compiler/compiler.go

@@ -1642,10 +1642,6 @@ func (b *builder) createFunctionCall(instr *ssa.CallCommon) (llvm.Value, error)
 			return b.createSyscall(instr)
 		case strings.HasPrefix(name, "syscall.rawSyscallNoError"):
 			return b.createRawSyscallNoError(instr)
-		case strings.HasPrefix(name, "runtime/volatile.Load"):
-			return b.createVolatileLoad(instr)
-		case strings.HasPrefix(name, "runtime/volatile.Store"):
-			return b.createVolatileStore(instr)
 		case name == "runtime.supportsRecover":
 			supportsRecover := uint64(0)
 			if b.supportsRecover() {

compiler/intrinsics.go

@@ -20,6 +20,10 @@ import (
 func (b *builder) defineIntrinsicFunction() {
 	name := b.fn.RelString(nil)
 	switch {
+	case strings.HasPrefix(name, "runtime/volatile.Load"):
+		b.createVolatileLoad()
+	case strings.HasPrefix(name, "runtime/volatile.Store"):
+		b.createVolatileStore()
 	case strings.HasPrefix(name, "sync/atomic.") && token.IsExported(b.fn.Name()):
 		b.createFunctionStart()
 		returnValue := b.createAtomicOp(b.fn.Name())

compiler/volatile.go

@@ -3,28 +3,25 @@ package compiler
 // This file implements volatile loads/stores in runtime/volatile.LoadT and
 // runtime/volatile.StoreT as compiler builtins.
 
-import (
-	"golang.org/x/tools/go/ssa"
-	"tinygo.org/x/go-llvm"
-)
-
 // createVolatileLoad is the implementation of the intrinsic function
 // runtime/volatile.LoadT().
-func (b *builder) createVolatileLoad(instr *ssa.CallCommon) (llvm.Value, error) {
-	addr := b.getValue(instr.Args[0])
-	b.createNilCheck(instr.Args[0], addr, "deref")
+func (b *builder) createVolatileLoad() {
+	b.createFunctionStart()
+	addr := b.getValue(b.fn.Params[0])
+	b.createNilCheck(b.fn.Params[0], addr, "deref")
 	val := b.CreateLoad(addr, "")
 	val.SetVolatile(true)
-	return val, nil
+	b.CreateRet(val)
 }
 
 // createVolatileStore is the implementation of the intrinsic function
 // runtime/volatile.StoreT().
-func (b *builder) createVolatileStore(instr *ssa.CallCommon) (llvm.Value, error) {
-	addr := b.getValue(instr.Args[0])
-	val := b.getValue(instr.Args[1])
-	b.createNilCheck(instr.Args[0], addr, "deref")
+func (b *builder) createVolatileStore() {
+	b.createFunctionStart()
+	addr := b.getValue(b.fn.Params[0])
+	val := b.getValue(b.fn.Params[1])
+	b.createNilCheck(b.fn.Params[0], addr, "deref")
 	store := b.CreateStore(val, addr)
 	store.SetVolatile(true)
-	return llvm.Value{}, nil
+	b.CreateRetVoid()
 }

testdata/atomic.go

@@ -3,6 +3,8 @@ package main
 import (
 	"sync/atomic"
 	"unsafe"
+
+	"runtime/volatile"
 )
 
 func main() {
@@ -82,7 +84,7 @@ func main() {
 	testValue(int(3), int(-2))
 	testValue("", "foobar", "baz")
 
-	// Test atomic operations as deferred values.
+	// Test atomic and volatile operations as deferred values.
 	testDefer()
 }
 
@@ -99,8 +101,11 @@ func testValue(values ...interface{}) {
 
 func testDefer() {
 	n1 := int32(5)
+	n2 := uint32(6)
 	defer func() {
 		println("deferred atomic add:", n1)
+		println("deferred volatile store:", n2)
 	}()
 	defer atomic.AddInt32(&n1, 3)
+	defer volatile.StoreUint32(&n2, 22)
 }

testdata/atomic.txt

@@ -34,3 +34,4 @@ StoreUint64: 20
 StoreUintptr: 20
 StorePointer: true
 deferred atomic add: 8
+deferred volatile store: 22