ssa: TestIf

ssa/stmt_builder.go

@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2024 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ssa
+
+import (
+	"github.com/goplus/llvm"
+)
+
+// -----------------------------------------------------------------------------
+
+type aBasicBlock struct {
+	impl llvm.BasicBlock
+	fn   Function
+	idx  int
+}
+
+// BasicBlock represents a basic block in a function.
+type BasicBlock = *aBasicBlock
+
+// Parent returns the function to which the basic block belongs.
+func (p BasicBlock) Parent() Function {
+	return p.fn
+}
+
+// Index returns the index of the basic block in the parent function.
+func (p BasicBlock) Index() int {
+	return p.idx
+}
+
+// -----------------------------------------------------------------------------
+
+type aBuilder struct {
+	impl llvm.Builder
+	fn   Function
+	prog Program
+}
+
+// Builder represents a builder for creating instructions in a function.
+type Builder = *aBuilder
+
+// SetBlock sets the current block to the specified basic block.
+func (b Builder) SetBlock(blk BasicBlock) Builder {
+	if b.fn != blk.fn {
+		panic("mismatched function")
+	}
+	b.impl.SetInsertPointAtEnd(blk.impl)
+	return b
+}
+
+// Return emits a return instruction.
+func (b Builder) Return(results ...Expr) {
+	switch n := len(results); n {
+	case 0:
+		b.impl.CreateRetVoid()
+	case 1:
+		b.impl.CreateRet(results[0].impl)
+	default:
+		b.impl.CreateAggregateRet(llvmValues(results))
+	}
+}
+
+// If emits an if instruction.
+func (b Builder) If(cond Expr, thenb, elseb BasicBlock) {
+	if b.fn != thenb.fn || b.fn != elseb.fn {
+		panic("mismatched function")
+	}
+	b.impl.CreateCondBr(cond.impl, thenb.impl, elseb.impl)
+}
+
+// -----------------------------------------------------------------------------