llvm-project/llgo/irgen/utils.go

41 lines
1.3 KiB
Go

//===- utils.go - misc utils ----------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements misellaneous utilities for IR generation.
//
//===----------------------------------------------------------------------===//
package irgen
import (
"llvm.org/llgo/third_party/gotools/go/types"
"llvm.org/llvm/bindings/go/llvm"
)
func (fr *frame) loadOrNull(cond, ptr llvm.Value, ty types.Type) *govalue {
startbb := fr.builder.GetInsertBlock()
loadbb := llvm.AddBasicBlock(fr.function, "")
contbb := llvm.AddBasicBlock(fr.function, "")
fr.builder.CreateCondBr(cond, loadbb, contbb)
fr.builder.SetInsertPointAtEnd(loadbb)
llty := fr.types.ToLLVM(ty)
typedptr := fr.builder.CreateBitCast(ptr, llvm.PointerType(llty, 0), "")
loadedval := fr.builder.CreateLoad(typedptr, "")
fr.builder.CreateBr(contbb)
fr.builder.SetInsertPointAtEnd(contbb)
llv := fr.builder.CreatePHI(llty, "")
llv.AddIncoming(
[]llvm.Value{llvm.ConstNull(llty), loadedval},
[]llvm.BasicBlock{startbb, loadbb},
)
return newValue(llv, ty)
}