Restore optimization that merges blocks when inline function

has single return value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48162 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Devang Patel 2008-03-10 18:34:00 +00:00
parent 641ca93cff
commit b8f198af1b

View File

@ -522,13 +522,14 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
// Handle all of the return instructions that we just cloned in, and eliminate
// any users of the original call/invoke instruction.
if (!Returns.empty()) {
const Type *RTy = CalledFunc->getReturnType();
const StructType *STy = dyn_cast<StructType>(RTy);
if (Returns.size() > 1 || STy) {
// The PHI node should go at the front of the new basic block to merge all
// possible incoming values.
SmallVector<PHINode *, 4> PHIs;
if (!TheCall->use_empty()) {
const Type *RTy = CalledFunc->getReturnType();
if (const StructType *STy = dyn_cast<StructType>(RTy)) {
if (STy) {
unsigned NumRetVals = STy->getNumElements();
// Create new phi nodes such that phi node number in the PHIs vector
// match corresponding return value operand number.
@ -557,10 +558,9 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
// Loop over all of the return instructions adding entries to the PHI node as
// appropriate.
if (!PHIs.empty()) {
const Type *RTy = CalledFunc->getReturnType();
// There is atleast one return value.
unsigned NumRetVals = 1;
if (const StructType *STy = dyn_cast<StructType>(RTy))
if (STy)
NumRetVals = STy->getNumElements();
for (unsigned j = 0; j < NumRetVals; ++j) {
PHINode *PHI = PHIs[j];
@ -579,8 +579,26 @@ bool llvm::InlineFunction(CallSite CS, CallGraph *CG, const TargetData *TD) {
for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
ReturnInst *RI = Returns[i];
new BranchInst(AfterCallBB, RI);
RI->getParent()->getInstList().erase(RI);
RI->eraseFromParent();
}
} else if (!Returns.empty()) {
// Otherwise, if there is exactly one return value, just replace anything
// using the return value of the call with the computed value.
if (!TheCall->use_empty())
TheCall->replaceAllUsesWith(Returns[0]->getReturnValue());
// Splice the code from the return block into the block that it will return
// to, which contains the code that was after the call.
BasicBlock *ReturnBB = Returns[0]->getParent();
AfterCallBB->getInstList().splice(AfterCallBB->begin(),
ReturnBB->getInstList());
// Update PHI nodes that use the ReturnBB to use the AfterCallBB.
ReturnBB->replaceAllUsesWith(AfterCallBB);
// Delete the return instruction now and empty ReturnBB now.
Returns[0]->eraseFromParent();
ReturnBB->eraseFromParent();
} else if (!TheCall->use_empty()) {
// No returns, but something is using the return value of the call. Just
// nuke the result.