[PartialInlining] Shrinkwrap allocas with live range contained in outline region.
Differential Revision: http://reviews.llvm.org/D33618
llvm-svn: 304245
diff --git a/llvm/lib/Transforms/Utils/CodeExtractor.cpp b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
index ed72099..24d28a6 100644
--- a/llvm/lib/Transforms/Utils/CodeExtractor.cpp
+++ b/llvm/lib/Transforms/Utils/CodeExtractor.cpp
@@ -27,6 +27,7 @@
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MDBuilder.h"
@@ -141,16 +142,77 @@
return false;
}
-void CodeExtractor::findInputsOutputs(ValueSet &Inputs,
- ValueSet &Outputs) const {
+void CodeExtractor::findAllocas(ValueSet &SinkCands) const {
+ Function *Func = (*Blocks.begin())->getParent();
+ for (BasicBlock &BB : *Func) {
+ if (Blocks.count(&BB))
+ continue;
+ for (Instruction &II : BB) {
+ auto *AI = dyn_cast<AllocaInst>(&II);
+ if (!AI)
+ continue;
+
+ // Returns true if matching life time markers are found within
+ // the outlined region.
+ auto GetLifeTimeMarkers = [&](Instruction *Addr) {
+ Instruction *LifeStart = nullptr, *LifeEnd = nullptr;
+ for (User *U : Addr->users()) {
+ if (!definedInRegion(Blocks, U))
+ return false;
+
+ IntrinsicInst *IntrInst = dyn_cast<IntrinsicInst>(U);
+ if (IntrInst) {
+ if (IntrInst->getIntrinsicID() == Intrinsic::lifetime_start)
+ LifeStart = IntrInst;
+ if (IntrInst->getIntrinsicID() == Intrinsic::lifetime_end)
+ LifeEnd = IntrInst;
+ }
+ }
+ return LifeStart && LifeEnd;
+ };
+
+ if (GetLifeTimeMarkers(AI)) {
+ SinkCands.insert(AI);
+ continue;
+ }
+
+ // Follow the bitcast:
+ Instruction *MarkerAddr = nullptr;
+ for (User *U : AI->users()) {
+ if (U->stripPointerCasts() == AI) {
+ Instruction *Bitcast = cast<Instruction>(U);
+ if (GetLifeTimeMarkers(Bitcast)) {
+ MarkerAddr = Bitcast;
+ continue;
+ }
+ }
+ if (!definedInRegion(Blocks, U)) {
+ MarkerAddr = nullptr;
+ break;
+ }
+ }
+ if (MarkerAddr) {
+ if (!definedInRegion(Blocks, MarkerAddr))
+ SinkCands.insert(MarkerAddr);
+ SinkCands.insert(AI);
+ }
+ }
+ }
+}
+
+void CodeExtractor::findInputsOutputs(ValueSet &Inputs, ValueSet &Outputs,
+ const ValueSet &SinkCands) const {
+
for (BasicBlock *BB : Blocks) {
// If a used value is defined outside the region, it's an input. If an
// instruction is used outside the region, it's an output.
for (Instruction &II : *BB) {
for (User::op_iterator OI = II.op_begin(), OE = II.op_end(); OI != OE;
- ++OI)
- if (definedInCaller(Blocks, *OI))
- Inputs.insert(*OI);
+ ++OI) {
+ Value *V = *OI;
+ if (!SinkCands.count(V) && definedInCaller(Blocks, V))
+ Inputs.insert(V);
+ }
for (User *U : II.users())
if (!definedInRegion(Blocks, U)) {
@@ -718,7 +780,7 @@
if (!isEligible())
return nullptr;
- ValueSet inputs, outputs;
+ ValueSet inputs, outputs, SinkingCands;
// Assumption: this is a single-entry code region, and the header is the first
// block in the region.
@@ -757,8 +819,15 @@
"newFuncRoot");
newFuncRoot->getInstList().push_back(BranchInst::Create(header));
+ findAllocas(SinkingCands);
+
// Find inputs to, outputs from the code region.
- findInputsOutputs(inputs, outputs);
+ findInputsOutputs(inputs, outputs, SinkingCands);
+
+ // Now sink all instructions which only have non-phi uses inside the region
+ for (auto *II : SinkingCands)
+ cast<Instruction>(II)->moveBefore(*newFuncRoot,
+ newFuncRoot->getFirstInsertionPt());
// Calculate the exit blocks for the extracted region and the total exit
// weights for each of those blocks.