[llvm] r371748 - [MemorySSA] Pass (for update) MSSAU when hoisting instructions.
Alina Sbirlea via llvm-commits
llvm-commits at lists.llvm.org
Thu Sep 12 10:12:51 PDT 2019
Author: asbirlea
Date: Thu Sep 12 10:12:51 2019
New Revision: 371748
URL: http://llvm.org/viewvc/llvm-project?rev=371748&view=rev
Log:
[MemorySSA] Pass (for update) MSSAU when hoisting instructions.
Summary: Pass MSSAU to makeLoopInvariant in order to properly update MSSA.
Reviewers: george.burgess.iv
Subscribers: Prazek, sanjoy.google, uabelho, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67470
Added:
llvm/trunk/test/Analysis/MemorySSA/loop-unswitch.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp?rev=371748&r1=371747&r2=371748&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopUnswitch.cpp Thu Sep 12 10:12:51 2019
@@ -420,7 +420,8 @@ enum OperatorChain {
/// cost of creating an entirely new loop.
static Value *FindLIVLoopCondition(Value *Cond, Loop *L, bool &Changed,
OperatorChain &ParentChain,
- DenseMap<Value *, Value *> &Cache) {
+ DenseMap<Value *, Value *> &Cache,
+ MemorySSAUpdater *MSSAU) {
auto CacheIt = Cache.find(Cond);
if (CacheIt != Cache.end())
return CacheIt->second;
@@ -438,7 +439,7 @@ static Value *FindLIVLoopCondition(Value
// TODO: Handle: br (VARIANT|INVARIANT).
// Hoist simple values out.
- if (L->makeLoopInvariant(Cond, Changed)) {
+ if (L->makeLoopInvariant(Cond, Changed, nullptr, MSSAU)) {
Cache[Cond] = Cond;
return Cond;
}
@@ -478,7 +479,7 @@ static Value *FindLIVLoopCondition(Value
// which will cause the branch to go away in one loop and the condition to
// simplify in the other one.
if (Value *LHS = FindLIVLoopCondition(BO->getOperand(0), L, Changed,
- ParentChain, Cache)) {
+ ParentChain, Cache, MSSAU)) {
Cache[Cond] = LHS;
return LHS;
}
@@ -486,7 +487,7 @@ static Value *FindLIVLoopCondition(Value
// operand(1).
ParentChain = NewChain;
if (Value *RHS = FindLIVLoopCondition(BO->getOperand(1), L, Changed,
- ParentChain, Cache)) {
+ ParentChain, Cache, MSSAU)) {
Cache[Cond] = RHS;
return RHS;
}
@@ -500,12 +501,12 @@ static Value *FindLIVLoopCondition(Value
/// Cond is a condition that occurs in L. If it is invariant in the loop, or has
/// an invariant piece, return the invariant along with the operator chain type.
/// Otherwise, return null.
-static std::pair<Value *, OperatorChain> FindLIVLoopCondition(Value *Cond,
- Loop *L,
- bool &Changed) {
+static std::pair<Value *, OperatorChain>
+FindLIVLoopCondition(Value *Cond, Loop *L, bool &Changed,
+ MemorySSAUpdater *MSSAU) {
DenseMap<Value *, Value *> Cache;
OperatorChain OpChain = OC_OpChainNone;
- Value *FCond = FindLIVLoopCondition(Cond, L, Changed, OpChain, Cache);
+ Value *FCond = FindLIVLoopCondition(Cond, L, Changed, OpChain, Cache, MSSAU);
// In case we do find a LIV, it can not be obtained by walking up a mixed
// operator chain.
@@ -694,8 +695,9 @@ bool LoopUnswitch::processCurrentLoop()
}
for (IntrinsicInst *Guard : Guards) {
- Value *LoopCond =
- FindLIVLoopCondition(Guard->getOperand(0), currentLoop, Changed).first;
+ Value *LoopCond = FindLIVLoopCondition(Guard->getOperand(0), currentLoop,
+ Changed, MSSAU.get())
+ .first;
if (LoopCond &&
UnswitchIfProfitable(LoopCond, ConstantInt::getTrue(Context))) {
// NB! Unswitching (if successful) could have erased some of the
@@ -735,8 +737,9 @@ bool LoopUnswitch::processCurrentLoop()
if (BI->isConditional()) {
// See if this, or some part of it, is loop invariant. If so, we can
// unswitch on it if we desire.
- Value *LoopCond = FindLIVLoopCondition(BI->getCondition(),
- currentLoop, Changed).first;
+ Value *LoopCond = FindLIVLoopCondition(BI->getCondition(), currentLoop,
+ Changed, MSSAU.get())
+ .first;
if (LoopCond && !EqualityPropUnSafe(*LoopCond) &&
UnswitchIfProfitable(LoopCond, ConstantInt::getTrue(Context), TI)) {
++NumBranches;
@@ -748,7 +751,7 @@ bool LoopUnswitch::processCurrentLoop()
Value *LoopCond;
OperatorChain OpChain;
std::tie(LoopCond, OpChain) =
- FindLIVLoopCondition(SC, currentLoop, Changed);
+ FindLIVLoopCondition(SC, currentLoop, Changed, MSSAU.get());
unsigned NumCases = SI->getNumCases();
if (LoopCond && NumCases) {
@@ -808,8 +811,9 @@ bool LoopUnswitch::processCurrentLoop()
for (BasicBlock::iterator BBI = (*I)->begin(), E = (*I)->end();
BBI != E; ++BBI)
if (SelectInst *SI = dyn_cast<SelectInst>(BBI)) {
- Value *LoopCond = FindLIVLoopCondition(SI->getCondition(),
- currentLoop, Changed).first;
+ Value *LoopCond = FindLIVLoopCondition(SI->getCondition(), currentLoop,
+ Changed, MSSAU.get())
+ .first;
if (LoopCond && UnswitchIfProfitable(LoopCond,
ConstantInt::getTrue(Context))) {
++NumSelects;
@@ -1123,8 +1127,9 @@ bool LoopUnswitch::TryTrivialLoopUnswitc
if (!BI->isConditional())
return false;
- Value *LoopCond = FindLIVLoopCondition(BI->getCondition(),
- currentLoop, Changed).first;
+ Value *LoopCond = FindLIVLoopCondition(BI->getCondition(), currentLoop,
+ Changed, MSSAU.get())
+ .first;
// Unswitch only if the trivial condition itself is an LIV (not
// partial LIV which could occur in and/or)
@@ -1157,8 +1162,9 @@ bool LoopUnswitch::TryTrivialLoopUnswitc
return true;
} else if (SwitchInst *SI = dyn_cast<SwitchInst>(CurrentTerm)) {
// If this isn't switching on an invariant condition, we can't unswitch it.
- Value *LoopCond = FindLIVLoopCondition(SI->getCondition(),
- currentLoop, Changed).first;
+ Value *LoopCond = FindLIVLoopCondition(SI->getCondition(), currentLoop,
+ Changed, MSSAU.get())
+ .first;
// Unswitch only if the trivial condition itself is an LIV (not
// partial LIV which could occur in and/or)
@@ -1240,6 +1246,9 @@ void LoopUnswitch::UnswitchNontrivialCon
LoopBlocks.clear();
NewBlocks.clear();
+ if (MSSAU && VerifyMemorySSA)
+ MSSA->verifyMemorySSA();
+
// First step, split the preheader and exit blocks, and add these blocks to
// the LoopBlocks list.
BasicBlock *NewPreheader =
Added: llvm/trunk/test/Analysis/MemorySSA/loop-unswitch.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/MemorySSA/loop-unswitch.ll?rev=371748&view=auto
==============================================================================
--- llvm/trunk/test/Analysis/MemorySSA/loop-unswitch.ll (added)
+++ llvm/trunk/test/Analysis/MemorySSA/loop-unswitch.ll Thu Sep 12 10:12:51 2019
@@ -0,0 +1,26 @@
+; RUN: opt -S -loop-unswitch -disable-basicaa -enable-mssa-loop-dependency -verify-memoryssa < %s | FileCheck %s
+; REQUIRES: asserts
+
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK-LABEL: @foo()
+; Function Attrs: readnone speculatable
+declare i32 @foo() #0
+
+define void @main() {
+entry:
+ br label %for.cond2682
+
+for.cond2682: ; preds = %if.then2712, %entry
+ %mul2708 = call i32 @foo()
+ %tobool2709 = icmp ne i32 %mul2708, 0
+ br i1 %tobool2709, label %if.then2712, label %lor.lhs.false2710
+
+lor.lhs.false2710: ; preds = %for.cond2682
+ unreachable
+
+if.then2712: ; preds = %for.cond2682
+ br label %for.cond2682
+}
+
+attributes #0 = { readnone speculatable }
More information about the llvm-commits
mailing list