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[JumpThread] Use AA in SimplifyPartiallyRedundantLoad()
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Summary: Use AA when scanning to find an available load value.

Reviewers: rengolin, mcrosier, hfinkel, trentxintong, dberlin

Reviewed By: rengolin, dberlin

Subscribers: aemerson, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D30352

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297284 91177308-0d34-0410-b5e6-96231b3b80d8
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Jun Bum Lim committed Mar 8, 2017
1 parent 48a60dc commit f45aefe
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Showing 3 changed files with 134 additions and 13 deletions.
5 changes: 4 additions & 1 deletion include/llvm/Transforms/Scalar/JumpThreading.h
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Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,7 @@
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BlockFrequencyInfo.h"
#include "llvm/Analysis/BlockFrequencyInfoImpl.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
Expand Down Expand Up @@ -60,6 +61,7 @@ enum ConstantPreference { WantInteger, WantBlockAddress };
class JumpThreadingPass : public PassInfoMixin<JumpThreadingPass> {
TargetLibraryInfo *TLI;
LazyValueInfo *LVI;
AliasAnalysis *AA;
std::unique_ptr<BlockFrequencyInfo> BFI;
std::unique_ptr<BranchProbabilityInfo> BPI;
bool HasProfileData = false;
Expand Down Expand Up @@ -90,7 +92,8 @@ class JumpThreadingPass : public PassInfoMixin<JumpThreadingPass> {

// Glue for old PM.
bool runImpl(Function &F, TargetLibraryInfo *TLI_, LazyValueInfo *LVI_,
bool HasProfileData_, std::unique_ptr<BlockFrequencyInfo> BFI_,
AliasAnalysis *AA_, bool HasProfileData_,
std::unique_ptr<BlockFrequencyInfo> BFI_,
std::unique_ptr<BranchProbabilityInfo> BPI_);

PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
Expand Down
31 changes: 20 additions & 11 deletions lib/Transforms/Scalar/JumpThreading.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,7 @@
#include "llvm/ADT/DenseSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/GlobalsModRef.h"
#include "llvm/Analysis/CFG.h"
#include "llvm/Analysis/BlockFrequencyInfoImpl.h"
Expand Down Expand Up @@ -91,6 +92,7 @@ namespace {
bool runOnFunction(Function &F) override;

void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequired<AAResultsWrapperPass>();
AU.addRequired<LazyValueInfoWrapperPass>();
AU.addPreserved<LazyValueInfoWrapperPass>();
AU.addPreserved<GlobalsAAWrapperPass>();
Expand All @@ -106,6 +108,7 @@ INITIALIZE_PASS_BEGIN(JumpThreading, "jump-threading",
"Jump Threading", false, false)
INITIALIZE_PASS_DEPENDENCY(LazyValueInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
INITIALIZE_PASS_END(JumpThreading, "jump-threading",
"Jump Threading", false, false)

Expand All @@ -123,6 +126,7 @@ bool JumpThreading::runOnFunction(Function &F) {
return false;
auto TLI = &getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
auto LVI = &getAnalysis<LazyValueInfoWrapperPass>().getLVI();
auto AA = &getAnalysis<AAResultsWrapperPass>().getAAResults();
std::unique_ptr<BlockFrequencyInfo> BFI;
std::unique_ptr<BranchProbabilityInfo> BPI;
bool HasProfileData = F.getEntryCount().hasValue();
Expand All @@ -131,7 +135,8 @@ bool JumpThreading::runOnFunction(Function &F) {
BPI.reset(new BranchProbabilityInfo(F, LI));
BFI.reset(new BlockFrequencyInfo(F, *BPI, LI));
}
return Impl.runImpl(F, TLI, LVI, HasProfileData, std::move(BFI),

return Impl.runImpl(F, TLI, LVI, AA, HasProfileData, std::move(BFI),
std::move(BPI));
}

Expand All @@ -140,6 +145,8 @@ PreservedAnalyses JumpThreadingPass::run(Function &F,

auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
auto &LVI = AM.getResult<LazyValueAnalysis>(F);
auto &AA = AM.getResult<AAManager>(F);

std::unique_ptr<BlockFrequencyInfo> BFI;
std::unique_ptr<BranchProbabilityInfo> BPI;
bool HasProfileData = F.getEntryCount().hasValue();
Expand All @@ -148,8 +155,9 @@ PreservedAnalyses JumpThreadingPass::run(Function &F,
BPI.reset(new BranchProbabilityInfo(F, LI));
BFI.reset(new BlockFrequencyInfo(F, *BPI, LI));
}
bool Changed =
runImpl(F, &TLI, &LVI, HasProfileData, std::move(BFI), std::move(BPI));

bool Changed = runImpl(F, &TLI, &LVI, &AA, HasProfileData, std::move(BFI),
std::move(BPI));

if (!Changed)
return PreservedAnalyses::all();
Expand All @@ -159,13 +167,15 @@ PreservedAnalyses JumpThreadingPass::run(Function &F,
}

bool JumpThreadingPass::runImpl(Function &F, TargetLibraryInfo *TLI_,
LazyValueInfo *LVI_, bool HasProfileData_,
LazyValueInfo *LVI_, AliasAnalysis *AA_,
bool HasProfileData_,
std::unique_ptr<BlockFrequencyInfo> BFI_,
std::unique_ptr<BranchProbabilityInfo> BPI_) {

DEBUG(dbgs() << "Jump threading on function '" << F.getName() << "'\n");
TLI = TLI_;
LVI = LVI_;
AA = AA_;
BFI.reset();
BPI.reset();
// When profile data is available, we need to update edge weights after
Expand Down Expand Up @@ -953,8 +963,8 @@ bool JumpThreadingPass::SimplifyPartiallyRedundantLoad(LoadInst *LI) {
// the entry to its block.
BasicBlock::iterator BBIt(LI);
bool IsLoadCSE;
if (Value *AvailableVal =
FindAvailableLoadedValue(LI, LoadBB, BBIt, DefMaxInstsToScan, nullptr, &IsLoadCSE)) {
if (Value *AvailableVal = FindAvailableLoadedValue(
LI, LoadBB, BBIt, DefMaxInstsToScan, AA, &IsLoadCSE)) {
// If the value of the load is locally available within the block, just use
// it. This frequently occurs for reg2mem'd allocas.

Expand Down Expand Up @@ -1001,9 +1011,8 @@ bool JumpThreadingPass::SimplifyPartiallyRedundantLoad(LoadInst *LI) {
// Scan the predecessor to see if the value is available in the pred.
BBIt = PredBB->end();
unsigned NumScanedInst = 0;
Value *PredAvailable =
FindAvailableLoadedValue(LI, PredBB, BBIt, DefMaxInstsToScan, nullptr,
&IsLoadCSE, &NumScanedInst);
Value *PredAvailable = FindAvailableLoadedValue(
LI, PredBB, BBIt, DefMaxInstsToScan, AA, &IsLoadCSE, &NumScanedInst);

// If PredBB has a single predecessor, continue scanning through the single
// predecessor.
Expand All @@ -1014,8 +1023,8 @@ bool JumpThreadingPass::SimplifyPartiallyRedundantLoad(LoadInst *LI) {
if (SinglePredBB) {
BBIt = SinglePredBB->end();
PredAvailable = FindAvailableLoadedValue(
LI, SinglePredBB, BBIt, (DefMaxInstsToScan - NumScanedInst),
nullptr, &IsLoadCSE, &NumScanedInst);
LI, SinglePredBB, BBIt, (DefMaxInstsToScan - NumScanedInst), AA,
&IsLoadCSE, &NumScanedInst);
}
}

Expand Down
111 changes: 110 additions & 1 deletion test/Transforms/JumpThreading/thread-loads.ll
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
; RUN: opt < %s -jump-threading -S | FileCheck %s
; RUN: opt < %s -passes=jump-threading -S | FileCheck %s
; RUN: opt < %s -aa-pipeline=basic-aa -passes=jump-threading -S | FileCheck %s

target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin7"
Expand Down Expand Up @@ -302,6 +302,115 @@ ret2:
ret void
}

define i32 @fn_noalias(i1 %c2,i64* noalias %P, i64* noalias %P2) {
; CHECK-LABEL: @fn_noalias
; CHECK-LABEL: cond1:
; CHECK: %[[LD1:.*]] = load i64, i64* %P
; CHECK: br i1 %c, label %[[THREAD:.*]], label %end
; CHECK-LABEL: cond2:
; CHECK: %[[LD2:.*]] = load i64, i64* %P
; CHECK-LABEL: cond3:
; CHECK: %[[PHI:.*]] = phi i64 [ %[[LD1]], %[[THREAD]] ], [ %[[LD2]], %cond2 ]
; CHECK: call void @fn3(i64 %[[PHI]])
entry:
br i1 %c2, label %cond2, label %cond1

cond1:
%l1 = load i64, i64* %P
store i64 42, i64* %P2
%c = icmp eq i64 %l1, 0
br i1 %c, label %cond2, label %end

cond2:
%l2 = load i64, i64* %P
call void @fn2(i64 %l2)
%c3 = icmp eq i64 %l2, 0
br i1 %c3, label %cond3, label %end

cond3:
call void @fn3(i64 %l2)
br label %end

end:
ret i32 0
}

; This tests if we can thread from %sw.bb.i to %do.body.preheader.i67 through
; %sw.bb21.i. To make this happen, %l2 should be detected as a partically
; redundant load with %l3 across the store to %phase in %sw.bb21.i.

%struct.NEXT_MOVE = type { i32, i32, i32* }
@hash_move = unnamed_addr global [65 x i32] zeroinitializer, align 4
@current_move = internal global [65 x i32] zeroinitializer, align 4
@last = internal unnamed_addr global [65 x i32*] zeroinitializer, align 8
@next_status = internal unnamed_addr global [65 x %struct.NEXT_MOVE] zeroinitializer, align 8
define fastcc i32 @Search(i64 %idxprom.i, i64 %idxprom.i89, i32 %c) {
; CHECK-LABEL: @Search
; CHECK-LABEL: sw.bb.i:
; CHECK: %[[LD1:.*]] = load i32, i32* %arrayidx185, align 4
; CHECK: %[[C1:.*]] = icmp eq i32 %[[LD1]], 0
; CHECK: br i1 %[[C1]], label %sw.bb21.i.thread, label %if.then.i64
; CHECK-LABEL: sw.bb21.i.thread:
; CHECK: br label %[[THREAD_TO:.*]]
; CHECK-LABEL: sw.bb21.i:
; CHECK: %[[LD2:.*]] = load i32, i32* %arrayidx185, align 4
; CHECK: %[[C2:.*]] = icmp eq i32 %[[LD2]], 0
; CHECK:br i1 %[[C2]], label %[[THREAD_TO]], label %cleanup
entry:
%arrayidx185 = getelementptr inbounds [65 x i32], [65 x i32]* @hash_move, i64 0, i64 %idxprom.i
%arrayidx307 = getelementptr inbounds [65 x i32], [65 x i32]* @current_move, i64 0, i64 %idxprom.i
%arrayidx89 = getelementptr inbounds [65 x i32*], [65 x i32*]* @last, i64 0, i64 %idxprom.i
%phase = getelementptr inbounds [65 x %struct.NEXT_MOVE], [65 x %struct.NEXT_MOVE]* @next_status, i64 0, i64 %idxprom.i, i32 0
br label %cond.true282

cond.true282:
switch i32 %c, label %sw.default.i [
i32 1, label %sw.bb.i
i32 0, label %sw.bb21.i
]

sw.default.i:
br label %cleanup

sw.bb.i:
%call.i62 = call fastcc i32* @GenerateCheckEvasions()
store i32* %call.i62, i32** %arrayidx89, align 8
%l2 = load i32, i32* %arrayidx185, align 4
%tobool.i63 = icmp eq i32 %l2, 0
br i1 %tobool.i63, label %sw.bb21.i, label %if.then.i64

if.then.i64: ; preds = %sw.bb.i
store i32 7, i32* %phase, align 8
store i32 %l2, i32* %arrayidx307, align 4
%call16.i = call fastcc i32 @ValidMove(i32 %l2)
%tobool17.i = icmp eq i32 %call16.i, 0
br i1 %tobool17.i, label %if.else.i65, label %cleanup

if.else.i65:
call void @f65()
br label %sw.bb21.i

sw.bb21.i:
store i32 10, i32* %phase, align 8
%l3= load i32, i32* %arrayidx185, align 4
%tobool27.i = icmp eq i32 %l3, 0
br i1 %tobool27.i, label %do.body.preheader.i67, label %cleanup

do.body.preheader.i67:
call void @f67()
ret i32 67

cleanup:
call void @Cleanup()
ret i32 0
}

declare fastcc i32* @GenerateCheckEvasions()
declare fastcc i32 @ValidMove(i32 %move)
declare void @f67()
declare void @Cleanup()
declare void @f65()

define i32 @fn_SinglePred(i1 %c2,i64* %P) {
; CHECK-LABEL: @fn_SinglePred
; CHECK-LABEL: entry:
Expand Down

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