[MemDep] Use PhiValuesAnalysis to improve alias analysis results

This is being done in order to make GVN able to better optimize certain inputs.
MemDep doesn't use PhiValues directly, but does need to notifiy it when things
get invalidated.

Differential Revision: https://reviews.llvm.org/D48489

llvm-svn: 338384

diff --git a/llvm/include/llvm/Analysis/MemoryDependenceAnalysis.h b/llvm/include/llvm/Analysis/MemoryDependenceAnalysis.h
index 1c6ec98..1c40cff 100644 (file)
--- a/llvm/include/llvm/Analysis/MemoryDependenceAnalysis.h
+++ b/llvm/include/llvm/Analysis/MemoryDependenceAnalysis.h
@@ -44,6 +44,7 @@ class Instruction;
 class LoadInst;
 class PHITransAddr;
 class TargetLibraryInfo;
+class PhiValues;
 class Value;
 
 /// A memory dependence query can return one of three different answers.
@@ -360,13 +361,14 @@ private:
   AssumptionCache ∾
   const TargetLibraryInfo &TLI;
   DominatorTree &DT;
+  PhiValues &PV;
   PredIteratorCache PredCache;
 
 public:
   MemoryDependenceResults(AliasAnalysis &AA, AssumptionCache &AC,
                           const TargetLibraryInfo &TLI,
-                          DominatorTree &DT)
-      : AA(AA), AC(AC), TLI(TLI), DT(DT) {}
+                          DominatorTree &DT, PhiValues &PV)
+      : AA(AA), AC(AC), TLI(TLI), DT(DT), PV(PV) {}
 
   /// Handle invalidation in the new PM.
   bool invalidate(Function &F, const PreservedAnalyses &PA,

diff --git a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
index 7eeefd5..feae53c 100644 (file)
--- a/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -26,6 +26,7 @@
 #include "llvm/Analysis/MemoryLocation.h"
 #include "llvm/Analysis/OrderedBasicBlock.h"
 #include "llvm/Analysis/PHITransAddr.h"
+#include "llvm/Analysis/PhiValues.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/Attributes.h"
@@ -1513,6 +1514,8 @@ void MemoryDependenceResults::invalidateCachedPointerInfo(Value *Ptr) {
   RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, false));
   // Flush load info for the pointer.
   RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair(Ptr, true));
+  // Invalidate phis that use the pointer.
+  PV.invalidateValue(Ptr);
 }
 
 void MemoryDependenceResults::invalidateCachedPredecessors() {
@@ -1671,6 +1674,9 @@ void MemoryDependenceResults::removeInstruction(Instruction *RemInst) {
     }
   }
 
+  // Invalidate phis that use the removed instruction.
+  PV.invalidateValue(RemInst);
+
   assert(!NonLocalDeps.count(RemInst) && "RemInst got reinserted?");
   LLVM_DEBUG(verifyRemoved(RemInst));
 }
@@ -1730,7 +1736,8 @@ MemoryDependenceAnalysis::run(Function &F, FunctionAnalysisManager &AM) {
   auto &AC = AM.getResult<AssumptionAnalysis>(F);
   auto &TLI = AM.getResult<TargetLibraryAnalysis>(F);
   auto &DT = AM.getResult<DominatorTreeAnalysis>(F);
-  return MemoryDependenceResults(AA, AC, TLI, DT);
+  auto &PV = AM.getResult<PhiValuesAnalysis>(F);
+  return MemoryDependenceResults(AA, AC, TLI, DT, PV);
 }
 
 char MemoryDependenceWrapperPass::ID = 0;
@@ -1741,6 +1748,7 @@ INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
 INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(PhiValuesWrapperPass)
 INITIALIZE_PASS_END(MemoryDependenceWrapperPass, "memdep",
                     "Memory Dependence Analysis", false, true)
 
@@ -1758,6 +1766,7 @@ void MemoryDependenceWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
   AU.addRequired<AssumptionCacheTracker>();
   AU.addRequired<DominatorTreeWrapperPass>();
+  AU.addRequired<PhiValuesWrapperPass>();
   AU.addRequiredTransitive<AAResultsWrapperPass>();
   AU.addRequiredTransitive<TargetLibraryInfoWrapperPass>();
 }
@@ -1773,7 +1782,8 @@ bool MemoryDependenceResults::invalidate(Function &F, const PreservedAnalyses &P
   // Check whether the analyses we depend on became invalid for any reason.
   if (Inv.invalidate<AAManager>(F, PA) ||
       Inv.invalidate<AssumptionAnalysis>(F, PA) ||
-      Inv.invalidate<DominatorTreeAnalysis>(F, PA))
+      Inv.invalidate<DominatorTreeAnalysis>(F, PA) ||
+      Inv.invalidate<PhiValuesAnalysis>(F, PA))
     return true;
 
   // Otherwise this analysis result remains valid.
@@ -1789,6 +1799,7 @@ bool MemoryDependenceWrapperPass::runOnFunction(Function &F) {
   auto &AC = getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
   auto &TLI = getAnalysis<TargetLibraryInfoWrapperPass>().getTLI();
   auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();
-  MemDep.emplace(AA, AC, TLI, DT);
+  auto &PV = getAnalysis<PhiValuesWrapperPass>().getResult();
+  MemDep.emplace(AA, AC, TLI, DT, PV);
   return false;
 }

diff --git a/llvm/test/Other/new-pm-defaults.ll b/llvm/test/Other/new-pm-defaults.ll
index fcbfc35..30ee219 100644 (file)
--- a/llvm/test/Other/new-pm-defaults.ll
+++ b/llvm/test/Other/new-pm-defaults.ll
@@ -170,17 +170,22 @@
 ; CHECK-Os-NEXT: Running pass: MergedLoadStoreMotionPass
 ; CHECK-Os-NEXT: Running pass: GVN
 ; CHECK-Os-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-Os-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-Oz-NEXT: Running pass: MergedLoadStoreMotionPass
 ; CHECK-Oz-NEXT: Running pass: GVN
 ; CHECK-Oz-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-Oz-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-O2-NEXT: Running pass: MergedLoadStoreMotionPass
 ; CHECK-O2-NEXT: Running pass: GVN
 ; CHECK-O2-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-O2-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-O3-NEXT: Running pass: MergedLoadStoreMotionPass
 ; CHECK-O3-NEXT: Running pass: GVN
 ; CHECK-O3-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-O3-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-O-NEXT: Running pass: MemCpyOptPass
 ; CHECK-O1-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-O1-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-O-NEXT: Running pass: SCCPPass
 ; CHECK-O-NEXT: Running pass: BDCEPass
 ; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis

diff --git a/llvm/test/Other/new-pm-lto-defaults.ll b/llvm/test/Other/new-pm-lto-defaults.ll
index 5bb4d9a..26680f5 100644 (file)
--- a/llvm/test/Other/new-pm-lto-defaults.ll
+++ b/llvm/test/Other/new-pm-lto-defaults.ll
@@ -81,6 +81,7 @@
 ; CHECK-O2-NEXT: Running pass: ModuleToPostOrderCGSCCPassAdaptor<{{.*}}PostOrderFunctionAttrsPass>
 ; CHECK-O2-NEXT: Running pass: ModuleToFunctionPassAdaptor<{{.*}}PassManager{{.*}}>
 ; CHECK-O2-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-O2-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-O2-NEXT: Running analysis: DemandedBitsAnalysis
 ; CHECK-O2-NEXT: Running pass: CrossDSOCFIPass
 ; CHECK-O2-NEXT: Running pass: LowerTypeTestsPass

diff --git a/llvm/test/Other/new-pm-thinlto-defaults.ll b/llvm/test/Other/new-pm-thinlto-defaults.ll
index 3ddae02..e1d3d1c 100644 (file)
--- a/llvm/test/Other/new-pm-thinlto-defaults.ll
+++ b/llvm/test/Other/new-pm-thinlto-defaults.ll
@@ -152,17 +152,22 @@
 ; CHECK-Os-NEXT: Running pass: MergedLoadStoreMotionPass
 ; CHECK-Os-NEXT: Running pass: GVN
 ; CHECK-Os-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-Os-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-Oz-NEXT: Running pass: MergedLoadStoreMotionPass
 ; CHECK-Oz-NEXT: Running pass: GVN
 ; CHECK-Oz-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-Oz-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-O2-NEXT: Running pass: MergedLoadStoreMotionPass
 ; CHECK-O2-NEXT: Running pass: GVN
 ; CHECK-O2-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-O2-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-O3-NEXT: Running pass: MergedLoadStoreMotionPass
 ; CHECK-O3-NEXT: Running pass: GVN
 ; CHECK-O3-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-O3-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-O-NEXT: Running pass: MemCpyOptPass
 ; CHECK-O1-NEXT: Running analysis: MemoryDependenceAnalysis
+; CHECK-O1-NEXT: Running analysis: PhiValuesAnalysis
 ; CHECK-O-NEXT: Running pass: SCCPPass
 ; CHECK-O-NEXT: Running pass: BDCEPass
 ; CHECK-O-NEXT: Running analysis: DemandedBitsAnalysis

diff --git a/llvm/test/Other/opt-O2-pipeline.ll b/llvm/test/Other/opt-O2-pipeline.ll
index 379c00c..b36bd24 100644 (file)
--- a/llvm/test/Other/opt-O2-pipeline.ll
+++ b/llvm/test/Other/opt-O2-pipeline.ll
@@ -121,6 +121,7 @@
 ; CHECK-NEXT:           Delete dead loops
 ; CHECK-NEXT:           Unroll loops
 ; CHECK-NEXT:         MergedLoadStoreMotion
+; CHECK-NEXT:         Phi Values Analysis
 ; CHECK-NEXT:         Basic Alias Analysis (stateless AA impl)
 ; CHECK-NEXT:         Function Alias Analysis Results
 ; CHECK-NEXT:         Memory Dependence Analysis
@@ -128,6 +129,7 @@
 ; CHECK-NEXT:         Lazy Block Frequency Analysis
 ; CHECK-NEXT:         Optimization Remark Emitter
 ; CHECK-NEXT:         Global Value Numbering
+; CHECK-NEXT:         Phi Values Analysis
 ; CHECK-NEXT:         Basic Alias Analysis (stateless AA impl)
 ; CHECK-NEXT:         Function Alias Analysis Results
 ; CHECK-NEXT:         Memory Dependence Analysis
@@ -147,6 +149,7 @@
 ; CHECK-NEXT:         Value Propagation
 ; CHECK-NEXT:         Basic Alias Analysis (stateless AA impl)
 ; CHECK-NEXT:         Function Alias Analysis Results
+; CHECK-NEXT:         Phi Values Analysis
 ; CHECK-NEXT:         Memory Dependence Analysis
 ; CHECK-NEXT:         Dead Store Elimination
 ; CHECK-NEXT:         Natural Loop Information

diff --git a/llvm/test/Other/opt-O3-pipeline.ll b/llvm/test/Other/opt-O3-pipeline.ll
index f5e4f50..096982a 100644 (file)
--- a/llvm/test/Other/opt-O3-pipeline.ll
+++ b/llvm/test/Other/opt-O3-pipeline.ll
@@ -125,6 +125,7 @@
 ; CHECK-NEXT:           Delete dead loops
 ; CHECK-NEXT:           Unroll loops
 ; CHECK-NEXT:         MergedLoadStoreMotion
+; CHECK-NEXT:         Phi Values Analysis
 ; CHECK-NEXT:         Basic Alias Analysis (stateless AA impl)
 ; CHECK-NEXT:         Function Alias Analysis Results
 ; CHECK-NEXT:         Memory Dependence Analysis
@@ -132,6 +133,7 @@
 ; CHECK-NEXT:         Lazy Block Frequency Analysis
 ; CHECK-NEXT:         Optimization Remark Emitter
 ; CHECK-NEXT:         Global Value Numbering
+; CHECK-NEXT:         Phi Values Analysis
 ; CHECK-NEXT:         Basic Alias Analysis (stateless AA impl)
 ; CHECK-NEXT:         Function Alias Analysis Results
 ; CHECK-NEXT:         Memory Dependence Analysis
@@ -151,6 +153,7 @@
 ; CHECK-NEXT:         Value Propagation
 ; CHECK-NEXT:         Basic Alias Analysis (stateless AA impl)
 ; CHECK-NEXT:         Function Alias Analysis Results
+; CHECK-NEXT:         Phi Values Analysis
 ; CHECK-NEXT:         Memory Dependence Analysis
 ; CHECK-NEXT:         Dead Store Elimination
 ; CHECK-NEXT:         Natural Loop Information

diff --git a/llvm/test/Other/opt-Os-pipeline.ll b/llvm/test/Other/opt-Os-pipeline.ll
index 7b84265..34b8fa8 100644 (file)
--- a/llvm/test/Other/opt-Os-pipeline.ll
+++ b/llvm/test/Other/opt-Os-pipeline.ll
@@ -108,6 +108,7 @@
 ; CHECK-NEXT:           Delete dead loops
 ; CHECK-NEXT:           Unroll loops
 ; CHECK-NEXT:         MergedLoadStoreMotion
+; CHECK-NEXT:         Phi Values Analysis
 ; CHECK-NEXT:         Basic Alias Analysis (stateless AA impl)
 ; CHECK-NEXT:         Function Alias Analysis Results
 ; CHECK-NEXT:         Memory Dependence Analysis
@@ -115,6 +116,7 @@
 ; CHECK-NEXT:         Lazy Block Frequency Analysis
 ; CHECK-NEXT:         Optimization Remark Emitter
 ; CHECK-NEXT:         Global Value Numbering
+; CHECK-NEXT:         Phi Values Analysis
 ; CHECK-NEXT:         Basic Alias Analysis (stateless AA impl)
 ; CHECK-NEXT:         Function Alias Analysis Results
 ; CHECK-NEXT:         Memory Dependence Analysis
@@ -134,6 +136,7 @@
 ; CHECK-NEXT:         Value Propagation
 ; CHECK-NEXT:         Basic Alias Analysis (stateless AA impl)
 ; CHECK-NEXT:         Function Alias Analysis Results
+; CHECK-NEXT:         Phi Values Analysis
 ; CHECK-NEXT:         Memory Dependence Analysis
 ; CHECK-NEXT:         Dead Store Elimination
 ; CHECK-NEXT:         Natural Loop Information

diff --git a/llvm/test/Transforms/GVN/PRE/pre-after-rle.ll b/llvm/test/Transforms/GVN/PRE/pre-after-rle.ll
index ff35e56..879d20e 100644 (file)
--- a/llvm/test/Transforms/GVN/PRE/pre-after-rle.ll
+++ b/llvm/test/Transforms/GVN/PRE/pre-after-rle.ll
@@ -63,10 +63,12 @@ preheader:
   %cmp = icmp slt i32 1, %h
   br i1 %cmp, label %body, label %exit
 
-; Alias analysis currently can't figure out %width doesn't alias %s, so just
-; check that the redundant load has been removed.
+; CHECK-LABEL: preheader.body_crit_edge:
+; CHECK: load i32, i32* %width, align 8
+
 ; CHECK-LABEL: body:
 ; CHECK-NOT: load i32*, i32** %start, align 8
+; CHECK-NOT: load i32, i32* %width, align 8
 body:
   %j = phi i32 [ 0, %preheader ], [ %j.next, %body ]
   %s = load i32*, i32** %start, align 8