Add changes under a flag, disabled by default.

Author: alinas

llvm/lib/Analysis/LazyValueInfo.cpp

@@ -59,6 +59,11 @@ INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
 INITIALIZE_PASS_END(LazyValueInfoWrapperPass, "lazy-value-info",
                 "Lazy Value Information Analysis", false, true)
 
+static cl::opt<bool> PerPredRanges(
+    "lvi-per-pred-ranges", cl::Hidden, cl::init(false),
+    cl::desc("Enable tracking of ranges for a value in a block for"
+             "each block predecessor (default = false)"));
+
 namespace llvm {
 FunctionPass *createLazyValueInfoPass() {
   return new LazyValueInfoWrapperPass();
@@ -246,7 +251,8 @@ void LazyValueInfoCache::eraseValue(Value *V) {
     Pair.second->OverDefined.erase(V);
     if (Pair.second->NonNullPointers)
       Pair.second->NonNullPointers->erase(V);
-    Pair.second->PredecessorLatticeElements.erase(V);
+    if (PerPredRanges)
+      Pair.second->PredecessorLatticeElements.erase(V);
   }
 
   auto HandleIt = ValueHandles.find_as(V);
@@ -262,9 +268,9 @@ void LVIValueHandle::deleted() {
 
 void LazyValueInfoCache::eraseBlock(BasicBlock *BB) {
   // Clear all when a BB is removed.
-  for (auto &Pair : BlockCache) {
-    Pair.second->PredecessorLatticeElements.clear();
-  }
+  if (PerPredRanges)
+    for (auto &Pair : BlockCache)
+      Pair.second->PredecessorLatticeElements.clear();
   BlockCache.erase(BB);
 }
 
@@ -746,11 +752,12 @@ LazyValueInfoImpl::solveBlockValueNonLocal(Value *Val, BasicBlock *BB) {
                         << Pred->getName() << "' (non local).\n");
       return Result;
     }
-
-    PredLatticeElements.insert({Pred, *EdgeResult});
+    if (PerPredRanges)
+      PredLatticeElements.insert({Pred, *EdgeResult});
   }
 
-  TheCache.insertPredecessorResults(Val, BB, PredLatticeElements);
+  if (PerPredRanges)
+    TheCache.insertPredecessorResults(Val, BB, PredLatticeElements);
 
   // Return the merged value, which is more precise than 'overdefined'.
   assert(!Result.isOverdefined());
@@ -788,10 +795,12 @@ LazyValueInfoImpl::solveBlockValuePHINode(PHINode *PN, BasicBlock *BB) {
       return Result;
     }
 
-    PredLatticeElements.insert({PhiBB, *EdgeResult});
+    if (PerPredRanges)
+      PredLatticeElements.insert({PhiBB, *EdgeResult});
   }
 
-  TheCache.insertPredecessorResults(PN, BB, PredLatticeElements);
+  if (PerPredRanges)
+    TheCache.insertPredecessorResults(PN, BB, PredLatticeElements);
 
   // Return the merged value, which is more precise than 'overdefined'.
   assert(!Result.isOverdefined() && "Possible PHI in entry block?");
@@ -1051,6 +1060,9 @@ LazyValueInfoImpl::solveBlockValueBinaryOpImpl(
   std::optional<ValueLatticeElement> MergedResult =
       ValueLatticeElement::getRange(OpFn(LHSRange, RHSRange));
 
+  if (!PerPredRanges)
+    return MergedResult;
+
   std::optional<BBLatticeElementMap> PredLHS =
       TheCache.getCachedPredecessorInfo(LHS, BB);
   if (!PredLHS)

llvm/test/Transforms/CorrelatedValuePropagation/track-predecessor-ranges.ll

@@ -1,5 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
-; RUN: opt < %s -passes="correlated-propagation" -S 2>&1 | FileCheck %s
+; RUN: opt < %s -passes="correlated-propagation"  -S 2>&1 | FileCheck %s
+; RUN: opt < %s -passes="correlated-propagation" -lvi-per-pred-ranges -S 2>&1 | FileCheck %s -check-prefix=LVI-PRED-RANGES
 
 @global = external local_unnamed_addr global [4338 x i32], align 16
 
@@ -17,7 +18,8 @@ define dso_local noundef zeroext i1 @bar(i64 noundef %arg, ptr noundef writeonly
 ; CHECK-NEXT:    [[PHI5:%.*]] = phi i64 [ 3, %[[BB]] ], [ 7, %[[BB2]] ]
 ; CHECK-NEXT:    [[ADD:%.*]] = add nuw nsw i64 [[PHI]], [[ARG]]
 ; CHECK-NEXT:    [[LSHR:%.*]] = lshr i64 [[ADD]], [[PHI5]]
-; CHECK-NEXT:    br i1 true, label %[[BB8:.*]], label %[[BB7:.*]]
+; CHECK-NEXT:    [[ICMP6:%.*]] = icmp samesign ult i64 [[LSHR]], 4338
+; CHECK-NEXT:    br i1 [[ICMP6]], label %[[BB8:.*]], label %[[BB7:.*]]
 ; CHECK:       [[BB7]]:
 ; CHECK-NEXT:    tail call void @llvm.ubsantrap(i8 18)
 ; CHECK-NEXT:    unreachable
@@ -31,6 +33,33 @@ define dso_local noundef zeroext i1 @bar(i64 noundef %arg, ptr noundef writeonly
 ; CHECK-NEXT:    [[PHI10:%.*]] = phi i1 [ true, %[[BB8]] ], [ false, %[[BB2]] ]
 ; CHECK-NEXT:    ret i1 [[PHI10]]
 ;
+; LVI-PRED-RANGES-LABEL: define dso_local noundef zeroext i1 @bar(
+; LVI-PRED-RANGES-SAME: i64 noundef [[ARG:%.*]], ptr noundef writeonly captures(none) [[ARG1:%.*]]) local_unnamed_addr {
+; LVI-PRED-RANGES-NEXT:  [[BB:.*]]:
+; LVI-PRED-RANGES-NEXT:    [[ICMP:%.*]] = icmp ult i64 [[ARG]], 1025
+; LVI-PRED-RANGES-NEXT:    br i1 [[ICMP]], label %[[BB4:.*]], label %[[BB2:.*]]
+; LVI-PRED-RANGES:       [[BB2]]:
+; LVI-PRED-RANGES-NEXT:    [[ICMP3:%.*]] = icmp ult i64 [[ARG]], 262145
+; LVI-PRED-RANGES-NEXT:    br i1 [[ICMP3]], label %[[BB4]], label %[[BB9:.*]]
+; LVI-PRED-RANGES:       [[BB4]]:
+; LVI-PRED-RANGES-NEXT:    [[PHI:%.*]] = phi i64 [ 7, %[[BB]] ], [ 15487, %[[BB2]] ]
+; LVI-PRED-RANGES-NEXT:    [[PHI5:%.*]] = phi i64 [ 3, %[[BB]] ], [ 7, %[[BB2]] ]
+; LVI-PRED-RANGES-NEXT:    [[ADD:%.*]] = add nuw nsw i64 [[PHI]], [[ARG]]
+; LVI-PRED-RANGES-NEXT:    [[LSHR:%.*]] = lshr i64 [[ADD]], [[PHI5]]
+; LVI-PRED-RANGES-NEXT:    br i1 true, label %[[BB8:.*]], label %[[BB7:.*]]
+; LVI-PRED-RANGES:       [[BB7]]:
+; LVI-PRED-RANGES-NEXT:    tail call void @llvm.ubsantrap(i8 18)
+; LVI-PRED-RANGES-NEXT:    unreachable
+; LVI-PRED-RANGES:       [[BB8]]:
+; LVI-PRED-RANGES-NEXT:    [[GETELEMENTPTR:%.*]] = getelementptr inbounds nuw [4338 x i32], ptr @global, i64 0, i64 [[LSHR]]
+; LVI-PRED-RANGES-NEXT:    [[LOAD:%.*]] = load i32, ptr [[GETELEMENTPTR]], align 4
+; LVI-PRED-RANGES-NEXT:    [[SEXT:%.*]] = sext i32 [[LOAD]] to i64
+; LVI-PRED-RANGES-NEXT:    store i64 [[SEXT]], ptr [[ARG1]], align 8
+; LVI-PRED-RANGES-NEXT:    br label %[[BB9]]
+; LVI-PRED-RANGES:       [[BB9]]:
+; LVI-PRED-RANGES-NEXT:    [[PHI10:%.*]] = phi i1 [ true, %[[BB8]] ], [ false, %[[BB2]] ]
+; LVI-PRED-RANGES-NEXT:    ret i1 [[PHI10]]
+;
 bb:
   %icmp = icmp ult i64 %arg, 1025
   br i1 %icmp, label %bb4, label %bb2