[ValueTracking] Handle range attributes (#85143)

Handle the range attribute in ValueTracking.

1 files changed, 34 insertions, 4 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 58bc68b..797665c 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -1500,14 +1500,20 @@ static void computeKnownBitsFromOperator(const Operator *I,
     break;
   }
   case Instruction::Call:
-  case Instruction::Invoke:
+  case Instruction::Invoke: {
     // If range metadata is attached to this call, set known bits from that,
     // and then intersect with known bits based on other properties of the
     // function.
     if (MDNode *MD =
             Q.IIQ.getMetadata(cast<Instruction>(I), LLVMContext::MD_range))
       computeKnownBitsFromRangeMetadata(*MD, Known);
-    if (const Value *RV = cast<CallBase>(I)->getReturnedArgOperand()) {
+
+    const auto *CB = cast<CallBase>(I);
+
+    if (std::optional<ConstantRange> Range = CB->getRange())
+      Known = Known.unionWith(Range->toKnownBits());
+
+    if (const Value *RV = CB->getReturnedArgOperand()) {
       if (RV->getType() == I->getType()) {
         computeKnownBits(RV, Known2, Depth + 1, Q);
         Known = Known.unionWith(Known2);
@@ -1679,6 +1685,7 @@ static void computeKnownBitsFromOperator(const Operator *I,
       }
     }
     break;
+  }
   case Instruction::ShuffleVector: {
     auto *Shuf = dyn_cast<ShuffleVectorInst>(I);
     // FIXME: Do we need to handle ConstantExpr involving shufflevectors?
@@ -1933,6 +1940,10 @@ void computeKnownBits(const Value *V, const APInt &DemandedElts,
   // assumptions.  Confirm that we've handled them all.
   assert(!isa<ConstantData>(V) && "Unhandled constant data!");
 
+  if (const auto *A = dyn_cast<Argument>(V))
+    if (std::optional<ConstantRange> Range = A->getRange())
+      Known = Range->toKnownBits();
+
   // All recursive calls that increase depth must come after this.
   if (Depth == MaxAnalysisRecursionDepth)
     return;
@@ -2783,6 +2794,11 @@ static bool isKnownNonZeroFromOperator(const Operator *I,
     } else {
       if (MDNode *Ranges = Q.IIQ.getMetadata(Call, LLVMContext::MD_range))
         return rangeMetadataExcludesValue(Ranges, APInt::getZero(BitWidth));
+      if (std::optional<ConstantRange> Range = Call->getRange()) {
+        const APInt ZeroValue(Range->getBitWidth(), 0);
+        if (!Range->contains(ZeroValue))
+          return true;
+      }
       if (const Value *RV = Call->getReturnedArgOperand())
         if (RV->getType() == I->getType() && isKnownNonZero(RV, Depth, Q))
           return true;
@@ -2921,6 +2937,13 @@ bool isKnownNonZero(const Value *V, const APInt &DemandedElts, unsigned Depth,
       return false;
   }
 
+  if (const auto *A = dyn_cast<Argument>(V))
+    if (std::optional<ConstantRange> Range = A->getRange()) {
+      const APInt ZeroValue(Range->getBitWidth(), 0);
+      if (!Range->contains(ZeroValue))
+        return true;
+    }
+
   if (!isa<Constant>(V) && isKnownNonZeroFromAssume(V, Q))
     return true;
 
@@ -9146,12 +9169,19 @@ ConstantRange llvm::computeConstantRange(const Value *V, bool ForSigned,
     // TODO: Return ConstantRange.
     setLimitForFPToI(cast<Instruction>(V), Lower, Upper);
     CR = ConstantRange::getNonEmpty(Lower, Upper);
-  }
+  } else if (const auto *A = dyn_cast<Argument>(V))
+    if (std::optional<ConstantRange> Range = A->getRange())
+      CR = *Range;
 
-  if (auto *I = dyn_cast<Instruction>(V))
+  if (auto *I = dyn_cast<Instruction>(V)) {
     if (auto *Range = IIQ.getMetadata(I, LLVMContext::MD_range))
       CR = CR.intersectWith(getConstantRangeFromMetadata(*Range));
 
+    if (const auto *CB = dyn_cast<CallBase>(V))
+      if (std::optional<ConstantRange> Range = CB->getRange())
+        CR = CR.intersectWith(*Range);
+  }
+
   if (CtxI && AC) {
     // Try to restrict the range based on information from assumptions.
     for (auto &AssumeVH : AC->assumptionsFor(V)) {