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-rw-r--r--llvm/lib/Analysis/InstructionSimplify.cpp4
-rw-r--r--llvm/lib/Analysis/ValueTracking.cpp98
-rw-r--r--llvm/lib/IR/Core.cpp4
-rw-r--r--llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp30
4 files changed, 117 insertions, 19 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp
index 07f4a8e..0d978d4 100644
--- a/llvm/lib/Analysis/InstructionSimplify.cpp
+++ b/llvm/lib/Analysis/InstructionSimplify.cpp
@@ -4164,6 +4164,10 @@ static Value *simplifyFCmpInst(CmpPredicate Pred, Value *LHS, Value *RHS,
return ConstantInt::get(RetTy, Pred == CmpInst::FCMP_UNO);
}
+ if (std::optional<bool> Res =
+ isImpliedByDomCondition(Pred, LHS, RHS, Q.CxtI, Q.DL))
+ return ConstantInt::getBool(RetTy, *Res);
+
const APFloat *C = nullptr;
match(RHS, m_APFloatAllowPoison(C));
std::optional<KnownFPClass> FullKnownClassLHS;
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 1eda7a7..a42c061 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -39,6 +39,7 @@
#include "llvm/IR/Attributes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constant.h"
+#include "llvm/IR/ConstantFPRange.h"
#include "llvm/IR/ConstantRange.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
@@ -9474,6 +9475,69 @@ isImpliedCondICmps(CmpPredicate LPred, const Value *L0, const Value *L1,
return std::nullopt;
}
+/// Return true if LHS implies RHS (expanded to its components as "R0 RPred R1")
+/// is true. Return false if LHS implies RHS is false. Otherwise, return
+/// std::nullopt if we can't infer anything.
+static std::optional<bool>
+isImpliedCondFCmps(FCmpInst::Predicate LPred, const Value *L0, const Value *L1,
+ FCmpInst::Predicate RPred, const Value *R0, const Value *R1,
+ const DataLayout &DL, bool LHSIsTrue) {
+ // The rest of the logic assumes the LHS condition is true. If that's not the
+ // case, invert the predicate to make it so.
+ if (!LHSIsTrue)
+ LPred = FCmpInst::getInversePredicate(LPred);
+
+ // We can have non-canonical operands, so try to normalize any common operand
+ // to L0/R0.
+ if (L0 == R1) {
+ std::swap(R0, R1);
+ RPred = FCmpInst::getSwappedPredicate(RPred);
+ }
+ if (R0 == L1) {
+ std::swap(L0, L1);
+ LPred = FCmpInst::getSwappedPredicate(LPred);
+ }
+ if (L1 == R1) {
+ // If we have L0 == R0 and L1 == R1, then make L1/R1 the constants.
+ if (L0 != R0 || match(L0, m_ImmConstant())) {
+ std::swap(L0, L1);
+ LPred = ICmpInst::getSwappedCmpPredicate(LPred);
+ std::swap(R0, R1);
+ RPred = ICmpInst::getSwappedCmpPredicate(RPred);
+ }
+ }
+
+ // Can we infer anything when the two compares have matching operands?
+ if (L0 == R0 && L1 == R1) {
+ if ((LPred & RPred) == LPred)
+ return true;
+ if ((LPred & ~RPred) == LPred)
+ return false;
+ }
+
+ // See if we can infer anything if operand-0 matches and we have at least one
+ // constant.
+ const APFloat *L1C, *R1C;
+ if (L0 == R0 && match(L1, m_APFloat(L1C)) && match(R1, m_APFloat(R1C))) {
+ if (std::optional<ConstantFPRange> DomCR =
+ ConstantFPRange::makeExactFCmpRegion(LPred, *L1C)) {
+ if (std::optional<ConstantFPRange> ImpliedCR =
+ ConstantFPRange::makeExactFCmpRegion(RPred, *R1C)) {
+ if (ImpliedCR->contains(*DomCR))
+ return true;
+ }
+ if (std::optional<ConstantFPRange> ImpliedCR =
+ ConstantFPRange::makeExactFCmpRegion(
+ FCmpInst::getInversePredicate(RPred), *R1C)) {
+ if (ImpliedCR->contains(*DomCR))
+ return false;
+ }
+ }
+ }
+
+ return std::nullopt;
+}
+
/// Return true if LHS implies RHS is true. Return false if LHS implies RHS is
/// false. Otherwise, return std::nullopt if we can't infer anything. We
/// expect the RHS to be an icmp and the LHS to be an 'and', 'or', or a 'select'
@@ -9529,15 +9593,24 @@ llvm::isImpliedCondition(const Value *LHS, CmpPredicate RHSPred,
LHSIsTrue = !LHSIsTrue;
// Both LHS and RHS are icmps.
- if (const auto *LHSCmp = dyn_cast<ICmpInst>(LHS))
- return isImpliedCondICmps(LHSCmp->getCmpPredicate(), LHSCmp->getOperand(0),
- LHSCmp->getOperand(1), RHSPred, RHSOp0, RHSOp1,
- DL, LHSIsTrue);
- const Value *V;
- if (match(LHS, m_NUWTrunc(m_Value(V))))
- return isImpliedCondICmps(CmpInst::ICMP_NE, V,
- ConstantInt::get(V->getType(), 0), RHSPred,
- RHSOp0, RHSOp1, DL, LHSIsTrue);
+ if (RHSOp0->getType()->getScalarType()->isIntOrPtrTy()) {
+ if (const auto *LHSCmp = dyn_cast<ICmpInst>(LHS))
+ return isImpliedCondICmps(LHSCmp->getCmpPredicate(),
+ LHSCmp->getOperand(0), LHSCmp->getOperand(1),
+ RHSPred, RHSOp0, RHSOp1, DL, LHSIsTrue);
+ const Value *V;
+ if (match(LHS, m_NUWTrunc(m_Value(V))))
+ return isImpliedCondICmps(CmpInst::ICMP_NE, V,
+ ConstantInt::get(V->getType(), 0), RHSPred,
+ RHSOp0, RHSOp1, DL, LHSIsTrue);
+ } else {
+ assert(RHSOp0->getType()->isFPOrFPVectorTy() &&
+ "Expected floating point type only!");
+ if (const auto *LHSCmp = dyn_cast<FCmpInst>(LHS))
+ return isImpliedCondFCmps(LHSCmp->getPredicate(), LHSCmp->getOperand(0),
+ LHSCmp->getOperand(1), RHSPred, RHSOp0, RHSOp1,
+ DL, LHSIsTrue);
+ }
/// The LHS should be an 'or', 'and', or a 'select' instruction. We expect
/// the RHS to be an icmp.
@@ -9574,6 +9647,13 @@ std::optional<bool> llvm::isImpliedCondition(const Value *LHS, const Value *RHS,
return InvertRHS ? !*Implied : *Implied;
return std::nullopt;
}
+ if (const FCmpInst *RHSCmp = dyn_cast<FCmpInst>(RHS)) {
+ if (auto Implied = isImpliedCondition(
+ LHS, RHSCmp->getPredicate(), RHSCmp->getOperand(0),
+ RHSCmp->getOperand(1), DL, LHSIsTrue, Depth))
+ return InvertRHS ? !*Implied : *Implied;
+ return std::nullopt;
+ }
const Value *V;
if (match(RHS, m_NUWTrunc(m_Value(V)))) {
diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
index 8b5965b..df0c85b 100644
--- a/llvm/lib/IR/Core.cpp
+++ b/llvm/lib/IR/Core.cpp
@@ -2994,6 +2994,8 @@ LLVMValueRef LLVMIsATerminatorInst(LLVMValueRef Inst) {
LLVMDbgRecordRef LLVMGetFirstDbgRecord(LLVMValueRef Inst) {
Instruction *Instr = unwrap<Instruction>(Inst);
+ if (!Instr->DebugMarker)
+ return nullptr;
auto I = Instr->DebugMarker->StoredDbgRecords.begin();
if (I == Instr->DebugMarker->StoredDbgRecords.end())
return nullptr;
@@ -3002,6 +3004,8 @@ LLVMDbgRecordRef LLVMGetFirstDbgRecord(LLVMValueRef Inst) {
LLVMDbgRecordRef LLVMGetLastDbgRecord(LLVMValueRef Inst) {
Instruction *Instr = unwrap<Instruction>(Inst);
+ if (!Instr->DebugMarker)
+ return nullptr;
auto I = Instr->DebugMarker->StoredDbgRecords.rbegin();
if (I == Instr->DebugMarker->StoredDbgRecords.rend())
return nullptr;
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 3df448d..8f60e50 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -17,6 +17,7 @@
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CmpInstAnalysis.h"
#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/OverflowInstAnalysis.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Analysis/VectorUtils.h"
@@ -42,6 +43,7 @@
#include "llvm/Support/KnownBits.h"
#include "llvm/Transforms/InstCombine/InstCombiner.h"
#include <cassert>
+#include <optional>
#include <utility>
#define DEBUG_TYPE "instcombine"
@@ -1451,10 +1453,16 @@ Instruction *InstCombinerImpl::foldSelectValueEquivalence(SelectInst &Sel,
return nullptr;
};
- if (Instruction *R = ReplaceOldOpWithNewOp(CmpLHS, CmpRHS))
- return R;
- if (Instruction *R = ReplaceOldOpWithNewOp(CmpRHS, CmpLHS))
- return R;
+ bool CanReplaceCmpLHSWithRHS = canReplacePointersIfEqual(CmpLHS, CmpRHS, DL);
+ if (CanReplaceCmpLHSWithRHS) {
+ if (Instruction *R = ReplaceOldOpWithNewOp(CmpLHS, CmpRHS))
+ return R;
+ }
+ bool CanReplaceCmpRHSWithLHS = canReplacePointersIfEqual(CmpRHS, CmpLHS, DL);
+ if (CanReplaceCmpRHSWithLHS) {
+ if (Instruction *R = ReplaceOldOpWithNewOp(CmpRHS, CmpLHS))
+ return R;
+ }
auto *FalseInst = dyn_cast<Instruction>(FalseVal);
if (!FalseInst)
@@ -1469,12 +1477,14 @@ Instruction *InstCombinerImpl::foldSelectValueEquivalence(SelectInst &Sel,
// Example:
// (X == 42) ? 43 : (X + 1) --> (X == 42) ? (X + 1) : (X + 1) --> X + 1
SmallVector<Instruction *> DropFlags;
- if (simplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, SQ,
- /* AllowRefinement */ false,
- &DropFlags) == TrueVal ||
- simplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, SQ,
- /* AllowRefinement */ false,
- &DropFlags) == TrueVal) {
+ if ((CanReplaceCmpLHSWithRHS &&
+ simplifyWithOpReplaced(FalseVal, CmpLHS, CmpRHS, SQ,
+ /* AllowRefinement */ false,
+ &DropFlags) == TrueVal) ||
+ (CanReplaceCmpRHSWithLHS &&
+ simplifyWithOpReplaced(FalseVal, CmpRHS, CmpLHS, SQ,
+ /* AllowRefinement */ false,
+ &DropFlags) == TrueVal)) {
for (Instruction *I : DropFlags) {
I->dropPoisonGeneratingAnnotations();
Worklist.add(I);
generated by cgit v1.1 at 2025-10-05 14:06:59 +0000