2 files changed, 107 insertions, 1 deletions
diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelperVectorOps.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelperVectorOps.cpp
index 123bf21f657c..fb33801a3a33 100644
--- a/llvm/lib/CodeGen/GlobalISel/CombinerHelperVectorOps.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelperVectorOps.cpp
@@ -77,7 +77,7 @@ bool CombinerHelper::matchExtractVectorElement(MachineInstr &MI,
 
   // Fold extractVectorElement(Vector, TOOLARGE) -> undef
   if (IndexC && VectorTy.isFixedVector() &&
-      IndexC->getZExtValue() >= VectorTy.getNumElements() &&
+      IndexC->uge(VectorTy.getNumElements()) &&
       isLegalOrBeforeLegalizer({TargetOpcode::G_IMPLICIT_DEF, {DstTy}})) {
     // For fixed-length vectors, it's invalid to extract out-of-range elements.
     MatchInfo = [=](MachineIRBuilder &B) { B.buildUndef(Dst); };
@@ -324,3 +324,26 @@ bool CombinerHelper::matchExtractVectorElementWithBuildVectorTrunc(
 
   return true;
 }
+
+bool CombinerHelper::matchInsertVectorElementOOB(MachineInstr &MI,
+                                                 BuildFnTy &MatchInfo) {
+  GInsertVectorElement *Insert = cast<GInsertVectorElement>(&MI);
+
+  Register Dst = Insert->getReg(0);
+  LLT DstTy = MRI.getType(Dst);
+  Register Index = Insert->getIndexReg();
+
+  if (!DstTy.isFixedVector())
+    return false;
+
+  std::optional<ValueAndVReg> MaybeIndex =
+      getIConstantVRegValWithLookThrough(Index, MRI);
+
+  if (MaybeIndex && MaybeIndex->Value.uge(DstTy.getNumElements()) &&
+      isLegalOrBeforeLegalizer({TargetOpcode::G_IMPLICIT_DEF, {DstTy}})) {
+    MatchInfo = [=](MachineIRBuilder &B) { B.buildUndef(Dst); };
+    return true;
+  }
+
+  return false;
+}
diff --git a/llvm/lib/CodeGen/GlobalISel/Utils.cpp b/llvm/lib/CodeGen/GlobalISel/Utils.cpp
index ae43e9ccf611..4e3781cb4e9d 100644
--- a/llvm/lib/CodeGen/GlobalISel/Utils.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/Utils.cpp
@@ -12,6 +12,7 @@
 #include "llvm/CodeGen/GlobalISel/Utils.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APInt.h"
+#include "llvm/Analysis/ValueTracking.h"
 #include "llvm/CodeGen/CodeGenCommonISel.h"
 #include "llvm/CodeGen/GlobalISel/GISelChangeObserver.h"
 #include "llvm/CodeGen/GlobalISel/GISelKnownBits.h"
@@ -28,6 +29,7 @@
 #include "llvm/CodeGen/StackProtector.h"
 #include "llvm/CodeGen/TargetInstrInfo.h"
 #include "llvm/CodeGen/TargetLowering.h"
+#include "llvm/CodeGen/TargetOpcodes.h"
 #include "llvm/CodeGen/TargetPassConfig.h"
 #include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/IR/Constants.h"
@@ -1709,3 +1711,84 @@ bool llvm::isPreISelGenericFloatingPointOpcode(unsigned Opc) {
     return false;
   }
 }
+
+namespace {
+enum class UndefPoisonKind {
+  PoisonOnly = (1 << 0),
+  UndefOnly = (1 << 1),
+  UndefOrPoison = PoisonOnly | UndefOnly,
+};
+}
+
+[[maybe_unused]] static bool includesPoison(UndefPoisonKind Kind) {
+  return (unsigned(Kind) & unsigned(UndefPoisonKind::PoisonOnly)) != 0;
+}
+
+[[maybe_unused]] static bool includesUndef(UndefPoisonKind Kind) {
+  return (unsigned(Kind) & unsigned(UndefPoisonKind::UndefOnly)) != 0;
+}
+
+static bool canCreateUndefOrPoison(Register Reg, const MachineRegisterInfo &MRI,
+                                   bool ConsiderFlagsAndMetadata,
+                                   UndefPoisonKind Kind) {
+  MachineInstr *RegDef = MRI.getVRegDef(Reg);
+
+  switch (RegDef->getOpcode()) {
+  case TargetOpcode::G_FREEZE:
+    return false;
+  default:
+    return true;
+  }
+}
+
+static bool isGuaranteedNotToBeUndefOrPoison(Register Reg,
+                                             const MachineRegisterInfo &MRI,
+                                             unsigned Depth,
+                                             UndefPoisonKind Kind) {
+  if (Depth >= MaxAnalysisRecursionDepth)
+    return false;
+
+  MachineInstr *RegDef = MRI.getVRegDef(Reg);
+
+  switch (RegDef->getOpcode()) {
+  case TargetOpcode::G_FREEZE:
+    return true;
+  case TargetOpcode::G_IMPLICIT_DEF:
+    return !includesUndef(Kind);
+  default:
+    return false;
+  }
+}
+
+bool llvm::canCreateUndefOrPoison(Register Reg, const MachineRegisterInfo &MRI,
+                                  bool ConsiderFlagsAndMetadata) {
+  return ::canCreateUndefOrPoison(Reg, MRI, ConsiderFlagsAndMetadata,
+                                  UndefPoisonKind::UndefOrPoison);
+}
+
+bool canCreatePoison(Register Reg, const MachineRegisterInfo &MRI,
+                     bool ConsiderFlagsAndMetadata = true) {
+  return ::canCreateUndefOrPoison(Reg, MRI, ConsiderFlagsAndMetadata,
+                                  UndefPoisonKind::PoisonOnly);
+}
+
+bool llvm::isGuaranteedNotToBeUndefOrPoison(Register Reg,
+                                            const MachineRegisterInfo &MRI,
+                                            unsigned Depth) {
+  return ::isGuaranteedNotToBeUndefOrPoison(Reg, MRI, Depth,
+                                            UndefPoisonKind::UndefOrPoison);
+}
+
+bool llvm::isGuaranteedNotToBePoison(Register Reg,
+                                     const MachineRegisterInfo &MRI,
+                                     unsigned Depth) {
+  return ::isGuaranteedNotToBeUndefOrPoison(Reg, MRI, Depth,
+                                            UndefPoisonKind::PoisonOnly);
+}
+
+bool llvm::isGuaranteedNotToBeUndef(Register Reg,
+                                    const MachineRegisterInfo &MRI,
+                                    unsigned Depth) {
+  return ::isGuaranteedNotToBeUndefOrPoison(Reg, MRI, Depth,
+                                            UndefPoisonKind::UndefOnly);
+}