[GlobalIsel] Import GEP flags

llvm#90824

Author: tschuett

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

@@ -1583,10 +1583,8 @@ bool IRTranslator::translateGetElementPtr(const User &U,
   LLT OffsetTy = getLLTForType(*OffsetIRTy, *DL);
 
   uint32_t Flags = 0;
-  if (isa<Instruction>(U)) {
-    const Instruction &I = cast<Instruction>(U);
-    Flags = MachineInstr::copyFlagsFromInstruction(I);
-  }
+  if (const Instruction *I = dyn_cast<Instruction>(&U))
+    Flags = MachineInstr::copyFlagsFromInstruction(*I);
 
   // Normalize Vector GEP - all scalar operands should be converted to the
   // splat vector.

llvm/lib/CodeGen/MachineInstr.cpp

@@ -576,6 +576,11 @@ uint32_t MachineInstr::copyFlagsFromInstruction(const Instruction &I) {
       MIFlags |= MachineInstr::MIFlag::NoSWrap;
     if (TI->hasNoUnsignedWrap())
       MIFlags |= MachineInstr::MIFlag::NoUWrap;
+  } else if (const GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(&I)) {
+    if (GEP->hasNoUnsignedSignedWrap())
+      MIFlags |= MachineInstr::MIFlag::NoSWrap;
+    if (GEP->hasNoUnsignedWrap())
+      MIFlags |= MachineInstr::MIFlag::NoUWrap;
   }
 
   // Copy the nonneg flag.