[InstSimplify] Simplify getoffset/getaddr folding. NFC

Now that we depend on C++14, we can use switches in constexpr functions
and no longer need to pass two template parameters.

Author: arichardson

llvm/include/llvm/IR/CheriIntrinsics.h

@@ -21,7 +21,8 @@
 namespace llvm {
 namespace cheri {
 
-inline Intrinsic::ID correspondingSetIntrinsic(Intrinsic::ID GetIntrin) {
+inline constexpr Intrinsic::ID
+correspondingSetIntrinsic(Intrinsic::ID GetIntrin) {
   switch (GetIntrin) {
   case Intrinsic::cheri_cap_offset_get:
     return Intrinsic::cheri_cap_offset_set;
@@ -33,7 +34,8 @@ inline Intrinsic::ID correspondingSetIntrinsic(Intrinsic::ID GetIntrin) {
     llvm_unreachable("No matching set intrinsic");
   }
 }
-inline Intrinsic::ID correspondingGetIntrinsic(Intrinsic::ID SetIntrin) {
+inline constexpr Intrinsic::ID
+correspondingGetIntrinsic(Intrinsic::ID SetIntrin) {
   switch (SetIntrin) {
   case Intrinsic::cheri_cap_offset_set:
     return Intrinsic::cheri_cap_offset_get;

llvm/lib/Analysis/InstructionSimplify.cpp

@@ -6366,9 +6366,10 @@ stripAndAccumulateGEPsAndPointerCastsSameRepr(Value *V, const DataLayout &DL,
   return Result;
 }
 
-template <Intrinsic::ID Intrin, Intrinsic::ID SetIntrin>
+template <Intrinsic::ID Intrin>
 static Value *inferCapabilityOffsetOrAddr(Value *V, Type *ResultTy,
                                           const DataLayout &DL) {
+  constexpr Intrinsic::ID SetIntrin = cheri::correspondingSetIntrinsic(Intrin);
   // Try to infer the offset/address from a prior setoffset/setaddr value
   Value *IntrinArg = nullptr;
   // getaddr(setaddr(A, B)) -> B and getoffset(setoffset(A, B)) -> B
@@ -6427,20 +6428,6 @@ static Value *inferCapabilityOffsetOrAddr(Value *V, Type *ResultTy,
   return nullptr;
 }
 
-Value *simplifyCapabilityGetOffset(Value *V, Type *ResultTy,
-                                   const DataLayout &DL) {
-  return inferCapabilityOffsetOrAddr<Intrinsic::cheri_cap_offset_get,
-                                     Intrinsic::cheri_cap_offset_set>(
-      V, ResultTy, DL);
-}
-
-Value *simplifyCapabilityGetAddress(Value *V, Type *ResultTy,
-                                    const DataLayout &DL) {
-  return inferCapabilityOffsetOrAddr<Intrinsic::cheri_cap_address_get,
-                                     Intrinsic::cheri_cap_address_set>(
-      V, ResultTy, DL);
-}
-
 static Value *simplifyUnaryIntrinsic(Function *F, Value *Op0,
                                      const SimplifyQuery &Q,
                                      const CallBase *Call) {
@@ -6519,11 +6506,13 @@ static Value *simplifyUnaryIntrinsic(Function *F, Value *Op0,
   case Intrinsic::cheri_cap_length_get:
     break;
   case Intrinsic::cheri_cap_address_get:
-    if (Value *V = simplifyCapabilityGetAddress(Op0, F->getReturnType(), Q.DL))
+    if (auto *V = inferCapabilityOffsetOrAddr<Intrinsic::cheri_cap_address_get>(
+            Op0, F->getReturnType(), Q.DL))
       return V;
     break;
   case Intrinsic::cheri_cap_offset_get:
-    if (Value *V = simplifyCapabilityGetOffset(Op0, F->getReturnType(), Q.DL))
+    if (auto *V = inferCapabilityOffsetOrAddr<Intrinsic::cheri_cap_offset_get>(
+            Op0, F->getReturnType(), Q.DL))
       return V;
     break;