[SimplifyInst] Push commuted op checks for and/or of icmp further down to avoid duplicate work

[craig.topper]

Summary

Previously, we called simplifyPossiblyCastedAndOrOfICmps twice with the operands commuted, but the call to simplifyAndOrOfICmpsWithConstants further down already handles commuting and doesn't need to be called both ways.

This patch pushes double calls further down to just the individual routines that need to be called twice.

[craig.topper]

Fix a compile failure from when I inlined simplifyPossiblyCastedAndOrOfICmps

[spatel]

LGTM.

lib/Analysis/InstructionSimplify.cpp

static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
   return nullptr;
 }
 
 Value *llvm::SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact,
                               const SimplifyQuery &Q) {
   return ::SimplifyAShrInst(Op0, Op1, isExact, Q, RecursionLimit);
 }
 
+/// Commuted variants are assumed to be handled by calling this function again
+/// with the parameters swapped.
 static Value *simplifyUnsignedRangeCheck(ICmpInst *ZeroICmp,
                                          ICmpInst *UnsignedICmp, bool IsAnd) {
   Value *X, *Y;
 
   ICmpInst::Predicate EqPred;
   if (!match(ZeroICmp, m_ICmp(EqPred, m_Value(Y), m_Zero())) ||
       !ICmpInst::isEquality(EqPred))
     return nullptr;
static Value *simplifyAndOrOfICmpsWithConstants(ICmpInst *Cmp0, ICmpInst *Cmp1,
   if (Range0.contains(Range1))
     return IsAnd ? Cmp1 : Cmp0;
   if (Range1.contains(Range0))
     return IsAnd ? Cmp0 : Cmp1;
 
   return nullptr;
 }
 
-/// Commuted variants are assumed to be handled by calling this function again
-/// with the parameters swapped.
-static Value *simplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
-  if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/true))
-    return X;
-
-  if (Value *X = simplifyAndOfICmpsWithSameOperands(Op0, Op1))
-    return X;
-
-  if (Value *X = simplifyAndOrOfICmpsWithConstants(Op0, Op1, true))
-    return X;
-
+static Value *simplifyAndOfICmpsWithAdd(ICmpInst *Op0, ICmpInst *Op1) {
   // (icmp (add V, C0), C1) & (icmp V, C0)
   ICmpInst::Predicate Pred0, Pred1;
   const APInt *C0, *C1;
   Value *V;
   if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_APInt(C0)), m_APInt(C1))))
     return nullptr;
 
   if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Value())))
if (C0->getBoolValue() && isNUW) {
     if (Delta == 1)
       if (Pred0 == ICmpInst::ICMP_ULE && Pred1 == ICmpInst::ICMP_UGT)
         return getFalse(ITy);
   }
 
   return nullptr;
 }
 
-/// Commuted variants are assumed to be handled by calling this function again
-/// with the parameters swapped.
-static Value *simplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
-  if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false))
+static Value *simplifyAndOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
+  if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/true))
+    return X;
+  if (Value *X = simplifyUnsignedRangeCheck(Op1, Op0, /*IsAnd=*/true))
     return X;
 
-  if (Value *X = simplifyOrOfICmpsWithSameOperands(Op0, Op1))
+  if (Value *X = simplifyAndOfICmpsWithSameOperands(Op0, Op1))
+    return X;
+  if (Value *X = simplifyAndOfICmpsWithSameOperands(Op1, Op0))
     return X;
 
-  if (Value *X = simplifyAndOrOfICmpsWithConstants(Op0, Op1, false))
+  if (Value *X = simplifyAndOrOfICmpsWithConstants(Op0, Op1, true))
+    return X;
+
+  if (Value *X = simplifyAndOfICmpsWithAdd(Op0, Op1))
+    return X;
+  if (Value *X = simplifyAndOfICmpsWithAdd(Op1, Op0))
     return X;
 
+  return nullptr;
+}
+
+static Value *simplifyOrOfICmpsWithAdd(ICmpInst *Op0, ICmpInst *Op1) {
   // (icmp (add V, C0), C1) | (icmp V, C0)
   ICmpInst::Predicate Pred0, Pred1;
   const APInt *C0, *C1;
   Value *V;
   if (!match(Op0, m_ICmp(Pred0, m_Add(m_Value(V), m_APInt(C0)), m_APInt(C1))))
     return nullptr;
 
   if (!match(Op1, m_ICmp(Pred1, m_Specific(V), m_Value())))
if (C0->getBoolValue() && isNUW) {
     if (Delta == 1)
       if (Pred0 == ICmpInst::ICMP_UGT && Pred1 == ICmpInst::ICMP_ULE)
         return getTrue(ITy);
   }
 
   return nullptr;
 }
 
-static Value *simplifyPossiblyCastedAndOrOfICmps(ICmpInst *Cmp0, ICmpInst *Cmp1,
-                                                 bool IsAnd, CastInst *Cast) {
-  Value *V =
-      IsAnd ? simplifyAndOfICmps(Cmp0, Cmp1) : simplifyOrOfICmps(Cmp0, Cmp1);
-  if (!V)
-    return nullptr;
-  if (!Cast)
-    return V;
+static Value *simplifyOrOfICmps(ICmpInst *Op0, ICmpInst *Op1) {
+  if (Value *X = simplifyUnsignedRangeCheck(Op0, Op1, /*IsAnd=*/false))
+    return X;
+  if (Value *X = simplifyUnsignedRangeCheck(Op1, Op0, /*IsAnd=*/false))
+    return X;
 
-  // If we looked through casts, we can only handle a constant simplification
-  // because we are not allowed to create a cast instruction here.
-  if (auto *C = dyn_cast<Constant>(V))
-    return ConstantExpr::getCast(Cast->getOpcode(), C, Cast->getType());
+  if (Value *X = simplifyOrOfICmpsWithSameOperands(Op0, Op1))
+    return X;
+  if (Value *X = simplifyOrOfICmpsWithSameOperands(Op1, Op0))
+    return X;
+
+  if (Value *X = simplifyAndOrOfICmpsWithConstants(Op0, Op1, false))
+    return X;
+
+  if (Value *X = simplifyOrOfICmpsWithAdd(Op0, Op1))
+    return X;
+  if (Value *X = simplifyOrOfICmpsWithAdd(Op1, Op0))
+    return X;
 
   return nullptr;
 }
 
 static Value *simplifyAndOrOfICmps(Value *Op0, Value *Op1, bool IsAnd) {
   // Look through casts of the 'and' operands to find compares.
   auto *Cast0 = dyn_cast<CastInst>(Op0);
   auto *Cast1 = dyn_cast<CastInst>(Op1);
   if (Cast0 && Cast1 && Cast0->getOpcode() == Cast1->getOpcode() &&
       Cast0->getSrcTy() == Cast1->getSrcTy()) {
     Op0 = Cast0->getOperand(0);
     Op1 = Cast1->getOperand(0);
   }
 
   auto *Cmp0 = dyn_cast<ICmpInst>(Op0);
   auto *Cmp1 = dyn_cast<ICmpInst>(Op1);
   if (!Cmp0 || !Cmp1)
     return nullptr;
 
-  if (Value *V = simplifyPossiblyCastedAndOrOfICmps(Cmp0, Cmp1, IsAnd, Cast0))
-    return V;
-  if (Value *V = simplifyPossiblyCastedAndOrOfICmps(Cmp1, Cmp0, IsAnd, Cast0))
+  Value *V =
+      IsAnd ? simplifyAndOfICmps(Cmp0, Cmp1) : simplifyOrOfICmps(Cmp0, Cmp1);
+  if (!V)
+    return nullptr;
+  if (!Cast)
     return V;
 
+  // If we looked through casts, we can only handle a constant simplification
+  // because we are not allowed to create a cast instruction here.
+  if (auto *C = dyn_cast<Constant>(V))
+    return ConstantExpr::getCast(Cast->getOpcode(), C, Cast->getType());
+
   return nullptr;
 }
 
 /// Given operands for an And, see if we can fold the result.
 /// If not, this returns null.
 static Value *SimplifyAndInst(Value *Op0, Value *Op1, const SimplifyQuery &Q,
                               unsigned MaxRecurse) {
   if (Constant *C = foldOrCommuteConstant(Instruction::And, Op0, Op1, Q))