vendor/llvm-project/llvmorg-15-init-15358-g53dc0f107877

1 files changed, 65 insertions, 50 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index 0598f751febe..f4d8b79a5311 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -693,9 +693,6 @@ unsigned FAddCombine::calcInstrNumber(const AddendVect &Opnds) {
   unsigned OpndNum = Opnds.size();
   unsigned InstrNeeded = OpndNum - 1;
 
-  // The number of addends in the form of "(-1)*x".
-  unsigned NegOpndNum = 0;
-
   // Adjust the number of instructions needed to emit the N-ary add.
   for (const FAddend *Opnd : Opnds) {
     if (Opnd->isConstant())
@@ -707,9 +704,6 @@ unsigned FAddCombine::calcInstrNumber(const AddendVect &Opnds) {
       continue;
 
     const FAddendCoef &CE = Opnd->getCoef();
-    if (CE.isMinusOne() || CE.isMinusTwo())
-      NegOpndNum++;
-
     // Let the addend be "c * x". If "c == +/-1", the value of the addend
     // is immediately available; otherwise, it needs exactly one instruction
     // to evaluate the value.
@@ -1277,7 +1271,7 @@ static Instruction *factorizeMathWithShlOps(BinaryOperator &I,
 }
 
 Instruction *InstCombinerImpl::visitAdd(BinaryOperator &I) {
-  if (Value *V = SimplifyAddInst(I.getOperand(0), I.getOperand(1),
+  if (Value *V = simplifyAddInst(I.getOperand(0), I.getOperand(1),
                                  I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
                                  SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
@@ -1375,6 +1369,13 @@ Instruction *InstCombinerImpl::visitAdd(BinaryOperator &I) {
     }
   }
 
+  // (A & 2^C1) + A => A & (2^C1 - 1) iff bit C1 in A is a sign bit
+  if (match(&I, m_c_Add(m_And(m_Value(A), m_APInt(C1)), m_Deferred(A))) &&
+      C1->isPowerOf2() && (ComputeNumSignBits(A) > C1->countLeadingZeros())) {
+    Constant *NewMask = ConstantInt::get(RHS->getType(), *C1 - 1);
+    return BinaryOperator::CreateAnd(A, NewMask);
+  }
+
   // A+B --> A|B iff A and B have no bits set in common.
   if (haveNoCommonBitsSet(LHS, RHS, DL, &AC, &I, &DT))
     return BinaryOperator::CreateOr(LHS, RHS);
@@ -1528,7 +1529,7 @@ static Instruction *factorizeFAddFSub(BinaryOperator &I,
 }
 
 Instruction *InstCombinerImpl::visitFAdd(BinaryOperator &I) {
-  if (Value *V = SimplifyFAddInst(I.getOperand(0), I.getOperand(1),
+  if (Value *V = simplifyFAddInst(I.getOperand(0), I.getOperand(1),
                                   I.getFastMathFlags(),
                                   SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
@@ -1687,7 +1688,8 @@ Value *InstCombinerImpl::OptimizePointerDifference(Value *LHS, Value *RHS,
   // Require at least one GEP with a common base pointer on both sides.
   if (auto *LHSGEP = dyn_cast<GEPOperator>(LHS)) {
     // (gep X, ...) - X
-    if (LHSGEP->getOperand(0) == RHS) {
+    if (LHSGEP->getOperand(0)->stripPointerCasts() ==
+        RHS->stripPointerCasts()) {
       GEP1 = LHSGEP;
     } else if (auto *RHSGEP = dyn_cast<GEPOperator>(RHS)) {
       // (gep X, ...) - (gep X, ...)
@@ -1749,7 +1751,7 @@ Value *InstCombinerImpl::OptimizePointerDifference(Value *LHS, Value *RHS,
 }
 
 Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) {
-  if (Value *V = SimplifySubInst(I.getOperand(0), I.getOperand(1),
+  if (Value *V = simplifySubInst(I.getOperand(0), I.getOperand(1),
                                  I.hasNoSignedWrap(), I.hasNoUnsignedWrap(),
                                  SQ.getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
@@ -2014,6 +2016,37 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) {
     }
   }
 
+  if (auto *II = dyn_cast<MinMaxIntrinsic>(Op1)) {
+    {
+      // sub(add(X,Y), s/umin(X,Y)) --> s/umax(X,Y)
+      // sub(add(X,Y), s/umax(X,Y)) --> s/umin(X,Y)
+      Value *X = II->getLHS();
+      Value *Y = II->getRHS();
+      if (match(Op0, m_c_Add(m_Specific(X), m_Specific(Y))) &&
+          (Op0->hasOneUse() || Op1->hasOneUse())) {
+        Intrinsic::ID InvID = getInverseMinMaxIntrinsic(II->getIntrinsicID());
+        Value *InvMaxMin = Builder.CreateBinaryIntrinsic(InvID, X, Y);
+        return replaceInstUsesWith(I, InvMaxMin);
+      }
+    }
+
+    {
+      // sub(add(X,Y),umin(Y,Z)) --> add(X,usub.sat(Y,Z))
+      // sub(add(X,Z),umin(Y,Z)) --> add(X,usub.sat(Z,Y))
+      Value *X, *Y, *Z;
+      if (match(Op1, m_OneUse(m_UMin(m_Value(Y), m_Value(Z))))) {
+        if (match(Op0, m_OneUse(m_c_Add(m_Specific(Y), m_Value(X)))))
+          return BinaryOperator::CreateAdd(
+              X, Builder.CreateIntrinsic(Intrinsic::usub_sat, I.getType(),
+                                         {Y, Z}));
+        if (match(Op0, m_OneUse(m_c_Add(m_Specific(Z), m_Value(X)))))
+          return BinaryOperator::CreateAdd(
+              X, Builder.CreateIntrinsic(Intrinsic::usub_sat, I.getType(),
+                                         {Z, Y}));
+      }
+    }
+  }
+
   {
     // If we have a subtraction between some value and a select between
     // said value and something else, sink subtraction into select hands, i.e.:
@@ -2089,36 +2122,6 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) {
     return BinaryOperator::CreateSub(X, Not);
   }
 
-  // TODO: This is the same logic as above but handles the cmp-select idioms
-  //       for min/max, so the use checks are increased to account for the
-  //       extra instructions. If we canonicalize to intrinsics, this block
-  //       can likely be removed.
-  {
-    Value *LHS, *RHS, *A;
-    Value *NotA = Op0, *MinMax = Op1;
-    SelectPatternFlavor SPF = matchSelectPattern(MinMax, LHS, RHS).Flavor;
-    if (!SelectPatternResult::isMinOrMax(SPF)) {
-      NotA = Op1;
-      MinMax = Op0;
-      SPF = matchSelectPattern(MinMax, LHS, RHS).Flavor;
-    }
-    if (SelectPatternResult::isMinOrMax(SPF) &&
-        match(NotA, m_Not(m_Value(A))) && (NotA == LHS || NotA == RHS)) {
-      if (NotA == LHS)
-        std::swap(LHS, RHS);
-      // LHS is now Y above and expected to have at least 2 uses (the min/max)
-      // NotA is expected to have 2 uses from the min/max and 1 from the sub.
-      if (isFreeToInvert(LHS, !LHS->hasNUsesOrMore(3)) &&
-          !NotA->hasNUsesOrMore(4)) {
-        Value *Not = Builder.CreateNot(MinMax);
-        if (NotA == Op0)
-          return BinaryOperator::CreateSub(Not, A);
-        else
-          return BinaryOperator::CreateSub(A, Not);
-      }
-    }
-  }
-
   // Optimize pointer differences into the same array into a size.  Consider:
   //  &A[10] - &A[0]: we should compile this to "10".
   Value *LHSOp, *RHSOp;
@@ -2149,11 +2152,11 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) {
     // B = ashr i32 A, 31 ; smear the sign bit
     // sub (xor A, B), B  ; flip bits if negative and subtract -1 (add 1)
     // --> (A < 0) ? -A : A
-    Value *Cmp = Builder.CreateICmpSLT(A, ConstantInt::getNullValue(Ty));
+    Value *IsNeg = Builder.CreateIsNeg(A);
     // Copy the nuw/nsw flags from the sub to the negate.
-    Value *Neg = Builder.CreateNeg(A, "", I.hasNoUnsignedWrap(),
-                                   I.hasNoSignedWrap());
-    return SelectInst::Create(Cmp, Neg, A);
+    Value *NegA = Builder.CreateNeg(A, "", I.hasNoUnsignedWrap(),
+                                    I.hasNoSignedWrap());
+    return SelectInst::Create(IsNeg, NegA, A);
   }
 
   // If we are subtracting a low-bit masked subset of some value from an add
@@ -2187,12 +2190,23 @@ Instruction *InstCombinerImpl::visitSub(BinaryOperator &I) {
     return replaceInstUsesWith(
         I, Builder.CreateIntrinsic(Intrinsic::usub_sat, {Ty}, {X, Op1}));
 
+  // Op0 - umin(X, Op0) --> usub.sat(Op0, X)
+  if (match(Op1, m_OneUse(m_c_UMin(m_Value(X), m_Specific(Op0)))))
+    return replaceInstUsesWith(
+        I, Builder.CreateIntrinsic(Intrinsic::usub_sat, {Ty}, {Op0, X}));
+
   // Op0 - umax(X, Op0) --> 0 - usub.sat(X, Op0)
   if (match(Op1, m_OneUse(m_c_UMax(m_Value(X), m_Specific(Op0))))) {
     Value *USub = Builder.CreateIntrinsic(Intrinsic::usub_sat, {Ty}, {X, Op0});
     return BinaryOperator::CreateNeg(USub);
   }
 
+  // umin(X, Op1) - Op1 --> 0 - usub.sat(Op1, X)
+  if (match(Op0, m_OneUse(m_c_UMin(m_Value(X), m_Specific(Op1))))) {
+    Value *USub = Builder.CreateIntrinsic(Intrinsic::usub_sat, {Ty}, {Op1, X});
+    return BinaryOperator::CreateNeg(USub);
+  }
+
   // C - ctpop(X) => ctpop(~X) if C is bitwidth
   if (match(Op0, m_SpecificInt(Ty->getScalarSizeInBits())) &&
       match(Op1, m_OneUse(m_Intrinsic<Intrinsic::ctpop>(m_Value(X)))))
@@ -2264,7 +2278,7 @@ static Instruction *hoistFNegAboveFMulFDiv(Instruction &I,
 Instruction *InstCombinerImpl::visitFNeg(UnaryOperator &I) {
   Value *Op = I.getOperand(0);
 
-  if (Value *V = SimplifyFNegInst(Op, I.getFastMathFlags(),
+  if (Value *V = simplifyFNegInst(Op, I.getFastMathFlags(),
                                   getSimplifyQuery().getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);
 
@@ -2287,10 +2301,11 @@ Instruction *InstCombinerImpl::visitFNeg(UnaryOperator &I) {
     // Unlike most transforms, this one is not safe to propagate nsz unless
     // it is present on the original select. (We are conservatively intersecting
     // the nsz flags from the select and root fneg instruction.)
-    auto propagateSelectFMF = [&](SelectInst *S) {
+    auto propagateSelectFMF = [&](SelectInst *S, bool CommonOperand) {
       S->copyFastMathFlags(&I);
       if (auto *OldSel = dyn_cast<SelectInst>(Op))
-        if (!OldSel->hasNoSignedZeros())
+        if (!OldSel->hasNoSignedZeros() && !CommonOperand &&
+            !isGuaranteedNotToBeUndefOrPoison(OldSel->getCondition()))
           S->setHasNoSignedZeros(false);
     };
     // -(Cond ? -P : Y) --> Cond ? P : -Y
@@ -2298,14 +2313,14 @@ Instruction *InstCombinerImpl::visitFNeg(UnaryOperator &I) {
     if (match(X, m_FNeg(m_Value(P)))) {
       Value *NegY = Builder.CreateFNegFMF(Y, &I, Y->getName() + ".neg");
       SelectInst *NewSel = SelectInst::Create(Cond, P, NegY);
-      propagateSelectFMF(NewSel);
+      propagateSelectFMF(NewSel, P == Y);
       return NewSel;
     }
     // -(Cond ? X : -P) --> Cond ? -X : P
     if (match(Y, m_FNeg(m_Value(P)))) {
       Value *NegX = Builder.CreateFNegFMF(X, &I, X->getName() + ".neg");
       SelectInst *NewSel = SelectInst::Create(Cond, NegX, P);
-      propagateSelectFMF(NewSel);
+      propagateSelectFMF(NewSel, P == X);
       return NewSel;
     }
   }
@@ -2314,7 +2329,7 @@ Instruction *InstCombinerImpl::visitFNeg(UnaryOperator &I) {
 }
 
 Instruction *InstCombinerImpl::visitFSub(BinaryOperator &I) {
-  if (Value *V = SimplifyFSubInst(I.getOperand(0), I.getOperand(1),
+  if (Value *V = simplifyFSubInst(I.getOperand(0), I.getOperand(1),
                                   I.getFastMathFlags(),
                                   getSimplifyQuery().getWithInstruction(&I)))
     return replaceInstUsesWith(I, V);