InstCombine: Refactor fmul/fdiv combines to handle vectors.

llvm-svn: 199598
llvm · Jan 19, 2014 · 76b15d0 · 76b15d0
1 parent c28a9a2
commit 76b15d0
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Showing 4 changed files with 118 additions and 65 deletions.
diff --git a/llvm/lib/Transforms/InstCombine/InstCombine.h b/llvm/lib/Transforms/InstCombine/InstCombine.h
@@ -116,7 +116,7 @@ class LLVM_LIBRARY_VISIBILITY InstCombiner
   Instruction *visitSub(BinaryOperator &I);
   Instruction *visitFSub(BinaryOperator &I);
   Instruction *visitMul(BinaryOperator &I);
-  Value *foldFMulConst(Instruction *FMulOrDiv, ConstantFP *C,
+  Value *foldFMulConst(Instruction *FMulOrDiv, Constant *C,
                        Instruction *InsertBefore);
   Instruction *visitFMul(BinaryOperator &I);
   Instruction *visitURem(BinaryOperator &I);

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -313,16 +313,41 @@ static void detectLog2OfHalf(Value *&Op, Value *&Y, IntrinsicInst *&Log2) {
    if (I->getOpcode() != Instruction::FMul || !I->hasUnsafeAlgebra())
      return;
 
-   ConstantFP *CFP = dyn_cast<ConstantFP>(I->getOperand(0));
-   if (CFP && CFP->isExactlyValue(0.5)) {
+   if (match(I->getOperand(0), m_SpecificFP(0.5)))
      Y = I->getOperand(1);
-     return;
-   }
-   CFP = dyn_cast<ConstantFP>(I->getOperand(1));
-   if (CFP && CFP->isExactlyValue(0.5))
+   else if (match(I->getOperand(1), m_SpecificFP(0.5)))
      Y = I->getOperand(0);
 }
 
+static bool isFiniteNonZeroFp(Constant *C) {
+  if (C->getType()->isVectorTy()) {
+    for (unsigned I = 0, E = C->getType()->getVectorNumElements(); I != E;
+         ++I) {
+      ConstantFP *CFP = dyn_cast<ConstantFP>(C->getAggregateElement(I));
+      if (!CFP || !CFP->getValueAPF().isFiniteNonZero())
+        return false;
+    }
+    return true;
+  }
+
+  return isa<ConstantFP>(C) &&
+         cast<ConstantFP>(C)->getValueAPF().isFiniteNonZero();
+}
+
+static bool isNormalFp(Constant *C) {
+  if (C->getType()->isVectorTy()) {
+    for (unsigned I = 0, E = C->getType()->getVectorNumElements(); I != E;
+         ++I) {
+      ConstantFP *CFP = dyn_cast<ConstantFP>(C->getAggregateElement(I));
+      if (!CFP || !CFP->getValueAPF().isNormal())
+        return false;
+    }
+    return true;
+  }
+
+  return isa<ConstantFP>(C) && cast<ConstantFP>(C)->getValueAPF().isNormal();
+}
+
 /// Helper function of InstCombiner::visitFMul(BinaryOperator(). It returns
 /// true iff the given value is FMul or FDiv with one and only one operand
 /// being a normal constant (i.e. not Zero/NaN/Infinity).
@@ -332,19 +357,13 @@ static bool isFMulOrFDivWithConstant(Value *V) {
              I->getOpcode() != Instruction::FDiv))
     return false;
 
-  ConstantFP *C0 = dyn_cast<ConstantFP>(I->getOperand(0));
-  ConstantFP *C1 = dyn_cast<ConstantFP>(I->getOperand(1));
+  Constant *C0 = dyn_cast<Constant>(I->getOperand(0));
+  Constant *C1 = dyn_cast<Constant>(I->getOperand(1));
 
   if (C0 && C1)
     return false;
 
-  return (C0 && C0->getValueAPF().isFiniteNonZero()) ||
-         (C1 && C1->getValueAPF().isFiniteNonZero());
-}
-
-static bool isNormalFp(const ConstantFP *C) {
-  const APFloat &Flt = C->getValueAPF();
-  return Flt.isNormal();
+  return (C0 && isFiniteNonZeroFp(C0)) || (C1 && isFiniteNonZeroFp(C1));
 }
 
 /// foldFMulConst() is a helper routine of InstCombiner::visitFMul().
@@ -354,41 +373,41 @@ static bool isNormalFp(const ConstantFP *C) {
 /// resulting expression. Note that this function could return NULL in
 /// case the constants cannot be folded into a normal floating-point.
 ///
-Value *InstCombiner::foldFMulConst(Instruction *FMulOrDiv, ConstantFP *C,
+Value *InstCombiner::foldFMulConst(Instruction *FMulOrDiv, Constant *C,
                                    Instruction *InsertBefore) {
   assert(isFMulOrFDivWithConstant(FMulOrDiv) && "V is invalid");
 
   Value *Opnd0 = FMulOrDiv->getOperand(0);
   Value *Opnd1 = FMulOrDiv->getOperand(1);
 
-  ConstantFP *C0 = dyn_cast<ConstantFP>(Opnd0);
-  ConstantFP *C1 = dyn_cast<ConstantFP>(Opnd1);
+  Constant *C0 = dyn_cast<Constant>(Opnd0);
+  Constant *C1 = dyn_cast<Constant>(Opnd1);
 
   BinaryOperator *R = 0;
 
   // (X * C0) * C => X * (C0*C)
   if (FMulOrDiv->getOpcode() == Instruction::FMul) {
     Constant *F = ConstantExpr::getFMul(C1 ? C1 : C0, C);
-    if (isNormalFp(cast<ConstantFP>(F)))
+    if (isNormalFp(F))
       R = BinaryOperator::CreateFMul(C1 ? Opnd0 : Opnd1, F);
   } else {
     if (C0) {
       // (C0 / X) * C => (C0 * C) / X
       if (FMulOrDiv->hasOneUse()) {
         // It would otherwise introduce another div.
-        ConstantFP *F = cast<ConstantFP>(ConstantExpr::getFMul(C0, C));
+        Constant *F = ConstantExpr::getFMul(C0, C);
         if (isNormalFp(F))
           R = BinaryOperator::CreateFDiv(F, Opnd1);
       }
     } else {
       // (X / C1) * C => X * (C/C1) if C/C1 is not a denormal
-      ConstantFP *F = cast<ConstantFP>(ConstantExpr::getFDiv(C, C1));
+      Constant *F = ConstantExpr::getFDiv(C, C1);
       if (isNormalFp(F)) {
         R = BinaryOperator::CreateFMul(Opnd0, F);
       } else {
         // (X / C1) * C => X / (C1/C)
         Constant *F = ConstantExpr::getFDiv(C1, C);
-        if (isNormalFp(cast<ConstantFP>(F)))
+        if (isNormalFp(F))
           R = BinaryOperator::CreateFDiv(Opnd0, F);
       }
     }
@@ -433,17 +452,15 @@ Instruction *InstCombiner::visitFMul(BinaryOperator &I) {
       return RI;
     }
 
-    ConstantFP *C = dyn_cast<ConstantFP>(Op1);
-    if (C && AllowReassociate && C->getValueAPF().isFiniteNonZero()) {
+    Constant *C = cast<Constant>(Op1);
+    if (AllowReassociate && isFiniteNonZeroFp(C)) {
       // Let MDC denote an expression in one of these forms:
       // X * C, C/X, X/C, where C is a constant.
       //
       // Try to simplify "MDC * Constant"
-      if (isFMulOrFDivWithConstant(Op0)) {
-        Value *V = foldFMulConst(cast<Instruction>(Op0), C, &I);
-        if (V)
+      if (isFMulOrFDivWithConstant(Op0))
+        if (Value *V = foldFMulConst(cast<Instruction>(Op0), C, &I))
           return ReplaceInstUsesWith(I, V);
-      }
 
       // (MDC +/- C1) * C => (MDC * C) +/- (C1 * C)
       Instruction *FAddSub = dyn_cast<Instruction>(Op0);
@@ -452,19 +469,18 @@ Instruction *InstCombiner::visitFMul(BinaryOperator &I) {
            FAddSub->getOpcode() == Instruction::FSub)) {
         Value *Opnd0 = FAddSub->getOperand(0);
         Value *Opnd1 = FAddSub->getOperand(1);
-        ConstantFP *C0 = dyn_cast<ConstantFP>(Opnd0);
-        ConstantFP *C1 = dyn_cast<ConstantFP>(Opnd1);
+        Constant *C0 = dyn_cast<Constant>(Opnd0);
+        Constant *C1 = dyn_cast<Constant>(Opnd1);
         bool Swap = false;
         if (C0) {
           std::swap(C0, C1);
           std::swap(Opnd0, Opnd1);
           Swap = true;
         }
 
-        if (C1 && C1->getValueAPF().isFiniteNonZero() &&
-            isFMulOrFDivWithConstant(Opnd0)) {
+        if (C1 && isFiniteNonZeroFp(C1) && isFMulOrFDivWithConstant(Opnd0)) {
           Value *M1 = ConstantExpr::getFMul(C1, C);
-          Value *M0 = isNormalFp(cast<ConstantFP>(M1)) ?
+          Value *M0 = isNormalFp(cast<Constant>(M1)) ?
                       foldFMulConst(cast<Instruction>(Opnd0), C, &I) :
                       0;
           if (M0 && M1) {
@@ -575,7 +591,8 @@ Instruction *InstCombiner::visitFMul(BinaryOperator &I) {
       if (!match(RHS, m_UIToFP(m_Value(C))))
         std::swap(LHS, RHS);
 
-      if (match(RHS, m_UIToFP(m_Value(C))) && C->getType()->isIntegerTy(1)) {
+      if (match(RHS, m_UIToFP(m_Value(C))) &&
+          C->getType()->getScalarType()->isIntegerTy(1)) {
         B = LHS;
         Value *Zero = ConstantFP::getNegativeZero(B->getType());
         return SelectInst::Create(C, B, Zero);
@@ -590,7 +607,7 @@ Instruction *InstCombiner::visitFMul(BinaryOperator &I) {
         std::swap(LHS, RHS);
 
       if (match(RHS, m_FSub(m_FPOne(), m_UIToFP(m_Value(C)))) &&
-          C->getType()->isIntegerTy(1)) {
+          C->getType()->getScalarType()->isIntegerTy(1)) {
         A = LHS;
         Value *Zero = ConstantFP::getNegativeZero(A->getType());
         return SelectInst::Create(C, Zero, A);
@@ -976,9 +993,12 @@ Instruction *InstCombiner::visitSDiv(BinaryOperator &I) {
 /// returned; otherwise, NULL is returned.
 ///
 static Instruction *CvtFDivConstToReciprocal(Value *Dividend,
-                                             ConstantFP *Divisor,
+                                             Constant *Divisor,
                                              bool AllowReciprocal) {
-  const APFloat &FpVal = Divisor->getValueAPF();
+  if (!isa<ConstantFP>(Divisor)) // TODO: handle vectors.
+    return 0;
+
+  const APFloat &FpVal = cast<ConstantFP>(Divisor)->getValueAPF();
   APFloat Reciprocal(FpVal.getSemantics());
   bool Cvt = FpVal.getExactInverse(&Reciprocal);
 
@@ -1010,32 +1030,29 @@ Instruction *InstCombiner::visitFDiv(BinaryOperator &I) {
   bool AllowReassociate = I.hasUnsafeAlgebra();
   bool AllowReciprocal = I.hasAllowReciprocal();
 
-  if (ConstantFP *Op1C = dyn_cast<ConstantFP>(Op1)) {
+  if (Constant *Op1C = dyn_cast<Constant>(Op1)) {
     if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
       if (Instruction *R = FoldOpIntoSelect(I, SI))
         return R;
 
     if (AllowReassociate) {
-      ConstantFP *C1 = 0;
-      ConstantFP *C2 = Op1C;
+      Constant *C1 = 0;
+      Constant *C2 = Op1C;
       Value *X;
       Instruction *Res = 0;
 
-      if (match(Op0, m_FMul(m_Value(X), m_ConstantFP(C1)))) {
+      if (match(Op0, m_FMul(m_Value(X), m_Constant(C1)))) {
         // (X*C1)/C2 => X * (C1/C2)
         //
         Constant *C = ConstantExpr::getFDiv(C1, C2);
-        const APFloat &F = cast<ConstantFP>(C)->getValueAPF();
-        if (F.isNormal())
+        if (isNormalFp(C))
           Res = BinaryOperator::CreateFMul(X, C);
-      } else if (match(Op0, m_FDiv(m_Value(X), m_ConstantFP(C1)))) {
+      } else if (match(Op0, m_FDiv(m_Value(X), m_Constant(C1)))) {
         // (X/C1)/C2 => X /(C2*C1) [=> X * 1/(C2*C1) if reciprocal is allowed]
         //
         Constant *C = ConstantExpr::getFMul(C1, C2);
-        const APFloat &F = cast<ConstantFP>(C)->getValueAPF();
-        if (F.isNormal()) {
-          Res = CvtFDivConstToReciprocal(X, cast<ConstantFP>(C),
-                                         AllowReciprocal);
+        if (isNormalFp(C)) {
+          Res = CvtFDivConstToReciprocal(X, C, AllowReciprocal);
           if (!Res)
             Res = BinaryOperator::CreateFDiv(X, C);
         }
@@ -1056,33 +1073,29 @@ Instruction *InstCombiner::visitFDiv(BinaryOperator &I) {
     return 0;
   }
 
-  if (AllowReassociate && isa<ConstantFP>(Op0)) {
-    ConstantFP *C1 = cast<ConstantFP>(Op0), *C2;
+  if (AllowReassociate && isa<Constant>(Op0)) {
+    Constant *C1 = cast<Constant>(Op0), *C2;
     Constant *Fold = 0;
     Value *X;
     bool CreateDiv = true;
 
     // C1 / (X*C2) => (C1/C2) / X
-    if (match(Op1, m_FMul(m_Value(X), m_ConstantFP(C2))))
+    if (match(Op1, m_FMul(m_Value(X), m_Constant(C2))))
       Fold = ConstantExpr::getFDiv(C1, C2);
-    else if (match(Op1, m_FDiv(m_Value(X), m_ConstantFP(C2)))) {
+    else if (match(Op1, m_FDiv(m_Value(X), m_Constant(C2)))) {
       // C1 / (X/C2) => (C1*C2) / X
       Fold = ConstantExpr::getFMul(C1, C2);
-    } else if (match(Op1, m_FDiv(m_ConstantFP(C2), m_Value(X)))) {
+    } else if (match(Op1, m_FDiv(m_Constant(C2), m_Value(X)))) {
       // C1 / (C2/X) => (C1/C2) * X
       Fold = ConstantExpr::getFDiv(C1, C2);
       CreateDiv = false;
     }
 
-    if (Fold) {
-      const APFloat &FoldC = cast<ConstantFP>(Fold)->getValueAPF();
-      if (FoldC.isNormal()) {
-        Instruction *R = CreateDiv ?
-                         BinaryOperator::CreateFDiv(Fold, X) :
-                         BinaryOperator::CreateFMul(X, Fold);
-        R->setFastMathFlags(I.getFastMathFlags());
-        return R;
-      }
+    if (Fold && isNormalFp(Fold)) {
+      Instruction *R = CreateDiv ? BinaryOperator::CreateFDiv(Fold, X)
+                                 : BinaryOperator::CreateFMul(X, Fold);
+      R->setFastMathFlags(I.getFastMathFlags());
+      return R;
     }
     return 0;
   }
@@ -1095,14 +1108,14 @@ Instruction *InstCombiner::visitFDiv(BinaryOperator &I) {
     if (Op0->hasOneUse() && match(Op0, m_FDiv(m_Value(X), m_Value(Y)))) {
       // (X/Y) / Z => X / (Y*Z)
       //
-      if (!isa<ConstantFP>(Y) || !isa<ConstantFP>(Op1)) {
+      if (!isa<Constant>(Y) || !isa<Constant>(Op1)) {
         NewInst = Builder->CreateFMul(Y, Op1);
         SimpR = BinaryOperator::CreateFDiv(X, NewInst);
       }
     } else if (Op1->hasOneUse() && match(Op1, m_FDiv(m_Value(X), m_Value(Y)))) {
       // Z / (X/Y) => Z*Y / X
       //
-      if (!isa<ConstantFP>(Y) || !isa<ConstantFP>(Op0)) {
+      if (!isa<Constant>(Y) || !isa<Constant>(Op0)) {
         NewInst = Builder->CreateFMul(Op0, Y);
         SimpR = BinaryOperator::CreateFDiv(NewInst, X);
       }

diff --git a/llvm/test/Transforms/InstCombine/add4.ll b/llvm/test/Transforms/InstCombine/add4.ll
@@ -77,3 +77,26 @@ define float @test7(float %A, float %B, i32 %C) {
 ; CHECK: uitofp
 }
 
+define <4 x float> @test8(<4 x float> %A, <4 x float> %B, <4 x i1> %C) {
+  ;;  B*(uitofp i1 C) + A*(1 - uitofp i1 C) -> select C, A, B
+  %cf = uitofp <4 x i1> %C to <4 x float>
+  %mc = fsub fast <4 x float> <float 1.0, float 1.0, float 1.0, float 1.0>, %cf
+  %p1 = fmul fast <4 x float> %A, %mc
+  %p2 = fmul fast <4 x float> %B, %cf
+  %s1 = fadd fast <4 x float> %p2, %p1
+  ret <4 x float> %s1
+; CHECK-LABEL: @test8(
+; CHECK: select <4 x i1> %C, <4 x float> %B, <4 x float> %A
+}
+
+define <4 x float> @test9(<4 x float> %A, <4 x float> %B, <4 x i1> %C) {
+  ;; A*(1 - uitofp i1 C) + B*(uitofp i1 C) -> select C, A, B
+  %cf = uitofp <4 x i1> %C to <4 x float>
+  %mc = fsub fast <4 x float> <float 1.0, float 1.0, float 1.0, float 1.0>, %cf
+  %p1 = fmul fast <4 x float> %A, %mc
+  %p2 = fmul fast <4 x float> %B, %cf
+  %s1 = fadd fast <4 x float> %p1, %p2
+  ret <4 x float> %s1
+; CHECK-LABEL: @test9
+; CHECK: select <4 x i1> %C, <4 x float> %B, <4 x float> %A
+}
diff --git a/llvm/test/Transforms/InstCombine/fast-math.ll b/llvm/test/Transforms/InstCombine/fast-math.ll
@@ -259,6 +259,14 @@ define float @fmul3(float %f1, float %f2) {
 ; CHECK: fmul fast float %f1, 3.000000e+00
 }
 
+define <4 x float> @fmul3_vec(<4 x float> %f1, <4 x float> %f2) {
+  %t1 = fdiv <4 x float> %f1, <float 2.0e+3, float 3.0e+3, float 2.0e+3, float 1.0e+3>
+  %t3 = fmul fast <4 x float> %t1, <float 6.0e+3, float 6.0e+3, float 2.0e+3, float 1.0e+3>
+  ret <4 x float> %t3
+; CHECK-LABEL: @fmul3_vec(
+; CHECK: fmul fast <4 x float> %f1, <float 3.000000e+00, float 2.000000e+00, float 1.000000e+00, float 1.000000e+00>
+}
+
 ; Rule "X/C1 * C2 => X * (C2/C1) is not applicable if C2/C1 is either a special
 ; value of a denormal. The 0x3810000000000000 here take value FLT_MIN
 ;
@@ -345,6 +353,15 @@ define float @fdiv2(float %x) {
 ; CHECK: fmul fast float %x, 0x3FE0B21660000000
 }
 
+define <2 x float> @fdiv2_vec(<2 x float> %x) {
+  %mul = fmul <2 x float> %x, <float 6.0, float 9.0>
+  %div1 = fdiv fast <2 x float> %mul, <float 2.0, float 3.0>
+  ret <2 x float> %div1
+
+; CHECK-LABEL: @fdiv2_vec(
+; CHECK: fmul fast <2 x float> %x, <float 3.000000e+00, float 3.000000e+00>
+}
+
 ; "X/C1 / C2 => X * (1/(C2*C1))" is disabled (for now) is C2/C1 is a denormal
 ;
 define float @fdiv3(float %x) {