Merge remote-tracking branch 'upstream/master' into merge-llvm

Conflicts:
	lib/CodeGen/AsmPrinter/AsmPrinter.cpp
	lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp
	lib/MC/MCAssembler.cpp
	lib/Support/Atomic.cpp
	lib/Support/Memory.cpp
	lib/Target/ARM/ARMJITInfo.cpp

Change-Id: Ib339baf88df5b04870c8df1bedcfe1f877ccab8d

1 files changed, 236 insertions, 18 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
index 2a7182f..d0f4392 100644
--- a/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
+++ b/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
@@ -13,8 +13,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "InstCombine.h"
-#include "llvm/IntrinsicInst.h"
 #include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/IR/IntrinsicInst.h"
 #include "llvm/Support/PatternMatch.h"
 using namespace llvm;
 using namespace PatternMatch;
@@ -37,7 +37,7 @@ static Value *simplifyValueKnownNonZero(Value *V, InstCombiner &IC) {
   if (match(V, m_LShr(m_OneUse(m_Shl(m_Value(PowerOf2), m_Value(A))),
                       m_Value(B))) &&
       // The "1" can be any value known to be a power of 2.
-      isPowerOfTwo(PowerOf2, IC.getTargetData())) {
+      isKnownToBeAPowerOfTwo(PowerOf2)) {
     A = IC.Builder->CreateSub(A, B);
     return IC.Builder->CreateShl(PowerOf2, A);
   }
@@ -45,8 +45,7 @@ static Value *simplifyValueKnownNonZero(Value *V, InstCombiner &IC) {
   // (PowerOfTwo >>u B) --> isExact since shifting out the result would make it
   // inexact.  Similarly for <<.
   if (BinaryOperator *I = dyn_cast<BinaryOperator>(V))
-    if (I->isLogicalShift() &&
-        isPowerOfTwo(I->getOperand(0), IC.getTargetData())) {
+    if (I->isLogicalShift() && isKnownToBeAPowerOfTwo(I->getOperand(0))) {
       // We know that this is an exact/nuw shift and that the input is a
       // non-zero context as well.
       if (Value *V2 = simplifyValueKnownNonZero(I->getOperand(0), IC)) {
@@ -252,24 +251,134 @@ Instruction *InstCombiner::visitMul(BinaryOperator &I) {
   return Changed ? &I : 0;
 }
 
+//
+// Detect pattern:
+//
+// log2(Y*0.5)
+//
+// And check for corresponding fast math flags
+//
+
+static void detectLog2OfHalf(Value *&Op, Value *&Y, IntrinsicInst *&Log2) {
+
+   if (!Op->hasOneUse())
+     return;
+
+   IntrinsicInst *II = dyn_cast<IntrinsicInst>(Op);
+   if (!II)
+     return;
+   if (II->getIntrinsicID() != Intrinsic::log2 || !II->hasUnsafeAlgebra())
+     return;
+   Log2 = II;
+
+   Value *OpLog2Of = II->getArgOperand(0);
+   if (!OpLog2Of->hasOneUse())
+     return;
+
+   Instruction *I = dyn_cast<Instruction>(OpLog2Of);
+   if (!I)
+     return;
+   if (I->getOpcode() != Instruction::FMul || !I->hasUnsafeAlgebra())
+     return;
+              
+   ConstantFP *CFP = dyn_cast<ConstantFP>(I->getOperand(0));
+   if (CFP && CFP->isExactlyValue(0.5)) {
+     Y = I->getOperand(1);
+     return;
+   }
+   CFP = dyn_cast<ConstantFP>(I->getOperand(1));
+   if (CFP && CFP->isExactlyValue(0.5))
+     Y = I->getOperand(0);
+} 
+
+/// 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).
+static bool isFMulOrFDivWithConstant(Value *V) {
+  Instruction *I = dyn_cast<Instruction>(V);
+  if (!I || (I->getOpcode() != Instruction::FMul && 
+             I->getOpcode() != Instruction::FDiv))
+    return false;
+
+  ConstantFP *C0 = dyn_cast<ConstantFP>(I->getOperand(0));
+  ConstantFP *C1 = dyn_cast<ConstantFP>(I->getOperand(1));
+
+  if (C0 && C1)
+    return false;
+
+  return (C0 && C0->getValueAPF().isNormal()) ||
+         (C1 && C1->getValueAPF().isNormal());
+}
+
+static bool isNormalFp(const ConstantFP *C) {
+  const APFloat &Flt = C->getValueAPF();
+  return Flt.isNormal() && !Flt.isDenormal();
+}
+
+/// foldFMulConst() is a helper routine of InstCombiner::visitFMul().
+/// The input \p FMulOrDiv is a FMul/FDiv with one and only one operand
+/// being a constant (i.e. isFMulOrFDivWithConstant(FMulOrDiv) == true).
+/// This function is to simplify "FMulOrDiv * C" and returns the 
+/// 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,
+                                   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);
+
+  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)))
+      R = BinaryOperator::CreateFMul(C1 ? Opnd0 : Opnd1, F);
+  } else {
+    if (C0) {
+      // (C0 / X) * C => (C0 * C) / X
+      ConstantFP *F = cast<ConstantFP>(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));
+      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)))
+          R = BinaryOperator::CreateFDiv(Opnd0, F);
+      }
+    }
+  }
+
+  if (R) {
+    R->setHasUnsafeAlgebra(true);
+    InsertNewInstWith(R, *InsertBefore);
+  }
+
+  return R;
+}
+
 Instruction *InstCombiner::visitFMul(BinaryOperator &I) {
   bool Changed = SimplifyAssociativeOrCommutative(I);
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
 
-  // Simplify mul instructions with a constant RHS.
-  if (Constant *Op1C = dyn_cast<Constant>(Op1)) {
-    if (ConstantFP *Op1F = dyn_cast<ConstantFP>(Op1C)) {
-      // "In IEEE floating point, x*1 is not equivalent to x for nans.  However,
-      // ANSI says we can drop signals, so we can do this anyway." (from GCC)
-      if (Op1F->isExactlyValue(1.0))
-        return ReplaceInstUsesWith(I, Op0);  // Eliminate 'fmul double %X, 1.0'
-    } else if (ConstantDataVector *Op1V = dyn_cast<ConstantDataVector>(Op1C)) {
-      // As above, vector X*splat(1.0) -> X in all defined cases.
-      if (ConstantFP *F = dyn_cast_or_null<ConstantFP>(Op1V->getSplatValue()))
-        if (F->isExactlyValue(1.0))
-          return ReplaceInstUsesWith(I, Op0);
-    }
+  if (isa<Constant>(Op0))
+    std::swap(Op0, Op1);
+
+  if (Value *V = SimplifyFMulInst(Op0, Op1, I.getFastMathFlags(), TD))
+    return ReplaceInstUsesWith(I, V);
 
+  // Simplify mul instructions with a constant RHS.
+  if (isa<Constant>(Op1)) {
     // Try to fold constant mul into select arguments.
     if (SelectInst *SI = dyn_cast<SelectInst>(Op0))
       if (Instruction *R = FoldOpIntoSelect(I, SI))
@@ -278,12 +387,120 @@ Instruction *InstCombiner::visitFMul(BinaryOperator &I) {
     if (isa<PHINode>(Op0))
       if (Instruction *NV = FoldOpIntoPhi(I))
         return NV;
+
+    ConstantFP *C = dyn_cast<ConstantFP>(Op1);
+    if (C && I.hasUnsafeAlgebra() && C->getValueAPF().isNormal()) {
+      // 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)
+          return ReplaceInstUsesWith(I, V);
+      }
+
+      // (MDC +/- C1) * C2 => (MDC * C2) +/- (C1 * C2)
+      Instruction *FAddSub = dyn_cast<Instruction>(Op0);
+      if (FAddSub &&
+          (FAddSub->getOpcode() == Instruction::FAdd ||
+           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);
+        bool Swap = false;
+        if (C0) {
+          std::swap(C0, C1);
+          std::swap(Opnd0, Opnd1);
+          Swap = true; 
+        }
+
+        if (C1 && C1->getValueAPF().isNormal() &&
+            isFMulOrFDivWithConstant(Opnd0)) {
+          Value *M0 = ConstantExpr::getFMul(C1, C);
+          Value *M1 = isNormalFp(cast<ConstantFP>(M0)) ? 
+                      foldFMulConst(cast<Instruction>(Opnd0), C, &I) :
+                      0;
+          if (M0 && M1) {
+            if (Swap && FAddSub->getOpcode() == Instruction::FSub)
+              std::swap(M0, M1);
+
+            Value *R = (FAddSub->getOpcode() == Instruction::FAdd) ?
+                        BinaryOperator::CreateFAdd(M0, M1) :
+                        BinaryOperator::CreateFSub(M0, M1);
+            Instruction *RI = cast<Instruction>(R);
+            RI->setHasUnsafeAlgebra(true);
+            return RI;
+          }
+        }
+      }
+    }
   }
 
   if (Value *Op0v = dyn_castFNegVal(Op0))     // -X * -Y = X*Y
     if (Value *Op1v = dyn_castFNegVal(Op1))
       return BinaryOperator::CreateFMul(Op0v, Op1v);
 
+  // Under unsafe algebra do:
+  // X * log2(0.5*Y) = X*log2(Y) - X
+  if (I.hasUnsafeAlgebra()) {
+    Value *OpX = NULL;
+    Value *OpY = NULL;
+    IntrinsicInst *Log2;
+    detectLog2OfHalf(Op0, OpY, Log2);
+    if (OpY) {
+      OpX = Op1;
+    } else {
+      detectLog2OfHalf(Op1, OpY, Log2);
+      if (OpY) {
+        OpX = Op0;
+      }
+    }
+    // if pattern detected emit alternate sequence
+    if (OpX && OpY) {
+      Log2->setArgOperand(0, OpY);
+      Value *FMulVal = Builder->CreateFMul(OpX, Log2);
+      Instruction *FMul = cast<Instruction>(FMulVal);
+      FMul->copyFastMathFlags(Log2);
+      Instruction *FSub = BinaryOperator::CreateFSub(FMulVal, OpX);
+      FSub->copyFastMathFlags(Log2);
+      return FSub;
+    }
+  }
+
+  // X * cond ? 1.0 : 0.0 => cond ? X : 0.0
+  if (I.hasNoNaNs() && I.hasNoSignedZeros()) {
+    Value *V0 = I.getOperand(0);
+    Value *V1 = I.getOperand(1);
+    Value *Cond, *SLHS, *SRHS;
+    bool Match = false;
+
+    if (match(V0, m_Select(m_Value(Cond), m_Value(SLHS), m_Value(SRHS)))) {
+      Match = true;
+    } else if (match(V1, m_Select(m_Value(Cond), m_Value(SLHS), 
+                     m_Value(SRHS)))) {
+      Match = true;
+      std::swap(V0, V1);
+    }
+
+    if (Match) {
+      ConstantFP *C0 = dyn_cast<ConstantFP>(SLHS);
+      ConstantFP *C1 = dyn_cast<ConstantFP>(SRHS);
+
+      if (C0 && C1 &&
+          ((C0->isZero() && C1->isExactlyValue(1.0)) ||
+           (C1->isZero() && C0->isExactlyValue(1.0)))) {
+        Value *T;
+        if (C0->isZero())
+          T = Builder->CreateSelect(Cond, SLHS, V1);
+        else
+          T = Builder->CreateSelect(Cond, V1, SRHS);
+        return ReplaceInstUsesWith(I, T);
+      }
+    }
+  }
+
   return Changed ? &I : 0;
 }
 
@@ -477,7 +694,8 @@ Instruction *InstCombiner::visitUDiv(BinaryOperator &I) {
     if (match(Op1, m_Shl(m_Power2(CI), m_Value(N))) ||
         match(Op1, m_ZExt(m_Shl(m_Power2(CI), m_Value(N))))) {
       if (*CI != 1)
-        N = Builder->CreateAdd(N, ConstantInt::get(I.getType(),CI->logBase2()));
+        N = Builder->CreateAdd(N,
+                               ConstantInt::get(N->getType(), CI->logBase2()));
       if (ZExtInst *Z = dyn_cast<ZExtInst>(Op1))
         N = Builder->CreateZExt(N, Z->getDestTy());
       if (I.isExact())