// floor((double)floatval) -> (double)floorf(floatval)
if (Callee->isIntrinsic()) {
- Module *M = CI->getParent()->getParent()->getParent();
+ Module *M = CI->getModule();
Intrinsic::ID IID = Callee->getIntrinsicID();
Function *F = Intrinsic::getDeclaration(M, IID, B.getFloatTy());
V = B.CreateCall(F, V);
return Ret;
}
+static Value *getPow(Value *InnerChain[33], unsigned Exp, IRBuilder<> &B) {
+ // Multiplications calculated using Addition Chains.
+ // Refer: http://wwwhomes.uni-bielefeld.de/achim/addition_chain.html
+
+ assert(Exp != 0 && "Incorrect exponent 0 not handled");
+
+ if (InnerChain[Exp])
+ return InnerChain[Exp];
+
+ static const unsigned AddChain[33][2] = {
+ {0, 0}, // Unused.
+ {0, 0}, // Unused (base case = pow1).
+ {1, 1}, // Unused (pre-computed).
+ {1, 2}, {2, 2}, {2, 3}, {3, 3}, {2, 5}, {4, 4},
+ {1, 8}, {5, 5}, {1, 10}, {6, 6}, {4, 9}, {7, 7},
+ {3, 12}, {8, 8}, {8, 9}, {2, 16}, {1, 18}, {10, 10},
+ {6, 15}, {11, 11}, {3, 20}, {12, 12}, {8, 17}, {13, 13},
+ {3, 24}, {14, 14}, {4, 25}, {15, 15}, {3, 28}, {16, 16},
+ };
+
+ InnerChain[Exp] = B.CreateFMul(getPow(InnerChain, AddChain[Exp][0], B),
+ getPow(InnerChain, AddChain[Exp][1], B));
+ return InnerChain[Exp];
+}
+
Value *LibCallSimplifier::optimizePow(CallInst *CI, IRBuilder<> &B) {
Function *Callee = CI->getCalledFunction();
Value *Ret = nullptr;
return B.CreateFMul(Op1, Op1, "pow2");
if (Op2C->isExactlyValue(-1.0)) // pow(x, -1.0) -> 1.0/x
return B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0), Op1, "powrecip");
+
+ // In -ffast-math, generate repeated fmul instead of generating pow(x, n).
+ if (unsafeFPMath) {
+ APFloat V = abs(Op2C->getValueAPF());
+ // We limit to a max of 7 fmul(s). Thus max exponent is 32.
+ // This transformation applies to integer exponents only.
+ if (V.compare(APFloat(V.getSemantics(), 32.0)) == APFloat::cmpGreaterThan ||
+ !V.isInteger())
+ return nullptr;
+
+ // We will memoize intermediate products of the Addition Chain.
+ Value *InnerChain[33] = {nullptr};
+ InnerChain[1] = Op1;
+ InnerChain[2] = B.CreateFMul(Op1, Op1);
+
+ // We cannot readily convert a non-double type (like float) to a double.
+ // So we first convert V to something which could be converted to double.
+ bool ignored;
+ V.convert(APFloat::IEEEdouble, APFloat::rmTowardZero, &ignored);
+ Value *FMul = getPow(InnerChain, V.convertToDouble(), B);
+ // For negative exponents simply compute the reciprocal.
+ if (Op2C->isNegative())
+ FMul = B.CreateFDiv(ConstantFP::get(CI->getType(), 1.0), FMul);
+ return FMul;
+ }
+
return nullptr;
}
LibFunc::Func Func;
Function *F = OpC->getCalledFunction();
- StringRef FuncName = F->getName();
- if ((TLI->getLibFunc(FuncName, Func) && TLI->has(Func) &&
- Func == LibFunc::pow) || F->getIntrinsicID() == Intrinsic::pow)
+ if (F && ((TLI->getLibFunc(F->getName(), Func) && TLI->has(Func) &&
+ Func == LibFunc::pow) || F->getIntrinsicID() == Intrinsic::pow))
return B.CreateFMul(OpC->getArgOperand(1),
EmitUnaryFloatFnCall(OpC->getOperand(0), Callee->getName(), B,
Callee->getAttributes()), "mul");
+
+ // log(exp2(y)) -> y*log(2)
+ if (F && Name == "log" && TLI->getLibFunc(F->getName(), Func) &&
+ TLI->has(Func) && Func == LibFunc::exp2)
+ return B.CreateFMul(
+ OpC->getArgOperand(0),
+ EmitUnaryFloatFnCall(ConstantFP::get(CI->getType(), 2.0),
+ Callee->getName(), B, Callee->getAttributes()),
+ "logmul");
return Ret;
}
//
// log, logf, logl:
// * log(exp(x)) -> x
-// * log(x**y) -> y*log(x)
// * log(exp(y)) -> y*log(e)
-// * log(exp2(y)) -> y*log(2)
// * log(exp10(y)) -> y*log(10)
// * log(sqrt(x)) -> 0.5*log(x)
-// * log(pow(x,y)) -> y*log(x)
//
// lround, lroundf, lroundl:
// * lround(cnst) -> cnst'