[llvm] r323824 - [Hexagon] Handle truncates in polynomial multiply idiom recognition
Krzysztof Parzyszek via llvm-commits
llvm-commits at lists.llvm.org
Tue Jan 30 14:03:59 PST 2018
Author: kparzysz
Date: Tue Jan 30 14:03:59 2018
New Revision: 323824
URL: http://llvm.org/viewvc/llvm-project?rev=323824&view=rev
Log:
[Hexagon] Handle truncates in polynomial multiply idiom recognition
This is in anticipation of https://reviews.llvm.org/D42424, which would
otherwise break one of the pmpy testcases.
Modified:
llvm/trunk/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp
Modified: llvm/trunk/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp?rev=323824&r1=323823&r2=323824&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp (original)
+++ llvm/trunk/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp Tue Jan 30 14:03:59 2018
@@ -608,9 +608,9 @@ namespace {
unsigned getInverseMxN(unsigned QP);
Value *generate(BasicBlock::iterator At, ParsedValues &PV);
- void setupSimplifier();
+ void setupPreSimplifier(Simplifier &S);
+ void setupPostSimplifier(Simplifier &S);
- Simplifier Simp;
Loop *CurLoop;
const DataLayout &DL;
const DominatorTree &DT;
@@ -985,6 +985,7 @@ bool PolynomialMultiplyRecognize::isProm
case Instruction::Xor:
case Instruction::LShr: // Shift right is ok.
case Instruction::Select:
+ case Instruction::Trunc:
return true;
case Instruction::ICmp:
if (CmpInst *CI = cast<CmpInst>(In))
@@ -998,6 +999,8 @@ bool PolynomialMultiplyRecognize::isProm
void PolynomialMultiplyRecognize::promoteTo(Instruction *In,
IntegerType *DestTy, BasicBlock *LoopB) {
+ Type *OrigTy = In->getType();
+
// Leave boolean values alone.
if (!In->getType()->isIntegerTy(1))
In->mutateType(DestTy);
@@ -1028,6 +1031,14 @@ void PolynomialMultiplyRecognize::promot
Z->eraseFromParent();
return;
}
+ if (TruncInst *T = dyn_cast<TruncInst>(In)) {
+ IntegerType *TruncTy = cast<IntegerType>(OrigTy);
+ Value *Mask = ConstantInt::get(DestTy, (1u << TruncTy->getBitWidth()) - 1);
+ Value *And = IRBuilder<>(In).CreateAnd(T->getOperand(0), Mask);
+ T->replaceAllUsesWith(And);
+ T->eraseFromParent();
+ return;
+ }
// Promote immediates.
for (unsigned i = 0, n = In->getNumOperands(); i != n; ++i) {
@@ -1569,8 +1580,8 @@ static bool hasZeroSignBit(const Value *
return false;
}
-void PolynomialMultiplyRecognize::setupSimplifier() {
- Simp.addRule("sink-zext",
+void PolynomialMultiplyRecognize::setupPreSimplifier(Simplifier &S) {
+ S.addRule("sink-zext",
// Sink zext past bitwise operations.
[](Instruction *I, LLVMContext &Ctx) -> Value* {
if (I->getOpcode() != Instruction::ZExt)
@@ -1591,7 +1602,7 @@ void PolynomialMultiplyRecognize::setupS
B.CreateZExt(T->getOperand(0), I->getType()),
B.CreateZExt(T->getOperand(1), I->getType()));
});
- Simp.addRule("xor/and -> and/xor",
+ S.addRule("xor/and -> and/xor",
// (xor (and x a) (and y a)) -> (and (xor x y) a)
[](Instruction *I, LLVMContext &Ctx) -> Value* {
if (I->getOpcode() != Instruction::Xor)
@@ -1609,7 +1620,7 @@ void PolynomialMultiplyRecognize::setupS
return B.CreateAnd(B.CreateXor(And0->getOperand(0), And1->getOperand(0)),
And0->getOperand(1));
});
- Simp.addRule("sink binop into select",
+ S.addRule("sink binop into select",
// (Op (select c x y) z) -> (select c (Op x z) (Op y z))
// (Op x (select c y z)) -> (select c (Op x y) (Op x z))
[](Instruction *I, LLVMContext &Ctx) -> Value* {
@@ -1635,7 +1646,7 @@ void PolynomialMultiplyRecognize::setupS
}
return nullptr;
});
- Simp.addRule("fold select-select",
+ S.addRule("fold select-select",
// (select c (select c x y) z) -> (select c x z)
// (select c x (select c y z)) -> (select c x z)
[](Instruction *I, LLVMContext &Ctx) -> Value* {
@@ -1654,7 +1665,7 @@ void PolynomialMultiplyRecognize::setupS
}
return nullptr;
});
- Simp.addRule("or-signbit -> xor-signbit",
+ S.addRule("or-signbit -> xor-signbit",
// (or (lshr x 1) 0x800.0) -> (xor (lshr x 1) 0x800.0)
[](Instruction *I, LLVMContext &Ctx) -> Value* {
if (I->getOpcode() != Instruction::Or)
@@ -1666,7 +1677,7 @@ void PolynomialMultiplyRecognize::setupS
return nullptr;
return IRBuilder<>(Ctx).CreateXor(I->getOperand(0), Msb);
});
- Simp.addRule("sink lshr into binop",
+ S.addRule("sink lshr into binop",
// (lshr (BitOp x y) c) -> (BitOp (lshr x c) (lshr y c))
[](Instruction *I, LLVMContext &Ctx) -> Value* {
if (I->getOpcode() != Instruction::LShr)
@@ -1688,7 +1699,7 @@ void PolynomialMultiplyRecognize::setupS
B.CreateLShr(BitOp->getOperand(0), S),
B.CreateLShr(BitOp->getOperand(1), S));
});
- Simp.addRule("expose bitop-const",
+ S.addRule("expose bitop-const",
// (BitOp1 (BitOp2 x a) b) -> (BitOp2 x (BitOp1 a b))
[](Instruction *I, LLVMContext &Ctx) -> Value* {
auto IsBitOp = [](unsigned Op) -> bool {
@@ -1717,6 +1728,34 @@ void PolynomialMultiplyRecognize::setupS
});
}
+void PolynomialMultiplyRecognize::setupPostSimplifier(Simplifier &S) {
+ S.addRule("(and (xor (and x a) y) b) -> (and (xor x y) b), if b == b&a",
+ [](Instruction *I, LLVMContext &Ctx) -> Value* {
+ if (I->getOpcode() != Instruction::And)
+ return nullptr;
+ Instruction *Xor = dyn_cast<Instruction>(I->getOperand(0));
+ ConstantInt *C0 = dyn_cast<ConstantInt>(I->getOperand(1));
+ if (!Xor || !C0)
+ return nullptr;
+ if (Xor->getOpcode() != Instruction::Xor)
+ return nullptr;
+ Instruction *And0 = dyn_cast<Instruction>(Xor->getOperand(0));
+ Instruction *And1 = dyn_cast<Instruction>(Xor->getOperand(1));
+ // Pick the first non-null and.
+ if (!And0 || And0->getOpcode() != Instruction::And)
+ std::swap(And0, And1);
+ ConstantInt *C1 = dyn_cast<ConstantInt>(And0->getOperand(1));
+ if (!C1)
+ return nullptr;
+ uint32_t V0 = C0->getZExtValue();
+ uint32_t V1 = C1->getZExtValue();
+ if (V0 != (V0 & V1))
+ return nullptr;
+ IRBuilder<> B(Ctx);
+ return B.CreateAnd(B.CreateXor(And0->getOperand(0), And1), C0);
+ });
+}
+
bool PolynomialMultiplyRecognize::recognize() {
DEBUG(dbgs() << "Starting PolynomialMultiplyRecognize on loop\n"
<< *CurLoop << '\n');
@@ -1746,10 +1785,11 @@ bool PolynomialMultiplyRecognize::recogn
Value *CIV = getCountIV(LoopB);
ParsedValues PV;
+ Simplifier PreSimp;
PV.IterCount = IterCount;
DEBUG(dbgs() << "Loop IV: " << *CIV << "\nIterCount: " << IterCount << '\n');
- setupSimplifier();
+ setupPreSimplifier(PreSimp);
// Perform a preliminary scan of select instructions to see if any of them
// looks like a generator of the polynomial multiply steps. Assume that a
@@ -1772,7 +1812,7 @@ bool PolynomialMultiplyRecognize::recogn
continue;
Simplifier::Context C(SI);
- Value *T = Simp.simplify(C);
+ Value *T = PreSimp.simplify(C);
SelectInst *SelI = (T && isa<SelectInst>(T)) ? cast<SelectInst>(T) : SI;
DEBUG(dbgs() << "scanSelect(pre-scan): " << PE(C, SelI) << '\n');
if (scanSelect(SelI, LoopB, EntryB, CIV, PV, true)) {
@@ -1798,6 +1838,24 @@ bool PolynomialMultiplyRecognize::recogn
// wide as the target's pmpy instruction.
if (!promoteTypes(LoopB, ExitB))
return false;
+ // Run post-promotion simplifications.
+ Simplifier PostSimp;
+ setupPostSimplifier(PostSimp);
+ for (Instruction &In : *LoopB) {
+ SelectInst *SI = dyn_cast<SelectInst>(&In);
+ if (!SI || !FeedsPHI(SI))
+ continue;
+ Simplifier::Context C(SI);
+ Value *T = PostSimp.simplify(C);
+ SelectInst *SelI = dyn_cast_or_null<SelectInst>(T);
+ if (SelI != SI) {
+ Value *NewSel = C.materialize(LoopB, SI->getIterator());
+ SI->replaceAllUsesWith(NewSel);
+ RecursivelyDeleteTriviallyDeadInstructions(SI, &TLI);
+ }
+ break;
+ }
+
if (!convertShiftsToLeft(LoopB, ExitB, IterCount))
return false;
cleanupLoopBody(LoopB);
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