maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[SelectionDAG] Allow constant folding for implicitly truncating BUILD_VECTOR nodes. 

In FoldConstantArithmetic, handle BUILD_VECTOR nodes that do implicit truncation on the elements.

This is similar to what is done in FoldConstantVectorArithmetic.

Differential Revision:
https://reviews.llvm.org/D36506

llvm-svn: 310593
This commit is contained in:
Guy Blank 2017-08-10 14:09:50 +00:00
parent 7235bcdf8f
commit 136b543745
2 changed files with 16 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
View File

@ -3968,18 +3968,31 @@ SDValue SelectionDAG::FoldConstantArithmetic(unsigned Opcode, const SDLoc &DL,
assert(BV1->getNumOperands() == BV2->getNumOperands() && "Out of sync!");
EVT SVT = VT.getScalarType();
EVT LegalSVT = SVT;
if (NewNodesMustHaveLegalTypes && LegalSVT.isInteger()) {
LegalSVT = TLI->getTypeToTransformTo(*getContext(), LegalSVT);
if (LegalSVT.bitsLT(SVT))
return SDValue();
}
SmallVector<SDValue, 4> Outputs;
for (unsigned I = 0, E = BV1->getNumOperands(); I != E; ++I) {
SDValue V1 = BV1->getOperand(I);
SDValue V2 = BV2->getOperand(I);
// Avoid BUILD_VECTOR nodes that perform implicit truncation.
// FIXME: This is valid and could be handled by truncation.
if (SVT.isInteger()) {
if (V1->getValueType(0).bitsGT(SVT))
V1 = getNode(ISD::TRUNCATE, DL, SVT, V1);
if (V2->getValueType(0).bitsGT(SVT))
V2 = getNode(ISD::TRUNCATE, DL, SVT, V2);
}
if (V1->getValueType(0) != SVT || V2->getValueType(0) != SVT)
return SDValue();
// Fold one vector element.
SDValue ScalarResult = getNode(Opcode, DL, SVT, V1, V2);
if (LegalSVT != SVT)
ScalarResult = getNode(ISD::SIGN_EXTEND, DL, LegalSVT, ScalarResult);
// Scalar folding only succeeded if the result is a constant or UNDEF.
if (!ScalarResult.isUndef() && ScalarResult.getOpcode() != ISD::Constant &&
@ -3998,6 +4011,7 @@ SDValue SelectionDAG::FoldConstantArithmetic(unsigned Opcode, const SDLoc &DL,
return getBuildVector(VT, SDLoc(), Outputs);
}
// TODO: Merge with FoldConstantArithmetic
SDValue SelectionDAG::FoldConstantVectorArithmetic(unsigned Opcode,
const SDLoc &DL, EVT VT,
ArrayRef<SDValue> Ops,

2
llvm/test/CodeGen/X86/avx512-intrinsics.ll
View File

@ -123,8 +123,6 @@ define i16 @test_kxnor(i16 %a0, i16 %a1) {
; CHECK-NEXT: kmovw %eax, %k2
; CHECK-NEXT: kxorw %k0, %k1, %k0
; CHECK-NEXT: kxorw %k0, %k2, %k0
; CHECK-NEXT: kxnorw %k0, %k0, %k1
; CHECK-NEXT: kxnorw %k1, %k0, %k0
; CHECK-NEXT: kmovw %k0, %eax
; CHECK-NEXT: ## kill: %AX<def> %AX<kill> %EAX<kill>
; CHECK-NEXT: retq