Revert r357256 "[DAGCombine] Improve Lifetime node chains."

As it caused a pathological compile-time regressionin V8, see PR41352.

> Improve both start and end lifetime nodes chain dependencies.
>
> Reviewers: courbet
>
> Reviewed By: courbet
>
> Subscribers: hiraditya, llvm-commits
>
> Tags: #llvm
>
> Differential Revision: https://reviews.llvm.org/D59795

This also reverts the follow-up r357309:

> [DAGCombiner] Rewrite ImproveLifetimeNodeChain to avoid DAG loop.
>
> Avoid EXPENSIVE_CHECK failure. NFCI.

llvm-svn: 357563
This commit is contained in:
Hans Wennborg 2019-04-03 07:41:58 +00:00
parent 2374bff376
commit 94b867dc7c
3 changed files with 16 additions and 31 deletions

View File

@ -427,10 +427,6 @@ namespace {
SDValue replaceStoreOfFPConstant(StoreSDNode *ST);
SDValue visitSTORE(SDNode *N);
SDValue ImproveLifetimeNodeChain(SDNode *N);
SDValue visitLIFETIME_START(SDNode *N);
SDValue visitLIFETIME_END(SDNode *N);
SDValue visitINSERT_VECTOR_ELT(SDNode *N);
SDValue visitEXTRACT_VECTOR_ELT(SDNode *N);
@ -1654,7 +1650,6 @@ SDValue DAGCombiner::visit(SDNode *N) {
case ISD::MLOAD: return visitMLOAD(N);
case ISD::MSCATTER: return visitMSCATTER(N);
case ISD::MSTORE: return visitMSTORE(N);
case ISD::LIFETIME_START: return visitLIFETIME_START(N);
case ISD::LIFETIME_END: return visitLIFETIME_END(N);
case ISD::FP_TO_FP16: return visitFP_TO_FP16(N);
case ISD::FP16_TO_FP: return visitFP16_TO_FP(N);
@ -15705,33 +15700,7 @@ SDValue DAGCombiner::visitSTORE(SDNode *N) {
return ReduceLoadOpStoreWidth(N);
}
SDValue DAGCombiner::ImproveLifetimeNodeChain(SDNode *N) {
auto Chain = N->getOperand(0);
auto NewChain = FindBetterChain(N, Chain);
if (NewChain != Chain) {
LifetimeSDNode *LN = cast<LifetimeSDNode>(N);
// Create New Node to prevent loop in CombineTo.
SDValue NewN = DAG.getLifetimeNode(N->getOpcode() == ISD::LIFETIME_START,
SDLoc(N), NewChain, LN->getFrameIndex(),
LN->hasOffset() ? LN->getSize() : -1,
LN->hasOffset() ? LN->getOffset() : -1);
AddToWorklist(NewN.getNode());
auto TF = DAG.getNode(ISD::TokenFactor, SDLoc(N), MVT::Other, Chain, NewN);
return CombineTo(N, TF);
}
return SDValue();
}
SDValue DAGCombiner::visitLIFETIME_START(SDNode *N) {
if (SDValue V = ImproveLifetimeNodeChain(N))
return V;
return SDValue();
}
SDValue DAGCombiner::visitLIFETIME_END(SDNode *N) {
if (SDValue V = ImproveLifetimeNodeChain(N))
return V;
const auto *LifetimeEnd = cast<LifetimeSDNode>(N);
if (!LifetimeEnd->hasOffset())
return SDValue();

View File

@ -94,6 +94,7 @@ define dso_local void @twoallocs(i8* nocapture %a, i8* nocapture %b) local_unnam
; AA-LABEL: twoallocs:
; AA: # %bb.0: # %entry
; AA-NEXT: vmovups (%rdi), %xmm0
; AA-NEXT: vmovaps %xmm0, -{{[0-9]+}}(%rsp)
; AA-NEXT: vmovups %xmm0, (%rsi)
; AA-NEXT: retq
entry:
@ -124,6 +125,7 @@ define dso_local void @onealloc_readback_1(i8* nocapture %a, i8* nocapture %b) l
; AA-LABEL: onealloc_readback_1:
; AA: # %bb.0: # %entry
; AA-NEXT: vmovups (%rsi), %xmm0
; AA-NEXT: vmovaps %xmm0, -{{[0-9]+}}(%rsp)
; AA-NEXT: vmovups %xmm0, (%rdi)
; AA-NEXT: retq
entry:
@ -153,6 +155,7 @@ define dso_local void @onealloc_readback_2(i8* nocapture %a, i8* nocapture %b) l
; AA-LABEL: onealloc_readback_2:
; AA: # %bb.0: # %entry
; AA-NEXT: vmovups (%rsi), %xmm0
; AA-NEXT: vmovaps %xmm0, -{{[0-9]+}}(%rsp)
; AA-NEXT: vmovups %xmm0, (%rdi)
; AA-NEXT: retq
entry:

View File

@ -80,6 +80,19 @@
; CHECK: ScopeEndSym {
; CHECK: Kind: S_END {{.*}}
; CHECK: }
; CHECK: BlockSym {
; CHECK: Kind: S_BLOCK32 {{.*}}
; CHECK: BlockName:
; CHECK: }
; CHECK: ScopeEndSym {
; CHECK: }
; CHECK: BlockSym {
; CHECK: Kind: S_BLOCK32 {{.*}}
; CHECK: BlockName:
; CHECK: }
; CHECK: ScopeEndSym {
; CHECK: Kind: S_END {{.*}}
; CHECK: }
; CHECK: ProcEnd {
; CHECK: }
;