[PATCH] D59897: [DAGCombiner] Teach TokenFactor pruning to peek through lifetime nodes

[Nirav Dave via Phabricator via llvm-commits]

niravd created this revision.
niravd added reviewers: courbet, jyknight.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.

Lifetime nodes were inhibiting TokenFactor simplification inhibiting chain-based optimizations.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D59897

Files:
  llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
  llvm/test/CodeGen/X86/swap.ll


Index: llvm/test/CodeGen/X86/swap.ll
===================================================================
--- llvm/test/CodeGen/X86/swap.ll
+++ llvm/test/CodeGen/X86/swap.ll
@@ -119,14 +119,11 @@
 ; NOAA-NEXT:    vmovaps %xmm0, -{{[0-9]+}}(%rsp)
 ; NOAA-NEXT:    vmovups (%rsi), %xmm0
 ; NOAA-NEXT:    vmovaps %xmm0, -{{[0-9]+}}(%rsp)
-; NOAA-NEXT:    vmovaps -{{[0-9]+}}(%rsp), %xmm0
 ; NOAA-NEXT:    vmovups %xmm0, (%rdi)
 ; NOAA-NEXT:    retq
 ;
 ; AA-LABEL: onealloc_readback_1:
 ; AA:       # %bb.0: # %entry
-; AA-NEXT:    vmovups (%rdi), %xmm0
-; AA-NEXT:    vmovaps %xmm0, -{{[0-9]+}}(%rsp)
 ; AA-NEXT:    vmovups (%rsi), %xmm0
 ; AA-NEXT:    vmovaps %xmm0, -{{[0-9]+}}(%rsp)
 ; AA-NEXT:    vmovups %xmm0, (%rdi)
@@ -152,14 +149,11 @@
 ; NOAA-NEXT:    vmovaps %xmm0, -{{[0-9]+}}(%rsp)
 ; NOAA-NEXT:    vmovups (%rsi), %xmm0
 ; NOAA-NEXT:    vmovaps %xmm0, -{{[0-9]+}}(%rsp)
-; NOAA-NEXT:    vmovaps -{{[0-9]+}}(%rsp), %xmm0
 ; NOAA-NEXT:    vmovups %xmm0, (%rdi)
 ; NOAA-NEXT:    retq
 ;
 ; AA-LABEL: onealloc_readback_2:
 ; AA:       # %bb.0: # %entry
-; AA-NEXT:    vmovups (%rdi), %xmm0
-; AA-NEXT:    vmovaps %xmm0, -{{[0-9]+}}(%rsp)
 ; AA-NEXT:    vmovups (%rsi), %xmm0
 ; AA-NEXT:    vmovaps %xmm0, -{{[0-9]+}}(%rsp)
 ; AA-NEXT:    vmovups %xmm0, (%rdi)
Index: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -1837,6 +1837,8 @@
       for (const SDValue &Op : CurNode->op_values())
         AddToWorklist(i, Op.getNode(), CurOpNumber);
       break;
+    case ISD::LIFETIME_START:
+    case ISD::LIFETIME_END:
     case ISD::CopyFromReg:
     case ISD::CopyToReg:
       AddToWorklist(i, CurNode->getOperand(0).getNode(), CurOpNumber);


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