From 55c921f4bf3470126c8eddbd70de6250bc740471 Mon Sep 17 00:00:00 2001
From: Nirav Dave <niravd@google.com>
Date: Mon, 18 Mar 2019 17:02:38 +0000
Subject: [PATCH] [DAG] Cleanup unused node in SimplifySelectCC.
Delete temporarily constructed node uses for analysis after it's use,
holding onto original input nodes. Ideally this would be rewritten
without making nodes, but this appears relatively complex.
Reviewers: spatel, RKSimon, craig.topper
Subscribers: jdoerfert, hiraditya, deadalnix, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D57921
llvm-svn: 356382
---
llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 15 +++++++--------
llvm/test/CodeGen/X86/xor.ll | 5 ++---
2 files changed, 9 insertions(+), 11 deletions(-)
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 43a1005d84aa..4ff48732ef6b 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -18934,14 +18934,13 @@ SDValue DAGCombiner::SimplifySelectCC(const SDLoc &DL, SDValue N0, SDValue N1,
auto *N3C = dyn_cast<ConstantSDNode>(N3.getNode());
// Determine if the condition we're dealing with is constant.
- SDValue SCC = SimplifySetCC(getSetCCResultType(CmpOpVT), N0, N1, CC, DL,
- false);
- if (SCC.getNode()) AddToWorklist(SCC.getNode());
-
- if (auto *SCCC = dyn_cast_or_null<ConstantSDNode>(SCC.getNode())) {
- // fold select_cc true, x, y -> x
- // fold select_cc false, x, y -> y
- return !SCCC->isNullValue() ? N2 : N3;
+ if (SDValue SCC = DAG.FoldSetCC(VT, N0, N1, CC, DL)) {
+ AddToWorklist(SCC.getNode());
+ if (auto *SCCC = dyn_cast<ConstantSDNode>(SCC)) {
+ // fold select_cc true, x, y -> x
+ // fold select_cc false, x, y -> y
+ return !(SCCC->isNullValue()) ? N2 : N3;
+ }
}
if (SDValue V =
diff --git a/llvm/test/CodeGen/X86/xor.ll b/llvm/test/CodeGen/X86/xor.ll
index f86b5812ace8..ba1a3df51cb7 100644
--- a/llvm/test/CodeGen/X86/xor.ll
+++ b/llvm/test/CodeGen/X86/xor.ll
@@ -419,15 +419,14 @@ define i32 @PR17487(i1 %tobool) {
;
; X64-LIN-LABEL: PR17487:
; X64-LIN: # %bb.0:
-; X64-LIN-NEXT: movd %edi, %xmm0
-; X64-LIN-NEXT: pextrw $0, %xmm0, %eax
+; X64-LIN-NEXT: movl %edi, %eax
; X64-LIN-NEXT: andl $1, %eax
; X64-LIN-NEXT: retq
;
; X64-WIN-LABEL: PR17487:
; X64-WIN: # %bb.0:
-; X64-WIN-NEXT: andb $1, %cl
; X64-WIN-NEXT: movzbl %cl, %eax
+; X64-WIN-NEXT: andl $1, %eax
; X64-WIN-NEXT: retq
%tmp = insertelement <2 x i1> undef, i1 %tobool, i32 1
%tmp1 = zext <2 x i1> %tmp to <2 x i64>