From d918576dc5ad47769f452f4863284b37f27455b8 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356382 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 15 +++++++--------
 test/CodeGen/X86/xor.ll                  |  5 ++---
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 43a1005d84a..4ff48732ef6 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/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/test/CodeGen/X86/xor.ll b/test/CodeGen/X86/xor.ll
index f86b5812ace..ba1a3df51cb 100644
--- a/test/CodeGen/X86/xor.ll
+++ b/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>
-- 
2.11.0