From 3bc859466b1d7c205b232df774faaece1ce7b8e7 Mon Sep 17 00:00:00 2001
From: Gerolf Hoflehner <ghoflehner@apple.com>
Date: Mon, 17 Feb 2014 03:06:16 +0000
Subject: [PATCH] fix for null VectorizedValue assertion in the SLP Vectorizer
 (in function vectorizeTree()). radar://16064178

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201501 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Vectorize/SLPVectorizer.cpp    |  6 +-
 .../SLPVectorizer/X86/crash_vectorizeTree.ll  | 65 +++++++++++++++++++
 2 files changed, 69 insertions(+), 2 deletions(-)
 create mode 100644 test/Transforms/SLPVectorizer/X86/crash_vectorizeTree.ll

diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp
index e2a1e5c32d2..360652f3dce 100644
--- a/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -779,7 +779,8 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth) {
       // Check for terminator values (e.g. invoke).
       for (unsigned j = 0; j < VL.size(); ++j)
         for (unsigned i = 0, e = PH->getNumIncomingValues(); i < e; ++i) {
-          TerminatorInst *Term = dyn_cast<TerminatorInst>(cast<PHINode>(VL[j])->getIncomingValue(i));
+          TerminatorInst *Term = dyn_cast<TerminatorInst>(
+              cast<PHINode>(VL[j])->getIncomingValueForBlock(PH->getIncomingBlock(i)));
           if (Term) {
             DEBUG(dbgs() << "SLP: Need to swizzle PHINodes (TerminatorInst use).\n");
             newTreeEntry(VL, false);
@@ -794,7 +795,8 @@ void BoUpSLP::buildTree_rec(ArrayRef<Value *> VL, unsigned Depth) {
         ValueList Operands;
         // Prepare the operand vector.
         for (unsigned j = 0; j < VL.size(); ++j)
-          Operands.push_back(cast<PHINode>(VL[j])->getIncomingValue(i));
+          Operands.push_back(cast<PHINode>(VL[j])->getIncomingValueForBlock(
+              PH->getIncomingBlock(i)));
 
         buildTree_rec(Operands, Depth + 1);
       }
diff --git a/test/Transforms/SLPVectorizer/X86/crash_vectorizeTree.ll b/test/Transforms/SLPVectorizer/X86/crash_vectorizeTree.ll
new file mode 100644
index 00000000000..c7ec98adf13
--- /dev/null
+++ b/test/Transforms/SLPVectorizer/X86/crash_vectorizeTree.ll
@@ -0,0 +1,65 @@
+; RUN: opt -slp-vectorizer -mtriple=x86_64-apple-macosx10.9.0 -mcpu=corei7-avx -S < %s | FileCheck %s
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.9.0"
+
+
+; This test used to crash because we were following phi chains incorrectly.
+; We used indices to get the incoming value of two phi nodes rather than 
+; incoming block lookup.
+; This can give wrong results when the ordering of incoming
+; edges in the two phi nodes don't match.
+;CHECK-LABEL: bar
+
+%0 = type { %1, %2 }
+%1 = type { double, double }
+%2 = type { double, double }
+
+
+;define fastcc void @bar() {
+define void @bar() {
+  %1 = getelementptr inbounds %0* undef, i64 0, i32 1, i32 0
+  %2 = getelementptr inbounds %0* undef, i64 0, i32 1, i32 1
+  %3 = getelementptr inbounds %0* undef, i64 0, i32 1, i32 0
+  %4 = getelementptr inbounds %0* undef, i64 0, i32 1, i32 1
+  %5 = getelementptr inbounds %0* undef, i64 0, i32 1, i32 0
+  %6 = getelementptr inbounds %0* undef, i64 0, i32 1, i32 1
+  br label %7
+
+; <label>:7                                       ; preds = %18, %17, %17, %0
+  %8 = phi double [ 2.800000e+01, %0 ], [ %11, %18 ], [ %11, %17 ], [ %11, %17 ]
+  %9 = phi double [ 1.800000e+01, %0 ], [ %10, %18 ], [ %10, %17 ], [ %10, %17 ]
+  store double %9, double* %1, align 8
+  store double %8, double* %2, align 8
+  %10 = load double* %3, align 8
+  %11 = load double* %4, align 8
+  br i1 undef, label %12, label %13
+
+; <label>:12                                      ; preds = %7
+  ret void
+
+; <label>:13                                      ; preds = %7
+  store double %10, double* %5, align 8
+  store double %11, double* %6, align 8
+  br i1 undef, label %14, label %15
+
+; <label>:14                                      ; preds = %13
+  br label %15
+
+; <label>:15                                      ; preds = %14, %13
+  br i1 undef, label %16, label %17
+
+; <label>:16                                      ; preds = %15
+  unreachable
+
+; <label>:17                                      ; preds = %15
+  switch i32 undef, label %18 [
+    i32 32, label %7
+    i32 103, label %7
+  ]
+
+; <label>:18                                      ; preds = %17
+  br i1 undef, label %7, label %19
+
+; <label>:19                                      ; preds = %18
+  unreachable
+}
-- 
2.34.1