From bba8da2ba0e4e88ba8b8125c6754d653c8ef1ef7 Mon Sep 17 00:00:00 2001
From: Nadav Rotem <nrotem@apple.com>
Date: Tue, 26 Nov 2013 17:29:19 +0000
Subject: [PATCH] PR18060 - When we RAUW values with ExtractElement
 instructions in some cases we generate PHI nodes with multiple entries from
 the same basic block but with different values. Enabling CSE on
 ExtractElement instructions make sure that all of the RAUWed instructions are
 the same.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195773 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Vectorize/SLPVectorizer.cpp   |  8 ++++
 test/Transforms/SLPVectorizer/X86/pr18060.ll | 47 ++++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 test/Transforms/SLPVectorizer/X86/pr18060.ll

diff --git a/lib/Transforms/Vectorize/SLPVectorizer.cpp b/lib/Transforms/Vectorize/SLPVectorizer.cpp
index f2a099ac691..78caab3b50a 100644
--- a/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -1591,6 +1591,8 @@ Value *BoUpSLP::vectorizeTree() {
     if (PHINode *PN = dyn_cast<PHINode>(Vec)) {
       Builder.SetInsertPoint(PN->getParent()->getFirstInsertionPt());
       Value *Ex = Builder.CreateExtractElement(Vec, Lane);
+      if (Instruction *Ins = dyn_cast<Instruction>(Ex))
+        GatherSeq.insert(Ins);
       User->replaceUsesOfWith(Scalar, Ex);
     } else if (isa<Instruction>(Vec)){
       if (PHINode *PH = dyn_cast<PHINode>(User)) {
@@ -1598,17 +1600,23 @@ Value *BoUpSLP::vectorizeTree() {
           if (PH->getIncomingValue(i) == Scalar) {
             Builder.SetInsertPoint(PH->getIncomingBlock(i)->getTerminator());
             Value *Ex = Builder.CreateExtractElement(Vec, Lane);
+            if (Instruction *Ins = dyn_cast<Instruction>(Ex))
+              GatherSeq.insert(Ins);
             PH->setOperand(i, Ex);
           }
         }
       } else {
         Builder.SetInsertPoint(cast<Instruction>(User));
         Value *Ex = Builder.CreateExtractElement(Vec, Lane);
+        if (Instruction *Ins = dyn_cast<Instruction>(Ex))
+          GatherSeq.insert(Ins);
         User->replaceUsesOfWith(Scalar, Ex);
      }
     } else {
       Builder.SetInsertPoint(F->getEntryBlock().begin());
       Value *Ex = Builder.CreateExtractElement(Vec, Lane);
+      if (Instruction *Ins = dyn_cast<Instruction>(Ex))
+        GatherSeq.insert(Ins);
       User->replaceUsesOfWith(Scalar, Ex);
     }
 
diff --git a/test/Transforms/SLPVectorizer/X86/pr18060.ll b/test/Transforms/SLPVectorizer/X86/pr18060.ll
new file mode 100644
index 00000000000..de9a4c3c245
--- /dev/null
+++ b/test/Transforms/SLPVectorizer/X86/pr18060.ll
@@ -0,0 +1,47 @@
+; RUN: opt < %s -basicaa -slp-vectorizer -dce -S -mtriple=x86_64-apple-macosx10.8.0 -mcpu=corei7
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128"
+target triple = "i386-pc-linux"
+
+; Function Attrs: nounwind
+define i32 @_Z16adjustFixupValueyj(i64 %Value, i32 %Kind) {
+entry:
+  %extract.t = trunc i64 %Value to i32
+  %extract = lshr i64 %Value, 12
+  %extract.t6 = trunc i64 %extract to i32
+  switch i32 %Kind, label %sw.default [
+    i32 0, label %return
+    i32 1, label %return
+    i32 129, label %sw.bb1
+    i32 130, label %sw.bb2
+  ]
+
+sw.default:                                       ; preds = %entry
+  call void @_Z25llvm_unreachable_internalv()
+  unreachable
+
+sw.bb1:                                           ; preds = %entry
+  %shr = lshr i64 %Value, 16
+  %extract.t5 = trunc i64 %shr to i32
+  %extract7 = lshr i64 %Value, 28
+  %extract.t8 = trunc i64 %extract7 to i32
+  br label %sw.bb2
+
+sw.bb2:                                           ; preds = %sw.bb1, %entry
+  %Value.addr.0.off0 = phi i32 [ %extract.t, %entry ], [ %extract.t5, %sw.bb1 ]
+  %Value.addr.0.off12 = phi i32 [ %extract.t6, %entry ], [ %extract.t8, %sw.bb1 ]
+  %conv6 = and i32 %Value.addr.0.off0, 4095
+  %conv4 = shl i32 %Value.addr.0.off12, 16
+  %shl = and i32 %conv4, 983040
+  %or = or i32 %shl, %conv6
+  %or11 = or i32 %or, 8388608
+  br label %return
+
+return:                                           ; preds = %sw.bb2, %entry, %entry
+  %retval.0 = phi i32 [ %or11, %sw.bb2 ], [ %extract.t, %entry ], [ %extract.t, %entry ]
+  ret i32 %retval.0
+}
+
+; Function Attrs: noreturn
+declare void @_Z25llvm_unreachable_internalv()
+
-- 
2.34.1