From d6f7252e2ec08a66f5765b25ce70c4358392d6c1 Mon Sep 17 00:00:00 2001
From: Wei Mi <wmi@google.com>
Date: Thu, 30 Jul 2015 17:40:39 +0000
Subject: [SLP vectorizer]: Choose the best consecutive candidate to pair with
 a store instruction.

The patch changes the SLPVectorizer::vectorizeStores to choose the immediate
succeeding or preceding candidate for a store instruction when it has multiple
consecutive candidates. In this way it has better chance to find more slp
vectorization opportunities.

Differential Revision: http://reviews.llvm.org/D10445

llvm-svn: 243666
---
 llvm/test/Transforms/SLPVectorizer/X86/pr23510.ll | 38 +++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 llvm/test/Transforms/SLPVectorizer/X86/pr23510.ll

(limited to 'llvm/test')

diff --git a/llvm/test/Transforms/SLPVectorizer/X86/pr23510.ll b/llvm/test/Transforms/SLPVectorizer/X86/pr23510.ll
new file mode 100644
index 00000000000..efdb0ecd999
--- /dev/null
+++ b/llvm/test/Transforms/SLPVectorizer/X86/pr23510.ll
@@ -0,0 +1,38 @@
+; PR23510
+; RUN: opt < %s -basicaa -slp-vectorizer -S | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+; CHECK-LABEL: @_Z3fooPml(
+; CHECK: lshr <2 x i64>
+; CHECK: lshr <2 x i64>
+
+@total = global i64 0, align 8
+
+define void @_Z3fooPml(i64* nocapture %a, i64 %i) {
+entry:
+  %tmp = load i64, i64* %a, align 8
+  %shr = lshr i64 %tmp, 4
+  store i64 %shr, i64* %a, align 8
+  %arrayidx1 = getelementptr inbounds i64, i64* %a, i64 1
+  %tmp1 = load i64, i64* %arrayidx1, align 8
+  %shr2 = lshr i64 %tmp1, 4
+  store i64 %shr2, i64* %arrayidx1, align 8
+  %arrayidx3 = getelementptr inbounds i64, i64* %a, i64 %i
+  %tmp2 = load i64, i64* %arrayidx3, align 8
+  %tmp3 = load i64, i64* @total, align 8
+  %add = add i64 %tmp3, %tmp2
+  store i64 %add, i64* @total, align 8
+  %tmp4 = load i64, i64* %a, align 8
+  %shr5 = lshr i64 %tmp4, 4
+  store i64 %shr5, i64* %a, align 8
+  %tmp5 = load i64, i64* %arrayidx1, align 8
+  %shr7 = lshr i64 %tmp5, 4
+  store i64 %shr7, i64* %arrayidx1, align 8
+  %tmp6 = load i64, i64* %arrayidx3, align 8
+  %tmp7 = load i64, i64* @total, align 8
+  %add9 = add i64 %tmp7, %tmp6
+  store i64 %add9, i64* @total, align 8
+  ret void
+}
-- 
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