From ef3e423e2313ee05ba136aafc1e34c45a2702577 Mon Sep 17 00:00:00 2001
From: Nadav Rotem <nrotem@apple.com>
Date: Fri, 10 May 2013 22:55:44 +0000
Subject: Add an additional testcase for PR15882.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181646 91177308-0d34-0410-b5e6-96231b3b80d8
---
 test/Transforms/LoopVectorize/reverse_iter.ll | 45 +++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 test/Transforms/LoopVectorize/reverse_iter.ll

(limited to 'test/Transforms')

diff --git a/test/Transforms/LoopVectorize/reverse_iter.ll b/test/Transforms/LoopVectorize/reverse_iter.ll
new file mode 100644
index 0000000..6ff4f1f
--- /dev/null
+++ b/test/Transforms/LoopVectorize/reverse_iter.ll
@@ -0,0 +1,45 @@
+; RUN: opt < %s  -loop-vectorize -force-vector-unroll=1 -force-vector-width=4 -dce -instcombine -S | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.8.0"
+
+; Make sure that the reverse iterators are calculated using 64bit arithmetic, not 32.
+;
+; int foo(int n, int *A) {
+;   int sum;
+;   for (int i=n; i > 0; i--)
+;     sum += A[i*2];
+;   return sum;
+; }
+;
+
+;CHECK: @foo
+;CHECK:  <i64 0, i64 -1, i64 -2, i64 -3>
+;CHECK: ret
+define i32 @foo(i32 %n, i32* nocapture %A) {
+  %1 = icmp sgt i32 %n, 0
+  br i1 %1, label %.lr.ph, label %._crit_edge
+
+.lr.ph:                                           ; preds = %0
+  %2 = sext i32 %n to i64
+  br label %3
+
+; <label>:3                                       ; preds = %.lr.ph, %3
+  %indvars.iv = phi i64 [ %2, %.lr.ph ], [ %indvars.iv.next, %3 ]
+  %sum.01 = phi i32 [ undef, %.lr.ph ], [ %9, %3 ]
+  %4 = trunc i64 %indvars.iv to i32
+  %5 = shl nsw i32 %4, 1
+  %6 = sext i32 %5 to i64
+  %7 = getelementptr inbounds i32* %A, i64 %6
+  %8 = load i32* %7, align 4
+  %9 = add nsw i32 %8, %sum.01
+  %indvars.iv.next = add i64 %indvars.iv, -1
+  %10 = trunc i64 %indvars.iv.next to i32
+  %11 = icmp sgt i32 %10, 0
+  br i1 %11, label %3, label %._crit_edge
+
+._crit_edge:                                      ; preds = %3, %0
+  %sum.0.lcssa = phi i32 [ undef, %0 ], [ %9, %3 ]
+  ret i32 %sum.0.lcssa
+}
+
-- 
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