[PATCH] D15906: [Vectorization] Actually return from error case in isStridedPtr

[Tim Shen via llvm-commits]

timshen updated this revision to Diff 44090.
timshen added a comment.

Yes, your test case is much simpler, thanks! :) I tweaked a bit (stride needs to be at least 2 to trigger interleave) to reveal the wrong behavior of the old opt. In such case it has to be a XFAIL, since what we hope is "interleave should not fire" - testing the correct code may be fragile.


http://reviews.llvm.org/D15906

Files:
  lib/Analysis/LoopAccessAnalysis.cpp
  test/Analysis/LoopAccessAnalysis/interleave_innermost.ll

Index: test/Analysis/LoopAccessAnalysis/interleave_innermost.ll
===================================================================
--- /dev/null
+++ test/Analysis/LoopAccessAnalysis/interleave_innermost.ll
@@ -0,0 +1,31 @@
+; RUN: opt -loop-vectorize -force-vector-interleave=1 -S < %s | FileCheck %s
+; CHECK: %[[PTR:[^ ]+]] = extractelement <4 x i32*> %broadcast.splat{{.*}}, i32 {{[0-9]+}}
+; CHECK: %[[ADJUSTED_PTR:[^ ]+]] = getelementptr i32, i32* %[[PTR]], i32 0
+; CHECK: %{{[^ ]+}} = bitcast i32* %[[ADJUSTED_PTR]] to <8 x i32>*
+; XFAIL: *
+
+target datalayout = "e-m:e-i64:64-n32:64"
+target triple = "powerpc64le-unknown-linux-gnu"
+
+define void @TestFoo(i1 %X, i1 %Y) {
+bb:
+  br label %.loopexit5.outer
+
+.loopexit5.outer:
+  br label %.lr.ph12
+
+.loopexit:
+  br i1 %X, label %.loopexit5.outer, label %.lr.ph12
+
+.lr.ph12:
+  %f.110 = phi i32* [ %tmp1, %.loopexit ], [ null, %.loopexit5.outer ]
+  %tmp1 = getelementptr inbounds i32, i32* %f.110, i64 -2
+  br i1 %Y, label %bb4, label %.loopexit
+
+bb4:
+  %j.27 = phi i32 [ 0, %.lr.ph12 ], [ %tmp7, %bb4 ]
+  %tmp5 = load i32, i32* %f.110, align 4
+  %tmp7 = add nsw i32 %j.27, 1
+  %exitcond = icmp eq i32 %tmp7, 0
+  br i1 %exitcond, label %.loopexit, label %bb4
+}
Index: lib/Analysis/LoopAccessAnalysis.cpp
===================================================================
--- lib/Analysis/LoopAccessAnalysis.cpp
+++ lib/Analysis/LoopAccessAnalysis.cpp
@@ -845,6 +845,7 @@
   if (Lp != AR->getLoop()) {
     DEBUG(dbgs() << "LAA: Bad stride - Not striding over innermost loop " <<
           *Ptr << " SCEV: " << *PtrScev << "\n");
+    return 0;
   }
 
   // The address calculation must not wrap. Otherwise, a dependence could be


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