[PATCH] D32893: Fix handling of signWrappedSets in access relations

[Maximilian Falkenstein via Phabricator via llvm-commits]

maxf created this revision.
maxf added a project: Polly.

Since r294891, in MemoryAccess::computeBoundsOnAccessRelation(), we skip
manually bounding the access relation in case the parameter of the load
instruction is already a wrapped set. Later on we assume that the lower
bound on the set is always smaller or equal to the upper bound on the
set. Bug 32715 manages to construct a sign wrapped set, in which case
the assertion does not necessarily hold. Fix this by handling a sign
wrapped set similar to a normal wrapped set, that is skipping the
computation.


https://reviews.llvm.org/D32893

Files:
  lib/Analysis/ScopInfo.cpp
  test/ScopInfo/sign_wrapped_set.ll


Index: test/ScopInfo/sign_wrapped_set.ll
===================================================================
--- /dev/null
+++ test/ScopInfo/sign_wrapped_set.ll
@@ -0,0 +1,37 @@
+; RUN: opt %loadPolly -polly-scops -analyze \
+; RUN: -polly-allow-nonaffine -polly-process-unprofitable < %s | FileCheck %s
+;
+; CHECK:         Domain :=
+; CHECK-NEXT:    [srcHeight] -> { Stmt_for_cond6_preheader_us[i0] : 0 <= i0 <= -3 + srcHeight };
+; CHECK-NEXT:    Schedule :=
+; CHECK-NEXT:    [srcHeight] -> { Stmt_for_cond6_preheader_us[i0] -> [i0] };
+target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+
+define void @test_case(i8* noalias nocapture readonly %src, i32 %srcHeight, i32 %srcStride) local_unnamed_addr {
+entry:
+  %extended = zext i32 %srcStride to i64
+  %sub = add i32 %srcHeight, -1
+  br label %for.cond6.preheader.us
+
+for.cond6.preheader.us:                           ; preds = %for.cond6.preheader.us, %entry
+  %srcPtr.075.us.pn = phi i8* [ %srcPtr.075.us, %for.cond6.preheader.us ], [ %src, %entry ]
+  %y.072.us = phi i32 [ %inc37.us, %for.cond6.preheader.us ], [ 1, %entry ]
+  %srcPtr.075.us = getelementptr inbounds i8, i8* %srcPtr.075.us.pn, i64 %extended
+  
+  %0 = load i8, i8* %srcPtr.075.us, align 1, !tbaa !0
+  %1 = add i8 %0, 1
+  store i8 %1, i8* %srcPtr.075.us, align 1, !tbaa !0
+  
+  %inc37.us = add nuw i32 %y.072.us, 1
+  %exitcond78 = icmp eq i32 %inc37.us, %sub
+  br i1 %exitcond78, label %for.cond.cleanup.loopexit, label %for.cond6.preheader.us
+
+for.cond.cleanup.loopexit:                        ; preds = %for.cond6.preheader.us
+  ret void
+}
+
+!0 = !{!1, !1, i64 0}
+!1 = !{!"omnipotent char", !2, i64 0}
+!2 = !{!"Simple C++ TBAA"}
+!3 = !{!4, !4, i64 0}
+!4 = !{!"float", !1, i64 0}
Index: lib/Analysis/ScopInfo.cpp
===================================================================
--- lib/Analysis/ScopInfo.cpp
+++ lib/Analysis/ScopInfo.cpp
@@ -788,7 +788,7 @@
   if (Range.isFullSet())
     return;
 
-  if (Range.isWrappedSet())
+  if (Range.isWrappedSet() | Range.isSignWrappedSet())
     return;
 
   bool isWrapping = Range.isSignWrappedSet();


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