From: Johannes Doerfert <doerfert@cs.uni-saarland.de>
Date: Sun, 3 May 2015 16:03:01 +0000 (+0000)
Subject: [FIX] Invalid recognition of multidimensional access
X-Git-Tag: llvmorg-3.7.0-rc1~5472
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8983031b5edd81f67504d81a7d693e5ee79baee6;p=platform%2Fupstream%2Fllvm.git

[FIX] Invalid recognition of multidimensional access

  In the lnt benchmark MultiSource/Benchmarks/MallocBench/gs/gs with
  scalar and PHI modeling we detected the multidimensional accesses
  with sizes variant in the SCoP. This will check the sizes for validity.

llvm-svn: 236395
---

diff --git a/polly/lib/Analysis/ScopDetection.cpp b/polly/lib/Analysis/ScopDetection.cpp
index db04f0b..f7ea6c4 100644
--- a/polly/lib/Analysis/ScopDetection.cpp
+++ b/polly/lib/Analysis/ScopDetection.cpp
@@ -488,6 +488,13 @@ bool ScopDetection::hasAffineMemoryAccesses(DetectionContext &Context) const {
     SE->findArrayDimensions(Terms, Shape->DelinearizedSizes,
                             Context.ElementSize[BasePointer]);
 
+    if (!AllowNonAffine)
+      for (const SCEV *DelinearizedSize : Shape->DelinearizedSizes)
+        if (hasScalarDepsInsideRegion(DelinearizedSize, &CurRegion))
+          invalid<ReportNonAffineAccess>(
+              Context, /*Assert=*/true, DelinearizedSize,
+              Context.Accesses[BasePointer].front().first, BaseValue);
+
     // No array shape derived.
     if (Shape->DelinearizedSizes.empty()) {
       if (AllowNonAffine)
diff --git a/polly/lib/Support/SCEVValidator.cpp b/polly/lib/Support/SCEVValidator.cpp
index 80c2249..f1d9443 100644
--- a/polly/lib/Support/SCEVValidator.cpp
+++ b/polly/lib/Support/SCEVValidator.cpp
@@ -559,6 +559,7 @@ std::vector<const SCEV *> getParamsInAffineExpr(const Region *R,
 
   SCEVValidator Validator(R, SE, BaseAddress);
   ValidatorResult Result = Validator.visit(Expr);
+  assert(Result.isValid() && "Requested parameters for an invalid SCEV!");
 
   return Result.getParameters();
 }
diff --git a/polly/test/ScopDetect/multidim_indirect_access.ll b/polly/test/ScopDetect/multidim_indirect_access.ll
new file mode 100644
index 0000000..b3edecb
--- /dev/null
+++ b/polly/test/ScopDetect/multidim_indirect_access.ll
@@ -0,0 +1,58 @@
+; RUN: opt %loadPolly -polly-detect-unprofitable -polly-detect -analyze < %s | FileCheck %s --check-prefix=INDEPENDENT
+; RUN: opt %loadPolly -polly-detect-unprofitable -polly-detect -analyze -polly-model-phi-nodes -disable-polly-intra-scop-scalar-to-array  < %s | FileCheck %s --check-prefix=NON_INDEPENDENT
+;
+; With the IndependentBlocks and PollyPrepare passes this will __correctly__
+; not be recognized as a SCoP and the debug states:
+;
+;   SCEV of PHI node refers to SSA names in region
+;
+; Without IndependentBlocks and PollyPrepare the access A[x] is mistakenly
+; treated as a multidimensional access with dimension size x. This test will
+; check that we correctly invalidate the region and do not detect a outer SCoP.
+;
+; FIXME:
+; We should detect the inner region but the PHI node in the exit blocks that.
+;
+;    void f(int *A, long N) {
+;      int j = 0;
+;      while (N > j) {
+;        int x = A[0];
+;        int i = 1;
+;        do {
+;          A[x] = 42;
+;          A += x;
+;        } while (i++ < N);
+;      }
+;    }
+;
+; INDEPENDENT-NOT: Valid
+; NON_INDEPENDENT-NOT: Valid
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @f(i32* %A, i64 %N) {
+bb:
+  br label %bb0
+
+bb0:
+  %j = phi i64 [ %j.next, %bb1 ], [ 1, %bb ]
+  %tmp = load i32, i32* %A, align 4
+  %exitcond0 = icmp sgt i64 %N, %j
+  %j.next = add nuw nsw i64 %j, 1
+  br i1 %exitcond0, label %bb1, label %bb13
+
+bb1:                                              ; preds = %bb7, %bb0
+  %i = phi i64 [ %i.next, %bb1 ], [ 1, %bb0 ]
+  %.0 = phi i32* [ %A, %bb0 ], [ %tmp12, %bb1 ]
+  %tmp8 = sext i32 %tmp to i64
+  %tmp9 = getelementptr inbounds i32, i32* %.0, i64 %tmp8
+  store i32 42, i32* %tmp9, align 4
+  %tmp11 = sext i32 %tmp to i64
+  %tmp12 = getelementptr inbounds i32, i32* %.0, i64 %tmp11
+  %i.next = add nuw nsw i64 %i, 1
+  %exitcond = icmp ne i64 %i, %N
+  br i1 %exitcond, label %bb1, label %bb0
+
+bb13:                                             ; preds = %bb1
+  ret void
+}