[polly] r225812 - Fix maxLoopDepth computation in ScopInfo

[David Peixotto]

Author: dpeixott
Date: Tue Jan 13 12:31:55 2015
New Revision: 225812

URL: http://llvm.org/viewvc/llvm-project?rev=225812&view=rev
Log:
Fix maxLoopDepth computation in ScopInfo

The max loop depth was incorrectly computed for scops that contain a
block from a loop but do not contain the entire loop. We need to
check that the full loop is contained in the region when computing
the max loop depth.

These scops occur when a region containing an inner loop is expanded
to include some blocks from the outer loop, but it cannot be fully
expanded to contain the outer loop because the region containing the
outer loop is invalid.

Differential Revision: http://reviews.llvm.org/D6913

Added:
    polly/trunk/test/ScopInfo/max-loop-depth.ll
Modified:
    polly/trunk/lib/Analysis/ScopInfo.cpp

Modified: polly/trunk/lib/Analysis/ScopInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/Analysis/ScopInfo.cpp?rev=225812&r1=225811&r2=225812&view=diff
==============================================================================
--- polly/trunk/lib/Analysis/ScopInfo.cpp (original)
+++ polly/trunk/lib/Analysis/ScopInfo.cpp Tue Jan 13 12:31:55 2015
@@ -1469,6 +1469,8 @@ static unsigned getMaxLoopDepthInRegion(
   unsigned MinLD = INT_MAX, MaxLD = 0;
   for (BasicBlock *BB : R.blocks()) {
     if (Loop *L = LI.getLoopFor(BB)) {
+      if (!R.contains(L))
+        continue;
       unsigned LD = L->getLoopDepth();
       MinLD = std::min(MinLD, LD);
       MaxLD = std::max(MaxLD, LD);
@@ -1672,6 +1674,7 @@ void Scop::print(raw_ostream &OS) const
   OS.indent(4) << "Function: " << getRegion().getEntry()->getParent()->getName()
                << "\n";
   OS.indent(4) << "Region: " << getNameStr() << "\n";
+  OS.indent(4) << "Max Loop Depth:  " << getMaxLoopDepth() << "\n";
   printContext(OS.indent(4));
   printAliasAssumptions(OS);
   printStatements(OS.indent(4));

Added: polly/trunk/test/ScopInfo/max-loop-depth.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/max-loop-depth.ll?rev=225812&view=auto
==============================================================================
--- polly/trunk/test/ScopInfo/max-loop-depth.ll (added)
+++ polly/trunk/test/ScopInfo/max-loop-depth.ll Tue Jan 13 12:31:55 2015
@@ -0,0 +1,79 @@
+; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
+;
+;    void bar();
+;    void foo(int *A, int *B, long int N, long int M) {
+;      for (long int j = 0; j < M; ++j) {
+;        bar();
+;        for (long int i = 0; i < N; ++i)
+;          A[i] += 1;
+;        for (long int i = 0; i < N; ++i)
+;          A[i] += 1;
+;      }
+;    }
+;
+; Test to check that the scop only counts loop depth for loops fully contained
+; in the scop.
+; CHECK: Max Loop Depth: 1
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @foo(i32* %A, i32* %B, i64 %N, i64 %M) {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc13, %entry
+  %j.0 = phi i64 [ 0, %entry ], [ %inc14, %for.inc13 ]
+  %cmp = icmp slt i64 %j.0, %M
+  br i1 %cmp, label %for.body, label %for.end15
+
+for.body:                                         ; preds = %for.cond
+  call void (...)* @bar() #2
+  br label %for.cond1
+
+for.cond1:                                        ; preds = %for.inc, %for.body
+  %i.0 = phi i64 [ 0, %for.body ], [ %inc, %for.inc ]
+  %cmp2 = icmp slt i64 %i.0, %N
+  br i1 %cmp2, label %for.body3, label %for.end
+
+for.body3:                                        ; preds = %for.cond1
+  %arrayidx = getelementptr inbounds i32* %A, i64 %i.0
+  %tmp = load i32* %arrayidx, align 4
+  %add = add nsw i32 %tmp, 1
+  store i32 %add, i32* %arrayidx, align 4
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body3
+  %inc = add nuw nsw i64 %i.0, 1
+  br label %for.cond1
+
+for.end:                                          ; preds = %for.cond1
+  br label %for.cond5
+
+for.cond5:                                        ; preds = %for.inc10, %for.end
+  %i4.0 = phi i64 [ 0, %for.end ], [ %inc11, %for.inc10 ]
+  %cmp6 = icmp slt i64 %i4.0, %N
+  br i1 %cmp6, label %for.body7, label %for.end12
+
+for.body7:                                        ; preds = %for.cond5
+  %arrayidx8 = getelementptr inbounds i32* %A, i64 %i4.0
+  %tmp1 = load i32* %arrayidx8, align 4
+  %add9 = add nsw i32 %tmp1, 1
+  store i32 %add9, i32* %arrayidx8, align 4
+  br label %for.inc10
+
+for.inc10:                                        ; preds = %for.body7
+  %inc11 = add nuw nsw i64 %i4.0, 1
+  br label %for.cond5
+
+for.end12:                                        ; preds = %for.cond5
+  br label %for.inc13
+
+for.inc13:                                        ; preds = %for.end12
+  %inc14 = add nuw nsw i64 %j.0, 1
+  br label %for.cond
+
+for.end15:                                        ; preds = %for.cond
+  ret void
+}
+
+declare void @bar(...) #1
+