[polly] r253788 - [FIX] Get the correct loop that surrounds a region

[Johannes Doerfert via llvm-commits]

Author: jdoerfert
Date: Sat Nov 21 10:56:13 2015
New Revision: 253788

URL: http://llvm.org/viewvc/llvm-project?rev=253788&view=rev
Log:
[FIX] Get the correct loop that surrounds a region

Added:
    polly/trunk/test/ScopInfo/two-loops-one-infinite.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=253788&r1=253787&r2=253788&view=diff
==============================================================================
--- polly/trunk/lib/Analysis/ScopInfo.cpp (original)
+++ polly/trunk/lib/Analysis/ScopInfo.cpp Sat Nov 21 10:56:13 2015
@@ -2551,8 +2551,23 @@ bool Scop::buildAliasGroups(AliasAnalysi
   return true;
 }
 
+/// @brief Get the smallest loop that contains @p R but is not in @p R.
 static Loop *getLoopSurroundingRegion(Region &R, LoopInfo &LI) {
+  // Start with the smallest loop containing the entry and expand that
+  // loop until it contains all blocks in the region. If there is a loop
+  // containing all blocks in the region check if it is itself contained
+  // and if so take the parent loop as it will be the smallest containing
+  // the region but not contained by it.
   Loop *L = LI.getLoopFor(R.getEntry());
+  while (L) {
+    bool AllContained = true;
+    for (auto *BB : R.blocks())
+      AllContained &= L->contains(BB);
+    if (AllContained)
+      break;
+    L = L->getParentLoop();
+  }
+
   return L ? (R.contains(L) ? L->getParentLoop() : L) : nullptr;
 }
 

Added: polly/trunk/test/ScopInfo/two-loops-one-infinite.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/two-loops-one-infinite.ll?rev=253788&view=auto
==============================================================================
--- polly/trunk/test/ScopInfo/two-loops-one-infinite.ll (added)
+++ polly/trunk/test/ScopInfo/two-loops-one-infinite.ll Sat Nov 21 10:56:13 2015
@@ -0,0 +1,48 @@
+; RUN: opt %loadPolly -polly-scops -analyze < %s | FileCheck %s
+;
+; Verify we detect and create the SCoP correctly
+;
+; CHECK:      Statements {
+; CHECK-NEXT:   Stmt_while_body_us
+; CHECK-NEXT:     Domain :=
+; CHECK-NEXT:       [a13] -> { Stmt_while_body_us[] };
+; CHECK-NEXT:     Schedule :=
+; CHECK-NEXT:       [a13] -> { Stmt_while_body_us[] -> [] };
+; CHECK-NEXT:     MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
+; CHECK-NEXT:       [a13] -> { Stmt_while_body_us[] -> MemRef_uuu[] };
+; CHECK-NEXT: }
+;
+target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n8:16:32-S64"
+
+define void @foo(i32* noalias nocapture readonly %xxx, i32* noalias nocapture readonly %yyy, i8*** nocapture readonly %zzz, i32 %conv6) {
+while.body.us.preheader:
+ %a2 = load i8**, i8*** %zzz, align 4  
+ %sub = add nsw i32 %conv6, -1 
+  br label %while.body.us
+
+while.body.us:                                    ; preds = %while.body.us.preheader, %if.then.us
+  %uuu = phi i32 [ %www, %if.then.us ], [ 0, %while.body.us.preheader ]
+  %a13 = load i32, i32* %yyy, align 8
+  %vvv = icmp sgt i32 %a13, 0
+  br i1 %vvv, label %while.body.13.us58.preheader, label %if.then.us
+
+while.body.13.us58.preheader:                     ; preds = %while.body.us
+  br label %while.body.13.us58
+
+if.then.us:                                       ; preds = %while.body.us
+  %add.us = add nuw nsw i32 %uuu, 1
+  tail call void @goo(i8** %a2, i32 %uuu, i8** %a2, i32 %add.us, i32 %sub, i32 %a13) #3
+  %www = add nuw nsw i32 %uuu, %conv6
+  %a14 = load i32, i32* %xxx, align 4
+  %cmp.us = icmp slt i32 %www, %a14
+  br i1 %cmp.us, label %while.body.us, label %while.end.21.loopexit145
+
+while.body.13.us58:
+    br label %while.body.13.us58
+
+while.end.21.loopexit145:
+  ret void
+}
+
+declare void @goo(i8**, i32, i8**, i32, i32, i32) #1
+