[llvm-commits] [llvm] r65902 - in /llvm/trunk: lib/Transforms/Scalar/LoopIndexSplit.cpp test/Transforms/LoopIndexSplit/2009-03-02-UpdateIterationSpace-crash.ll

[Devang Patel]

Author: dpatel
Date: Mon Mar  2 17:39:14 2009
New Revision: 65902

URL: http://llvm.org/viewvc/llvm-project?rev=65902&view=rev
Log:
If branch conditions' one successor is dominating another non-latch successor then this loop's iteration space can not be restricted. In this example block bb5 is always executed.

Added:
    llvm/trunk/test/Transforms/LoopIndexSplit/2009-03-02-UpdateIterationSpace-crash.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/LoopIndexSplit.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/LoopIndexSplit.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopIndexSplit.cpp?rev=65902&r1=65901&r2=65902&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LoopIndexSplit.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LoopIndexSplit.cpp Mon Mar  2 17:39:14 2009
@@ -532,6 +532,21 @@
   BasicBlock *ExitingBlock = ExitCondition->getParent();
   if (!cleanBlock(ExitingBlock)) return false;
 
+  // If the merge point for BR is not loop latch then skip this loop.
+  if (BR->getSuccessor(0) != Latch) {
+    DominanceFrontier::iterator DF0 = DF->find(BR->getSuccessor(0));
+    assert (DF0 != DF->end() && "Unable to find dominance frontier");
+    if (!DF0->second.count(Latch))
+      return false;
+  }
+  
+  if (BR->getSuccessor(1) != Latch) {
+    DominanceFrontier::iterator DF1 = DF->find(BR->getSuccessor(1));
+    assert (DF1 != DF->end() && "Unable to find dominance frontier");
+    if (!DF1->second.count(Latch))
+      return false;
+  }
+    
   // Verify that loop exiting block has only two predecessor, where one pred
   // is split condition block. The other predecessor will become exiting block's
   // dominator after CFG is updated. TODO : Handle CFG's where exiting block has

Added: llvm/trunk/test/Transforms/LoopIndexSplit/2009-03-02-UpdateIterationSpace-crash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopIndexSplit/2009-03-02-UpdateIterationSpace-crash.ll?rev=65902&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/LoopIndexSplit/2009-03-02-UpdateIterationSpace-crash.ll (added)
+++ llvm/trunk/test/Transforms/LoopIndexSplit/2009-03-02-UpdateIterationSpace-crash.ll Mon Mar  2 17:39:14 2009
@@ -0,0 +1,64 @@
+; RUN: llvm-as < %s | opt -loop-index-split -disable-output
+	%struct.CGPoint = type { double, double }
+	%struct.IBCFMutableDictionary = type { %struct.NSMutableArray, %struct.__CFDictionary*, %struct.NSSortDescriptor*, %struct.NSSortDescriptor* }
+	%struct.IBInspectorMode = type opaque
+	%struct.IBInspectorModeView = type { %struct.NSView, %struct.NSArray*, %struct.IBCFMutableDictionary*, %struct.IBInspectorMode*, %struct.IBInspectorMode*, %struct.IBInspectorMode*, %struct.objc_selector*, %struct.NSObject* }
+	%struct.NSArray = type { %struct.NSObject }
+	%struct.NSImage = type { %struct.NSObject, %struct.NSArray*, %struct.CGPoint, %struct.__imageFlags, %struct.NSObject*, %struct._NSImageAuxiliary* }
+	%struct.NSMutableArray = type { %struct.NSArray }
+	%struct.NSObject = type { %struct.objc_class* }
+	%struct.NSRect = type { %struct.CGPoint, %struct.CGPoint }
+	%struct.NSResponder = type { %struct.NSObject, %struct.NSObject* }
+	%struct.NSSortDescriptor = type { %struct.NSObject, i64, %struct.NSArray*, %struct.objc_selector*, %struct.NSObject* }
+	%struct.NSURL = type { %struct.NSObject, %struct.NSArray*, %struct.NSURL*, i8*, i8* }
+	%struct.NSView = type { %struct.NSResponder, %struct.NSRect, %struct.NSRect, %struct.NSObject*, %struct.NSObject*, %struct.NSWindow*, %struct.NSObject*, %struct.NSObject*, %struct.NSObject*, %struct.NSObject*, %struct._NSViewAuxiliary*, %struct._VFlags, %struct.__VFlags2 }
+	%struct.NSWindow = type { %struct.NSResponder, %struct.NSRect, %struct.NSObject*, %struct.NSObject*, %struct.NSResponder*, %struct.NSView*, %struct.NSView*, %struct.NSObject*, %struct.NSObject*, i32, i64, i32, %struct.NSArray*, %struct.NSObject*, i8, i8, i8, i8, i8*, i8*, %struct.NSImage*, i32, %struct.NSMutableArray*, %struct.NSURL*, %struct.CGPoint*, %struct.NSArray*, %struct.NSArray*, %struct.__wFlags, %struct.NSObject*, %struct.NSView*, %struct.NSWindowAuxiliary* }
+	%struct.NSWindowAuxiliary = type opaque
+	%struct._NSImageAuxiliary = type opaque
+	%struct._NSViewAuxiliary = type opaque
+	%struct._VFlags = type <{ i8, i8, i8, i8 }>
+	%struct.__CFDictionary = type opaque
+	%struct.__VFlags2 = type <{ i32 }>
+	%struct.__imageFlags = type <{ i8, [3 x i8] }>
+	%struct.__wFlags = type <{ i8, i8, i8, i8, i8, i8, i8, i8 }>
+	%struct.objc_class = type opaque
+	%struct.objc_selector = type opaque
+
+define %struct.NSArray* @"\01-[IBInspectorModeView calculateModeRects]"(%struct.IBInspectorModeView* %self, %struct.objc_selector* %_cmd) optsize ssp {
+entry:
+	br i1 false, label %bb7, label %bb
+
+bb:		; preds = %entry
+	br i1 false, label %bb.nph, label %bb7.loopexit
+
+bb.nph:		; preds = %bb
+	br label %bb1
+
+bb1:		; preds = %bb6, %bb.nph
+	%midx.01 = phi i64 [ %3, %bb6 ], [ 0, %bb.nph ]		; <i64> [#uses=3]
+	%0 = icmp sge i64 %midx.01, 0		; <i1> [#uses=1]
+	%1 = icmp sle i64 %midx.01, 0		; <i1> [#uses=1]
+	%2 = and i1 %0, %1		; <i1> [#uses=1]
+	br i1 %2, label %bb4, label %bb5
+
+bb4:		; preds = %bb1
+	br label %bb5
+
+bb5:		; preds = %bb4, %bb1
+	%modeWidth.0 = phi double [ 0.000000e+00, %bb1 ], [ 0.000000e+00, %bb4 ]		; <double> [#uses=0]
+	%3 = add i64 %midx.01, 1		; <i64> [#uses=1]
+	br label %bb6
+
+bb6:		; preds = %bb5
+	%4 = icmp slt i64 0, 0		; <i1> [#uses=1]
+	br i1 %4, label %bb1, label %bb6.bb7.loopexit_crit_edge
+
+bb6.bb7.loopexit_crit_edge:		; preds = %bb6
+	br label %bb7.loopexit
+
+bb7.loopexit:		; preds = %bb6.bb7.loopexit_crit_edge, %bb
+	br label %bb7
+
+bb7:		; preds = %bb7.loopexit, %entry
+	ret %struct.NSArray* null
+}