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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65902 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Devang Patel 2009-03-02 23:39:14 +00:00
parent 24e338e8a3
commit cf42ee42b1
2 changed files with 79 additions and 0 deletions

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@ -532,6 +532,21 @@ bool LoopIndexSplit::updateLoopIterationSpace() {
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

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@ -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
}