Don't crash analyzing certain quadratics (addrec of {X,+,Y,+,1}).
We're still waiting on code that actually analyzes them properly. llvm-svn: 58592
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@ -2604,6 +2604,11 @@ SolveQuadraticEquation(const SCEVAddRecExpr *AddRec, ScalarEvolution &SE) {
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// The divisions must be performed as signed divisions.
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APInt NegB(-B);
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APInt TwoA( A << 1 );
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if (TwoA.isMinValue()) {
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SCEV *CNC = new SCEVCouldNotCompute();
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return std::make_pair(CNC, CNC);
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}
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ConstantInt *Solution1 = ConstantInt::get((NegB + SqrtVal).sdiv(TwoA));
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ConstantInt *Solution2 = ConstantInt::get((NegB - SqrtVal).sdiv(TwoA));
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@ -0,0 +1,21 @@
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; RUN: llvm-as < %s | opt -analyze -scalar-evolution
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; PR1827
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declare void @use(i32)
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define void @foo() {
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entry:
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br label %loop_1
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loop_1: ; preds = %loop_1, %entry
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%a = phi i32 [ 2, %entry ], [ %b, %loop_1 ] ; <i32> [#uses=2]
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%c = phi i32 [ 5, %entry ], [ %d, %loop_1 ] ; <i32> [#uses=1]
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%b = add i32 %a, 1 ; <i32> [#uses=1]
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%d = add i32 %c, %a ; <i32> [#uses=3]
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%A = icmp ult i32 %d, 50 ; <i1> [#uses=1]
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br i1 %A, label %loop_1, label %endloop
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endloop: ; preds = %loop_1
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call void @use(i32 %d)
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ret void
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}
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