diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index e0750053eb9..ceded879b0f 100644 --- a/lib/Analysis/ScalarEvolution.cpp +++ b/lib/Analysis/ScalarEvolution.cpp @@ -2604,6 +2604,11 @@ SolveQuadraticEquation(const SCEVAddRecExpr *AddRec, ScalarEvolution &SE) { // The divisions must be performed as signed divisions. APInt NegB(-B); APInt TwoA( A << 1 ); + if (TwoA.isMinValue()) { + SCEV *CNC = new SCEVCouldNotCompute(); + return std::make_pair(CNC, CNC); + } + ConstantInt *Solution1 = ConstantInt::get((NegB + SqrtVal).sdiv(TwoA)); ConstantInt *Solution2 = ConstantInt::get((NegB - SqrtVal).sdiv(TwoA)); diff --git a/test/Analysis/ScalarEvolution/2008-11-02-QuadraticCrash.ll b/test/Analysis/ScalarEvolution/2008-11-02-QuadraticCrash.ll new file mode 100644 index 00000000000..c6cb87fca14 --- /dev/null +++ b/test/Analysis/ScalarEvolution/2008-11-02-QuadraticCrash.ll @@ -0,0 +1,21 @@ +; RUN: llvm-as < %s | opt -analyze -scalar-evolution +; PR1827 + +declare void @use(i32) + +define void @foo() { +entry: + br label %loop_1 + +loop_1: ; preds = %loop_1, %entry + %a = phi i32 [ 2, %entry ], [ %b, %loop_1 ] ; [#uses=2] + %c = phi i32 [ 5, %entry ], [ %d, %loop_1 ] ; [#uses=1] + %b = add i32 %a, 1 ; [#uses=1] + %d = add i32 %c, %a ; [#uses=3] + %A = icmp ult i32 %d, 50 ; [#uses=1] + br i1 %A, label %loop_1, label %endloop + +endloop: ; preds = %loop_1 + call void @use(i32 %d) + ret void +}