diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp index 3e6af58aa93..31d3ccca36a 100644 --- a/lib/Analysis/ValueTracking.cpp +++ b/lib/Analysis/ValueTracking.cpp @@ -1028,9 +1028,11 @@ static Value *GetLinearExpression(Value *V, APInt &Scale, APInt &Offset, const Value *llvm::DecomposeGEPExpression(const Value *V, int64_t &BaseOffs, SmallVectorImpl > &VarIndices, const TargetData *TD) { - // FIXME: Should limit depth like getUnderlyingObject? + // Limit recursion depth to limit compile time in crazy cases. + unsigned MaxLookup = 6; + BaseOffs = 0; - while (1) { + do { // See if this is a bitcast or GEP. const Operator *Op = dyn_cast(V); if (Op == 0) { @@ -1128,7 +1130,10 @@ const Value *llvm::DecomposeGEPExpression(const Value *V, int64_t &BaseOffs, // Analyze the base pointer next. V = GEPOp->getOperand(0); - } + } while (--MaxLookup); + + // If the chain of expressions is too deep, just return early. + return V; } diff --git a/test/Transforms/DeadStoreElimination/crash.ll b/test/Transforms/DeadStoreElimination/crash.ll index 7f82cbfd926..f89f8f5185c 100644 --- a/test/Transforms/DeadStoreElimination/crash.ll +++ b/test/Transforms/DeadStoreElimination/crash.ll @@ -1,4 +1,4 @@ -; RUN: opt < %s -dse | llvm-dis +; RUN: opt < %s -dse -S target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128" target triple = "i386-apple-darwin10.0" @@ -24,3 +24,20 @@ bb: ; preds = %bb, %entry %2 = tail call signext i8 @foo(i8 signext undef, i8 signext 1) nounwind ; [#uses=1] br label %bb } + +define fastcc i32 @test2() nounwind ssp { +bb14: ; preds = %bb4 + %0 = bitcast i8* undef to i8** ; [#uses=1] + %1 = getelementptr inbounds i8** %0, i64 undef ; [#uses=1] + %2 = bitcast i8** %1 to i16* ; [#uses=2] + %3 = getelementptr inbounds i16* %2, i64 undef ; [#uses=1] + %4 = bitcast i16* %3 to i8* ; [#uses=1] + %5 = getelementptr inbounds i8* %4, i64 undef ; [#uses=1] + %6 = getelementptr inbounds i16* %2, i64 undef ; [#uses=1] + store i16 undef, i16* %6, align 2 + %7 = getelementptr inbounds i8* %5, i64 undef ; [#uses=1] + call void @llvm.memcpy.i64(i8* %7, i8* undef, i64 undef, i32 1) nounwind + unreachable +} + +declare void @llvm.memcpy.i64(i8* nocapture, i8* nocapture, i64, i32) nounwind