From 033e0a94cbb3df8e0f48cebe0ac5b4a024c85b2d Mon Sep 17 00:00:00 2001 From: Hal Finkel Date: Tue, 9 Jul 2013 18:16:16 +0000 Subject: Don't crash in SE dealing with ashr x, -1 ScalarEvolution::getSignedRange uses ComputeNumSignBits from ValueTracking on ashr instructions. ComputeNumSignBits can return zero, but this case was not handled correctly by the code in getSignedRange which was calling: APInt::getSignedMinValue(BitWidth).ashr(NS - 1) with NS = 0, resulting in an assertion failure in APInt::ashr. Now, we just return the conservative result (as with NS == 1). Another bug found by llvm-stress. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185955 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/CodeGen/PowerPC/ashr-neg1.ll | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 test/CodeGen/PowerPC/ashr-neg1.ll (limited to 'test/CodeGen/PowerPC/ashr-neg1.ll') diff --git a/test/CodeGen/PowerPC/ashr-neg1.ll b/test/CodeGen/PowerPC/ashr-neg1.ll new file mode 100644 index 00000000000..28e74f4d298 --- /dev/null +++ b/test/CodeGen/PowerPC/ashr-neg1.ll @@ -0,0 +1,18 @@ +; RUN: llc -mtriple=powerpc64-unknown-linux-gnu -mcpu=pwr7 < %s +target triple = "powerpc64-unknown-linux-gnu" + +define void @autogen_SD30723(i32) { +BB: + br label %CF80 + +CF80: ; preds = %CF80, %BB + %B = ashr i32 %0, -1 + br i1 undef, label %CF80, label %CF84 + +CF84: ; preds = %CF84, %CF80 + %Cmp62 = icmp sge i32 undef, %B + br i1 %Cmp62, label %CF84, label %CF85 + +CF85: ; preds = %CF85, %CF84 + br label %CF85 +} -- cgit v1.2.3