llvm-6502/test/CodeGen/PowerPC/ashr-neg1.ll
Hal Finkel 033e0a94cb 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
2013-07-09 18:16:16 +00:00

19 lines
545 B
LLVM

; 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
}