LICM crash, "Uses remain when a value is destroyed"

[nlewycky]

Bugzilla Link	908
Resolution	FIXED
Resolved on	Nov 07, 2018 00:17
Version	trunk
OS	All
Attachments	simplified testcase

Extended Description

MultiSource/Applications/oggenc picked up a failure in the nightly run. It
appears to be in the loop invariant code motion pass. Here's what happens:

$ ~/llvm/Debug/bin/opt -licm bugpoint-reduced-simplified.bc
WARNING: You're attempting to print out a bytecode file.
This is inadvisable as it may cause display problems. If
you REALLY want to taste LLVM bytecode first-hand, you
can force output with the `-f' option.

While deleting: uint %tmp16.i
Use still stuck around after Def is destroyed: %exitcond155 = seteq uint 0,
%tmp16.i ; [#uses=0]

opt: Value.cpp:59: virtual llvm::Value::~Value(): Assertion `use_begin() ==
use_end() && "Uses remain when a value is destroyed!"' failed.
/home/nicholas/llvm/Debug/bin/opt((anonymous
namespace)::PrintStackTrace()+0x1a)[0x873245c]
/home/nicholas/llvm/Debug/bin/opt((anonymous
namespace)::SignalHandler(int)+0x110)[0x8732720]
[0xffffe500]
Aborted

[nlewycky]

assigned to @lattner

[lattner]

Fixed.  Testcase here: 
Transforms/LICM/2006-09-12-DeadUserOfSunkInstr.ll

Patch here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20060911/037730.html

Thanks!

-Chris

[nlewycky]

Verified. Thanks Chris!