Indvars Pass Turns a Counted Loop into an Infinite Loop

[llvmbot]

Bugzilla Link	8078
Resolution	FIXED
Resolved on	Sep 03, 2010 21:43
Version	unspecified
OS	Linux
Attachments	Test case, Bitcode from testcase compiled with -O2
Reporter	LLVM Bugzilla Contributor
CC	@sunfishcode

Extended Description

Transforms an ordinary counted loop into an infinite loop. I have attached C source code and llvm bitcode to demonstrate the bug. To reproduce:

$ clang -O2 ./KS-2.c -emit-llvm -c -o ks.all.ll
$ clang ks.all.ll -o ks.all
$ ./ks.all
0 + 1: 1
$ opt ks.all.ll -indvars -o ks.all.indvars.ll
$ clang ks.all.indvars.ll -o ks.all.indvars
$ ./ks.all.indvars
0 + 1: 1
0 + 1: 1
0 + 1: 1
...

[sunfishcode]

Fixed in 113057.