[Bug c/88481] -O1 causes optimizer to drop 'then' clause in conditional

[heinrich.seebauer at swistec dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88481

--- Comment #8 from Heinrich Seebauer <heinrich.seebauer at swistec dot de> ---
Sorry, my comment was lost completely after uploading the attachment.
Try again...

So I hope, I got this right.

-fdbg-cnt=if_conversion:xx,if_after_combine:yy

xx      yy      result
-----------------------
20      20      success
20      21      fail
0       21      fail
21      20      fail

tested with -fdbg-cnt=if_conversion:20,if_after_combine:21 -fno-if-conversion
and got functioning code.

I did gdb stepping in the source file where I observed, that the condition was
true, but the branch was not executed. Same with the tests here - they were all
strepped via source code.