assigned to @lattner

I reduced it with this command:

bugpoint -llc-safe Output/consumer-typeset.noopt-llvm.bc cat Output/gccas-pass-args -append-
exit-code -Xlinker=-lm -input=/dev/null -output=Output/consumer-typeset.out-nat -timeout=500
--tool-args --args -- -I data/include -D data/data -F data/font -C data/maps -H data/hyph large.lout

Bugpoint gets confused because GCC ICEs on the CBE output (thus the -llc-safe mode).

I gets it down to: opt bugpoint-tooptimize.bc -load-vn -gcse -instcombine -break-crit-edges

I'll investigate.

-Chris

I really need to get bugpoint fixed on Linux. This is frustrating that I can't
reduce anything on Linux except on rare occasion. I tried -llc-safe!

Yes, you do :)

It took at lot of scrutinizing, but it looks like instcombine is miscompiling:

define bool %test(i8 %A, i8 %B) {
%a = zext i8 %A to i32 ; [#uses=1]
%b = zext i8 %B to i32 ; [#uses=1]
%c = icmp sgt i32 %a, %b ; [#uses=1]
ret bool %c
}

into:

define bool %test(i8 %A, i8 %B) {
%c = icmp sgt i8 %A, %B ; [#uses=1]
ret bool %c
}

Here is one instcombine bugfix:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070108/042635.html

Testcase here: Transforms/InstCombine/2007-01-13-ExtCompareMiscompile.ll

This is not sufficient to fix consumer-typeset though. Rebugpointing.

Here is one instcombine bugfix:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070108/042635.html

Testcase here: Transforms/InstCombine/2007-01-13-ExtCompareMiscompile.ll

The next bug isn't in instcombine. Closing this bug to keep things simple.

-Chris

Works on Linux too.

mentioned in issue llvm/llvm-bugzilla-archive#1940