https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90957
Bug ID: 90957
Summary: 453.povray is miscompiled with -flto -static
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: lto
Assignee: unassigned at gcc dot gnu.org
Reporter: mkuvyrkov at gcc dot gnu.org
CC: marxin at gcc dot gnu.org
Target Milestone: ---
Created attachment 46509
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46509&action=edit
Script to reproduce
453.povray is miscompiled with -static -flto on arm-linux-gnueabihf. The
failure confirmed vs trunk and gcc-8-branch, didn't check other releases.
Failure seems to occur only when both -static -flto are used together; -Ox
flags don't affect the outcome.
I've reduce the problem to a single object povms.o. The failure occurs when
povms.o is compiled with "-flto -static" and the rest of benchmark is compiled
with "-static". Compiling povms.o with "-static" makes the failure go away.
Attached is a script to reproduce: it uses Arm's pre-built cross-toolchain as
base install and replaces compiler with a freshly built one. You need to
supply your own sources of 453.povray and an aarch32 machine. Tested on armv7,
but armv8 should do as well.
# Produce good binary
./povray-build.sh true
# Produce bad binary
./povray-build.sh false
