Similar to the previous commit, to avoid undefined behaviour we need
to avoid evaluating out-of-bounds shifts, even if their result is going
to ignored by being multiplied by 0 later.
Detected by running a subset of the test suite with
-Dsanitize=address,undefined on x86_64.
Signed-off-by: Simon McVittie <smcv@debian.org>
If, for example, e == 0, it is undefined behaviour to compute an
expression involving an out-of-range shift by (125 - e), even if the
result is in fact irrelevant because it's going to be multiplied by 0.
This was already fixed for the memorytexture test in
commit 5d1b839 "testsuite: Fix another ubsan warning", so use the
implementation from that test everywhere. It's in the header as an
inline function to keep the linking of the relevant tests simple:
its only caller in production code is fp16.c, so there will be no
duplication outside the test suite.
Detected by running a subset of the test suite with
-Dsanitize=address,undefined on x86_64.
Signed-off-by: Simon McVittie <smcv@debian.org>
The IFUNC resolvers that we are using here get
run early, before asan had a chance to set up its
plumbing, and therefore things go badly if they
are compiled with asan. Turning it off makes things
work again.
The gcc bug tracking this problem:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110442
Thanks to Jakub Jelinek and Florian Weimer for
analyzing this and recommending the workaround.