commit b26588f0cb42a6a37ad7c303e61b23f471758e0c
author Andrew Pinski <quic_apinski@quicinc.com> Wed Jul 16 09:31:35 2025 -0700
committer Andrew Pinski <quic_apinski@quicinc.com> Sat Jul 26 11:21:35 2025 -0700
tree 2a6a5939ae4398cc390a89184082f0ccd54bbaeb
parent e34c0fee14670a93f84a21afb63dc66a19ffb988

gcse: Skip hardreg pre when the hardreg is never live [PR121095]

r15-6789-ge7f98d9603808b added a new RTL pass for hardreg PRE for the hard register
of FPM_REGNUM, this pass could get expensive if you have a large number of basic blocks
and the hard register was never live so it does nothing in the end.
In the aarch64 case, FPM_REGNUM is only used for FP8 related code so it has a high probability
of not being used. So skipping the pass for that register can improve both compile time and memory
usage.

Build and tested for aarch64-linux-gnu.

	PR middle-end/121095
gcc/ChangeLog:

	* gcse.cc (execute_hardreg_pre): Skip if the hardreg which is never live.

Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
(cherry picked from commit 6916639b48357334579cf94717a3e51dd003e940)