https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81572
Bug ID: 81572
Summary: gcc-7 regression: unnecessary vector regmove on
compare
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: zoltan at hidvegi dot com
CC: segher at gcc dot gnu.org, wschmidt at gcc dot gnu.org
Target Milestone: ---
Target: powerpc64le-unknown-linux-gnu
CC: segher at gcc dot gnu.org, wschmidt at gcc dot gnu.org
Created attachment 41843
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41843&action=edit
gcc-7 -O2 generates unnecessary vector regmove
This sequence generate an unnecessary regmove with gcc-7 that did not happen
with gcc-6. The gcc-7 code is like this:
xxlor 32,34,34
xxlandc 35,34,35
vcmpequb. 2,0,3
mfcr 3,2
rlwinm 3,3,25,1
blr
gcc-6 does not generate the xxlor 32,34,34 move.
