https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102811
Bug ID: 102811
Summary: vcvtph2ps and vcvtps2ph should be used to convert
_Float16 to SFmode with -mf16c
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: ubizjak at gmail dot com
Target Milestone: ---
The following testcase:
_Float16 test (_Float16 a, _Float16 b)
{
return a + b;
}
compiles with -O2 -mf16c to:
--cut here--
subq $24, %rsp
pextrw $0, %xmm1, 14(%rsp)
call __extendhfsf2
pinsrw $0, 14(%rsp), %xmm1
vmovss %xmm0, 8(%rsp)
vmovss %xmm1, %xmm1, %xmm0
call __extendhfsf2
vaddss 8(%rsp), %xmm0, %xmm0
call __truncsfhf2
addq $24, %rsp
ret
--cut here--
Instead of calling __extendhfsf2 and __truncsfhf2, we should use vcvtph2ps and
vcvtps2ph (with zeroed elements 1..3) for -m16c targets.
