https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100868
Bug ID: 100868
Summary: PPC: Inefficient code for vec_reve(vector double)
Product: gcc
Version: 8.3.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: jens.seifert at de dot ibm.com
Target Milestone: ---
Input:
vector double reve(vector double a)
{
return vec_reve(a);
}
creates:
_Z4reveDv2_d:
.LFB3:
.cfi_startproc
.LCF3:
0: addis 2,12,.TOC.-.LCF3@ha
addi 2,2,.TOC.-.LCF3@l
.localentry _Z4reveDv2_d,.-_Z4reveDv2_d
addis 9,2,.LC2@toc@ha
addi 9,9,.LC2@toc@l
lvx 0,0,9
xxlnor 32,32,32
vperm 2,2,2,0
blr
Optimal sequence would be:
vector double reve_pwr7(vector double a)
{
return vec_xxpermdi(a,a,2);
}
which creates:
_Z9reve_pwr7Dv2_d:
.LFB4:
.cfi_startproc
xxpermdi 34,34,34,2
blr
