https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93129
Bug ID: 93129
Summary: PPC memset not using vector instruction on >= Power8
Product: gcc
Version: 8.3.0
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:
void memclear16(char *p)
{
memset(p, 0, 16);
}
void memFF16(char *p)
{
memset(p, 0xFF, 16);
}
Output:
._Z10memclear16Pc:
LFB..0:
li 9,0
std 9,0(3)
std 9,8(3)
blr
._Z7memFF16Pc:
LFB..1:
mflr 0
li 5,16
li 4,255
std 0,16(1)
stdu 1,-112(1)
LCFI..0:
bl .memset
nop
addi 1,1,112
LCFI..1:
ld 0,16(1)
mtlr 0
LCFI..2:
blr
Expected output:
vsplitb + vector store
Unaligned vector stores only perform on >= Power8, vector stores should be used
only on >= Power8. On Power7 you would need to know it is at least 8-byte
aligned.
vsplitb has the -16..+15 limit. On Power9 a splat for 0.255 exists.
