http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54065
Bug #: 54065
Summary: [SH] Prefer @(R0,Rn) addressing for floating-point
load/store
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: target
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: olege...@gcc.gnu.org
Target: sh*-*-*
The following function
float test00 (float* x)
{
return x[10] + x[1] + x[20] + x[30];
}
compiled with e.g. '-O2 -m4-single -ml' results in:
mov r4,r2
mov r4,r1
add #40,r2
add #4,r1
fmov.s @r2,fr0
fmov.s @r1,fr1
add #76,r1
add #120,r4
fadd fr1,fr0
fmov.s @r1,fr1
fadd fr1,fr0
fmov.s @r4,fr1
rts
fadd fr1,fr0
which would be better as:
mov #40,r0
fmov.s @(r0,r2),fr0
mov #4,r0
fmov.s @(r0,r1),fr1
mov #80,r0
fadd fr1,fr0
fmov.s @(r0,r1),fr1
mov #120,r0
fadd fr1,fr0
fmov.s @(r0,r4),fr1
rts
fadd fr1,fr0
In sh.md (around line 11724) there are some old peephole patterns that were
supposed to handle this case, I guess. However, they seem to be defunct.
