459a9b5949
Because lwzu or stwu moves the pointer, I can remove an addi instruction from the loop, so the loop is slightly faster. I wrote a benchmark in Modula-2 that exercises some of these loops. I measured its time on my old PowerPC Mac. Its user time decreases from 8.401s to 8.217s with the tighter loops.
16 lines
273 B
ArmAsm
16 lines
273 B
ArmAsm
.sect .text
|
|
|
|
! Create empty set.
|
|
! Stack: ( size -- set )
|
|
|
|
.define .zer
|
|
.zer:
|
|
lwz r3, 0(sp) ! r3 = size
|
|
srwi r7, r3, 2
|
|
mtspr ctr, r7 ! ctr = size / 4
|
|
addi sp, sp, 4 ! drop size from stack
|
|
li r4, 0
|
|
|
|
1: stwu r4, -4(sp) ! push zero
|
|
bdnz 1b ! loop ctr times
|
|
blr
|