https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114782
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I should note I tested aarch64 (where lea 3 operand instructions are still
cheap) and powerpc (where lea like instructions don't exist) and they produce
what I expect, aarch64 produces an lea like instruction while powerpc produces
no shifts/multiplies for the loop.
PowerPC:
.L3:
addi 9,9,-1
add 8,8,10
subf 7,9,6
addi 10,10,5
cmpw 0,9,7
bgt 0,.L3
aarch64 (default tuning):
.L3:
add w3, w0, w0, lsl 2
sub w1, w1, #1
add w0, w0, 1
add w2, w2, w3
cmp w1, w0
bgt .L3
aarch64 (thunderxt99 tuning):
.L3:
sub w0, w0, #1
add w2, w2, w1
add w1, w1, 5
sub w3, w4, w0
cmp w0, w3
bgt .L3
