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[Bug target/56219] avr-gcc-4.7.2 missing __uint24 loop optimisation
- From: "demiurg_spb at freemail dot ru" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Wed, 06 Feb 2013 12:34:53 +0000
- Subject: [Bug target/56219] avr-gcc-4.7.2 missing __uint24 loop optimisation
- Auto-submitted: auto-generated
- References: <bug-56219-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56219
--- Comment #1 from demiurg_spb at freemail dot ru 2013-02-06 12:34:53 UTC ---
It would be optimal move outside loop all extra instructions, and use temp
register r0 more active.
ldi r24,0
ldi r25,lo8(4) // outside loop
.L2:
mov r30,r24
andi r30,lo8(7)
mul r30,r25
movw r30,r0
subi r30,lo8(-(br.1322))
sbci r31,hi8(-(br.1322))
lpm r0,Z // use r0 as temp
sts 100,r0
subi r24,lo8(-(1))
rjmp .L2
clr __zero_reg__ // outside loop