------- Comment #3 from hjl dot tools at gmail dot com 2010-06-09 00:59 -------
The old scheduler:
;; ======================================================
;; -- basic block 2 from 37 to 42 -- after reload
;; ======================================================
;; 0--> 37 [--sp]=bp :atom-dual-2c
;; 1--> 44 {cx=0;clobber flags;} :atom-simple-either
;; 2--> 38 bp=sp :atom-simple-either
;; 6--> 26 ax=[bp+0x8] :atom-simple-either
;; 6--> 27 dx=[bp+0xc] :atom-simple-either
;; 7--> 45 flags=cmp(ax,0) :atom-simple-either
;; 8--> 46 strict_low_part=flags!=0 :atom-simple-either
;; 8--> 13 {ax=-ax;clobber flags;} :atom-simple-either
;; 9--> 11 {dx=cx+dx;clobber flags;} :atom-simple-either
;; 10--> 12 {dx=-dx;clobber flags;} :atom-simple-either
;; 10--> 23 use ax :nothing
;; 11--> 41 {bp=[sp];sp=sp+0x4;} :atom-dual-2c
;; 12--> 42 return :atom-dual-1c
;; Ready list (final):
;; total time = 12
;; new head = 37
;; new tail = 42
The new one:
;; ======================================================
;; -- basic block 2 from 37 to 42 -- after reload
;; ======================================================
;; 0--> 37 [--sp]=bp :atom-dual-2c
;; 1--> 44 {cx=0;clobber flags;} :atom-simple-either
;; 2--> 38 bp=sp :atom-simple-either
;; 6--> 26 ax=[bp+0x8] :atom-simple-either
;; 6--> 27 dx=[bp+0xc] :atom-simple-either
;; 7--> 45 flags=cmp(ax,0) :atom-simple-either
;; 8--> 46 strict_low_part=flags!=0 :atom-simple-either
;; 8--> 13 {ax=-ax;clobber flags;} :atom-simple-either
;; 9--> 41 {bp=[sp];sp=sp+0x4;} :atom-dual-2c
;; 12--> 11 {dx=cx+dx;clobber flags;} :atom-simple-either
;; 12--> 12 {dx=-dx;clobber flags;} :atom-simple-either
;; 13--> 23 use ax :nothing
;; 13--> 42 return :atom-dual-1c
;; Ready list (final):
;; total time = 13
;; new head = 37
;; new tail = 42
It is slower.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44470
