https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110034
Bug ID: 110034
Summary: The first popped allcono doesn't take precedence over
later popped in ira coloring
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: guihaoc at gcc dot gnu.org
Target Milestone: ---
Followings are ira dumps from a test case. r134 has only one cp(shuffle) with
r173. The r173 and r124 both have preferred hard register r3. r134 is first
popped the register but it fails to get hard register r3 as the conflict cost
is high. If r173 is aheaf of r134, the r134 can get hard register r3 as there
is no hop between r3 and r134 after r173 is assigned r3. Seems the first popped
allcono(r134) doesn't take precedence over later popped allcono(r124).
r173 has a preferred hard register and has no conflict allcono. So r173 can
always be assigned r3.
;; a29(r173,l0) conflicts:
;; total conflict hard regs:
;; conflict hard regs:
...
cp11:a18(r134)<->a29(r173)@125:shuffle
pref0:a12(r158)<-hr100@711
pref1:a23(r144)<-hr100@920
pref2:a25(r140)<-hr100@1842
pref3:a29(r173)<-hr3@2000
pref4:a0(r124)<-hr3@125
...
Start updating from pref of hr3 for a29r173:
a18r134 (hr3): update cost by -62, conflict cost by -62
...
Pushing a1(r169,l0)(cost 0)
Pushing a0(r124,l0)(cost 0)
Pushing a22(r146,l0)(cost 0)
Pushing a20(r125,l0)(cost 0)
Pushing a29(r173,l0)(cost 0)
Pushing a18(r134,l0)(cost 0)
Popping a18(r134,l0) -- (9=0,0) (10=0,0) (8=0,0) (7=0,0) (6=0,0) (5=0,0)
(4=0,0) (3=-62,147) (11=0,0) (0=8000,8000) (31=7,7) (30=7,7) (29=7,7) (28=7,7)
(27=7,7) (26=7,7) (25=7,7) (24=7,7) (23=7,7) (22=7,7) (21=7,7) (20=7,7)
(19=7,7) (18=7,7) (17=7,7) (16=7,7) (15=7,7) (14=7,7) (12=0,0)
Start restoring from a18r134:
a29r173 (hr3): update cost by -62, conflict cost by -62
Start updating from a18r134 by copies:
a29r173 (hr9): update cost by -250, conflict cost by -250
assign reg 9
Popping a29(r173,l0) -- (9=1750,1750) (10=2000,2000) (8=2000,2000)
(7=2000,2000) (6=2000,2000) (5=2000,2000) (4=2000,2000) (3=-2062,-2062)
(11=2000,2000) (0=2000,2000) (31=2007,2007) (30=2007,2007) (29=2007,2007)
(28=2007,2007) (27=2007,2007) (26=2007,2007) (25=2007,2007) (24=2007,2007)
(23=2007,2007) (22=2007,2007) (21=2007,2007) (20=2007,2007) (19=2007,2007)
(18=2007,2007) (17=2007,2007) (16=2007,2007) (15=2007,2007) (14=2007,2007)
(12=2000,2000)
Start restoring from a29r173:
Start updating from a29r173 by copies:
assign reg 3
...
Popping a0(r124,l0) -- (8=0,0) (7=0,0) (6=0,0) (5=0,0) (4=0,0)
(3=-250,-250) (11=0,0) (0=0,0) (31=7,7) (30=7,7) (29=7,7) (28=7,7) (27=7,7)
(26=7,7) (25=7,7) (24=7,7) (23=7,7) (22=7,7) (21=7,7) (20=7,7) (19=7,7)
(18=7,7) (17=7,7) (16=7,7) (15=7,7) (14=7,7) (12=0,0)
Start restoring from a0r124:
Start updating from a0r124 by copies:
a1r169 (hr3): update cost by -44, conflict cost by -44
a2r177 (hr3): update cost by -11, conflict cost by -11
assign reg 3
