https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114591
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2024-04-04
Target| |x86_64
Ever confirmed|0 |1
Status|UNCONFIRMED |NEW
Component|rtl-optimization |target
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
IRA in GCC 12+ has:
```
Loop 0 (parent -1, header bb2, depth 0)
bbs: 2
all: 0r85 1r82
modified regnos: 82 85
border:
Pressure: GENERAL_REGS=1
Hard reg set forest:
0:( 0-6 8-15 20-51)@0
1:( 0-6 36-43)@26000
Spill a1(r82,l0)
Allocno a0r85 of GENERAL_REGS(15) has 15 avail. regs 0-6 36-43, node:
0-6 36-43 (confl regs = 7-35 44-75)
Forming thread from colorable bucket:
Forming thread by copy 0:a0r85-a1r82 (freq=1000):
Result (freq=5000): a0r85(2000) a1r82(3000)
Pushing a0(r85,l0)(cost 0)
Popping a0(r85,l0) -- assign reg 0
Disposition:
1:r82 l0 mem 0:r85 l0 0
New iteration of spill/restore move
+++Costs: overall 1000, reg -1000, mem 2000, ld 0, st 0, move 0
+++ move loops 0, new jumps 0
```
While before it was:
```
Loop 0 (parent -1, header bb2, depth 0)
bbs: 2
all: 0r85 1r82
modified regnos: 82 85
border:
Pressure: GENERAL_REGS=1
Hard reg set forest:
0:( 0-6 8-15 20-51)@0
1:( 0-6 36-43)@46000
Allocno a0r85 of GENERAL_REGS(15) has 15 avail. regs 0-6 36-43, node:
0-6 36-43 (confl regs = 7-35 44-75)
Allocno a1r82 of GENERAL_REGS(15) has 15 avail. regs 0-6 36-43, node:
0-6 36-43 (confl regs = 7-35 44-75)
Forming thread from colorable bucket:
Forming thread by copy 0:a0r85-a1r82 (freq=1000):
Result (freq=5000): a0r85(2000) a1r82(3000)
Pushing a0(r85,l0)(cost 0)
Pushing a1(r82,l0)(cost 0)
Popping a1(r82,l0) -- assign reg 0
Popping a0(r85,l0) -- assign reg 0
Disposition:
1:r82 l0 0 0:r85 l0 0
New iteration of spill/restore move
+++Costs: overall 5000, reg 5000, mem 0, ld 0, st 0, move 0
+++ move loops 0, new jumps 0
```
Notice: ` Spill a1(r82,l0)` in GCC 12+
