lifning
/
gpsp
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Do not use stack in mips stubs 

No need for it (faster) and avoid mis-aligning it across calls
This commit is contained in:
David Guillen Fandos 2021-04-03 23:43:32 +02:00
parent 5b5a4db6c2
commit 5bee4d66c2
1 changed files with 6 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
psp/mips_stub.S
View File

@ -391,8 +391,7 @@ execute_read_spsr:
# $4: Current pc # $4: Current pc
execute_swi: execute_swi:
add $sp, $sp, -4 # push $ra sw $ra, REG_SAVE3($16)
sw $ra, ($sp)
sw $4, SUPERVISOR_LR($16) # store next PC in the supervisor's LR sw $4, SUPERVISOR_LR($16) # store next PC in the supervisor's LR
collapse_flags # get cpsr in $2 collapse_flags # get cpsr in $2
sw $2, SUPERVISOR_SPSR($16) # save cpsr in SUPERVISOR_CPSR sw $2, SUPERVISOR_SPSR($16) # save cpsr in SUPERVISOR_CPSR
@ -402,10 +401,10 @@ execute_swi:
save_registers save_registers
li $4, 3 # 3 is supervisor mode li $4, 3 # 3 is supervisor mode
cfncall set_cpu_mode, 5 # set the CPU mode to supervisor cfncall set_cpu_mode, 5 # set the CPU mode to supervisor
lw $ra, REG_SAVE3($16)
restore_registers restore_registers
lw $ra, ($sp) # pop $ra
jr $ra # return jr $ra # return
add $sp, $sp, 4 # fix stack (delay slot) nop
# $4: pc to restore to # $4: pc to restore to
# returns in $4 # returns in $4
@ -420,15 +419,13 @@ execute_spsr_restore:
lw $1, SPSR_BASE($2) # $1 = spsr[cpu_mode] lw $1, SPSR_BASE($2) # $1 = spsr[cpu_mode]
sw $1, REG_CPSR($16) # cpsr = spsr[cpu_mode] sw $1, REG_CPSR($16) # cpsr = spsr[cpu_mode]
extract_flags_body # extract flags from $1 extract_flags_body # extract flags from $1
addiu $sp, $sp, -4 sw $ra, REG_SAVE3($16)
sw $ra, ($sp)
save_registers save_registers
cfncall execute_spsr_restore_body, 6 # do the dirty work in this C function cfncall execute_spsr_restore_body, 6 # do the dirty work in this C function
restore_registers restore_registers
addu $4, $2, $0 # move return value to $4 lw $ra, REG_SAVE3($16)
lw $ra, ($sp)
jr $ra jr $ra
addiu $sp, $sp, 4 addu $4, $2, $0 # move return value to $4
no_spsr_restore: no_spsr_restore:
jr $ra jr $ra