Files
open-roms/c64/basic/operators/oper_add.s
T

73 lines
1.0 KiB
ArmAsm

// #LAYOUT# STD * #TAKE
// #LAYOUT# * BASIC_0 #TAKE
// #LAYOUT# * * #IGNORE
oper_add:
// This operator can be used either with two strings, or with two floats
// First check whether arguments match and then choose the variant
pla
cmp VALTYP
bne_16 do_TYPE_MISMATCH_error
lda VALTYP
bmi oper_add_strings
// FALLTROUGH
oper_add_floats:
// XXX implement this
jmp do_NOT_IMPLEMENTED_error
oper_add_strings:
// Retrieve string address
pla
sta __FAC2+2
pla
sta __FAC2+1
// Pull string length
pla
sta __FAC2+0
beq oper_add_strings_end // if string 2 is empty, we have nothing to do
// If string 1 is empty, just copy the metadata
lda __FAC1+0
bne !+
lda __FAC2+0
sta __FAC1+0
lda __FAC2+1
sta __FAC1+1
lda __FAC2+2
sta __FAC1+2
jmp FRMEVL_continue
!:
// Allocate memory for concatenated string
clc
adc __FAC2+0
bcs_16 do_STRING_TOO_LONG_error
jsr alloc_temp_string
.break
// XXX finish the implementation
oper_add_strings_end:
jmp FRMEVL_continue