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6502bench/SourceGen/SGTestData/Source/20212-reloc-data-main.S
Andy McFadden cc6ebaffc5 Update relocation data handling
When we have relocation data available, the code currently skips the
process of matching an address with a label for a PEA instruction when
the instruction in question doesn't have reloc data.  This does a
great job of separating code that pushes parts of addresses from code
that pushes constants.

This change expands the behavior to exclude instructions with 16-bit
address operands that use the Data Bank Register, e.g. "LDA abs"
and "LDA abs,X".  This is particularly useful for code that accesses
structured data using the operand as the structure offset, e.g.
"LDX addr" / "LDA $0000,X"

The 20212-reloc-data test has been updated to check the behavior.
2020-07-10 17:41:38 -07:00

111 lines
2.6 KiB
ArmAsm

; Copyright 2020 faddenSoft. All Rights Reserved.
; See the LICENSE.txt file for distribution terms (Apache 2.0).
;
; Assembler: Merlin 32
;
; Segment #1 : code; main segment, loads anywhere
BANK2_START EXT
BANK2_MOV_DST EXT
BANK8_START EXT
BANK8_ADDR EXT
BANK8_MOV_SRC EXT
ADDR_FFE0 EXT
; expected to start at $02/0000
REL ;generate relocatable code
start
clc
xce
sep #$30
mx %11
ldal start
nop
jsl BANK2_START
jsl BANK8_START
ldal BANK2_START
lda BANK2_START
lda #<BANK2_START
lda #>BANK2_START
lda #^BANK2_START
ldal BANK8_ADDR
lda BANK8_ADDR
lda #<BANK8_ADDR
lda #>BANK8_ADDR
lda #^BANK8_ADDR
nop
; Do some stuff with 16-bit registers. Merlin 32 treats <>^ as shift
; operations rather than byte selectors.
rep #$30
mx %00
lda #<BANK8_ADDR
lda #>BANK8_ADDR
lda #^BANK8_ADDR
nop
; Check MVN/MVP. Handing them correctly requires having two different
; symbol refs on a single instruction.
lda #15
ldx #BANK8_MOV_SRC
ldy #BANK2_MOV_DST
mvn #^BANK8_MOV_SRC,#^BANK2_MOV_DST
nop
; Test whether we're finding symbols for 16-bit address operands
; without reloc data.
lda: $0000,y
sta: $0002,y
check_pea
pea $0000
pea $f000
pea BANK8_ADDR
pea ^BANK8_ADDR
pea check_pea
pea >check_pea
pea ^check_pea
pea check_pea+18
pea check_pea+$1000
nop
jmp :skipdata
; Generate 2/3/4-byte refs. The OMF reloc entry generated by Merlin32
; for ADRL is only 3 bytes wide.
dw ADDR_FFE0
adr ADDR_FFE0
adrl ADDR_FFE0
:skipdata
; Check a situation where we block a relocation from being fully formed.
; The access to addr_dat+2 and addr_dat cause labels to be auto-generated.
; Because we access the high part first, there's no opportunity to find
; a pre-existing label nearby. If the reloc code generates a 3-byte or
; 4-byte data item at addr_dat, the label at addr_dat+2 will be hidden.
phk
plb
lda #$0000
asl A
asl A
tax
lda addr_dat+2,X
pha
lda addr_dat,X
pha
beq :skip_ad
rts
addr_dat
adrl check_pea
adrl :skipdata
:skip_ad
rts