tests: add a test on branching instructions

Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>

3 files changed, 205 insertions, 0 deletions

diff --git a/scripts/test-e2e.sh b/scripts/test-e2e.sh
index be43685..573a729 100755
--- a/scripts/test-e2e.sh
+++ b/scripts/test-e2e.sh
@@ -294,6 +294,12 @@ echo "test: runrom => cmp.nes"
 diff tests/out/cmp.txt tests/expected/runrom/cmp.txt
 exit_code=$((exit_code + $?))
 
+echo "test: runrom => branching.nes"
+./target/debug/nasm -Werror --asan -o tests/out/branching.nes tests/runrom/branching.s
+./target/debug/runrom --function --dump-memory tests/out/branching.nes > tests/out/branching.txt
+diff tests/out/branching.txt tests/expected/runrom/branching.txt
+exit_code=$((exit_code + $?))
+
 echo "test: runrom => misc.nes"
 ./target/debug/nasm -Werror --asan --write-info --allow-unused --out tests/out/misc.nes tests/runrom/misc.s
 ./target/debug/runrom --nasm .nasm --dump-memory --function tests/out/misc.nes > tests/out/misc-all.txt
diff --git a/tests/expected/runrom/branching.txt b/tests/expected/runrom/branching.txt
new file mode 100644
index 0000000..8c2eb7f
--- /dev/null
+++ b/tests/expected/runrom/branching.txt
@@ -0,0 +1,71 @@
+<start>		PC: $8000, cycles: 7, registers: [a: $00, x: $00, y: $00, sp: $FD], status: ----I--
+ldx #$0A	PC: $8002, cycles: 9, registers: [a: $00, x: $0A, y: $00, sp: $FD], status: ----I--
+ldy #$05	PC: $8004, cycles: 11, registers: [a: $00, x: $0A, y: $05, sp: $FD], status: ----I--
+lda $030C, y	PC: $8007, cycles: 15, registers: [a: $00, x: $0A, y: $05, sp: $FD], status: ----IZ-
+cmp $0300, x	PC: $800A, cycles: 19, registers: [a: $00, x: $0A, y: $05, sp: $FD], status: ----IZC
+bcc $1F		PC: $800C, cycles: 21, registers: [a: $00, x: $0A, y: $05, sp: $FD], status: ----IZC
+dex		PC: $800D, cycles: 23, registers: [a: $00, x: $09, y: $05, sp: $FD], status: ----I-C
+dex		PC: $800E, cycles: 25, registers: [a: $00, x: $08, y: $05, sp: $FD], status: ----I-C
+dey		PC: $800F, cycles: 27, registers: [a: $00, x: $08, y: $04, sp: $FD], status: ----I-C
+cpy #$FF	PC: $8011, cycles: 29, registers: [a: $00, x: $08, y: $04, sp: $FD], status: ----I--
+bne $F1		PC: $8004, cycles: 32, registers: [a: $00, x: $08, y: $04, sp: $FD], status: ----I--
+lda $030C, y	PC: $8007, cycles: 36, registers: [a: $00, x: $08, y: $04, sp: $FD], status: ----IZ-
+cmp $0300, x	PC: $800A, cycles: 40, registers: [a: $00, x: $08, y: $04, sp: $FD], status: ----IZC
+bcc $1F		PC: $800C, cycles: 42, registers: [a: $00, x: $08, y: $04, sp: $FD], status: ----IZC
+dex		PC: $800D, cycles: 44, registers: [a: $00, x: $07, y: $04, sp: $FD], status: ----I-C
+dex		PC: $800E, cycles: 46, registers: [a: $00, x: $06, y: $04, sp: $FD], status: ----I-C
+dey		PC: $800F, cycles: 48, registers: [a: $00, x: $06, y: $03, sp: $FD], status: ----I-C
+cpy #$FF	PC: $8011, cycles: 50, registers: [a: $00, x: $06, y: $03, sp: $FD], status: ----I--
+bne $F1		PC: $8004, cycles: 53, registers: [a: $00, x: $06, y: $03, sp: $FD], status: ----I--
+lda $030C, y	PC: $8007, cycles: 57, registers: [a: $00, x: $06, y: $03, sp: $FD], status: ----IZ-
+cmp $0300, x	PC: $800A, cycles: 61, registers: [a: $00, x: $06, y: $03, sp: $FD], status: ----IZC
+bcc $1F		PC: $800C, cycles: 63, registers: [a: $00, x: $06, y: $03, sp: $FD], status: ----IZC
+dex		PC: $800D, cycles: 65, registers: [a: $00, x: $05, y: $03, sp: $FD], status: ----I-C
+dex		PC: $800E, cycles: 67, registers: [a: $00, x: $04, y: $03, sp: $FD], status: ----I-C
+dey		PC: $800F, cycles: 69, registers: [a: $00, x: $04, y: $02, sp: $FD], status: ----I-C
+cpy #$FF	PC: $8011, cycles: 71, registers: [a: $00, x: $04, y: $02, sp: $FD], status: ----I--
+bne $F1		PC: $8004, cycles: 74, registers: [a: $00, x: $04, y: $02, sp: $FD], status: ----I--
+lda $030C, y	PC: $8007, cycles: 78, registers: [a: $00, x: $04, y: $02, sp: $FD], status: ----IZ-
+cmp $0300, x	PC: $800A, cycles: 82, registers: [a: $00, x: $04, y: $02, sp: $FD], status: ----IZC
+bcc $1F		PC: $800C, cycles: 84, registers: [a: $00, x: $04, y: $02, sp: $FD], status: ----IZC
+dex		PC: $800D, cycles: 86, registers: [a: $00, x: $03, y: $02, sp: $FD], status: ----I-C
+dex		PC: $800E, cycles: 88, registers: [a: $00, x: $02, y: $02, sp: $FD], status: ----I-C
+dey		PC: $800F, cycles: 90, registers: [a: $00, x: $02, y: $01, sp: $FD], status: ----I-C
+cpy #$FF	PC: $8011, cycles: 92, registers: [a: $00, x: $02, y: $01, sp: $FD], status: ----I--
+bne $F1		PC: $8004, cycles: 95, registers: [a: $00, x: $02, y: $01, sp: $FD], status: ----I--
+lda $030C, y	PC: $8007, cycles: 99, registers: [a: $00, x: $02, y: $01, sp: $FD], status: ----IZ-
+cmp $0300, x	PC: $800A, cycles: 103, registers: [a: $00, x: $02, y: $01, sp: $FD], status: ----IZC
+bcc $1F		PC: $800C, cycles: 105, registers: [a: $00, x: $02, y: $01, sp: $FD], status: ----IZC
+dex		PC: $800D, cycles: 107, registers: [a: $00, x: $01, y: $01, sp: $FD], status: ----I-C
+dex		PC: $800E, cycles: 109, registers: [a: $00, x: $00, y: $01, sp: $FD], status: ----IZC
+dey		PC: $800F, cycles: 111, registers: [a: $00, x: $00, y: $00, sp: $FD], status: ----IZC
+cpy #$FF	PC: $8011, cycles: 113, registers: [a: $00, x: $00, y: $00, sp: $FD], status: ----I--
+bne $F1		PC: $8004, cycles: 116, registers: [a: $00, x: $00, y: $00, sp: $FD], status: ----I--
+lda $030C, y	PC: $8007, cycles: 120, registers: [a: $00, x: $00, y: $00, sp: $FD], status: ----IZ-
+cmp $0300, x	PC: $800A, cycles: 124, registers: [a: $00, x: $00, y: $00, sp: $FD], status: ----IZC
+bcc $1F		PC: $800C, cycles: 126, registers: [a: $00, x: $00, y: $00, sp: $FD], status: ----IZC
+dex		PC: $800D, cycles: 128, registers: [a: $00, x: $FF, y: $00, sp: $FD], status: ----I-C
+dex		PC: $800E, cycles: 130, registers: [a: $00, x: $FE, y: $00, sp: $FD], status: N---I-C
+dey		PC: $800F, cycles: 132, registers: [a: $00, x: $FE, y: $FF, sp: $FD], status: ----I-C
+cpy #$FF	PC: $8011, cycles: 134, registers: [a: $00, x: $FE, y: $FF, sp: $FD], status: ----IZC
+bne $F1		PC: $8013, cycles: 136, registers: [a: $00, x: $FE, y: $FF, sp: $FD], status: ----IZC
+bit $27		PC: $8015, cycles: 139, registers: [a: $00, x: $FE, y: $FF, sp: $FD], status: ----IZC
+bpl $2F		PC: $8046, cycles: 142, registers: [a: $00, x: $FE, y: $FF, sp: $FD], status: ----IZC
+rts		PC: $8047, cycles: 148, registers: [a: $00, x: $FE, y: $FF, sp: $FD], status: ----IZC
+<end>
+
+== Memory dump ==
+
+[$27] = $00 [reads=1, writes=0]
+[$300] = $00 [reads=1, writes=0]
+[$302] = $00 [reads=1, writes=0]
+[$304] = $00 [reads=1, writes=0]
+[$306] = $00 [reads=1, writes=0]
+[$308] = $00 [reads=1, writes=0]
+[$30A] = $00 [reads=1, writes=0]
+[$30C] = $00 [reads=1, writes=0]
+[$30D] = $00 [reads=1, writes=0]
+[$30E] = $00 [reads=1, writes=0]
+[$30F] = $00 [reads=1, writes=0]
+[$310] = $00 [reads=1, writes=0]
+[$311] = $00 [reads=1, writes=0]
diff --git a/tests/runrom/branching.s b/tests/runrom/branching.s
new file mode 100644
index 0000000..a96888c
--- /dev/null
+++ b/tests/runrom/branching.s
@@ -0,0 +1,128 @@
+.segment "HEADER"
+    .byte 'N', 'E', 'S', $1A
+    .byte $02, $01
+    .byte $00
+    .byte $00
+
+.segment "CHARS"
+.byte 0
+
+.segment "VECTORS"
+    .addr reset, reset, reset
+
+.segment "CODE"
+;; asan:stack full
+
+;; From: https://git.mssola.com/nes/jetpac.nes/.
+.scope Globals
+    ;; | Bit | Short name       | Meaning                  |
+    ;; |-----+------------------+--------------------------|
+    ;; |   7 | enabled          | Multiplayer enabled.     |
+    ;; | 6-3 | -                | Unused.                  |
+    ;; |   2 | player's 2 state | 0: over; 1: alive        |
+    ;; |   1 | player's 1 state | 0: over; 1: alive        |
+    ;; |   0 | active           | 0: player 1; 1: player 2 |
+    zp_multiplayer = $27
+
+    ;; Extra bitmap that was needed beyond the ones that we already have. Yeah,
+    ;; I know, bad planning from my side, but now it's a bit complex to untangle
+    ;; variables like 'Globals::zp_flags'.
+    ;;
+    ;; | Bit | Short name       | Meaning                          |
+    ;; |-----+------------------+----------------------------------|
+    ;; |   7 | score            | The score has been updated.      |
+    ;; |   6 | high             | The high score has been updated. |
+    ;; | 5-0 | -                | Unused.                          |
+    zp_extra_flags = $28
+.endscope
+
+;; From: https://git.mssola.com/nes/jetpac.nes/.
+.scope Score
+    ;; Scores for both players are stored in a single buffer. Even indeces
+    ;; contain digits for the first player, and odd indeces contain digits for
+    ;; the second player. Digits are stored in little-endian format.
+    ;;
+    ;; Interweaving digits this way might seem weird, but it actually makes
+    ;; indexing things super easy: the 'active' bit from
+    ;; 'Globals::zp_multiplayer' can be used to index the first item, and then
+    ;; it's a matter of advancing the 'x' register twice in order to get the
+    ;; next digit.
+    PLAYERS_BUFF_SIZE = $0C
+    m_players = $300     ; asan:reserve PLAYERS_BUFF_SIZE
+
+    ;; The high score for this session.
+    m_hi = $30C           ; asan:reserve $06
+.endscope
+
+;; This is basically Score::save_hi_score() from
+;; https://git.mssola.com/nes/jetpac.nes/.
+.proc reset
+    ;;;
+    ;; Check player 1.
+
+    ldx #(Score::PLAYERS_BUFF_SIZE - 2)
+    ldy #5
+
+@player1_loop:
+    lda Score::m_hi, y
+    cmp Score::m_players, x
+    bcc @save_player1
+    dex
+    dex
+    dey
+    cpy #$FF
+    bne @player1_loop
+
+    ;; No dice! If we are in multiplayer mode, then check player 2,
+    ;; otherwise just quit.
+    bit Globals::zp_multiplayer
+    bpl @end
+
+    ;;;
+    ;; Check player 2.
+
+    ldx #(Score::PLAYERS_BUFF_SIZE - 1)
+    ldy #5
+
+@player2_loop:
+    lda Score::m_hi, y
+    cmp Score::m_players, x
+    bcc @save_player2
+    dex
+    dex
+    dey
+    cpy #$FF
+    bne @player2_loop
+
+    ;; Not player 2 either. Just quit.
+    rts
+
+    ;;;
+    ;; One of the players actually achieved a high score. Let's save it.
+
+@save_player1:
+    ldx #0
+    beq @save
+@save_player2:
+    ldx #1
+
+@save:
+    ldy #0
+@save_loop:
+    lda Score::m_players, x
+    sta Score::m_hi, y
+
+    inx
+    inx
+    iny
+    cpy #6
+    bne @save_loop
+
+    ;; And set the 'high' bit so this change is reflected on screen.
+    lda Globals::zp_extra_flags
+    ora #$40
+    sta Globals::zp_extra_flags
+
+@end:
+    rts
+.endproc