some more review before bed.

This commit is contained in:
ed
2026-08-05 02:00:41 -04:00
parent f25765a7b7
commit 6f2eff920d
7 changed files with 408 additions and 503 deletions
+134 -304
View File
@@ -180,6 +180,140 @@ internal MipsAtom_(gp_screen_init) atom_info(atom_phase(screen_init), atom_reads
mac_yield(),
};
/* ----- pad_apply_input -----
* Reads pad[0].buttons + pad[0].left_x;
* Applies the input-semantics deltas to cube_rot.y + floor_rot.y:
* - D-pad Left: cube_rot.y += 30, floor_rot.y += 5
* - D-pad Right: cube_rot.y -= 30, floor_rot.y -= 5
* - Analog stick X (dead zone 0x70..0x90):
* cube delta = (0x80 - left_x) >> 2 (range approx -32..+32)
* floor delta = (0x80 - left_x) >> 5 (range approx -4..+4)
* - D-pad + analog deltas add when used together.
*
* Convention:
* pad_state = 0 means no buttons active.
* The fail-safe zero-button value flows through unchanged, so a disconnected/fresh pad produces no rotation.
* The branch_le_zero pattern below matches the existing pad_input_demo convention (atom body lines 248/257).
*
* Signed-delta trick:
* load_byte_u zero-extends left_x to 32 bits; sub_u from 0x80 wraps to a SIGNED two's-complement value in the negative range;
* shift_aright (sra) then correctly sign-extends the shift for both positive (left_x < 0x80) and negative (left_x > 0x80) cases.
* Digital pads publish left_x = 0x80 → delta = 0 → no rotation, so the analog step is naturally a no-op for digital controllers.
*/
typedef Struct_(Binds_PadApplyInput) {
PadState* state;
V3_S2* cube_rot;
V3_S2* floor_rot;
};
enum {
R_PadStateT5 = R_T5 atom_reg,
R_CubeRot = R_T1 atom_reg,
R_FloorRot = R_T2 atom_reg,
};
internal MipsAtom_(pad_apply_input) atom_info(atom_bind(Binds_PadApplyInput)
, atom_reads(R_T0, R_CubeRot, R_FloorRot, R_T3, R_T4, R_PadStateT5, R_TapePtr)
, atom_writes( R_CubeRot, R_FloorRot)
) {
/* Pop Binds from tape (state, cube_rot, floor_rot) */
load_word(R_PadStateT5, R_TapePtr, O_(Binds_PadApplyInput,state)),
load_word(R_CubeRot, R_TapePtr, O_(Binds_PadApplyInput,cube_rot)),
load_word(R_FloorRot, R_TapePtr, O_(Binds_PadApplyInput,floor_rot)),
add_ui_self( R_TapePtr, S_(Binds_PadApplyInput)),
/* Load pad[0].buttons into R_T0. */
load_word(R_T0, R_PadStateT5, O_(PadState,buttons)), nop,
// Note(Ed): Potential op with delay slot?
/* D-pad Left: cube_rot.y += 30, floor_rot.y += 5. */
and_i(R_T3, R_T0, pad0_(Pad_Left)), branch_le_zero(R_T3, atom_offset(dpad_left, exit_dpad_left)),
load_half( R_T4, R_CubeRot, O_(V3_S2,y)), /* BD-slot */
load_half( R_T3, R_FloorRot, O_(V3_S2,y)),
add_si( R_T4, R_T4, 30),
add_si( R_T3, R_T3, 5),
store_half(R_T4, R_CubeRot, O_(V3_S2,y)),
store_half(R_T3, R_FloorRot, O_(V3_S2,y)),
atom_label(exit_dpad_left)
/* D-pad Right: cube_rot.y -= 30, floor_rot.y -= 5. */
and_i(R_T3, R_T0, pad0_(Pad_Right)), branch_le_zero(R_T3, atom_offset(dpad_right, exit_dpad_right)),
load_half( R_T4, R_CubeRot, O_(V3_S2,y)), /* BD-slot */
load_half( R_T3, R_FloorRot, O_(V3_S2,y)),
add_si( R_T4, R_T4, -30),
add_si( R_T3, R_T3, -5),
store_half(R_T4, R_CubeRot, O_(V3_S2,y)),
store_half(R_T3, R_FloorRot, O_(V3_S2,y)),
atom_label(exit_dpad_right)
/* Analog left-stick X: dead zone 0x70..0x90.
* Cube delta = (0x80 - left_x) >> 2; floor delta = (0x80 - left_x) >> 5. */
load_byte_u(R_T3, R_PadStateT5, O_(PadState,left_x)),
/* Dead-zone check: skip analog if left_x in [0x70, 0x90] inclusive. Outside dead zone on LOW side: left_x < 0x70 (strictly).
* set_lt_u(R_T4, R_T3, R_T4=0x70) → R_T4 = (left_x < 0x70) ? 1 : 0. */
add_ui(R_T4, R_0, 0x70), set_lt_u(R_T4, R_T3, R_T4), branch_ne(R_T4, R_0, atom_offset(dead_zone_low_check, dead_low_active)),
add_ui(R_T4, R_0, 0x80), /* BD-slot: pre-load 0x80 for dead_low_active */
atom_label(dead_check_upper)
/* left_x >= 0x70 → check upper bound. */
load_byte_u(R_T3, R_PadStateT5, O_(PadState,left_x)), /* reload */
add_ui( R_T4, R_0, 0x90),
/* R_T4 = (0x90 < left_x) ? 1 : 0 → (left_x > 0x90) ? 1 : 0 */
set_lt_u(R_T4, R_T4, R_T3), branch_ne(R_T4, R_0, atom_offset(dead_zone_high_check, dead_high_active)),
add_ui( R_T4, R_0, 0x80), /* BD-slot: pre-load 0x80 for dead_high_active */
jump_rel(atom_offset(dead_zone_skip, exit_stick)),
mac_yield_load(),
atom_label(dead_low_active)
/* R_T3 = left_x (from line 632 lbu; not clobbered between dead_zone_low_check branch + its BD-slot `add_ui R_T4, 0x80`).
* The earlier `load_byte_u(R_T3, ...)` reload was redundant and introduced a load-use hazard on the next `sub_u`.
* R_T4 = 0x80 from the BD-slot of `dead_zone_low_check`'s branch_ne. */
sub_u( R_T3, R_T4, R_T3), /* R_T3 = 0x80 - left_x */
/* delta = 0x80 - left_x (positive). */
/* R_T4 = cube_delta */
shift_aright(R_T4, R_T3, 2),
load_half( R_T0, R_CubeRot, O_(V3_S2,y)),
nop,
add_u( R_T0, R_T0, R_T4),
store_half( R_T0, R_CubeRot, O_(V3_S2,y)),
/* R_T4 = floor_delta — moved into the load-delay slot of the floor load below (fills the 1-instruction gap;
* doesn't read R_T0; R_T4 settles by the subsequent add_u). */
load_half( R_T0, R_FloorRot, O_(V3_S2,y)),
shift_aright(R_T4, R_T3, 5),
add_u( R_T0, R_T0, R_T4),
store_half( R_T0, R_FloorRot, O_(V3_S2,y)),
jump_rel(atom_offset(end_low, exit_stick)),
mac_yield_load(),
atom_label(dead_high_active)
/* R_T3 = left_x (from line 641 lbu in dead_check_upper; not clobbered between dead_zone_high_check branch + its BD-slot `add_ui R_T4, 0x80`).
* The earlier `load_byte_u(R_T3, ...)` reload was redundant and introduced a load-use hazard on the next `sub_u`.
* R_T4 = 0x80 from the BD-slot of `dead_zone_high_check`'s branch_ne. */
sub_u( R_T3, R_T4, R_T3),
/* delta = 0x80 - left_x (signed negative). */
shift_aright(R_T4, R_T3, 2), /* R_T4 = cube_delta (signed) */
load_half( R_T0, R_CubeRot, O_(V3_S2,y)),
nop,
add_u( R_T0, R_T0, R_T4),
store_half( R_T0, R_CubeRot, O_(V3_S2,y)),
/* R_T4 = floor_delta (signed) — moved into the load-delay slot of the floor load below. */
load_half( R_T0, R_FloorRot, O_(V3_S2,y)),
shift_aright(R_T4, R_T3, 5),
add_u( R_T0, R_T0, R_T4),
store_half( R_T0, R_FloorRot, O_(V3_S2,y)),
atom_label(no_jump_fallthrough)
mac_yield_load(),
atom_label(exit_stick)
/* NOT mac_yield() — R_AtomJmp was already loaded in the BD-slot of the dead-zone/exit branch. */
mac_yield_tail(),
};
enum {
R_PrimCursor = R_T7 atom_reg atom_type(U4*), /* VRAM output cursor (primitive buffer) */
R_FaceCursor = R_T4 atom_reg atom_type(V4_S2*), /* Cube face-index cursor (V4_S2*); floor context switches to V3_S2* via atom_phase */
@@ -331,308 +465,4 @@ internal MipsAtom_(sync_primitive_arena) atom_info(atom_bind(Binds_SyncPrimitive
mac_yield()
};
/* ----- pad_bios_snapshot -----
* Per-frame snapshot of one BIOS pad buffer into PadState.
* Decoder (branch ladder on raw[0] status + raw[1] id):
* 1. raw[0] == 0xFF -> Disconnected (buttons=0, axes=0x80)
* 2. raw[0]==0 && raw[1]==0 -> Pending (buttons=0, axes=0x80)
* 3. raw[1] == 0x41 -> Digital (buttons normalized; axes=0x80)
* 4. raw[1] == 0x53 -> AnalogStick (buttons normalized; axes from raw[4..7])
* 5. raw[1] in 0x7x -> AnalogPad (buttons normalized; axes from raw[4..7])
* 6. else -> Unsupported (buttons=0, axes=0x80)
*
* Buttons normalization: byte_swap16((~raw_buttons) & 0xFFFF).
* raw_buttons = load_half_u(raw, 2) = raw[2] | (raw[3] << 8).
* byte_swap16(x) = (x >> 8) | (x << 8); nor(x, R_0) = ~x. store_half truncates to 16 bits so the upper-16 mask is implicit in the store.
*
* Register use (atom-local; no wave-context touched):
* R_T0 = raw base (kept throughout; axes loads read raw[4..7] from R_T0)
* R_T1 = state base (kept throughout; all stores go through R_T1)
* R_T2 = raw[0] status (alive across the disc/pending/id dispatch, then dead)
* R_T3 = raw[1] id (alive across the id dispatch, then dead)
* R_T4 = scratch (shifts, compares, immediate loads, store values)
* R_T5 = scratch (parallel lui+ori for the 0x80808080 axes constant + byte-swap target)
*/
enum {
R_PadRaw = R_T0 atom_reg atom_type(U1),
R_PadState = R_T1 atom_reg,
R_RawStatus = R_T2 atom_reg,
R_RawId = R_T3 atom_reg,
};
typedef Struct_(Binds_PadBiosSnapshot) {
PadBiosRaw* raw;
PadState* state;
};
internal MipsAtom_(pad_bios_snapshot) atom_info(atom_bind(Binds_PadBiosSnapshot)
, atom_reads( R_PadRaw, R_PadState, R_RawStatus, R_RawId, R_T4, R_T5, R_TapePtr)
, atom_writes(R_PadRaw, R_PadState, R_RawStatus, R_RawId, R_T4, R_T5, R_TapePtr)
) {
/* === Bind consumption: T0 = raw, T1 = state, advance R_TapePtr by 8. */
load_word(R_PadRaw, R_TapePtr, O_(Binds_PadBiosSnapshot,raw)),
load_word(R_PadState, R_TapePtr, O_(Binds_PadBiosSnapshot,state)),
add_ui_self( R_TapePtr, S_(Binds_PadBiosSnapshot)),
/* === Read raw[0] (status) + raw[1] (id) */
load_byte_u(R_RawStatus, R_PadRaw, 0),
load_byte_u(R_RawId, R_PadRaw, 1),
atom_label(snap_root) /* === Case 1: Disconnected (status == 0xFF). */
add_ui(R_T4, R_0, 0xFF), branch_ne(R_RawStatus, R_T4, atom_offset(snap_root, skip_disconnected)),
/* BD-slot: pre-compute PadStatus_Disconnected. Branch reads R_T4=0xFF in EX before this WB completes.
* If branch NOT taken (fall through to pending/id_dispatch), R_T4 is overwritten by the next case body's add_ui — harmless. */
atom_label(disconnected) /* === Disconnected body. */
/* R_T4 = PadStatus_Disconnected from snap_root BD-slot. */
store_word(R_T4, R_PadState, O_(PadState,status)),
store_half(R_0, R_PadState, O_(PadState,buttons)),
/* axes = 0x80808080 (centered) — single sw writes the 4-byte axes block at offset 8 (left_x, left_y, right_x, right_y). */
load_upper_i(R_T4, 0x8080), or_i_self(R_T4, 0x8080),
store_word( R_T4, R_PadState, O_(PadState,left_x)),
store_byte( R_RawId, R_PadState, O_(PadState,id)),
jump_rel(atom_offset(disconnected, snap_end)),
/* BD-slot: load next atom's entry point (replaces the nop).
* The unconditional branch always jumps to snap_end, where mac_yield_tail()
* transfers control to R_AtomJmp without re-loading it. */
mac_yield_load(),
atom_label(skip_disconnected)
/* === Case 2: Pending (status == 0 && id == 0)
* Combined check: if (status | id) != 0 then skip to id_dispatch.
* Falls through to the Pending case only when both are zero. */
or_u_self(R_RawStatus, R_RawId), branch_ne(R_RawStatus, R_0, atom_offset(case_2, id_dispatch)),
/* BD-slot: pre-compute PadStatus_Pending. Branch reads R_RawStatus in EX before this WB completes.
* If branch NOT taken (fall through to id_dispatch), R_T4 is overwritten by the digital/analog body add_ui — harmless. */
atom_label(pending) /* === Pending body */
/* R_T4 = PadStatus_Pending from case_2 BD-slot. */
store_word(R_T4, R_PadState, O_(PadState,status)),
store_half(R_0, R_PadState, O_(PadState,buttons)),
/* axes = 0x80808080 (centered) — single sw writes the 4-byte axes block at offset 8 (left_x, left_y, right_x, right_y). */
load_upper_i(R_T4, 0x8080), or_i_self(R_T4, 0x8080),
store_word( R_T4, R_PadState, O_(PadState,left_x)),
store_byte( R_RawId, R_PadState, O_(PadState,id)),
jump_rel(atom_offset(pending, snap_end)),
mac_yield_load(),
atom_label(id_dispatch) /* === Case 3-6: ID dispatch */
add_ui(R_T4, R_0, 0x41), branch_ne(R_RawId, R_T4, atom_offset(id_dispatch, try_analog_stick)),
/* BD-slot: pre-compute PadStatus_Digital. Branch reads R_RawId in EX before this WB completes.
* If branch NOT taken (fall through to try_analog_stick), R_T4 is overwritten by the analog body add_ui. */
/* === Digital body (status, buttons normalize, axes=0x80, id, branch. */
/* R_T4 = PadStatus_Digital from id_dispatch BD-slot. */
store_word( R_T4, R_PadState, O_(PadState,status)),
load_half_u(R_T4, R_PadRaw, 2 * S_(U1)),
/* Fill R_T4's load-delay slot with the 0x80808080 axes constant into R_T5
* (R_T5 is dead on this path; it's only consumed at the analog_pad range check). */
load_upper_i(R_T5, 0x8080), or_i_self(R_T5, 0x8080),
nor_u( R_T4, R_T4, R_0), /* raw_buttons is already in host bit order; no swap needed */
store_half( R_T4, R_PadState, O_(PadState,buttons)),
/* axes = 0x80808080 (centered) — single sw writes the 4-byte axes block at offset 8 (left_x, left_y, right_x, right_y). */
store_word( R_T5, R_PadState, O_(PadState,left_x)),
add_ui( R_T4, R_0, 0x41),
store_byte( R_T4, R_PadState, O_(PadState,id)),
jump_rel(atom_offset(id_dispatch, snap_end)),
mac_yield_load(),
atom_label(try_analog_stick) /* === Case 4: AnalogStick (id == 0x53)*/
add_ui(R_T4, R_0, 0x53), branch_ne(R_RawId, R_T4, atom_offset(try_analog_stick, try_analog_pad)),
/* BD-slot: pre-compute PadStatus_AnalogStick. Branch reads R_RawId in EX before this WB completes.
* If branch NOT taken (fall through to try_analog_pad), R_T4 is overwritten by the analog_pad body add_ui. */
atom_label(analog_stick) /* === AnalogStick body
* Axes are loaded as two halfwords: raw[6..7] → left_xy (sh at offset 8), raw[4..5] → right_xy (sh at offset 10).
* R_T5 holds left_xy / id-value in turn (it's dead on this path — only consumed at the analog_pad range check). */
/* R_T4 = PadStatus_AnalogStick from try_analog_stick BD-slot. */
store_word( R_T4, R_PadState, O_(PadState,status)),
load_half_u( R_T4, R_PadRaw, 2 * S_(U1)), /* R_T4 = raw_buttons */
load_half_u( R_T5, R_PadRaw, 6 * S_(U1)), /* R_T5 = left_xy; fills R_T4's load-delay slot (doesn't read R_T4) */
nor_u( R_T4, R_T4, R_0), /* R_T4 = ~raw_buttons */
store_half( R_T4, R_PadState, O_(PadState,buttons)),
load_half_u( R_T4, R_PadRaw, 4 * S_(U1)), /* R_T4 = right_xy; fills R_T5's load-delay slot */
store_half( R_T5, R_PadState, O_(PadState,left_x)), /* R_T5 settled, store left_xy */
store_half( R_T4, R_PadState, O_(PadState,right_x)),
add_ui( R_T5, R_0, 0x53), /* R_T5 = id value (clobbers left_xy, already stored) */
store_byte( R_T5, R_PadState, O_(PadState,id)),
jump_rel(atom_offset(analog_stick, snap_end)),
mac_yield_load(),
atom_label(try_analog_pad) /* === Case 5-6: AnalogPad (id & 0xF0 == 0x70) */
and_i( R_T4, R_RawId, 0xF0),
add_ui( R_T5, R_0, 0x70),
branch_ne(R_T4, R_T5, atom_offset(try_analog_pad, try_unsupported)),
/* BD-slot: pre-compute PadStatus_AnalogPad. Branch reads R_T4 in EX before this WB completes.
* If branch NOT taken (fall through to try_unsupported), R_T4 is overwritten by the unsupported body add_ui. */
atom_label(analog_pad) /* === AnalogPad body
* Same shape as AnalogStick with AnalogPad status. R_T5 holds left_xy (it's dead on this path). */
/* R_T4 = PadStatus_AnalogPad from try_analog_pad BD-slot. */
store_word( R_T4, R_PadState, O_(PadState,status)),
load_half_u(R_T4, R_PadRaw, 2 * S_(U1)), /* R_T4 = raw_buttons */
load_half_u(R_T5, R_PadRaw, 6 * S_(U1)), /* R_T5 = left_xy; fills R_T4's load-delay slot */
nor_u( R_T4, R_T4, R_0), /* R_T4 = ~raw_buttons */
store_half( R_T4, R_PadState, O_(PadState,buttons)),
load_half_u(R_T4, R_PadRaw, 4 * S_(U1)), /* R_T4 = right_xy; fills R_T5's load-delay slot */
store_half( R_T5, R_PadState, O_(PadState,left_x)), /* R_T5 settled, store left_xy */
store_half( R_T4, R_PadState, O_(PadState,right_x)),
store_byte( R_RawId, R_PadState, O_(PadState,id)),
jump_rel(atom_offset(analog_pad, snap_end)),
mac_yield_load(),
atom_label(try_unsupported) /* === Case 7: Unsupported — fall through from the AnalogPad range-check miss. */
add_ui( R_T4, R_0, PadStatus_Unsupported),
store_word(R_T4, R_PadState, O_(PadState,status)),
store_half(R_0, R_PadState, O_(PadState,buttons)),
/* axes = 0x80808080 (centered) — single sw writes the 4-byte axes block at offset 8 (left_x, left_y, right_x, right_y). */
load_upper_i(R_T4, 0x8080), or_i_self(R_T4, 0x8080),
store_word( R_T4, R_PadState, O_(PadState,left_x)),
add_ui( R_T4, R_0, 0xFF), /* 0xFF sentinel: "unknown id" */
store_byte( R_T4, R_PadState, O_(PadState,id)),
/* Fall through to snap_end. */
atom_label(no_jump_fallthrough)
mac_yield_load(),
atom_label(snap_end)
/* NOT mac_yield() — R_AtomJmp was already loaded in the BD-slot of the case-exit branch. */
mac_yield_tail(),
};
/* ----- pad_apply_input -----
* Reads pad[0].buttons + pad[0].left_x;
* Applies the input-semantics deltas to cube_rot.y + floor_rot.y:
* - D-pad Left: cube_rot.y += 30, floor_rot.y += 5
* - D-pad Right: cube_rot.y -= 30, floor_rot.y -= 5
* - Analog stick X (dead zone 0x70..0x90):
* cube delta = (0x80 - left_x) >> 2 (range approx -32..+32)
* floor delta = (0x80 - left_x) >> 5 (range approx -4..+4)
* - D-pad + analog deltas add when used together.
*
* Convention:
* pad_state = 0 means no buttons active.
* The fail-safe zero-button value flows through unchanged, so a disconnected/fresh pad produces no rotation.
* The branch_le_zero pattern below matches the existing pad_input_demo convention (atom body lines 248/257).
*
* Signed-delta trick:
* load_byte_u zero-extends left_x to 32 bits; sub_u from 0x80 wraps to a SIGNED two's-complement value in the negative range;
* shift_aright (sra) then correctly sign-extends the shift for both positive (left_x < 0x80) and negative (left_x > 0x80) cases.
* Digital pads publish left_x = 0x80 → delta = 0 → no rotation, so the analog step is naturally a no-op for digital controllers.
*/
typedef Struct_(Binds_PadApplyInput) {
PadState* state;
V3_S2* cube_rot;
V3_S2* floor_rot;
};
enum {
R_PadStateT5 = R_T5 atom_reg,
R_CubeRot = R_T1 atom_reg,
R_FloorRot = R_T2 atom_reg,
};
internal MipsAtom_(pad_apply_input) atom_info(atom_bind(Binds_PadApplyInput)
, atom_reads(R_T0, R_CubeRot, R_FloorRot, R_T3, R_T4, R_PadStateT5, R_TapePtr)
, atom_writes( R_CubeRot, R_FloorRot)
) {
/* Pop Binds from tape (state, cube_rot, floor_rot) */
load_word(R_PadStateT5, R_TapePtr, O_(Binds_PadApplyInput,state)),
load_word(R_CubeRot, R_TapePtr, O_(Binds_PadApplyInput,cube_rot)),
load_word(R_FloorRot, R_TapePtr, O_(Binds_PadApplyInput,floor_rot)),
add_ui_self( R_TapePtr, S_(Binds_PadApplyInput)),
/* Load pad[0].buttons into R_T0. */
load_word(R_T0, R_PadStateT5, O_(PadState,buttons)), nop,
// Note(Ed): Potential op with delay slot?
/* D-pad Left: cube_rot.y += 30, floor_rot.y += 5. */
and_i(R_T3, R_T0, pad0_(Pad_Left)), branch_le_zero(R_T3, atom_offset(dpad_left, exit_dpad_left)),
load_half( R_T4, R_CubeRot, O_(V3_S2,y)), /* BD-slot */
load_half( R_T3, R_FloorRot, O_(V3_S2,y)),
add_si( R_T4, R_T4, 30),
add_si( R_T3, R_T3, 5),
store_half(R_T4, R_CubeRot, O_(V3_S2,y)),
store_half(R_T3, R_FloorRot, O_(V3_S2,y)),
atom_label(exit_dpad_left)
/* D-pad Right: cube_rot.y -= 30, floor_rot.y -= 5. */
and_i(R_T3, R_T0, pad0_(Pad_Right)), branch_le_zero(R_T3, atom_offset(dpad_right, exit_dpad_right)),
load_half( R_T4, R_CubeRot, O_(V3_S2,y)), /* BD-slot */
load_half( R_T3, R_FloorRot, O_(V3_S2,y)),
add_si( R_T4, R_T4, -30),
add_si( R_T3, R_T3, -5),
store_half(R_T4, R_CubeRot, O_(V3_S2,y)),
store_half(R_T3, R_FloorRot, O_(V3_S2,y)),
atom_label(exit_dpad_right)
/* Analog left-stick X: dead zone 0x70..0x90.
* Cube delta = (0x80 - left_x) >> 2; floor delta = (0x80 - left_x) >> 5. */
load_byte_u(R_T3, R_PadStateT5, O_(PadState,left_x)),
/* Dead-zone check: skip analog if left_x in [0x70, 0x90] inclusive. Outside dead zone on LOW side: left_x < 0x70 (strictly).
* set_lt_u(R_T4, R_T3, R_T4=0x70) → R_T4 = (left_x < 0x70) ? 1 : 0. */
add_ui(R_T4, R_0, 0x70), set_lt_u(R_T4, R_T3, R_T4), branch_ne(R_T4, R_0, atom_offset(dead_zone_low_check, dead_low_active)),
add_ui(R_T4, R_0, 0x80), /* BD-slot: pre-load 0x80 for dead_low_active */
atom_label(dead_check_upper)
/* left_x >= 0x70 → check upper bound. */
load_byte_u(R_T3, R_PadStateT5, O_(PadState,left_x)), /* reload */
add_ui( R_T4, R_0, 0x90),
/* R_T4 = (0x90 < left_x) ? 1 : 0 → (left_x > 0x90) ? 1 : 0 */
set_lt_u(R_T4, R_T4, R_T3), branch_ne(R_T4, R_0, atom_offset(dead_zone_high_check, dead_high_active)),
add_ui( R_T4, R_0, 0x80), /* BD-slot: pre-load 0x80 for dead_high_active */
jump_rel(atom_offset(dead_zone_skip, exit_stick)),
mac_yield_load(),
atom_label(dead_low_active)
/* R_T3 = left_x (from line 632 lbu; not clobbered between dead_zone_low_check branch + its BD-slot `add_ui R_T4, 0x80`).
* The earlier `load_byte_u(R_T3, ...)` reload was redundant and introduced a load-use hazard on the next `sub_u`.
* R_T4 = 0x80 from the BD-slot of `dead_zone_low_check`'s branch_ne. */
sub_u( R_T3, R_T4, R_T3), /* R_T3 = 0x80 - left_x */
/* delta = 0x80 - left_x (positive). */
/* R_T4 = cube_delta */
shift_aright(R_T4, R_T3, 2),
load_half( R_T0, R_CubeRot, O_(V3_S2,y)),
nop,
add_u( R_T0, R_T0, R_T4),
store_half( R_T0, R_CubeRot, O_(V3_S2,y)),
/* R_T4 = floor_delta — moved into the load-delay slot of the floor load below (fills the 1-instruction gap;
* doesn't read R_T0; R_T4 settles by the subsequent add_u). */
load_half( R_T0, R_FloorRot, O_(V3_S2,y)),
shift_aright(R_T4, R_T3, 5),
add_u( R_T0, R_T0, R_T4),
store_half( R_T0, R_FloorRot, O_(V3_S2,y)),
jump_rel(atom_offset(end_low, exit_stick)),
mac_yield_load(),
atom_label(dead_high_active)
/* R_T3 = left_x (from line 641 lbu in dead_check_upper; not clobbered between dead_zone_high_check branch + its BD-slot `add_ui R_T4, 0x80`).
* The earlier `load_byte_u(R_T3, ...)` reload was redundant and introduced a load-use hazard on the next `sub_u`.
* R_T4 = 0x80 from the BD-slot of `dead_zone_high_check`'s branch_ne. */
sub_u( R_T3, R_T4, R_T3),
/* delta = 0x80 - left_x (signed negative). */
shift_aright(R_T4, R_T3, 2), /* R_T4 = cube_delta (signed) */
load_half( R_T0, R_CubeRot, O_(V3_S2,y)),
nop,
add_u( R_T0, R_T0, R_T4),
store_half( R_T0, R_CubeRot, O_(V3_S2,y)),
/* R_T4 = floor_delta (signed) — moved into the load-delay slot of the floor load below. */
load_half( R_T0, R_FloorRot, O_(V3_S2,y)),
shift_aright(R_T4, R_T3, 5),
add_u( R_T0, R_T0, R_T4),
store_half( R_T0, R_FloorRot, O_(V3_S2,y)),
atom_label(no_jump_fallthrough)
mac_yield_load(),
atom_label(exit_stick)
/* NOT mac_yield() — R_AtomJmp was already loaded in the BD-slot of the dead-zone/exit branch. */
mac_yield_tail(),
};
#pragma endregion Baked Atoms