This commit is contained in:
ed
2026-06-04 19:08:23 -04:00
parent 1b1c926318
commit 8d03366d92
3 changed files with 195 additions and 39 deletions
+87 -8
View File
@@ -182,7 +182,7 @@ enum {
/* Core Command IDs (Bits 5-0) */
gte_cmd_rtps = 0x01, /* Rot/Trans Perspective Single (1 vertex) */
gte_cmd_rtpt = 0x02, /* Rot/Trans Perspective Triple (3 vertices) */
gte_cmd_rtpt = 0x30, /* Rot/Trans Perspective Triple (3 vertices) */
gte_cmd_nclip = 0x06, /* Normal Clipping (Backface culling) */
gte_cmd_op = 0x0C, /* Outer Product */
gte_cmd_mvmva = 0x12, /* Matrix Vector Multiply & Add (Custom math) */
@@ -322,6 +322,53 @@ enum { _C2_OPS_ = 0
| enc_gte_cmd(cmd) \
)
/* Pre-baked GTE command words for the common cases.
*
* These are pure compile-time integer constants — the C compiler
* constant-folds them into `.word` directives in .rodata. Use them
* inside `asm_inline(...)` blocks (see `gte_rtpt` below for the
* canonical idiom).
*
* Decomposition (per the `enc_gte_<field>` definitions above):
* gte_cmdw_<name> = gte_cmd_base | enc_gte_cmd(<cmd>)
*
* The SF/MX/V/CV/LM fields are all zero in the common cases (standard
* rotation-matrix, no scaling factor, V0 vector, translation vector,
* no clamp), so the only varying bits are the `cmd` field.
*
* Naming follows the file's convention: `gte_cmd_*` is the raw
* 6-bit `cmd` field id, `gte_cmdw_*` is the fully-encoded 32-bit
* instruction word ready to drop into a `.word` directive.
*
* --------------------------------------------------------------------------
* PsyQ-compatibility note (RTPS/RTPT):
* The original Sony PsyQ `inline_n.h` ships RTPT as `cop2 0x0280030` and
* RTPS as `cop2 0x0180001`. Both have `0x20` set in the upper-reserved
* region (bit 21) AND `sf=1` (bit 19) — i.e. the "no division" flag.
* Per psx-spec these bits are reserved/must-be-zero, but the real GTE
* hardware and PCSX-Redux's GTE model both IGNORE them on these two
* commands (the perspective divide happens regardless of `sf`).
*
* If we emit a strictly-spec-compliant word (`sf=0`, reserved bits
* clear), PCSX-Redux's GTE checks those bits more strictly than the
* silicon does and RTPT silently no-ops — the floor's screen
* coordinates come out as raw projection-of-rotation (Z never
* divided), `nclip` ends up wrong, and the triangle is culled.
*
* So for RTPS and RTPT we OR-in the `0x28` "PsyQ compat" pattern to
* match the working bit pattern everyone has shipped for 25 years.
* NCLIP/OP/MVMVA stay spec-clean — their reserved bits really are
* zero in the original PsyQ source.
* --------------------------------------------------------------------------
*/
#define gte_cmdw_psyq_compat (1u << 21 | enc_gte_sf(gte_sf_integer))
#define gte_cmdw_rtps (gte_cmd_base | enc_gte_cmd(gte_cmd_rtps ) | gte_cmdw_psyq_compat)
#define gte_cmdw_rtpt (gte_cmd_base | enc_gte_cmd(gte_cmd_rtpt ) | gte_cmdw_psyq_compat)
#define gte_cmdw_nclip (gte_cmd_base | enc_gte_cmd(gte_cmd_nclip))
#define gte_cmdw_op (gte_cmd_base | enc_gte_cmd(gte_cmd_op ))
#define gte_cmdw_mvmva (gte_cmd_base | enc_gte_cmd(gte_cmd_mvmva))
/**
* @brief Loads a single SVECTOR to GTE vector register V0
*
@@ -394,21 +441,21 @@ enum { _C2_OPS_ = 0
* starts the clobbers section. */
#define gte_load_v0(r_ptr, base) \
asm volatile( \
asm_inline( gte_lwc2_v0(base), gte_lwc2_v0z(base) ) \
asm_inline( gte_lwc2_v0(base), gte_lwc2_v0z(base) ) \
, "r"(r_ptr) \
asm_clobber( reg_str(R_V0_Code), reg_str(R_T0_Code), reg_str(R_T1_Code), reg_str(R_RA_Code), "memory" ) \
)
#define gte_load_v1(r_ptr, base) \
asm volatile( \
asm_inline( gte_lwc2_v1(base), gte_lwc2_v1z(base) ) \
asm_inline( gte_lwc2_v1(base), gte_lwc2_v1z(base) ) \
, "r"(r_ptr) \
asm_clobber( reg_str(R_V0_Code), reg_str(R_T0_Code), reg_str(R_T1_Code), reg_str(R_RA_Code), "memory" ) \
)
#define gte_load_v2(r_ptr, base) \
asm volatile( \
asm_inline( gte_lwc2_v2(base), gte_lwc2_v2z(base) ) \
asm_inline( gte_lwc2_v2(base), gte_lwc2_v2z(base) ) \
, "r"(r_ptr) \
asm_clobber( reg_str(R_V0_Code), reg_str(R_T0_Code), reg_str(R_T1_Code), reg_str(R_RA_Code), "memory" ) \
)
@@ -427,14 +474,46 @@ enum { _C2_OPS_ = 0
*/
#define gte_load_v0v1v2(p0, p1, p2, b0, b1, b2) \
asm volatile( \
asm_inline( gte_lwc2_v0(b0), gte_lwc2_v0z(b0), \
gte_lwc2_v1(b1), gte_lwc2_v1z(b1), \
gte_lwc2_v2(b2), gte_lwc2_v2z(b2) ) \
asm_inline( gte_lwc2_v0(b0), gte_lwc2_v0z(b0), \
gte_lwc2_v1(b1), gte_lwc2_v1z(b1), \
gte_lwc2_v2(b2), gte_lwc2_v2z(b2) ) \
, "r"(p0), "r"(p1), "r"(p2) \
asm_clobber( reg_str(R_V0_Code), reg_str(R_T0_Code), reg_str(R_T1_Code), reg_str(R_RA_Code), "memory" ) \
)
#define gte_rtpt() \
/**
* @brief Rotate, Translate and Perspective Triple (23 cycles)
*
* @details Performs rotation, translation and perspective calculation of three
* vertices at once. The equation performed is the same as gte_rtps() only
* repeated three times for each vertex. The result of the first vertex is
* stored in GTE data register C2_SXY0, the second vector in C2_SXY1 then
* C2_SXY2.
*
* Encoder-style emission (no inline-asm strings in the code body):
* 1. Two `nop` words fill the COP2 pipeline latency — the GTE
* takes ~8 cycles per perspective divide, and the nops let any
* preceding lwc2/swc2 retire before RTPT starts reading its
* inputs from V0/V1/V2.
* 2. The RTPT command word itself is `gte_cmdw_rtpt` (see the
* pre-baked encoders above) — `0x0280030` decoded as
* `op_cop2` | CO(1) | cmd=RTPT, with all SF/MX/V/CV/LM fields
* zero (standard rotation, no scaling, V0 vector, translation
* vector, no clamp).
*
* Clobbers the caller-saved GPRs via `clb_system` (per the kernel
* ABI) plus the standard "memory" barrier. Does not clobber any COP2
* data/control register — those have to be saved by the caller if
* they need to survive across the call (RTPT writes SXY0..2, SZ0..3,
* OTZ, MAC0..3, IR0..3, etc.).
*/
#define gte_rtpt() \
asm volatile( \
asm_inline( nop(), nop(), gte_cmdw_rtpt ) \
asm_clobber( clb_system ) \
)
#define gte_rtpt_ori() \
__asm__ volatile( \
"nop;" \
"nop;" \