diff options
Diffstat (limited to 'misc/dreamcast/ViewportTransform.S')
| -rw-r--r-- | misc/dreamcast/ViewportTransform.S | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/misc/dreamcast/ViewportTransform.S b/misc/dreamcast/ViewportTransform.S new file mode 100644 index 0000000..19d3052 --- /dev/null +++ b/misc/dreamcast/ViewportTransform.S @@ -0,0 +1,218 @@ +! ========================================================= +! ======================== PROCESSOR INFO ================= +! ========================================================= +! The SH4 can dual issue (i.e. parallel execution) two instructions +! as long as the groups of the two instructions are different: +! * LS - most APU and FPU register load/stores +! * EX - most APU arithmetic instructions +! * MT - TST, CMP, NOP, MOV Rm,Rn +! * FE - most FPU arithmetic instructions +! * CO - other instructions (NOTE: Cannot be exeucted in parallel) + +! Thee following general aspects of instructions are important to note per the SH4 manual: +! * Issue rate: Interval between the issue of an instruction and that of the next instruction +! * Latency: Interval between the issue of an instruction and the generation of its result (completion) +! * Latency is also the interval between the execution of two instructions with an interdependent relationship. +! (although different cases may either increase or decrease Latency) +! + + +! ========================================================= +! ======================== REGISTER USAGES ================ +! ========================================================= +! SH4 C ABI: +! - R0 to R3 are return values (can be overwritten) +! - R4 to R7 are input arguments (can be overwritten) +! - R8 to R13 are non-volatile (must be restored at end) +! - R14 is the frame pointer (must be restored at end) +! - R15 is the stack pointer (must be restored at end) +! - FR0 to FR3 are return values (can be overwritten) +! - FR4 to FR11 are input arguments (can be overwritten) +! - FR12 to FR13 are non-volatile (must be restored at end) + +!r0 = clip flags +!r1 = GPU command +!r2 = temp +!r3 = prefetch address +!r4 = src pointer ARG +!r5 = dst pointer ARG +!r6 = quads count ARG +!r7 = ? + +!fr0 = temp +!fr1 = u +!fr2 = v +!fr3 = c +!fr4 = x +!fr5 = y +!fr6 = z +!fr7 = w +!fr8 = VIEWPORT_HWIDTH +!fr9 = VIEWPORT_HHEIGHT +!fr10 = VIEWPORT_X_PLUS_HWIDTH +!fr11 = VIEWPORT_Y_PLUS_HHEIGHT + +!fv4 = XYZW + + +! ========================================================= +! ========================= VERTEX LOADING ================ +! ========================================================= +.macro LoadColouredVertex +! LOAD XYZ + fmov @r4+, fr4 ! LS, X = src->x + fmov @r4+, fr5 ! LS, Y = src->y + fmov @r4+, fr6 ! LS, Z = src->z + fldi1 fr7 ! LS, W = 1.0 +! PREPARE NEXT VERTEX + add #16, r3 ! EX, r3 += VERTEX_STRIDE + pref @r3 ! LS, PREFETCH r3 (next vertex) + add #64, r5 ! EX, r5 += 2 * sizeof(VERTEX) +! TRANSFORM VERTEX + ftrv xmtrx, fv4 ! FE, TRANSFORM(XYZW) +! LOAD ATTRIBUTES + fmov @r4+,fr3 ! LS, C = src->color +.endm + +.macro LoadTexturedVertex +! LOAD XYZ + fmov @r4+, fr4 ! LS, X = src->x + fmov @r4+, fr5 ! LS, Y = src->y + fmov @r4+, fr6 ! LS, Z = src->z + fldi1 fr7 ! LS, W = 1.0 +! PREPARE NEXT VERTEX + add #24, r3 ! EX, r3 += VERTEX_STRIDE + pref @r3 ! LS, PREFETCH r3 (next vertex) + add #64, r5 ! EX, r5 += 2 * sizeof(VERTEX) +! TRANSFORM VERTEX + ftrv xmtrx, fv4 ! FE, TRANSFORM(XYZW) +! LOAD ATTRIBUTES + fmov @r4+,fr3 ! LS, C = src->color + fmov @r4+,fr1 ! LS, U = src->u + fmov @r4+,fr2 ! LS, V = src->v +.endm + +! ========================================================= +! ========================= VERTEX OUTPUT ================= +! ========================================================= +! To take advantage of SH4 dual instruction processing, +! clipflag calculation and vertex output are interleaved +.macro ProcessVertex1 + fmov.s fr7,@-r5 ! LS, dst->w = W + fmov.s fr3,@-r5 ! LS, dst->c = C + fneg fr7 ! LS, W = -W + fmov.s fr2,@-r5 ! LS, dst->v = V + fcmp/gt fr7,fr6 ! FE, T = Z > W (i.e. Z > -W) + fmov.s fr1,@-r5 ! LS, dst->u = U + movt r0 ! EX, CLIPFLAGS = T + fmov.s fr6,@-r5 ! LS, dst->z = Z + fmov.s fr5,@-r5 ! LS, dst->y = Y + fmov.s fr4,@-r5 ! LS, dst->x = X + mov.l r1,@-r5 ! LS, dst->flags = CMD_VERT +.endm + +.macro ProcessVertex2 + fmov.s fr7,@-r5 ! LS, dst->w = W + fmov.s fr3,@-r5 ! LS, dst->c = C + fneg fr7 ! LS, W = -W + fmov.s fr2,@-r5 ! LS, dst->v = V + fcmp/gt fr7,fr6 ! FE, T = Z > W (i.e. Z > -W) + fmov.s fr1,@-r5 ! LS, dst->u = U + movt r2 ! EX, tmp = T + fmov.s fr6,@-r5 ! LS, dst->z = Z + add r2,r2 ! EX, tmp = tmp + tmp + fmov.s fr5,@-r5 ! LS, dst->y = Y + or r2,r0 ! EX, CLIPFLAGS |= tmp (T << 1) + fmov.s fr4,@-r5 ! LS, dst->x = X + mov.l r1,@-r5 ! LS, dst->flags = CMD_VERT +.endm + +.macro ProcessVertex3 + fmov.s fr7,@-r5 ! LS, dst->w = W + fmov.s fr3,@-r5 ! LS, dst->c = C + fneg fr7 ! LS, W = -W + fmov.s fr2,@-r5 ! LS, dst->v = V + fcmp/gt fr7,fr6 ! FE, T = Z > W (i.e. Z > -W) + fmov.s fr1,@-r5 ! LS, dst->u = U + movt r2 ! EX, tmp = T + fmov.s fr6,@-r5 ! LS, dst->z = Z + fmov.s fr5,@-r5 ! LS, dst->y = Y + shll2 r2 ! EX, tmp = tmp << 2 + fmov.s fr4,@-r5 ! LS, dst->x = X + or r2,r0 ! EX, CLIPFLAGS |= tmp (T << 2) + mov.l r1,@-r5 ! LS, dst->flags = CMD_VERT +.endm + +.macro ProcessVertex4 eos_addr + fmov.s fr7,@-r5 ! LS, dst->w = W + fmov.s fr3,@-r5 ! LS, dst->c = C + fneg fr7 ! LS, W = -W + fmov.s fr2,@-r5 ! LS, dst->v = V + fcmp/gt fr7,fr6 ! FE, T = Z > W (i.e. Z > -W) + fmov.s fr1,@-r5 ! LS, dst->u = U + movt r2 ! EX, tmp = T + fmov.s fr6,@-r5 ! LS, dst->z = Z + shll2 r2 ! EX, tmp = tmp << 2 + fmov.s fr5,@-r5 ! LS, dst->y = Y + add r2,r2 ! EX, tmp = (tmp << 2) + (tmp << 2) + fmov.s fr4,@-r5 ! LS, dst->x = X + mov.l \eos_addr, r1 ! LS, r1 = GPU EOS command + or r2,r0 ! EX, CLIPFLAGS |= tmp (T << 3) + or r0,r1 ! EX, r1 |= CLIPFLAGS + mov.l r1,@-r5 ! LS, dst->flags = GPU EOS | CLIPFLAGS +.endm + + +! ========================================================= +! ====================== VIEWPORT TRANSFORM =============== +! ========================================================= +!r2 = return addr +!r0 = temp +!r5 = dst pointer + +!fr0 = temp +!fr4 = temp +!fr5 = temp +!fr5 = temp +!fr8 = VIEWPORT_HWIDTH +!fr9 = VIEWPORT_HHEIGHT +!fr10 = VIEWPORT_X_PLUS_HWIDTH +!fr11 = VIEWPORT_Y_PLUS_HHEIGHT + +.macro ViewportTransformSetup vp_addr + mova \vp_addr, r0 ! EX, r0 = &VIEWPORT + fmov.s @r0+,fr8 ! LS, fr8 = VIEWPORT_HWIDTH + fmov.s @r0+,fr9 ! LS, fr9 = VIEWPORT_HHEIGHT + fmov.s @r0+,fr10 ! LS, fr10 = VIEWPORT_X_PLUS_HWIDTH + fmov.s @r0+,fr11 ! LS, fr11 = VIEWPORT_Y_PLUS_HHEIGHT + nop ! MT (align to even instructions boundary) +.endm + +.macro ViewportTransformVertex +! INVERSE W CALCULATION + add #28, r5 ! EX, r5 = &vertex->w + fmov.s @r5,fr0 ! LS, fr0 = vertex->w + fmul fr0,fr0 ! FE, fr0 = fr0 * fr0 + add #-24, r5 ! EX, r5 = &vertex->x + fsrra fr0 ! FE, fr0 = 1 / sqrt(fr0) -> 1 / vertex->w + +! TRANSFORM X + fmov.s @r5,fr4 ! LS, fr4 = vertex->x + fmov fr10,fr5 ! LS, fr5 = VIEWPORT_X_PLUS_HWIDTH + fmul fr8,fr4 ! FE, fr4 = VIEWPORT_HWIDTH * vertex->x + fmac fr0,fr4,fr5 ! FE, fr5 = fr0 * fr4 + fr5 -- (X * F * hwidth) + x_plus_hwidth + fmov.s fr5,@r5 ! LS, vertex->x = fr5 + add #4, r5 ! EX, r5 = &vertex->y + +! TRANSFORM Y + fmov.s @r5,fr4 ! LS, fr4 = vertex->y + fmov fr11,fr5 ! LS, fr5 = VIEWPORT_Y_PLUS_HHEIGHT + fmul fr9,fr4 ! FE, fr4 = VIEWPORT_HHEIGHT * vertex->y + fmac fr0,fr4,fr5 ! FE, fr5 = fr0 * fr4 + fr5 -- (Y * F * hheight) + y_plus_hheight + fmov.s fr5,@r5 ! LS, vertex->y = fr5 + add #4, r5 ! EX, r5 = &vertex->z + +! ASSIGN Z + fmov.s fr0,@r5 ! LS, vertex->z = fr0 + add #20, r5 ! EX, r5 += 20 (points to start of next vertex) +.endm |