! =========================================================
! ======================== 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