diff --git a/bitmul.s b/bitmul.s deleted file mode 100644 index df84704..0000000 --- a/bitmul.s +++ /dev/null @@ -1,124 +0,0 @@ -; the old 16-bit bit-and-shift multiplier -; copied from old code, won't compile as-is - -; inner loop for imul16 -; bitnum < 8: 25 or 41 cycles -; bitnum >= 8: 30 or 46 cycles -.macro bitmul16 arg1, arg2, result, bitnum - .local zero - .local one - .local next - - ; does 16-bit adds - ; arg1 and arg2 are treated as unsigned - ; negative signed inputs must be flipped first - - ; 7 cycles up to the branch - - ; check if arg1 has 0 or 1 bit in this place - ; 5 cycles either way - .if bitnum < 8 - lda arg1 ; 3 cyc - and #(1 << (bitnum)) ; 2 cyc - .else - lda arg1 + 1 ; 3 cyc - and #(1 << ((bitnum) - 8)) ; 2 cyc - .endif - bne one ; 2 cyc - -zero: ; 18 cyc, 23 cyc - lsr result + 3 ; 5 cyc - jmp next ; 3 cyc - -one: ; 32 cyc, 37 cyc - ; 16-bit add on the top bits - clc ; 2 cyc - lda result + 2 ; 3 cyc - adc arg2 ; 3 cyc - sta result + 2 ; 3 cyc - lda result + 3 ; 3 cyc - adc arg2 + 1 ; 3 cyc - ror a ; 2 cyc - get a jump on the shift - sta result + 3 ; 3 cyc -next: - ror result + 2 ; 5 cyc - ror result + 1 ; 5 cyc - .if bitnum >= 8 - ; we can save 5 cycles * 8 bits = 40 cycles total by skipping this byte - ; when it's all uninitialized data - ror result ; 5 cyc - .endif - -.endmacro - -; 5 to 25 cycles -.macro check_sign arg - ; Check sign bit and flip argument to postive, - ; keeping a count of sign bits in the X register. - .local positive - lda arg + 1 ; 3 cyc - bpl positive ; 2 cyc - neg16 arg ; 18 cyc - inx ; 2 cyc -positive: -.endmacro - -; 518 - 828 cyc -.macro imul16 dest, arg1, arg2 - copy16 FR0, arg1 ; 12 cyc - copy16 FR1, arg2 ; 12 cyc - jsr imul16_func ; 470-780 cyc - copy32 dest, FR2 ; 24 cyc -.endmacro - - -.macro shift_round_16 arg, shift - .repeat shift - shl32 arg - .endrepeat - round16 arg -.endmacro - -.macro imul16_round dest, arg1, arg2, shift - copy16 FR0, arg1 ; 12 cyc - copy16 FR1, arg2 ; 12 cyc - jsr imul16_func ; 470-780 cyc - shift_round_16 FR2, shift - copy16 dest, FR2 + 2 ; 12 cyc -.endmacro - -; min 470 cycles -; max 780 cycles -.proc imul16_func - arg1 = FR0 ; 16-bit arg (clobbered) - arg2 = FR1 ; 16-bit arg (clobbered) - result = FR2 ; 32-bit result - - ldx #0 ; 2 cyc - ; counts the number of sign bits in X - check_sign arg1 ; 5 to 25 cyc - check_sign arg2 ; 5 to 25 cyc - - ; zero out the 32-bit temp's top 16 bits - lda #0 ; 2 cyc - sta result + 2 ; 3 cyc - sta result + 3 ; 3 cyc - ; the bottom two bytes will get cleared by the shifts - - ; unrolled loop for maximum speed, at the cost - ; of a larger routine - ; 440 to 696 cycles - .repeat 16, bitnum - ; bitnum < 8: 25 or 41 cycles - ; bitnum >= 8: 30 or 46 cycles - bitmul16 arg1, arg2, result, bitnum - .endrepeat - - ; In case of mixed input signs, return a negative result. - cpx #1 ; 2 cyc - bne positive_result ; 2 cyc - neg32 result ; 34 cyc -positive_result: - - rts ; 6 cyc -.endproc diff --git a/mandel-core.s b/mandel-core.s index 5080d7e..34dff8b 100644 --- a/mandel-core.s +++ b/mandel-core.s @@ -563,13 +563,12 @@ sqr16_patch_offset = 8 ; input: arg as u8 ; output: dest as u16 ; clobbers a, x -; 19 cyc .macro sqr8 dest, arg - ldx arg ; 3 cyc - lda sqr_lobyte,x ; 5 cyc - sta dest ; 3 cyc - lda sqr_hibyte,x ; 5 cyc - sta dest + 1 ; 3 cyc + ldx arg + lda sqr_lobyte,x + sta dest + lda sqr_hibyte,x + sta dest + 1 .endmacro .segment "TABLES" @@ -771,10 +770,6 @@ inner_loop: .endproc -; min low-mem: 81 * 4 + 28 * 2 + 10 + 6 = 396 cyc -; max low-mem: 92 * 4 + 28 * 2 + 50 + 6 = 480 cyc -; min ext-mem: 51 * 4 + 28 * 2 + 10 + 6 = 276 cyc -; max low-mem: 70 * 4 + 28 * 2 + 50 + 6 = 392 cyc .macro imul16_impl xe .local arg1 .local arg2 @@ -792,37 +787,32 @@ inner_loop: ; h1*256*(h2*256 + l2) + l1*(h2*256 + l2) ; h1*h2*256*256 + h1*l2*256 + h2*l1*256 + l1*l2 - imul8 result, arg1, arg2, xe ; 81-92 or 51-70 + imul8 result, arg1, arg2, xe - imul8 result + 2, arg1 + 1, arg2 + 1, xe ; 81-92 or 51-70 + imul8 result + 2, arg1 + 1, arg2 + 1, xe - imul8 inter, arg1 + 1, arg2, xe ; 81-92 or 51-70 - add16 result + 1, result + 1, inter ; 20 cyc - add_carry result + 3 ; 8 cyc + imul8 inter, arg1 + 1, arg2, xe + add16 result + 1, result + 1, inter + add_carry result + 3 - imul8 inter, arg1, arg2 + 1, xe ; 81-92 or 51-70 - add16 result + 1, result + 1, inter ; 20 cyc - add_carry result + 3 ; 8 cyc + imul8 inter, arg1, arg2 + 1, xe + add16 result + 1, result + 1, inter + add_carry result + 3 ; In case of negative inputs, adjust high word ; https://stackoverflow.com/a/28827013 - ; 10-50 cycles - lda arg1 + 1 ; 3 cyc - bpl arg1_pos ; 2 cyc - sub16 result + 2, result + 2, arg2 ; 20 cyc + lda arg1 + 1 + bpl arg1_pos + sub16 result + 2, result + 2, arg2 arg1_pos: - lda arg2 + 1 ; 3 cyc - bpl arg2_pos ; 2 cyc - sub16 result + 2, result + 2, arg1 ; 20 cyc + lda arg2 + 1 + bpl arg2_pos + sub16 result + 2, result + 2, arg1 arg2_pos: rts ; 6 cyc .endmacro -; min base ram: 19 * 2 + 81 + 28 * 2 + 6 = 181 -; max base ram: 19 * 2 + 92 + 28 * 2 + 6 = 192 -; min ext ram: 19 * 2 + 51 + 28 * 2 + 6 = 151 -; max ext ram: 19 * 2 + 70 + 28 * 2 + 6 = 170 .macro sqr16_impl xe .scope arg = FR0 ; 16-bit arg (clobbered) @@ -830,9 +820,9 @@ arg2_pos: ;inter = temp2 inter = FR1 - lda arg + 1 ; 3 cyc - bpl arg_pos ; 2 cyc - neg16 arg ; 18 cyc + lda arg + 1 + bpl arg_pos + neg16 arg arg_pos: ; hl * hl @@ -840,15 +830,15 @@ arg2_pos: ; h*256*(h*256 + l) + l*(h*256 + l) ; h*h*256*256 + h*l*256 + h*l*256 + l*l - sqr8 result, arg ; 19 cyc + sqr8 result, arg - sqr8 result + 2, arg + 1 ; 19 cyc + sqr8 result + 2, arg + 1 - imul8 inter, arg + 1, arg, xe ; 81-92 / 51-70 cyc - add16 result + 1, result + 1, inter ; 20 cyc - add_carry result + 3 ; 8 cyc - add16 result + 1, result + 1, inter ; 20 cyc - add_carry result + 3 ; 8 cyc + imul8 inter, arg + 1, arg, xe + add16 result + 1, result + 1, inter + add_carry result + 3 + add16 result + 1, result + 1, inter + add_carry result + 3 rts ; 6 cyc .endscope