Use end-of-line comments in planner.cpp

This commit is contained in:
Scott Lahteine 2018-04-15 19:02:30 -05:00
parent 6c7a17dba6
commit 8f57e098de

View file

@ -406,300 +406,300 @@ void Planner::init() {
register const uint8_t* ptab = inv_tab; register const uint8_t* ptab = inv_tab;
__asm__ __volatile__( __asm__ __volatile__(
/* %8:%7:%6 = interval*/ // %8:%7:%6 = interval
/* r31:r30: MUST be those registers, and they must point to the inv_tab */ // r31:r30: MUST be those registers, and they must point to the inv_tab
" clr %13" "\n\t" /* %13 = 0 */ " clr %13" "\n\t" // %13 = 0
/* Now we must compute */ // Now we must compute
/* result = 0xFFFFFF / d */ // result = 0xFFFFFF / d
/* %8:%7:%6 = interval*/ // %8:%7:%6 = interval
/* %16:%15:%14 = nr */ // %16:%15:%14 = nr
/* %13 = 0*/ // %13 = 0
/* A plain division of 24x24 bits should take 388 cycles to complete. We will */ // A plain division of 24x24 bits should take 388 cycles to complete. We will
/* use Newton-Raphson for the calculation, and will strive to get way less cycles*/ // use Newton-Raphson for the calculation, and will strive to get way less cycles
/* for the same result - Using C division, it takes 500cycles to complete .*/ // for the same result - Using C division, it takes 500cycles to complete .
" clr %3" "\n\t" /* idx = 0 */ " clr %3" "\n\t" // idx = 0
" mov %14,%6" "\n\t" " mov %14,%6" "\n\t"
" mov %15,%7" "\n\t" " mov %15,%7" "\n\t"
" mov %16,%8" "\n\t" /* nr = interval */ " mov %16,%8" "\n\t" // nr = interval
" tst %16" "\n\t" /* nr & 0xFF0000 == 0 ? */ " tst %16" "\n\t" // nr & 0xFF0000 == 0 ?
" brne 2f" "\n\t" /* No, skip this */ " brne 2f" "\n\t" // No, skip this
" mov %16,%15" "\n\t" " mov %16,%15" "\n\t"
" mov %15,%14" "\n\t" /* nr <<= 8, %14 not needed */ " mov %15,%14" "\n\t" // nr <<= 8, %14 not needed
" subi %3,-8" "\n\t" /* idx += 8 */ " subi %3,-8" "\n\t" // idx += 8
" tst %16" "\n\t" /* nr & 0xFF0000 == 0 ? */ " tst %16" "\n\t" // nr & 0xFF0000 == 0 ?
" brne 2f" "\n\t" /* No, skip this */ " brne 2f" "\n\t" // No, skip this
" mov %16,%15" "\n\t" /* nr <<= 8, %14 not needed */ " mov %16,%15" "\n\t" // nr <<= 8, %14 not needed
" clr %15" "\n\t" /* We clear %14 */ " clr %15" "\n\t" // We clear %14
" subi %3,-8" "\n\t" /* idx += 8 */ " subi %3,-8" "\n\t" // idx += 8
/* here %16 != 0 and %16:%15 contains at least 9 MSBits, or both %16:%15 are 0 */ // here %16 != 0 and %16:%15 contains at least 9 MSBits, or both %16:%15 are 0
"2:" "\n\t" "2:" "\n\t"
" cpi %16,0x10" "\n\t" /* (nr & 0xf00000) == 0 ? */ " cpi %16,0x10" "\n\t" // (nr & 0xf00000) == 0 ?
" brcc 3f" "\n\t" /* No, skip this */ " brcc 3f" "\n\t" // No, skip this
" swap %15" "\n\t" /* Swap nibbles */ " swap %15" "\n\t" // Swap nibbles
" swap %16" "\n\t" /* Swap nibbles. Low nibble is 0 */ " swap %16" "\n\t" // Swap nibbles. Low nibble is 0
" mov %14, %15" "\n\t" " mov %14, %15" "\n\t"
" andi %14,0x0f" "\n\t" /* Isolate low nibble */ " andi %14,0x0f" "\n\t" // Isolate low nibble
" andi %15,0xf0" "\n\t" /* Keep proper nibble in %15 */ " andi %15,0xf0" "\n\t" // Keep proper nibble in %15
" or %16, %14" "\n\t" /* %16:%15 <<= 4 */ " or %16, %14" "\n\t" // %16:%15 <<= 4
" subi %3,-4" "\n\t" /* idx += 4 */ " subi %3,-4" "\n\t" // idx += 4
"3:" "\n\t" "3:" "\n\t"
" cpi %16,0x40" "\n\t" /* (nr & 0xc00000) == 0 ? */ " cpi %16,0x40" "\n\t" // (nr & 0xc00000) == 0 ?
" brcc 4f" "\n\t" /* No, skip this*/ " brcc 4f" "\n\t" // No, skip this
" add %15,%15" "\n\t" " add %15,%15" "\n\t"
" adc %16,%16" "\n\t" " adc %16,%16" "\n\t"
" add %15,%15" "\n\t" " add %15,%15" "\n\t"
" adc %16,%16" "\n\t" /* %16:%15 <<= 2 */ " adc %16,%16" "\n\t" // %16:%15 <<= 2
" subi %3,-2" "\n\t" /* idx += 2 */ " subi %3,-2" "\n\t" // idx += 2
"4:" "\n\t" "4:" "\n\t"
" cpi %16,0x80" "\n\t" /* (nr & 0x800000) == 0 ? */ " cpi %16,0x80" "\n\t" // (nr & 0x800000) == 0 ?
" brcc 5f" "\n\t" /* No, skip this */ " brcc 5f" "\n\t" // No, skip this
" add %15,%15" "\n\t" " add %15,%15" "\n\t"
" adc %16,%16" "\n\t" /* %16:%15 <<= 1 */ " adc %16,%16" "\n\t" // %16:%15 <<= 1
" inc %3" "\n\t" /* idx += 1 */ " inc %3" "\n\t" // idx += 1
/* Now %16:%15 contains its MSBit set to 1, or %16:%15 is == 0. We are now absolutely sure*/ // Now %16:%15 contains its MSBit set to 1, or %16:%15 is == 0. We are now absolutely sure
/* we have at least 9 MSBits available to enter the initial estimation table*/ // we have at least 9 MSBits available to enter the initial estimation table
"5:" "\n\t" "5:" "\n\t"
" add %15,%15" "\n\t" " add %15,%15" "\n\t"
" adc %16,%16" "\n\t" /* %16:%15 = tidx = (nr <<= 1), we lose the top MSBit (always set to 1, %16 is the index into the inverse table)*/ " adc %16,%16" "\n\t" // %16:%15 = tidx = (nr <<= 1), we lose the top MSBit (always set to 1, %16 is the index into the inverse table)
" add r30,%16" "\n\t" /* Only use top 8 bits */ " add r30,%16" "\n\t" // Only use top 8 bits
" adc r31,%13" "\n\t" /* r31:r30 = inv_tab + (tidx) */ " adc r31,%13" "\n\t" // r31:r30 = inv_tab + (tidx)
" lpm %14, Z" "\n\t" /* %14 = inv_tab[tidx] */ " lpm %14, Z" "\n\t" // %14 = inv_tab[tidx]
" ldi %15, 1" "\n\t" /* %15 = 1 %15:%14 = inv_tab[tidx] + 256 */ " ldi %15, 1" "\n\t" // %15 = 1 %15:%14 = inv_tab[tidx] + 256
/* We must scale the approximation to the proper place*/ // We must scale the approximation to the proper place
" clr %16" "\n\t" /* %16 will always be 0 here */ " clr %16" "\n\t" // %16 will always be 0 here
" subi %3,8" "\n\t" /* idx == 8 ? */ " subi %3,8" "\n\t" // idx == 8 ?
" breq 6f" "\n\t" /* yes, no need to scale*/ " breq 6f" "\n\t" // yes, no need to scale
" brcs 7f" "\n\t" /* If C=1, means idx < 8, result was negative!*/ " brcs 7f" "\n\t" // If C=1, means idx < 8, result was negative!
/* idx > 8, now %3 = idx - 8. We must perform a left shift. idx range:[1-8]*/ // idx > 8, now %3 = idx - 8. We must perform a left shift. idx range:[1-8]
" sbrs %3,0" "\n\t" /* shift by 1bit position?*/ " sbrs %3,0" "\n\t" // shift by 1bit position?
" rjmp 8f" "\n\t" /* No*/ " rjmp 8f" "\n\t" // No
" add %14,%14" "\n\t" " add %14,%14" "\n\t"
" adc %15,%15" "\n\t" /* %15:16 <<= 1*/ " adc %15,%15" "\n\t" // %15:16 <<= 1
"8:" "\n\t" "8:" "\n\t"
" sbrs %3,1" "\n\t" /* shift by 2bit position?*/ " sbrs %3,1" "\n\t" // shift by 2bit position?
" rjmp 9f" "\n\t" /* No*/ " rjmp 9f" "\n\t" // No
" add %14,%14" "\n\t" " add %14,%14" "\n\t"
" adc %15,%15" "\n\t" " adc %15,%15" "\n\t"
" add %14,%14" "\n\t" " add %14,%14" "\n\t"
" adc %15,%15" "\n\t" /* %15:16 <<= 1*/ " adc %15,%15" "\n\t" // %15:16 <<= 1
"9:" "\n\t" "9:" "\n\t"
" sbrs %3,2" "\n\t" /* shift by 4bits position?*/ " sbrs %3,2" "\n\t" // shift by 4bits position?
" rjmp 16f" "\n\t" /* No*/ " rjmp 16f" "\n\t" // No
" swap %15" "\n\t" /* Swap nibbles. lo nibble of %15 will always be 0*/ " swap %15" "\n\t" // Swap nibbles. lo nibble of %15 will always be 0
" swap %14" "\n\t" /* Swap nibbles*/ " swap %14" "\n\t" // Swap nibbles
" mov %12,%14" "\n\t" " mov %12,%14" "\n\t"
" andi %12,0x0f" "\n\t" /* isolate low nibble*/ " andi %12,0x0f" "\n\t" // isolate low nibble
" andi %14,0xf0" "\n\t" /* and clear it*/ " andi %14,0xf0" "\n\t" // and clear it
" or %15,%12" "\n\t" /* %15:%16 <<= 4*/ " or %15,%12" "\n\t" // %15:%16 <<= 4
"16:" "\n\t" "16:" "\n\t"
" sbrs %3,3" "\n\t" /* shift by 8bits position?*/ " sbrs %3,3" "\n\t" // shift by 8bits position?
" rjmp 6f" "\n\t" /* No, we are done */ " rjmp 6f" "\n\t" // No, we are done
" mov %16,%15" "\n\t" " mov %16,%15" "\n\t"
" mov %15,%14" "\n\t" " mov %15,%14" "\n\t"
" clr %14" "\n\t" " clr %14" "\n\t"
" jmp 6f" "\n\t" " jmp 6f" "\n\t"
/* idx < 8, now %3 = idx - 8. Get the count of bits */ // idx < 8, now %3 = idx - 8. Get the count of bits
"7:" "\n\t" "7:" "\n\t"
" neg %3" "\n\t" /* %3 = -idx = count of bits to move right. idx range:[1...8]*/ " neg %3" "\n\t" // %3 = -idx = count of bits to move right. idx range:[1...8]
" sbrs %3,0" "\n\t" /* shift by 1 bit position ?*/ " sbrs %3,0" "\n\t" // shift by 1 bit position ?
" rjmp 10f" "\n\t" /* No, skip it*/ " rjmp 10f" "\n\t" // No, skip it
" asr %15" "\n\t" /* (bit7 is always 0 here)*/ " asr %15" "\n\t" // (bit7 is always 0 here)
" ror %14" "\n\t" " ror %14" "\n\t"
"10:" "\n\t" "10:" "\n\t"
" sbrs %3,1" "\n\t" /* shift by 2 bit position ?*/ " sbrs %3,1" "\n\t" // shift by 2 bit position ?
" rjmp 11f" "\n\t" /* No, skip it*/ " rjmp 11f" "\n\t" // No, skip it
" asr %15" "\n\t" /* (bit7 is always 0 here)*/ " asr %15" "\n\t" // (bit7 is always 0 here)
" ror %14" "\n\t" " ror %14" "\n\t"
" asr %15" "\n\t" /* (bit7 is always 0 here)*/ " asr %15" "\n\t" // (bit7 is always 0 here)
" ror %14" "\n\t" " ror %14" "\n\t"
"11:" "\n\t" "11:" "\n\t"
" sbrs %3,2" "\n\t" /* shift by 4 bit position ?*/ " sbrs %3,2" "\n\t" // shift by 4 bit position ?
" rjmp 12f" "\n\t" /* No, skip it*/ " rjmp 12f" "\n\t" // No, skip it
" swap %15" "\n\t" /* Swap nibbles*/ " swap %15" "\n\t" // Swap nibbles
" andi %14, 0xf0" "\n\t" /* Lose the lowest nibble*/ " andi %14, 0xf0" "\n\t" // Lose the lowest nibble
" swap %14" "\n\t" /* Swap nibbles. Upper nibble is 0*/ " swap %14" "\n\t" // Swap nibbles. Upper nibble is 0
" or %14,%15" "\n\t" /* Pass nibble from upper byte*/ " or %14,%15" "\n\t" // Pass nibble from upper byte
" andi %15, 0x0f" "\n\t" /* And get rid of that nibble*/ " andi %15, 0x0f" "\n\t" // And get rid of that nibble
"12:" "\n\t" "12:" "\n\t"
" sbrs %3,3" "\n\t" /* shift by 8 bit position ?*/ " sbrs %3,3" "\n\t" // shift by 8 bit position ?
" rjmp 6f" "\n\t" /* No, skip it*/ " rjmp 6f" "\n\t" // No, skip it
" mov %14,%15" "\n\t" " mov %14,%15" "\n\t"
" clr %15" "\n\t" " clr %15" "\n\t"
"6:" "\n\t" /* %16:%15:%14 = initial estimation of 0x1000000 / d*/ "6:" "\n\t" // %16:%15:%14 = initial estimation of 0x1000000 / d
/* Now, we must refine the estimation present on %16:%15:%14 using 1 iteration*/ // Now, we must refine the estimation present on %16:%15:%14 using 1 iteration
/* of Newton-Raphson. As it has a quadratic convergence, 1 iteration is enough*/ // of Newton-Raphson. As it has a quadratic convergence, 1 iteration is enough
/* to get more than 18bits of precision (the initial table lookup gives 9 bits of*/ // to get more than 18bits of precision (the initial table lookup gives 9 bits of
/* precision to start from). 18bits of precision is all what is needed here for result */ // precision to start from). 18bits of precision is all what is needed here for result
/* %8:%7:%6 = d = interval*/ // %8:%7:%6 = d = interval
/* %16:%15:%14 = x = initial estimation of 0x1000000 / d*/ // %16:%15:%14 = x = initial estimation of 0x1000000 / d
/* %13 = 0*/ // %13 = 0
/* %3:%2:%1:%0 = working accumulator*/ // %3:%2:%1:%0 = working accumulator
/* Compute 1<<25 - x*d. Result should never exceed 25 bits and should always be positive*/ // Compute 1<<25 - x*d. Result should never exceed 25 bits and should always be positive
" clr %0" "\n\t" " clr %0" "\n\t"
" clr %1" "\n\t" " clr %1" "\n\t"
" clr %2" "\n\t" " clr %2" "\n\t"
" ldi %3,2" "\n\t" /* %3:%2:%1:%0 = 0x2000000*/ " ldi %3,2" "\n\t" // %3:%2:%1:%0 = 0x2000000
" mul %6,%14" "\n\t" /* r1:r0 = LO(d) * LO(x)*/ " mul %6,%14" "\n\t" // r1:r0 = LO(d) * LO(x)
" sub %0,r0" "\n\t" " sub %0,r0" "\n\t"
" sbc %1,r1" "\n\t" " sbc %1,r1" "\n\t"
" sbc %2,%13" "\n\t" " sbc %2,%13" "\n\t"
" sbc %3,%13" "\n\t" /* %3:%2:%1:%0 -= LO(d) * LO(x)*/ " sbc %3,%13" "\n\t" // %3:%2:%1:%0 -= LO(d) * LO(x)
" mul %7,%14" "\n\t" /* r1:r0 = MI(d) * LO(x)*/ " mul %7,%14" "\n\t" // r1:r0 = MI(d) * LO(x)
" sub %1,r0" "\n\t" " sub %1,r0" "\n\t"
" sbc %2,r1" "\n\t" " sbc %2,r1" "\n\t"
" sbc %3,%13" "\n\t" /* %3:%2:%1:%0 -= MI(d) * LO(x) << 8*/ " sbc %3,%13" "\n\t" // %3:%2:%1:%0 -= MI(d) * LO(x) << 8
" mul %8,%14" "\n\t" /* r1:r0 = HI(d) * LO(x)*/ " mul %8,%14" "\n\t" // r1:r0 = HI(d) * LO(x)
" sub %2,r0" "\n\t" " sub %2,r0" "\n\t"
" sbc %3,r1" "\n\t" /* %3:%2:%1:%0 -= MIL(d) * LO(x) << 16*/ " sbc %3,r1" "\n\t" // %3:%2:%1:%0 -= MIL(d) * LO(x) << 16
" mul %6,%15" "\n\t" /* r1:r0 = LO(d) * MI(x)*/ " mul %6,%15" "\n\t" // r1:r0 = LO(d) * MI(x)
" sub %1,r0" "\n\t" " sub %1,r0" "\n\t"
" sbc %2,r1" "\n\t" " sbc %2,r1" "\n\t"
" sbc %3,%13" "\n\t" /* %3:%2:%1:%0 -= LO(d) * MI(x) << 8*/ " sbc %3,%13" "\n\t" // %3:%2:%1:%0 -= LO(d) * MI(x) << 8
" mul %7,%15" "\n\t" /* r1:r0 = MI(d) * MI(x)*/ " mul %7,%15" "\n\t" // r1:r0 = MI(d) * MI(x)
" sub %2,r0" "\n\t" " sub %2,r0" "\n\t"
" sbc %3,r1" "\n\t" /* %3:%2:%1:%0 -= MI(d) * MI(x) << 16*/ " sbc %3,r1" "\n\t" // %3:%2:%1:%0 -= MI(d) * MI(x) << 16
" mul %8,%15" "\n\t" /* r1:r0 = HI(d) * MI(x)*/ " mul %8,%15" "\n\t" // r1:r0 = HI(d) * MI(x)
" sub %3,r0" "\n\t" /* %3:%2:%1:%0 -= MIL(d) * MI(x) << 24*/ " sub %3,r0" "\n\t" // %3:%2:%1:%0 -= MIL(d) * MI(x) << 24
" mul %6,%16" "\n\t" /* r1:r0 = LO(d) * HI(x)*/ " mul %6,%16" "\n\t" // r1:r0 = LO(d) * HI(x)
" sub %2,r0" "\n\t" " sub %2,r0" "\n\t"
" sbc %3,r1" "\n\t" /* %3:%2:%1:%0 -= LO(d) * HI(x) << 16*/ " sbc %3,r1" "\n\t" // %3:%2:%1:%0 -= LO(d) * HI(x) << 16
" mul %7,%16" "\n\t" /* r1:r0 = MI(d) * HI(x)*/ " mul %7,%16" "\n\t" // r1:r0 = MI(d) * HI(x)
" sub %3,r0" "\n\t" /* %3:%2:%1:%0 -= MI(d) * HI(x) << 24*/ " sub %3,r0" "\n\t" // %3:%2:%1:%0 -= MI(d) * HI(x) << 24
/* %3:%2:%1:%0 = (1<<25) - x*d [169]*/ // %3:%2:%1:%0 = (1<<25) - x*d [169]
/* We need to multiply that result by x, and we are only interested in the top 24bits of that multiply*/ // We need to multiply that result by x, and we are only interested in the top 24bits of that multiply
/* %16:%15:%14 = x = initial estimation of 0x1000000 / d*/ // %16:%15:%14 = x = initial estimation of 0x1000000 / d
/* %3:%2:%1:%0 = (1<<25) - x*d = acc*/ // %3:%2:%1:%0 = (1<<25) - x*d = acc
/* %13 = 0 */ // %13 = 0
/* result = %11:%10:%9:%5:%4*/ // result = %11:%10:%9:%5:%4
" mul %14,%0" "\n\t" /* r1:r0 = LO(x) * LO(acc)*/ " mul %14,%0" "\n\t" // r1:r0 = LO(x) * LO(acc)
" mov %4,r1" "\n\t" " mov %4,r1" "\n\t"
" clr %5" "\n\t" " clr %5" "\n\t"
" clr %9" "\n\t" " clr %9" "\n\t"
" clr %10" "\n\t" " clr %10" "\n\t"
" clr %11" "\n\t" /* %11:%10:%9:%5:%4 = LO(x) * LO(acc) >> 8*/ " clr %11" "\n\t" // %11:%10:%9:%5:%4 = LO(x) * LO(acc) >> 8
" mul %15,%0" "\n\t" /* r1:r0 = MI(x) * LO(acc)*/ " mul %15,%0" "\n\t" // r1:r0 = MI(x) * LO(acc)
" add %4,r0" "\n\t" " add %4,r0" "\n\t"
" adc %5,r1" "\n\t" " adc %5,r1" "\n\t"
" adc %9,%13" "\n\t" " adc %9,%13" "\n\t"
" adc %10,%13" "\n\t" " adc %10,%13" "\n\t"
" adc %11,%13" "\n\t" /* %11:%10:%9:%5:%4 += MI(x) * LO(acc) */ " adc %11,%13" "\n\t" // %11:%10:%9:%5:%4 += MI(x) * LO(acc)
" mul %16,%0" "\n\t" /* r1:r0 = HI(x) * LO(acc)*/ " mul %16,%0" "\n\t" // r1:r0 = HI(x) * LO(acc)
" add %5,r0" "\n\t" " add %5,r0" "\n\t"
" adc %9,r1" "\n\t" " adc %9,r1" "\n\t"
" adc %10,%13" "\n\t" " adc %10,%13" "\n\t"
" adc %11,%13" "\n\t" /* %11:%10:%9:%5:%4 += MI(x) * LO(acc) << 8*/ " adc %11,%13" "\n\t" // %11:%10:%9:%5:%4 += MI(x) * LO(acc) << 8
" mul %14,%1" "\n\t" /* r1:r0 = LO(x) * MIL(acc)*/ " mul %14,%1" "\n\t" // r1:r0 = LO(x) * MIL(acc)
" add %4,r0" "\n\t" " add %4,r0" "\n\t"
" adc %5,r1" "\n\t" " adc %5,r1" "\n\t"
" adc %9,%13" "\n\t" " adc %9,%13" "\n\t"
" adc %10,%13" "\n\t" " adc %10,%13" "\n\t"
" adc %11,%13" "\n\t" /* %11:%10:%9:%5:%4 = LO(x) * MIL(acc)*/ " adc %11,%13" "\n\t" // %11:%10:%9:%5:%4 = LO(x) * MIL(acc)
" mul %15,%1" "\n\t" /* r1:r0 = MI(x) * MIL(acc)*/ " mul %15,%1" "\n\t" // r1:r0 = MI(x) * MIL(acc)
" add %5,r0" "\n\t" " add %5,r0" "\n\t"
" adc %9,r1" "\n\t" " adc %9,r1" "\n\t"
" adc %10,%13" "\n\t" " adc %10,%13" "\n\t"
" adc %11,%13" "\n\t" /* %11:%10:%9:%5:%4 += MI(x) * MIL(acc) << 8*/ " adc %11,%13" "\n\t" // %11:%10:%9:%5:%4 += MI(x) * MIL(acc) << 8
" mul %16,%1" "\n\t" /* r1:r0 = HI(x) * MIL(acc)*/ " mul %16,%1" "\n\t" // r1:r0 = HI(x) * MIL(acc)
" add %9,r0" "\n\t" " add %9,r0" "\n\t"
" adc %10,r1" "\n\t" " adc %10,r1" "\n\t"
" adc %11,%13" "\n\t" /* %11:%10:%9:%5:%4 += MI(x) * MIL(acc) << 16*/ " adc %11,%13" "\n\t" // %11:%10:%9:%5:%4 += MI(x) * MIL(acc) << 16
" mul %14,%2" "\n\t" /* r1:r0 = LO(x) * MIH(acc)*/ " mul %14,%2" "\n\t" // r1:r0 = LO(x) * MIH(acc)
" add %5,r0" "\n\t" " add %5,r0" "\n\t"
" adc %9,r1" "\n\t" " adc %9,r1" "\n\t"
" adc %10,%13" "\n\t" " adc %10,%13" "\n\t"
" adc %11,%13" "\n\t" /* %11:%10:%9:%5:%4 = LO(x) * MIH(acc) << 8*/ " adc %11,%13" "\n\t" // %11:%10:%9:%5:%4 = LO(x) * MIH(acc) << 8
" mul %15,%2" "\n\t" /* r1:r0 = MI(x) * MIH(acc)*/ " mul %15,%2" "\n\t" // r1:r0 = MI(x) * MIH(acc)
" add %9,r0" "\n\t" " add %9,r0" "\n\t"
" adc %10,r1" "\n\t" " adc %10,r1" "\n\t"
" adc %11,%13" "\n\t" /* %11:%10:%9:%5:%4 += MI(x) * MIH(acc) << 16*/ " adc %11,%13" "\n\t" // %11:%10:%9:%5:%4 += MI(x) * MIH(acc) << 16
" mul %16,%2" "\n\t" /* r1:r0 = HI(x) * MIH(acc)*/ " mul %16,%2" "\n\t" // r1:r0 = HI(x) * MIH(acc)
" add %10,r0" "\n\t" " add %10,r0" "\n\t"
" adc %11,r1" "\n\t" /* %11:%10:%9:%5:%4 += MI(x) * MIH(acc) << 24*/ " adc %11,r1" "\n\t" // %11:%10:%9:%5:%4 += MI(x) * MIH(acc) << 24
" mul %14,%3" "\n\t" /* r1:r0 = LO(x) * HI(acc)*/ " mul %14,%3" "\n\t" // r1:r0 = LO(x) * HI(acc)
" add %9,r0" "\n\t" " add %9,r0" "\n\t"
" adc %10,r1" "\n\t" " adc %10,r1" "\n\t"
" adc %11,%13" "\n\t" /* %11:%10:%9:%5:%4 = LO(x) * HI(acc) << 16*/ " adc %11,%13" "\n\t" // %11:%10:%9:%5:%4 = LO(x) * HI(acc) << 16
" mul %15,%3" "\n\t" /* r1:r0 = MI(x) * HI(acc)*/ " mul %15,%3" "\n\t" // r1:r0 = MI(x) * HI(acc)
" add %10,r0" "\n\t" " add %10,r0" "\n\t"
" adc %11,r1" "\n\t" /* %11:%10:%9:%5:%4 += MI(x) * HI(acc) << 24*/ " adc %11,r1" "\n\t" // %11:%10:%9:%5:%4 += MI(x) * HI(acc) << 24
" mul %16,%3" "\n\t" /* r1:r0 = HI(x) * HI(acc)*/ " mul %16,%3" "\n\t" // r1:r0 = HI(x) * HI(acc)
" add %11,r0" "\n\t" /* %11:%10:%9:%5:%4 += MI(x) * HI(acc) << 32*/ " add %11,r0" "\n\t" // %11:%10:%9:%5:%4 += MI(x) * HI(acc) << 32
/* At this point, %11:%10:%9 contains the new estimation of x. */ // At this point, %11:%10:%9 contains the new estimation of x.
/* Finally, we must correct the result. Estimate remainder as*/ // Finally, we must correct the result. Estimate remainder as
/* (1<<24) - x*d*/ // (1<<24) - x*d
/* %11:%10:%9 = x*/ // %11:%10:%9 = x
/* %8:%7:%6 = d = interval" "\n\t" /* */ // %8:%7:%6 = d = interval" "\n\t"
" ldi %3,1" "\n\t" " ldi %3,1" "\n\t"
" clr %2" "\n\t" " clr %2" "\n\t"
" clr %1" "\n\t" " clr %1" "\n\t"
" clr %0" "\n\t" /* %3:%2:%1:%0 = 0x1000000*/ " clr %0" "\n\t" // %3:%2:%1:%0 = 0x1000000
" mul %6,%9" "\n\t" /* r1:r0 = LO(d) * LO(x)*/ " mul %6,%9" "\n\t" // r1:r0 = LO(d) * LO(x)
" sub %0,r0" "\n\t" " sub %0,r0" "\n\t"
" sbc %1,r1" "\n\t" " sbc %1,r1" "\n\t"
" sbc %2,%13" "\n\t" " sbc %2,%13" "\n\t"
" sbc %3,%13" "\n\t" /* %3:%2:%1:%0 -= LO(d) * LO(x)*/ " sbc %3,%13" "\n\t" // %3:%2:%1:%0 -= LO(d) * LO(x)
" mul %7,%9" "\n\t" /* r1:r0 = MI(d) * LO(x)*/ " mul %7,%9" "\n\t" // r1:r0 = MI(d) * LO(x)
" sub %1,r0" "\n\t" " sub %1,r0" "\n\t"
" sbc %2,r1" "\n\t" " sbc %2,r1" "\n\t"
" sbc %3,%13" "\n\t" /* %3:%2:%1:%0 -= MI(d) * LO(x) << 8*/ " sbc %3,%13" "\n\t" // %3:%2:%1:%0 -= MI(d) * LO(x) << 8
" mul %8,%9" "\n\t" /* r1:r0 = HI(d) * LO(x)*/ " mul %8,%9" "\n\t" // r1:r0 = HI(d) * LO(x)
" sub %2,r0" "\n\t" " sub %2,r0" "\n\t"
" sbc %3,r1" "\n\t" /* %3:%2:%1:%0 -= MIL(d) * LO(x) << 16*/ " sbc %3,r1" "\n\t" // %3:%2:%1:%0 -= MIL(d) * LO(x) << 16
" mul %6,%10" "\n\t" /* r1:r0 = LO(d) * MI(x)*/ " mul %6,%10" "\n\t" // r1:r0 = LO(d) * MI(x)
" sub %1,r0" "\n\t" " sub %1,r0" "\n\t"
" sbc %2,r1" "\n\t" " sbc %2,r1" "\n\t"
" sbc %3,%13" "\n\t" /* %3:%2:%1:%0 -= LO(d) * MI(x) << 8*/ " sbc %3,%13" "\n\t" // %3:%2:%1:%0 -= LO(d) * MI(x) << 8
" mul %7,%10" "\n\t" /* r1:r0 = MI(d) * MI(x)*/ " mul %7,%10" "\n\t" // r1:r0 = MI(d) * MI(x)
" sub %2,r0" "\n\t" " sub %2,r0" "\n\t"
" sbc %3,r1" "\n\t" /* %3:%2:%1:%0 -= MI(d) * MI(x) << 16*/ " sbc %3,r1" "\n\t" // %3:%2:%1:%0 -= MI(d) * MI(x) << 16
" mul %8,%10" "\n\t" /* r1:r0 = HI(d) * MI(x)*/ " mul %8,%10" "\n\t" // r1:r0 = HI(d) * MI(x)
" sub %3,r0" "\n\t" /* %3:%2:%1:%0 -= MIL(d) * MI(x) << 24*/ " sub %3,r0" "\n\t" // %3:%2:%1:%0 -= MIL(d) * MI(x) << 24
" mul %6,%11" "\n\t" /* r1:r0 = LO(d) * HI(x)*/ " mul %6,%11" "\n\t" // r1:r0 = LO(d) * HI(x)
" sub %2,r0" "\n\t" " sub %2,r0" "\n\t"
" sbc %3,r1" "\n\t" /* %3:%2:%1:%0 -= LO(d) * HI(x) << 16*/ " sbc %3,r1" "\n\t" // %3:%2:%1:%0 -= LO(d) * HI(x) << 16
" mul %7,%11" "\n\t" /* r1:r0 = MI(d) * HI(x)*/ " mul %7,%11" "\n\t" // r1:r0 = MI(d) * HI(x)
" sub %3,r0" "\n\t" /* %3:%2:%1:%0 -= MI(d) * HI(x) << 24*/ " sub %3,r0" "\n\t" // %3:%2:%1:%0 -= MI(d) * HI(x) << 24
/* %3:%2:%1:%0 = r = (1<<24) - x*d*/ // %3:%2:%1:%0 = r = (1<<24) - x*d
/* %8:%7:%6 = d = interval */ // %8:%7:%6 = d = interval
/* Perform the final correction*/ // Perform the final correction
" sub %0,%6" "\n\t" " sub %0,%6" "\n\t"
" sbc %1,%7" "\n\t" " sbc %1,%7" "\n\t"
" sbc %2,%8" "\n\t" /* r -= d*/ " sbc %2,%8" "\n\t" // r -= d
" brcs 14f" "\n\t" /* if ( r >= d) */ " brcs 14f" "\n\t" // if ( r >= d)
/* %11:%10:%9 = x */ // %11:%10:%9 = x
" ldi %3,1" "\n\t" " ldi %3,1" "\n\t"
" add %9,%3" "\n\t" " add %9,%3" "\n\t"
" adc %10,%13" "\n\t" " adc %10,%13" "\n\t"
" adc %11,%13" "\n\t" /* x++*/ " adc %11,%13" "\n\t" // x++
"14:" "\n\t" "14:" "\n\t"
/* Estimation is done. %11:%10:%9 = x */ // Estimation is done. %11:%10:%9 = x
" clr __zero_reg__" "\n\t" /* Make C runtime happy */ " clr __zero_reg__" "\n\t" // Make C runtime happy
/* [211 cycles total]*/ // [211 cycles total]
: "=r" (r2), : "=r" (r2),
"=r" (r3), "=r" (r3),
"=r" (r4), "=r" (r4),