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Merge branch 'MK3_3.12_Optimizations' of https://github.com/leptun/Prusa-Firmware into MK3_3.12_Optimizations

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Guðni Már Gilbert 2022-02-01 18:37:57 +00:00
commit 8681d84c44
1 changed files with 31 additions and 26 deletions
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57
Firmware/speed_lookuptable.h
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@ -8,30 +8,36 @@ extern const uint16_t speed_lookuptable_slow[256][2] PROGMEM;
#ifndef _NO_ASM
// intRes = intIn1 * intIn2 >> 8
// uses:
// r26 to store 0
// r27 to store the byte 1 of the 24 bit result
#define MultiU16X8toH16(intRes, charIn1, intIn2) \
asm volatile ( \
"clr r26 \n\t" \
"mul %A1, %B2 \n\t" \
"movw %A0, r0 \n\t" \
"mul %A1, %A2 \n\t" \
"add %A0, r1 \n\t" \
"adc %B0, r26 \n\t" \
"lsr r0 \n\t" \
"adc %A0, r26 \n\t" \
"adc %B0, r26 \n\t" \
"clr r1 \n\t" \
: \
"=&r" (intRes) \
: \
"d" (charIn1), \
"d" (intIn2) \
: \
"r26" \
)
// return ((x * y) >> 8) with rounding when shifting right
FORCE_INLINE uint16_t MUL8x16R8(uint8_t x, uint16_t y) {
uint16_t out;
__asm__ (
// %0 out
// %1 x
// %2 y
// uint8_t: %An or %n
// uint16_t: %Bn %An
// __uint24: %Cn %Bn %An
// uint32_t: %Dn %Cn %Bn %An
//
//
// B2 A2 *
// A1
//---------
// B0 A0 RR
"mul %B2, %A1" "\n\t"
"movw %0, r0" "\n\t"
"mul %A2, %A1" "\n\t"
"lsl r0" "\n\t" //push MSB to carry for rounding
"adc %A0, r1" "\n\t" //add with carry (for rounding)
"clr r1" "\n\t" //make r1 __zero_reg__ again
"adc %B0, r1" "\n\t" //propagate carry of addition (add 0 with carry)
: "=&r" (out)
: "r" (x), "r" (y)
: "r0", "r1" //clobbers: Technically these are either scratch registers or always 0 registers, but I'm making sure the compiler knows just in case.
);
return out;
}
// intRes = longIn1 * longIn2 >> 24
// uses:
@ -115,8 +121,7 @@ FORCE_INLINE unsigned short calc_timer(uint16_t step_rate, uint8_t& step_loops)
unsigned short table_address = (unsigned short)&speed_lookuptable_fast[(unsigned char)(step_rate>>8)][0];
unsigned char tmp_step_rate = (step_rate & 0x00ff);
uint16_t gain = (uint16_t)pgm_read_word_near(table_address+2);
MultiU16X8toH16(timer, tmp_step_rate, gain);
timer = (unsigned short)pgm_read_word_near(table_address) - timer;
timer = (unsigned short)pgm_read_word_near(table_address) - MUL8x16R8(tmp_step_rate, gain);
}
else { // lower step rates
unsigned short table_address = (unsigned short)&speed_lookuptable_slow[0][0];