129 lines
2.5 KiB
C
129 lines
2.5 KiB
C
// guest openmusiclabs 6.8.11
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// taken from http://mekonik.wordpress.com/2009/03/18/arduino-avr-gcc-multiplication/
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// added MultiSU16XConst8toH16
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// although the constant multiplies arent any faster
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// than just creating a local variable equal to your constant
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// added MultiU16x8toH16
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// multiplies 16 bit X 8 bit
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// stores lower 16 bits
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#define MultiSU16X8toL16(intRes, int16In, int8In) \
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asm volatile ( \
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"mul %A1, %2 \n\t"\
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"movw %A0, r0 \n\t"\
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"mulsu %B1, %2 \n\t"\
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"add %B0, r0 \n\t"\
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"clr r1"\
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: \
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"=&r" (intRes) \
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: \
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"a" (int16In), \
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"a" (int8In) \
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)
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// multiplies 16 bit number X 8 bit constant
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// saves lower 16 bit
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// 8 cycles
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#define MultiSU16XConst8toL16(intRes, int16In, int8In) \
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asm volatile ( \
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"ldi r22, %2 \n\t"\
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"mul %A1, r22 \n\t"\
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"movw %A0, r0 \n\t"\
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"mulsu %B1, r22 \n\t"\
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"add %B0, r0 \n\t"\
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"clr r1 \n\t"\
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: \
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"=&r" (intRes) \
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: \
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"a" (int16In), \
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"M" (int8In) \
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:\
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"r22"\
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)
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// multiplies 16 bit number X 8 bit constant
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// saves higher 16 bit
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// 8 cycles
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#define MultiSU16XConst8toH16(intRes, int16In, int8In) \
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asm volatile ( \
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"clr r26 \n\t"\
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"ldi r22, %2 \n\t"\
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"mulsu %B1, r22 \n\t"\
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"movw %A0, r0 \n\t"\
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"mul %A1, r22 \n\t"\
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"add %A0, r1 \n\t"\
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"adc %B0, r26 \n\t"\
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"clr r1 \n\t"\
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: \
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"=&r" (intRes) \
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: \
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"a" (int16In), \
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"M" (int8In) \
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:\
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"r22", \
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"r26"\
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)
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// multiplies 16 bit number X 8 bit and stores 2 high bytes
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#define MultiSU16X8toH16(intRes, int16In, int8In) \
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asm volatile ( \
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"clr r26 \n\t"\
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"mulsu %B1, %A2 \n\t"\
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"movw %A0, r0 \n\t"\
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"mul %A1, %A2 \n\t"\
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"add %A0, r1 \n\t"\
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"adc %B0, r26 \n\t"\
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"clr r1 \n\t"\
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: \
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"=&r" (intRes) \
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: \
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"a" (int16In), \
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"a" (int8In) \
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:\
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"r26"\
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)
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// multiplies 16 bit signed number X 8 bit and stores 2 high bytes
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// rounds the number based on the MSB of the lowest byte
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#define MultiSU16X8toH16Round(intRes, int16In, int8In) \
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asm volatile ( \
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"clr r26 \n\t"\
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"mulsu %B1, %A2 \n\t"\
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"movw %A0, r0 \n\t"\
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"mul %A1, %A2 \n\t"\
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"add %A0, r1 \n\t"\
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"adc %B0, r26 \n\t"\
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"lsl r0 \n\t"\
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"adc %A0, r26 \n\t"\
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"adc %B0, r26 \n\t"\
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"clr r1 \n\t"\
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: \
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"=&r" (intRes) \
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: \
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"a" (int16In), \
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"a" (int8In) \
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:\
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"r26"\
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)
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// multiplies 16 bit number X 8 bit and stores 2 high bytes
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#define MultiU16X8toH16(intRes, int16In, int8In) \
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asm volatile ( \
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"clr r26 \n\t"\
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"mul %B1, %A2 \n\t"\
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"movw %A0, r0 \n\t"\
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"mul %A1, %A2 \n\t"\
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"add %A0, r1 \n\t"\
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"adc %B0, r26 \n\t"\
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"clr r1 \n\t"\
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: \
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"=&r" (intRes) \
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: \
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"a" (int16In), \
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"a" (int8In) \
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:\
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"r26"\
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)
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