Another optimization question - can I speed up this 32 bit multiply?

Projects Programming
17

Now I'm getting "expected unqualified ID before string constant" on:
"mul %A1, %A2 \n\t" \

#define MultiU8X16to24(longRes, charIn1, intIn2) \
asm volatile ( \
"clr r16 \n\t" \      
"mul %A1, %A2 \n\t" \  
"movw %A0, r0 \n\t" \  
"mov %C0, r16 \n\t" \  
"mov %D0, r16 \n\t" \   
"mul %A1, %B2 \n\t" \ 
"add %B0, r0 \n\t" \   
"adc %C0, r1 \n\t" \   
"adc %D0, r16 \n\t" \ 
"clr r1 \n\t" \        
: \                  
"=&r" (longRes) \  
: \                
"a" (charIn1), \ 
"a" (intIn2) \
: \                
"r16" \            
)