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need some help with inline assembler (addcs)

Tim Herbig

Hello,

I want add some inline assembler in my c-code: but at the moment I get some errors.


 unsigned int sum=0;

 __asm ("adds   %0, %1, %1, lsl #16   \n\ 
                         addcs   %0, %0, #0x10000"
                        : "=r" (sum)
                        : "r" (sum)
                        : "cc");
                        return (~sum) >> 16;

The error messages for this line (addcs %0, %0, #0x10000") are "expected an expression" and "Missing operand". Do Keil know the assembler code "addcs"?

best regards
Tim

Parents
  • 0 in reply to ImPer Westermark

    There are at least three possible ARM compilers, and there is no single standard for inlining assembler.

    I'm working with the uvision mdk keil compiler.

    On the other hand - exactly why do you want to inline assembler?

    It's the checksum calculation for ip pkts - so I hope to get a faster calculation using assembler instead of c-code.

Reply
  • 0 in reply to ImPer Westermark

    There are at least three possible ARM compilers, and there is no single standard for inlining assembler.

    I'm working with the uvision mdk keil compiler.

    On the other hand - exactly why do you want to inline assembler?

    It's the checksum calculation for ip pkts - so I hope to get a faster calculation using assembler instead of c-code.

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