CODEWITHSUNDEEP
assemblyxcode4.5
Chris Ivan Schrago
Chris Ivan Schrago

Reputation: 61

Port asm in Xcode 4.5

Hope someone can help me out with this. I never learned ASM so I can't do anything with this snippet. But I need it for processing and it worked fine for me (was part of a code snippet i used for VC++ programming earlier, now I'm on Xcode 4.5), so I don't know how it exactly works.

I read on some posts, that I have to set quotes. BUT: Where?

    asm(
    fld newVal
    fabs
    fcom oldMax
    fstsw ax
    sahf
    jna else_
    fstp oldMax; // |newVal| > oldMax; pop to oldMax
    jmp endif_
else_:
    ffree st(0)
endif_:
     );

I tried quotes on every line, on beginning and ending. Don't work.

Upvotes: 1

Views: 620

Answers (1)

Will
Will

Reputation: 4713

asm is the Visual Studio syntax, GCC and Clang use __asm__ for assembly language. Your code also appears to be in Intel syntax, GCC usually uses a slightly different syntax called AT&T. You can find out more at the GCC ASM how to.

Something like this would be a good place to get started:

__asm__(
"fld %0\n"
"fabs\n"
"fcom %1\n"
"fstsw %%ax\n"
"sahf\n"
"jna 1f\n"
"fstp %1 ; |newVal| > oldMax; pop to oldMax\n"
"jmp 2f\n"
"1:\n"
"ffree %%st0\n"
"2:\n"
 : "=r"(newVal)
 : "r"(oldMax)
 : "%st0"
 );

Upvotes: 2

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