[Python-Dev] Re: acceptability of asm in python code?
Mats Wichmann
mats@laplaza.org
Sat, 08 Mar 2003 15:31:25 -0700
>
>In the BINARY_ADD opcode, and in most arithmetic opcodes, there is a line
>that checks for overflow that looks like this:
>
>if ((i^a) < 0 && (i^b) < 0) goto slow_add;
>
>I got a small speedup by replacing this with a macro defined thusly:
>
>#if defined(_MSC_VER) and defined(_M_IX86)
>#define IF_OVERFLOW_GOTO(X) __asm { jo X };
>#else
>#define IF_OVERFLOW_GOTO(X) if ((i^a) < 0 && (i^b) < 0) goto X;
>#endif
>
>Would this case be an acceptable use of snippets of inline assembler?
I'd personally be more comfortable if we didn't go
down that road; there are compilers that don't support
asm's (e.g. the Intel Linux compilers).