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73 points ingve | 1 comments | | HN request time: 0.208s | source
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tom_ ◴[] No.42477165[source]
It's always been a mystery to me why people put up with this stuff. Adding strings to the assembler output is fine if you want to assemble some unsupported instruction, and a useful getout clause. But as the only option, it sucks, and it's no fun if you want to insert more than 1 instruction.

I used CodeWarrior for PowerPC about 15 years ago, and its inline assembler was very easy to use. No markup required, and you didn't even have to really understand the ABI. Write a C function, add "register" to the parameters, put register variables inside the function, add an asm block inside it, then do your worst. It'd track variable liveness to allocate registers, and rearrange instructions to lengthen dependency chains. Any problems, you'd get an error. Very nice.

replies(4): >>42477331 #>>42477671 #>>42477682 #>>42479166 #
1. astrange ◴[] No.42477682[source]
Most of the time I've used inline assembly it's because the compiler was optimizing something badly. I don't want it to rearrange anything.

(Scheduling is almost useless on modern desktop CPUs anyway, except for some instruction fusion patterns.)