[LLVMdev] inline asm question

[Richard Pennington]

Eli Friedman wrote:
> 2009/8/2 Richard Pennington <rich at pennware.com>:
>> The following fails on x86_64 because of the output constraint '0'.
>> My question is, is this legal. LLVM complains about the size difference
>> (32 vs 64), but it is the same register (ax).
>> Works on x86.
>>
>> %42 = call i64 asm sideeffect "syscall\0A\09",
>> "={ax},0,{di},~{dirflag},~{fpsr},~{flags}"(i64 231, i64 %41) nounwind
>>          ; <i64> [#uses=2]
>>
>> -Rich
> 
> Can you give a complete testcase?  Running the following through
> "llvm-as | llc -march=x86-64" works just fine:
> define void @a() {
> call i64 asm sideeffect "syscall\0A\09",
> "={ax},0,{di},~{dirflag},~{fpsr},~{flags}"(i64 231, i64 123) nounwind
> ret void
> }

Sorry Eli, I copied from a version that I got to pass.
The original was
call i64 asm sideeffect "syscall\0A\09",
"={ax},0,{di},~{dirflag},~{fpsr},~{flags}"(i32 231, i64 123) nounwind
ret void}

The return value(in ax) is i64. The first input arg (in ax) is i32.

Not sure how to deal with that,

-Rich