BTW in your test file, you can directly append your bytes slice.
b1 = append(b1, vs...)
and slicesEqual is redundant, bytes.Equal does test the length of two 

On Tuesday, September 20, 2016 at 6:56:55 AM UTC+8, Caleb Spare wrote:
> I'm trying to call a Go function from asm and I'm having trouble figuring 
> out the details.
> (In the past I've always endeavored to avoid this situation and make all 
> my asm functions be leaf functions, but in my current use case it would be 
> most helpful to be able to call a Go helper.)
> See the demo code at 
> or go get 
> For 
> ​the​
>  demo, I have a small function with an append-style API:
> func X(b []byte) []byte
> This calls a Go helper growSlice.
> This code sometimes works, but if I run `go test -count 1000` I'll quickly 
> see
> runtime: frame untyped locals 
> 0xc420042bf8+0x30
> fatal error: missing stackmap
> ...
> I've read through the Runtime Coordination section of the 
> ​asm
>  walkthrough ( several times, but I 
> don't see the problem.
> Here is my understanding of a few relevant bits of that section (which 
> might be incorrect):
> If the results will hold live pointers during a call instruction, the 
>> function should start by zeroing the results and then executing the 
>> pseudo-instruction GO_RESULTS_INITIALIZED.
> This doesn't seem to apply to my code because the results aren't populated 
> until after the CALL.
> If a function has no local stack frame, the pointer information can be 
>> omitted. This is indicated by a local frame size annotation of $0-n on the 
>> TEXT instruction. The pointer information can also be omitted if the 
>> function contains no call instructions. Otherwise, the local stack frame 
>> must not contain pointers, and the assembly must confirm this fact by 
>> executing the pseudo-instruction NO_LOCAL_POINTERS.
> ​My function makes a CALL with arguments. But it has to ​have a pointer 
> (the slice) on the local stack frame in order to pass to that helper. I 
> don't really understand what this section means.
> `go vet` doesn't say anything about my code.
> Any ideas?
> Thanks!
> Caleb

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