instanceof code and OptimizedTypeCheckViolated

[Tom Rodriguez]

It’s probably some minor difference in the profile.  You can use -Dgraal.traceMethodDataFilter=class.method to dump the method data used for that method.  In general I would think for GPU we’d want to avoid any overly optimistic profile based optimization since deopt is likely to be hugely expensive for GPU or at least a waste of compute resources.  TypeCheckMinProfileHitProbability appears to control this code, so you might try overriding it with a higher value.

I’m actually unclear under what conditions instanceofWithProfile will win over a straight instance of test.  Maybe interface types or deep hierarchies?

tom

On Jan 27, 2014, at 12:59 PM, Deneau, Tom <tom.deneau at amd.com> wrote:

> Question on some instanceof codegen in one of our hsail junits
> 
> Java code is:
> 
>    float[] outArray;
>    Shape[] inShapeArray;
>  (gid)->{
>      outArray[gid] = (inShapeArray[gid] instanceof Circle ? 1.0f : 2.0f);
>   });
> 
> The inShapeArray is 50/50 Circle and non-Circle (and we have executed as java first so have some profiling)
> 
> Yet the generated code is taking a deopt path for reason OptimizedTypeCheckViolated when it is not a circle.
> So the code to store 2.0 is never generated.
> 
> In igv, I can see that this happens when we inline InstanceOfSnippets.instanceofWithProfile
> 
> This doesn't happen on every codegen, sometimes the 2.0 store block is generated nicely.
> 
> This used to work fine until I think a few weeks ago...
> 
> Any suggestions?
> 
> -- Tom
> 
> 
> @L7:
> 	ld_global_u32 $d0, [$d0 + 8];
> 	shl_u64 $d0, $d0, 3;
> 	mov_b64 $d2, 0x1000fcd88;                  // check if class == Circle
> 	cmp_ne_b1_s64 $c0, $d2, $d0;
> 	cbr $c0, @L11;
> @L8:
> 	ld_global_s32 $s1, [$d1 + 12];
> 	cmp_ge_b1_u32 $c0, $s0, $s1;
> 	cbr $c0, @L10;
> @L9:
> 	cvt_s64_s32 $d0, $s0;                      // code that stores 1.0f for Circle case
> 	mul_s64 $d0, $d0, 4;
> 	add_u64 $d1, $d1, $d0;
> 	mov_b32 $s0, 1.0f;
> 	st_global_f32 $s0, [$d1 + 16];
> 	ret;
> @L1:
> 	mov_b32 $s0, -21259;
> @L13:
> 	ret;
> @L11:
>      // not a Circle, deoptimize with OptimizedTypeCheckViolated reason
>