instanceof code and OptimizedTypeCheckViolated
Tom Rodriguez
tom.rodriguez at oracle.com
Mon Jan 27 13:37:53 PST 2014
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
>
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