Cannot create Program from binary

[yves-surrel]

From the doc class pyopencl.Program(context, devices, binaries), existing binaries can be provided to create a Program. However, this simple example fails:

import os
import pyopencl as cl

# Kernel function
src = """
__kernel void test(
    __global int *a)
{
    a[get_global_id(0)] = 0;
}
"""

platforms = cl.get_platforms()

for platform in platforms:
    devices = platform.get_devices()
    for i_device, device in enumerate(devices):
        ctx = cl.Context([device])
        prg = cl.Program(ctx, src).build()
        binary, = prg.get_info(cl.program_info.BINARIES)
        # Create Program from binary
        prg1 = cl.Program(ctx, (device,), (binary,))
        try:
            print(prg1.all_kernels())
        except cl.LogicError as e:
            print(e)

The result is:

clCreateKernelsInProgram failed: INVALID_PROGRAM_EXECUTABLE

for all devices found in the platform.

MacOS 11.6.4 Big Sur, Macbook Pro.
On the Windows side (BootCamp), it crashes Python.

[inducer]

You need:

prg1 = cl.Program(ctx, (device,), (binary,)).build()

(Yes, even binaries need to be built. Look it up in the spec. :)

[yves-surrel]

So simple! Actually, I had guessed that long ago. Unfortunately, it does not work:

import os
import pyopencl as cl

# Kernel function
src = """
__kernel void test(
    __global int *a)
{
    a[get_global_id(0)] = 0;
}
"""

platforms = cl.get_platforms()

for platform in platforms:
    devices = platform.get_devices()
    for i_device, device in enumerate(devices):
        ctx = cl.Context([device])
        prg = cl.Program(ctx, src).build()
        binary, = prg.get_info(cl.program_info.BINARIES)
        # Create Program from binary
        try:
            prg1 = cl.Program(ctx, (device,), (binary,)).build()
        except cl.RuntimeError as e:
            print(1, e)

prints:

1 clBuildProgram failed: BUILD_PROGRAM_FAILURE - clBuildProgram failed: BUILD_PROGRAM_FAILURE - clBuildProgram failed: BUILD_PROGRAM_FAILURE

Build on <pyopencl.Device 'Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz' on 'Apple' at 0xffffffff>:


(options: -I /Users/yves/miniconda3/lib/python3.8/site-packages/pyopencl-2021.2.6-py3.8-macosx-10.9-x86_64.egg/pyopencl/cl)

You can see two things:
1 - Still an error
2 - The exception is not properly catched (there should be three lines 1 because I have three devices.

EDITED :
BTW, I have re-re-read the doc, I see nowhere that program created from built binaries should be built (again)...

[inducer]

I have re-re-read the doc, I see nowhere that program created from built binaries should be built (again)...

The CL 3.0 Spec, Section 5.8.4 says:

clBuildProgram must be called for program created using clCreateProgramWithSource, clCreateProgramWithIL or clCreateProgramWithBinary to build the program executable for one or more devices associated with program.

The exception is not properly catched (there should be three lines 1 because I have three devices.

Why not catch https://documen.tician.de/pyopencl/runtime.html#pyopencl.Error instead of cl.RuntimeError?

[yves-surrel]

The CL 3.0 Spec

Ah ah! I was concentrated on the pyOpenCL doc. I humbly suggest that a word about this is added in the pyOpenCL class pyopencl.Program(context, devices, binaries) documentation about this...

Why not catch https://documen.tician.de/pyopencl/runtime.html#pyopencl.Error instead of cl.RuntimeError?

Because without the try...exceptstructure, the output is:

RuntimeError: clBuildProgram failed: BUILD_PROGRAM_FAILURE - clBuildProgram failed: BUILD_PROGRAM_FAILURE - clBuildProgram failed: BUILD_PROGRAM_FAILURE

Build on <pyopencl.Device 'Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz' on 'Apple' at 0xffffffff>:

However, using except cl.Error as e:or even the generic except Exception as e: does not change anything.

Latest news

Only the device Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz raises the Exception. The code works for all other 2 devices on my MBP. Does it provide you any hint?

BTW this explain why there is only one exception catched! Sorry...

FYI the binary bytes content is

bplist00[d4][01][02][03][04][05][06][07][08]_[10][0f]clBinaryVersion\clBinaryData_[10][11]clPlatformVersion^clBinaryDriver[11][01][02]O[10]5/private/var/db/CVMS/cvmsCodeSignObjIs1zWPcqldHAlFQQ[00]_[10]!OpenCL 1.2 (Sep  5 2021 22:39:07)S1.1[08][11]#0DSV[8e][b2][00][00][00][00][00][00][01][01][00][00][00][00][00][00][00][09][00][00][00][00][00][00][00][00][00][00][00][00][00][00][00][b6]

where non printable bytes are replaced by [xx]. Seems to be an intermediate representation (IR) as per Khronos OpenCL doc, but it should work the same.

[inducer]

I humbly suggest that a word about this is added in the pyOpenCL class pyopencl.Program(context, devices, binaries) documentation about this...

I mostly don't want to do this, otherwise I'd be in the business of ultimately copy-pasting the entire spec into the pyopencl docs, which would lead nowhere good.

[yves-surrel]

I understand...

[yves-surrel]

Any idea why Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz is not building ? Am I missing some option (e.g. about caching)? AFAIU, pyopencl is internally using disk caching so...?