Debugging Gradescope Autograder
This document is aimed at students who want to better understand how the Gradescope Autograder works and how they can debug they debug their code.
Introduction
The Gradescope Autograder has access to an Intel x86_64 CPU. As such, we are the Intel OpenAPI Runtime to run your OpenCL code. This is likely different then the platform you have used to develop it. DSMLP also has this driver available, but it is not the default.
Accessing Intel OpenAPI Runtime on DSMLP
The starter code in the helper_lib supports overriding the platform and device index. If you know the platform and device index, you can override these at runtime with by executing PLATFORM_INDEX=p DEVICE_INDEX=d make run.
To get p and d, you can execute clinfo. Here is an example output.
59960@ccrutchf-1340126:~$ clinfo
Number of platforms 2
Platform Name Portable Computing Language
Platform Vendor The pocl project
Platform Version OpenCL 3.0 PoCL 6.0 Linux, Release, RELOC, LLVM 14.0.0, SLEEF, CUDA, POCL_DEBUG
Platform Profile FULL_PROFILE
Platform Extensions cl_khr_icd cl_khr_priority_hints cl_khr_throttle_hints cl_pocl_content_size cl_ext_buffer_device_address
Platform Extensions with Version cl_khr_icd 0x400000 (1.0.0)
cl_khr_priority_hints 0x400000 (1.0.0)
cl_khr_throttle_hints 0x400000 (1.0.0)
cl_pocl_content_size 0x400000 (1.0.0)
cl_ext_buffer_device_address 0x1000 (0.1.0)
Platform Numeric Version 0xc00000 (3.0.0)
Platform Extensions function suffix POCL
Platform Host timer resolution 1ns
Platform Name Intel(R) OpenCL
Platform Vendor Intel(R) Corporation
Platform Version OpenCL 3.0 LINUX
Platform Profile FULL_PROFILE
Platform Extensions cl_khr_spirv_linkonce_odr cl_khr_fp64 cl_khr_fp16 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_3d_image_writes cl_khr_byte_addressable_store cl_khr_depth_images cl_khr_extended_bit_ops cl_khr_icd cl_khr_il_program cl_khr_suggested_local_work_size cl_intel_unified_shared_memory cl_intel_devicelib_assert cl_khr_subgroup_ballot cl_khr_subgroup_shuffle cl_khr_subgroup_shuffle_relative cl_khr_subgroup_extended_types cl_khr_subgroup_non_uniform_arithmetic cl_khr_subgroup_non_uniform_vote cl_khr_subgroup_clustered_reduce cl_intel_subgroups cl_intel_subgroups_char cl_intel_subgroups_short cl_intel_subgroups_long cl_intel_required_subgroup_size cl_intel_spirv_subgroups cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_intel_device_attribute_query cl_intel_exec_by_local_thread cl_intel_vec_len_hint cl_intel_device_partition_by_names cl_khr_spir cl_khr_image2d_from_buffer cl_intel_concurrent_dispatch
Platform Extensions with Version cl_khr_spirv_linkonce_odr 0x400000 (1.0.0)
cl_khr_fp64 0x400000 (1.0.0)
cl_khr_fp16 0x400000 (1.0.0)
cl_khr_global_int32_base_atomics 0x400000 (1.0.0)
cl_khr_global_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_local_int32_base_atomics 0x400000 (1.0.0)
cl_khr_local_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_3d_image_writes 0x400000 (1.0.0)
cl_khr_byte_addressable_store 0x400000 (1.0.0)
cl_khr_depth_images 0x400000 (1.0.0)
cl_khr_extended_bit_ops 0x400000 (1.0.0)
cl_khr_icd 0x400000 (1.0.0)
cl_khr_il_program 0x400000 (1.0.0)
cl_khr_suggested_local_work_size 0x400000 (1.0.0)
cl_intel_unified_shared_memory 0x400000 (1.0.0)
cl_intel_devicelib_assert 0x400000 (1.0.0)
cl_khr_subgroup_ballot 0x400000 (1.0.0)
cl_khr_subgroup_shuffle 0x400000 (1.0.0)
cl_khr_subgroup_shuffle_relative 0x400000 (1.0.0)
cl_khr_subgroup_extended_types 0x400000 (1.0.0)
cl_khr_subgroup_non_uniform_arithmetic 0x400000 (1.0.0)
cl_khr_subgroup_non_uniform_vote 0x400000 (1.0.0)
cl_khr_subgroup_clustered_reduce 0x400000 (1.0.0)
cl_intel_subgroups 0x400000 (1.0.0)
cl_intel_subgroups_char 0x400000 (1.0.0)
cl_intel_subgroups_short 0x400000 (1.0.0)
cl_intel_subgroups_long 0x400000 (1.0.0)
cl_intel_required_subgroup_size 0x400000 (1.0.0)
cl_intel_spirv_subgroups 0x400000 (1.0.0)
cl_khr_int64_base_atomics 0x400000 (1.0.0)
cl_khr_int64_extended_atomics 0x400000 (1.0.0)
cl_intel_device_attribute_query 0x400000 (1.0.0)
cl_intel_exec_by_local_thread 0x400000 (1.0.0)
cl_intel_vec_len_hint 0x400000 (1.0.0)
cl_intel_device_partition_by_names 0x400000 (1.0.0)
cl_khr_spir 0x400000 (1.0.0)
cl_khr_image2d_from_buffer 0x400000 (1.0.0)
cl_intel_concurrent_dispatch 0x400000 (1.0.0)
Platform Numeric Version 0xc00000 (3.0.0)
Platform Extensions function suffix INTEL
Platform Host timer resolution 1ns
Platform Name Portable Computing Language
Number of devices 2
Device Name cpu-cascadelake-Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz
Device Vendor GenuineIntel
Device Vendor ID 0x10006
Device Version OpenCL 3.0 PoCL HSTR: cpu-x86_64-pc-linux-gnu-cascadelake
Device Numeric Version 0xc00000 (3.0.0)
Driver Version 6.0
Device OpenCL C Version OpenCL C 1.2 PoCL
Device OpenCL C all versions OpenCL C 0x400000 (1.0.0)
OpenCL C 0x401000 (1.1.0)
OpenCL C 0x402000 (1.2.0)
OpenCL C 0xc00000 (3.0.0)
Device OpenCL C features __opencl_c_3d_image_writes 0xc00000 (3.0.0)
__opencl_c_images 0xc00000 (3.0.0)
__opencl_c_atomic_order_acq_rel 0xc00000 (3.0.0)
__opencl_c_atomic_order_seq_cst 0xc00000 (3.0.0)
__opencl_c_atomic_scope_device 0xc00000 (3.0.0)
__opencl_c_program_scope_global_variables 0xc00000 (3.0.0)
__opencl_c_atomic_scope_all_devices 0xc00000 (3.0.0)
__opencl_c_generic_address_space 0xc00000 (3.0.0)
__opencl_c_work_group_collective_functions 0xc00000 (3.0.0)
__opencl_c_read_write_images 0xc00000 (3.0.0)
__opencl_c_subgroups 0xc00000 (3.0.0)
__opencl_c_fp64 0xc00000 (3.0.0)
__opencl_c_ext_fp32_global_atomic_add 0xc00000 (3.0.0)
__opencl_c_ext_fp32_local_atomic_add 0xc00000 (3.0.0)
__opencl_c_ext_fp32_global_atomic_min_max 0xc00000 (3.0.0)
__opencl_c_ext_fp32_local_atomic_min_max 0xc00000 (3.0.0)
__opencl_c_ext_fp64_global_atomic_add 0xc00000 (3.0.0)
__opencl_c_ext_fp64_local_atomic_add 0xc00000 (3.0.0)
__opencl_c_ext_fp64_global_atomic_min_max 0xc00000 (3.0.0)
__opencl_c_ext_fp64_local_atomic_min_max 0xc00000 (3.0.0)
__opencl_c_int64 0xc00000 (3.0.0)
Latest comfornace test passed v2022-04-19-01
Device Type CPU
Device Profile FULL_PROFILE
Device Available Yes
Compiler Available Yes
Linker Available Yes
Max compute units 64
Max clock frequency 3900MHz
Device Partition (core)
Max number of sub-devices 64
Supported partition types equally, by counts
Supported affinity domains (n/a)
Max work item dimensions 3
Max work item sizes 4096x4096x4096
Max work group size 4096
Preferred work group size multiple (device) 8
Preferred work group size multiple (kernel) 8
Max sub-groups per work group 128
Sub-group sizes (Intel) 1, 2, 4, 8, 16, 32, 64, 128, 256, 512
Preferred / native vector sizes
char 16 / 16
short 16 / 16
int 16 / 16
long 8 / 8
half 0 / 0 (n/a)
float 16 / 16
double 8 / 8 (cl_khr_fp64)
Half-precision Floating-point support (n/a)
Single-precision Floating-point support (core)
Denormals Yes
Infinity and NANs Yes
Round to nearest Yes
Round to zero Yes
Round to infinity Yes
IEEE754-2008 fused multiply-add Yes
Support is emulated in software No
Correctly-rounded divide and sqrt operations Yes
Double-precision Floating-point support (cl_khr_fp64)
Denormals Yes
Infinity and NANs Yes
Round to nearest Yes
Round to zero Yes
Round to infinity Yes
IEEE754-2008 fused multiply-add Yes
Support is emulated in software No
Address bits 64, Little-Endian
Global memory size 402161725440 (374.5GiB)
Error Correction support No
Max memory allocation 137438953472 (128GiB)
Unified memory for Host and Device Yes
Shared Virtual Memory (SVM) capabilities (core)
Coarse-grained buffer sharing Yes
Fine-grained buffer sharing Yes
Fine-grained system sharing Yes
Atomics Yes
Minimum alignment for any data type 128 bytes
Alignment of base address 1024 bits (128 bytes)
Preferred alignment for atomics
SVM 64 bytes
Global 64 bytes
Local 64 bytes
Atomic memory capabilities relaxed, acquire/release, sequentially-consistent, work-group scope, device scope, all-devices scope
Atomic fence capabilities relaxed, acquire/release, sequentially-consistent, work-item scope, work-group scope, device scope
Max size for global variable 64000 (62.5KiB)
Preferred total size of global vars 1048576 (1024KiB)
Global Memory cache type Read/Write
Global Memory cache size 23068672 (22MiB)
Global Memory cache line size 64 bytes
Image support Yes
Max number of samplers per kernel 16
Max size for 1D images from buffer 8589934592 pixels
Max 1D or 2D image array size 2048 images
Max 2D image size 65536x65536 pixels
Max 3D image size 2048x2048x2048 pixels
Max number of read image args 128
Max number of write image args 128
Max number of read/write image args 128
Pipe support No
Max number of pipe args 0
Max active pipe reservations 0
Max pipe packet size 0
Local memory type Global
Local memory size 1048576 (1024KiB)
Max number of constant args 8
Max constant buffer size 1048576 (1024KiB)
Generic address space support Yes
Max size of kernel argument 1024
Queue properties (on host)
Out-of-order execution Yes
Profiling Yes
Device enqueue capabilities (n/a)
Queue properties (on device)
Out-of-order execution No
Profiling No
Preferred size 0
Max size 0
Max queues on device 0
Max events on device 0
Prefer user sync for interop Yes
Profiling timer resolution 1ns
Execution capabilities
Run OpenCL kernels Yes
Run native kernels Yes
Non-uniform work-groups No
Work-group collective functions Yes
Sub-group independent forward progress Yes
IL version (n/a)
ILs with version (n/a)
printf() buffer size 16777216 (16MiB)
Built-in kernels pocl.add.i8;org.khronos.openvx.scale_image.nn.u8;org.khronos.openvx.scale_image.bl.u8;org.khronos.openvx.tensor_convert_depth.wrap.u8.f32
Built-in kernels with version pocl.add.i8 0x402000 (1.2.0)
org.khronos.openvx.scale_image.nn.u8 0x402000 (1.2.0)
org.khronos.openvx.scale_image.bl.u8 0x402000 (1.2.0)
org.khronos.openvx.tensor_convert_depth.wrap.u8.f32 0x402000 (1.2.0)
Device Extensions cl_khr_byte_addressable_store cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_3d_image_writes cl_khr_command_buffer cl_khr_command_buffer_multi_device cl_khr_subgroups cl_intel_unified_shared_memory cl_ext_buffer_device_address cl_pocl_svm_rect cl_pocl_command_buffer_svm cl_pocl_command_buffer_host_buffer cl_khr_subgroup_ballot cl_khr_subgroup_shuffle cl_intel_subgroups cl_intel_subgroups_short cl_ext_float_atomics cl_intel_required_subgroup_size cl_khr_fp64 cl_khr_int64_base_atomics cl_khr_int64_extended_atomics
Device Extensions with Version cl_khr_byte_addressable_store 0x400000 (1.0.0)
cl_khr_global_int32_base_atomics 0x400000 (1.0.0)
cl_khr_global_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_local_int32_base_atomics 0x400000 (1.0.0)
cl_khr_local_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_3d_image_writes 0x400000 (1.0.0)
cl_khr_command_buffer 0x9004 (0.9.4)
cl_khr_command_buffer_multi_device 0x9001 (0.9.1)
cl_khr_subgroups 0x400000 (1.0.0)
cl_intel_unified_shared_memory 0x400000 (1.0.0)
cl_ext_buffer_device_address 0x1000 (0.1.0)
cl_pocl_svm_rect 0x9000 (0.9.0)
cl_pocl_command_buffer_svm 0x9000 (0.9.0)
cl_pocl_command_buffer_host_buffer 0x9000 (0.9.0)
cl_khr_subgroup_ballot 0x400000 (1.0.0)
cl_khr_subgroup_shuffle 0x400000 (1.0.0)
cl_intel_subgroups 0x400000 (1.0.0)
cl_intel_subgroups_short 0x400000 (1.0.0)
cl_ext_float_atomics 0x400000 (1.0.0)
cl_intel_required_subgroup_size 0x400000 (1.0.0)
cl_khr_fp64 0x400000 (1.0.0)
cl_khr_int64_base_atomics 0x400000 (1.0.0)
cl_khr_int64_extended_atomics 0x400000 (1.0.0)
Device Name NVIDIA GeForce RTX 2080 Ti
Device Vendor NVIDIA Corporation
Device Vendor ID 0x10de
Device Version OpenCL 3.0 PoCL HSTR: CUDA-sm_75
Device Numeric Version 0xc00000 (3.0.0)
Driver Version 6.0
Device OpenCL C Version OpenCL C 1.2 PoCL
Device OpenCL C all versions OpenCL C 0x400000 (1.0.0)
OpenCL C 0x401000 (1.1.0)
OpenCL C 0x402000 (1.2.0)
OpenCL C 0xc00000 (3.0.0)
Device OpenCL C features __opencl_c_images 0xc00000 (3.0.0)
__opencl_c_atomic_order_acq_rel 0xc00000 (3.0.0)
__opencl_c_atomic_order_seq_cst 0xc00000 (3.0.0)
__opencl_c_atomic_scope_device 0xc00000 (3.0.0)
__opencl_c_program_scope_global_variables 0xc00000 (3.0.0)
__opencl_c_generic_address_space 0xc00000 (3.0.0)
__opencl_c_fp16 0xc00000 (3.0.0)
__opencl_c_fp64 0xc00000 (3.0.0)
Latest comfornace test passed (n/a)
Device Type GPU
Device Topology (NV) PCI-E, 0000:da:00.0
Device Profile FULL_PROFILE
Device Available Yes
Compiler Available Yes
Linker Available Yes
Max compute units 68
Max clock frequency 1620MHz
Compute Capability (NV) 7.5
Device Partition (core)
Max number of sub-devices 1
Supported partition types None
Supported affinity domains (n/a)
Max work item dimensions 3
Max work item sizes 1024x1024x64
Max work group size 1024
Preferred work group size multiple (device) 32
Preferred work group size multiple (kernel) 32
Warp size (NV) 32
Max sub-groups per work group 32
Preferred / native vector sizes
char 1 / 1
short 1 / 1
int 1 / 1
long 1 / 1
half 0 / 0 (cl_khr_fp16)
float 1 / 1
double 1 / 1 (cl_khr_fp64)
Half-precision Floating-point support (cl_khr_fp16)
Denormals No
Infinity and NANs Yes
Round to nearest Yes
Round to zero No
Round to infinity No
IEEE754-2008 fused multiply-add No
Support is emulated in software No
Single-precision Floating-point support (core)
Denormals Yes
Infinity and NANs Yes
Round to nearest Yes
Round to zero Yes
Round to infinity Yes
IEEE754-2008 fused multiply-add Yes
Support is emulated in software No
Correctly-rounded divide and sqrt operations No
Double-precision Floating-point support (cl_khr_fp64)
Denormals Yes
Infinity and NANs Yes
Round to nearest Yes
Round to zero Yes
Round to infinity Yes
IEEE754-2008 fused multiply-add Yes
Support is emulated in software No
Address bits 64, Little-Endian
Global memory size 11546394624 (10.75GiB)
Error Correction support No
Max memory allocation 11381768192 (10.6GiB)
Unified memory for Host and Device No
Integrated memory (NV) No
Shared Virtual Memory (SVM) capabilities (core)
Coarse-grained buffer sharing Yes
Fine-grained buffer sharing Yes
Fine-grained system sharing No
Atomics No
Minimum alignment for any data type 128 bytes
Alignment of base address 4096 bits (512 bytes)
Preferred alignment for atomics
SVM 64 bytes
Global 64 bytes
Local 64 bytes
Atomic memory capabilities relaxed, work-group scope
Atomic fence capabilities relaxed, acquire/release, work-group scope
Max size for global variable 0
Preferred total size of global vars 0
Global Memory cache type None
Image support No
Pipe support No
Max number of pipe args 0
Max active pipe reservations 0
Max pipe packet size 0
Local memory type Local
Local memory size 49152 (48KiB)
Registers per block (NV) 65536
Max number of constant args 8
Max constant buffer size 65536 (64KiB)
Generic address space support Yes
Max size of kernel argument 4352 (4.25KiB)
Queue properties (on host)
Out-of-order execution No
Profiling Yes
Device enqueue capabilities (n/a)
Queue properties (on device)
Out-of-order execution No
Profiling No
Preferred size 0
Max size 0
Max queues on device 0
Max events on device 0
Prefer user sync for interop Yes
Profiling timer resolution 1ns
Execution capabilities
Run OpenCL kernels Yes
Run native kernels No
Non-uniform work-groups No
Work-group collective functions No
Sub-group independent forward progress Yes
Kernel execution timeout (NV) No
Concurrent copy and kernel execution (NV) Yes
Number of async copy engines 3
IL version (n/a)
ILs with version (n/a)
printf() buffer size 16777216 (16MiB)
Built-in kernels pocl.mul.i32;pocl.add.i32;pocl.dnn.conv2d_int8_relu;pocl.sgemm.local.f32;pocl.sgemm.tensor.f16f16f32;pocl.sgemm_ab.tensor.f16f16f32;pocl.abs.f32;pocl.add.i8;org.khronos.openvx.scale_image.nn.u8;org.khronos.openvx.scale_image.bl.u8;org.khronos.openvx.tensor_convert_depth.wrap.u8.f32
Built-in kernels with version pocl.mul.i32 0x402000 (1.2.0)
pocl.add.i32 0x402000 (1.2.0)
pocl.dnn.conv2d_int8_relu 0x402000 (1.2.0)
pocl.sgemm.local.f32 0x402000 (1.2.0)
pocl.sgemm.tensor.f16f16f32 0x402000 (1.2.0)
pocl.sgemm_ab.tensor.f16f16f32 0x402000 (1.2.0)
pocl.abs.f32 0x402000 (1.2.0)
pocl.add.i8 0x402000 (1.2.0)
org.khronos.openvx.scale_image.nn.u8 0x402000 (1.2.0)
org.khronos.openvx.scale_image.bl.u8 0x402000 (1.2.0)
org.khronos.openvx.tensor_convert_depth.wrap.u8.f32 0x402000 (1.2.0)
Device Extensions cl_khr_byte_addressable_store cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_nv_device_attribute_query cl_khr_fp16 cl_khr_fp64 cl_ext_buffer_device_address cl_khr_subgroup_ballot cl_khr_subgroup_shuffle
Device Extensions with Version cl_khr_byte_addressable_store 0x400000 (1.0.0)
cl_khr_global_int32_base_atomics 0x400000 (1.0.0)
cl_khr_global_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_local_int32_base_atomics 0x400000 (1.0.0)
cl_khr_local_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_int64_base_atomics 0x400000 (1.0.0)
cl_khr_int64_extended_atomics 0x400000 (1.0.0)
cl_nv_device_attribute_query 0x400000 (1.0.0)
cl_khr_fp16 0x400000 (1.0.0)
cl_khr_fp64 0x400000 (1.0.0)
cl_ext_buffer_device_address 0x1000 (0.1.0)
cl_khr_subgroup_ballot 0x400000 (1.0.0)
cl_khr_subgroup_shuffle 0x400000 (1.0.0)
Platform Name Intel(R) OpenCL
Number of devices 1
Device Name Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz
Device Vendor Intel(R) Corporation
Device Vendor ID 0x8086
Device Version OpenCL 3.0 (Build 0)
Device Numeric Version 0xc00000 (3.0.0)
Driver Version 2024.18.12.0.05_160000
Device OpenCL C Version OpenCL C 3.0
Device OpenCL C all versions OpenCL C 0xc00000 (3.0.0)
OpenCL C 0x800000 (2.0.0)
OpenCL C 0x402000 (1.2.0)
OpenCL C 0x401000 (1.1.0)
OpenCL C 0x400000 (1.0.0)
Device OpenCL C features __opencl_c_3d_image_writes 0xc00000 (3.0.0)
__opencl_c_atomic_order_acq_rel 0xc00000 (3.0.0)
__opencl_c_atomic_order_seq_cst 0xc00000 (3.0.0)
__opencl_c_atomic_scope_device 0xc00000 (3.0.0)
__opencl_c_atomic_scope_all_devices 0xc00000 (3.0.0)
__opencl_c_device_enqueue 0xc00000 (3.0.0)
__opencl_c_generic_address_space 0xc00000 (3.0.0)
__opencl_c_fp64 0xc00000 (3.0.0)
__opencl_c_images 0xc00000 (3.0.0)
__opencl_c_int64 0xc00000 (3.0.0)
__opencl_c_pipes 0xc00000 (3.0.0)
__opencl_c_program_scope_global_variables 0xc00000 (3.0.0)
__opencl_c_read_write_images 0xc00000 (3.0.0)
__opencl_c_subgroups 0xc00000 (3.0.0)
__opencl_c_work_group_collective_functions 0xc00000 (3.0.0)
Latest comfornace test passed v2023-10-10-00
Device Type CPU
Device Profile FULL_PROFILE
Device Available Yes
Compiler Available Yes
Linker Available Yes
Max compute units 64
Max clock frequency 2300MHz
Device Partition (core)
Max number of sub-devices 64
Supported partition types by counts, equally, by names (Intel), by affinity domain
Supported affinity domains NUMA, next partitionable
Max work item dimensions 3
Max work item sizes 8192x8192x8192
Max work group size 8192
Preferred work group size multiple (device) 128
Preferred work group size multiple (kernel) 128
Max sub-groups per work group 2048
Sub-group sizes (Intel) 4, 8, 16, 32, 64
Preferred / native vector sizes
char 1 / 64
short 1 / 32
int 1 / 16
long 1 / 8
half 1 / 32 (cl_khr_fp16)
float 1 / 16
double 1 / 8 (cl_khr_fp64)
Half-precision Floating-point support (cl_khr_fp16)
Denormals No
Infinity and NANs Yes
Round to nearest Yes
Round to zero No
Round to infinity No
IEEE754-2008 fused multiply-add No
Support is emulated in software No
Single-precision Floating-point support (core)
Denormals Yes
Infinity and NANs Yes
Round to nearest Yes
Round to zero No
Round to infinity No
IEEE754-2008 fused multiply-add No
Support is emulated in software No
Correctly-rounded divide and sqrt operations No
Double-precision Floating-point support (cl_khr_fp64)
Denormals Yes
Infinity and NANs Yes
Round to nearest Yes
Round to zero Yes
Round to infinity Yes
IEEE754-2008 fused multiply-add Yes
Support is emulated in software No
Address bits 64, Little-Endian
Global memory size 404309209088 (376.5GiB)
Error Correction support No
Max memory allocation 202154604544 (188.3GiB)
Unified memory for Host and Device Yes
Shared Virtual Memory (SVM) capabilities (core)
Coarse-grained buffer sharing Yes
Fine-grained buffer sharing Yes
Fine-grained system sharing Yes
Atomics Yes
Minimum alignment for any data type 128 bytes
Alignment of base address 1024 bits (128 bytes)
Preferred alignment for atomics
SVM 64 bytes
Global 64 bytes
Local 0 bytes
Atomic memory capabilities relaxed, acquire/release, sequentially-consistent, work-group scope, device scope, all-devices scope
Atomic fence capabilities relaxed, acquire/release, sequentially-consistent, work-item scope, work-group scope, device scope, all-devices scope
Max size for global variable 65536 (64KiB)
Preferred total size of global vars 65536 (64KiB)
Global Memory cache type Read/Write
Global Memory cache size 262144 (256KiB)
Global Memory cache line size 64 bytes
Image support Yes
Max number of samplers per kernel 480
Max size for 1D images from buffer 12634662784 pixels
Max 1D or 2D image array size 2048 images
Base address alignment for 2D image buffers 64 bytes
Pitch alignment for 2D image buffers 64 pixels
Max 2D image size 16384x16384 pixels
Max 3D image size 2048x2048x2048 pixels
Max number of read image args 480
Max number of write image args 480
Max number of read/write image args 480
Pipe support Yes
Max number of pipe args 16
Max active pipe reservations 4095
Max pipe packet size 1024
Local memory type Global
Local memory size 262144 (256KiB)
Max number of constant args 480
Max constant buffer size 131072 (128KiB)
Generic address space support Yes
Max size of kernel argument 3840 (3.75KiB)
Queue properties (on host)
Out-of-order execution Yes
Profiling Yes
Local thread execution (Intel) Yes
Device enqueue capabilities supported, replaceable default queue
Queue properties (on device)
Out-of-order execution Yes
Profiling Yes
Preferred size 4294967295 (4GiB)
Max size 4294967295 (4GiB)
Max queues on device 4294967295
Max events on device 4294967295
Prefer user sync for interop No
Profiling timer resolution 1ns
Execution capabilities
Run OpenCL kernels Yes
Run native kernels Yes
Non-uniform work-groups Yes
Work-group collective functions Yes
Sub-group independent forward progress No
IL version SPIR-V_1.0 SPIR-V_1.1 SPIR-V_1.2 SPIR-V_1.3 SPIR-V_1.4
ILs with version SPIR-V 0x400000 (1.0.0)
SPIR-V 0x401000 (1.1.0)
SPIR-V 0x402000 (1.2.0)
SPIR-V 0x403000 (1.3.0)
SPIR-V 0x404000 (1.4.0)
SPIR versions 1.2
printf() buffer size 1048576 (1024KiB)
Built-in kernels (n/a)
Built-in kernels with version (n/a)
Device Extensions cl_khr_spirv_linkonce_odr cl_khr_fp64 cl_khr_fp16 cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_3d_image_writes cl_khr_byte_addressable_store cl_khr_depth_images cl_khr_extended_bit_ops cl_khr_icd cl_khr_il_program cl_khr_suggested_local_work_size cl_intel_unified_shared_memory cl_intel_devicelib_assert cl_khr_subgroup_ballot cl_khr_subgroup_shuffle cl_khr_subgroup_shuffle_relative cl_khr_subgroup_extended_types cl_khr_subgroup_non_uniform_arithmetic cl_khr_subgroup_non_uniform_vote cl_khr_subgroup_clustered_reduce cl_intel_subgroups cl_intel_subgroups_char cl_intel_subgroups_short cl_intel_subgroups_long cl_intel_required_subgroup_size cl_intel_spirv_subgroups cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_intel_device_attribute_query cl_intel_exec_by_local_thread cl_intel_vec_len_hint cl_intel_device_partition_by_names cl_khr_spir cl_khr_image2d_from_buffer cl_intel_concurrent_dispatch
Device Extensions with Version cl_khr_spirv_linkonce_odr 0x400000 (1.0.0)
cl_khr_fp64 0x400000 (1.0.0)
cl_khr_fp16 0x400000 (1.0.0)
cl_khr_global_int32_base_atomics 0x400000 (1.0.0)
cl_khr_global_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_local_int32_base_atomics 0x400000 (1.0.0)
cl_khr_local_int32_extended_atomics 0x400000 (1.0.0)
cl_khr_3d_image_writes 0x400000 (1.0.0)
cl_khr_byte_addressable_store 0x400000 (1.0.0)
cl_khr_depth_images 0x400000 (1.0.0)
cl_khr_extended_bit_ops 0x400000 (1.0.0)
cl_khr_icd 0x400000 (1.0.0)
cl_khr_il_program 0x400000 (1.0.0)
cl_khr_suggested_local_work_size 0x400000 (1.0.0)
cl_intel_unified_shared_memory 0x400000 (1.0.0)
cl_intel_devicelib_assert 0x400000 (1.0.0)
cl_khr_subgroup_ballot 0x400000 (1.0.0)
cl_khr_subgroup_shuffle 0x400000 (1.0.0)
cl_khr_subgroup_shuffle_relative 0x400000 (1.0.0)
cl_khr_subgroup_extended_types 0x400000 (1.0.0)
cl_khr_subgroup_non_uniform_arithmetic 0x400000 (1.0.0)
cl_khr_subgroup_non_uniform_vote 0x400000 (1.0.0)
cl_khr_subgroup_clustered_reduce 0x400000 (1.0.0)
cl_intel_subgroups 0x400000 (1.0.0)
cl_intel_subgroups_char 0x400000 (1.0.0)
cl_intel_subgroups_short 0x400000 (1.0.0)
cl_intel_subgroups_long 0x400000 (1.0.0)
cl_intel_required_subgroup_size 0x400000 (1.0.0)
cl_intel_spirv_subgroups 0x400000 (1.0.0)
cl_khr_int64_base_atomics 0x400000 (1.0.0)
cl_khr_int64_extended_atomics 0x400000 (1.0.0)
cl_intel_device_attribute_query 0x400000 (1.0.0)
cl_intel_exec_by_local_thread 0x400000 (1.0.0)
cl_intel_vec_len_hint 0x400000 (1.0.0)
cl_intel_device_partition_by_names 0x400000 (1.0.0)
cl_khr_spir 0x400000 (1.0.0)
cl_khr_image2d_from_buffer 0x400000 (1.0.0)
cl_intel_concurrent_dispatch 0x400000 (1.0.0)
NULL platform behavior
clGetPlatformInfo(NULL, CL_PLATFORM_NAME, ...) Portable Computing Language
clGetDeviceIDs(NULL, CL_DEVICE_TYPE_ALL, ...) Success [POCL]
clCreateContext(NULL, ...) [default] Success [POCL]
clCreateContext(NULL, ...) [other] Success [INTEL]
clCreateContextFromType(NULL, CL_DEVICE_TYPE_DEFAULT) Success (1)
Platform Name Portable Computing Language
Device Name cpu-cascadelake-Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz
clCreateContextFromType(NULL, CL_DEVICE_TYPE_CPU) Success (1)
Platform Name Portable Computing Language
Device Name cpu-cascadelake-Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz
clCreateContextFromType(NULL, CL_DEVICE_TYPE_GPU) Success (1)
Platform Name Portable Computing Language
Device Name NVIDIA GeForce RTX 2080 Ti
clCreateContextFromType(NULL, CL_DEVICE_TYPE_ACCELERATOR) No devices found in platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_CUSTOM) No devices found in platform
clCreateContextFromType(NULL, CL_DEVICE_TYPE_ALL) Success (2)
Platform Name Portable Computing Language
Device Name cpu-cascadelake-Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz
Device Name NVIDIA GeForce RTX 2080 Ti
ICD loader properties
ICD loader Name OpenCL ICD Loader
ICD loader Vendor OCL Icd free software
ICD loader Version 2.2.14
ICD loader Profile OpenCL 3.0
While this result is quite verbose, we can see that Platform 1 is Intel(R) OpenCL and Device 0 is Intel(R) Xeon(R) Gold 5218 CPU @ 2.30GHz. This is the platform and device index we are interested in to best match Gradescope.
Therefore, to reproduce the results that Gradescope has, we can execute PLATFORM_INDEX=1 DEVICE_INDEX=0 make run.