vadd_event

Vector Addition — Immediate Command List with Events

Note

SYCL is used to write this kernel, which is not a common practice. Please also have a look at the OpenCL kernel examples like image_scale.

The same vector addition workload as the vadd example, but driven by an immediate command list and events instead of explicit command queues. This demonstrates fine-grained dependency tracking: memory copies signal events, and the kernel launch waits on those events before executing.

What It Does

1. Discovers a GPU device and prints its basic & compute properties
2. Allocates host and device memory for two float32 vectors (256 MiB each)
3. Fills both vectors with random values
4. Loads a SPIR-V kernel (vector_add) that computes a[i] += b[i] in parallel
5. Creates an event pool with 3 events to express data-flow dependencies
6. Submits all work through a single immediate command list:
   • Two H→D copies, each signaling its own event
   • Kernel launch that waits on both copy events before executing
   • D→H copy that waits on the kernel event
7. Synchronizes via HostSynchronize on the immediate command list
8. Validates every element against the CPU reference

Key Difference from vadd

Aspect	vadd	vadd_event
Submission	3 separate command lists executed on a command queue	1 immediate command list
Synchronization	zeCommandQueueSynchronize	zeCommandListHostSynchronize
Dependencies	Implicit via command list ordering + barriers	Explicit via events (wait lists)

Run

go run main.go

Sample Output

===============  Device Basic Properties  ===============
Running on device: ID = 32103 , Name = Intel(R) Graphics @ 0.00 GHz.
=============== Device Compute Properties ===============
Max Group Size (X, Y, Z):    (1024, 1024, 1024)
Max Group Count (X, Y, Z):   (4294967295, 4294967295, 4294967295)
Max Total Group Size:        1024
Max Shared Local Memory:     65536
Num Subgroup Sizes:          3
Subgroup Sizes:              [8 16 32 0 0 0 0 0]
=============== Computation Configuration ===============
Group Size (X, Y, Z):        (1024, 1, 1)
Group Count:                 65536
Total Elements (N):          67108864
Buffer Size:                 256 MiB
===============    Calculation Results    ===============
GPU Execution Time:          51.768500 ms
GPU Throughput:              5.19 GiB/s
===============    Validation Results    ===============
CPU Execution Time:          38.237400 ms
CPU Throughput:              7.02 GiB/s
Test Passed!!!