#include "test_framework.hpp" #include // LDS bank conflict test - stride-32 access pattern // Targets SQ_LDS_BANK_CONFLICT counter __global__ void lds_conflicts_kernel(float* output, const float* input) { __shared__ float shared_mem[1024]; int tid = threadIdx.x; int gid = blockIdx.x * blockDim.x + threadIdx.x; // Write with stride to cause bank conflicts // On AMD GPUs, LDS has 32 banks int write_idx = (tid * 32) % 1024; shared_mem[write_idx] = input[gid]; __syncthreads(); // Read with stride to cause bank conflicts int read_idx = (tid * 32 + 1) % 1024; float val = shared_mem[read_idx]; // Multiple rounds of conflicting access for (int i = 0; i < 10; i++) { write_idx = ((tid + i) * 32) % 1024; shared_mem[write_idx] = val * 1.01f; __syncthreads(); read_idx = ((tid + i + 1) * 32) % 1024; val = shared_mem[read_idx]; __syncthreads(); } output[gid] = val; } class LDSConflictsTest : public test_framework::TestBase { public: LDSConflictsTest() : TestBase("LDS Conflicts - Bank Conflicts") {} bool setup() override { size_ = 256 * 1024; // 256K elements // Allocate device memory d_input_ = hip_utils::allocateDeviceWithValue(size_, 1.0f); d_output_ = hip_utils::allocateDevice(size_); std::cout << " Array size: " << size_ << " elements" << std::endl; std::cout << " LDS size per block: 1024 floats (4 KB)" << std::endl; std::cout << " Access pattern: stride-32 (causes bank conflicts)" << std::endl; return true; } bool execute() override { dim3 block_size(256); dim3 grid_size(size_ / block_size.x); test_framework::KernelRunner runner("lds_conflicts_kernel", grid_size, block_size); runner.launch(lds_conflicts_kernel, d_output_, d_input_); return true; } void cleanup() override { hip_utils::freeDevice(d_input_); hip_utils::freeDevice(d_output_); } private: float* d_input_ = nullptr; float* d_output_ = nullptr; size_t size_; }; int main() { LDSConflictsTest test; return test.run(); }