// SPDX-License-Identifier: BSD-3-Clause
/*
 * streams_events_probe.cu - instrumented victory_streams_events.
 *
 * Same 3-stream event chain (c0 = a0+b0; c1 = (a1+b1)+c0; c2 = (a2+b2)+c1)
 * but with per-buffer diagnostics: device pointers, per-buffer bad counts,
 * and the first 8 expected/actual values of every output so a stale-input
 * vs stale-readback failure is distinguishable in one run.
 *
 * Output lines:
 *   DEVICE ...
 *   DPTRS da0..dc2 (device), ha0..hc2 (host)
 *   BUF s=<n> bad=<n>
 *   FIRST s=<n> exp=<v0..v7> got=<v0..v7>
 *   STREAMS3 n=<count> bad=<mismatches>
 *   STATUS OK|FAIL
 */

#include <cstdio>
#include <cstdlib>
#include <cstdint>
#include <cuda_runtime.h>

#define CHECK(x)                                                         \
	do {                                                             \
		cudaError_t e_ = (x);                                    \
		if (e_ != cudaSuccess) {                                 \
			printf("CUDA_ERROR %s at line %d\n",             \
			       cudaGetErrorString(e_), __LINE__);        \
			printf("STATUS FAIL\n");                         \
			return 1;                                        \
		}                                                        \
	} while (0)

#define NSTREAMS 3

__global__ void vadd(const float *a, const float *b, float *c, int n)
{
	int i = blockIdx.x * blockDim.x + threadIdx.x;

	if (i < n)
		c[i] = a[i] + b[i];
}

__global__ void vadd_into(float *c, const float *s, int n)
{
	int i = blockIdx.x * blockDim.x + threadIdx.x;

	if (i < n)
		c[i] = c[i] + s[i];
}

int main(void)
{
	cudaDeviceProp prop;
	const int n = 1 << 16;
	size_t bytes = (size_t)n * sizeof(float);
	float *h_a[NSTREAMS], *h_b[NSTREAMS], *h_c[NSTREAMS];
	float *d_a[NSTREAMS], *d_b[NSTREAMS], *d_c[NSTREAMS];
	cudaStream_t st[NSTREAMS];
	cudaEvent_t ev[NSTREAMS], t0, t1;
	float ms = 0.0f;
	int bad = 0, i, s;
	const int grid = (n + 255) / 256;

	setvbuf(stdout, NULL, _IONBF, 0);

	CHECK(cudaGetDeviceProperties(&prop, 0));
	printf("DEVICE %s cc=%d.%d sm=%d mem=%llu\n", prop.name,
	       prop.major, prop.minor, prop.multiProcessorCount,
	       (unsigned long long)prop.totalGlobalMem);

	for (s = 0; s < NSTREAMS; s++) {
		h_a[s] = (float *)malloc(bytes);
		h_b[s] = (float *)malloc(bytes);
		h_c[s] = (float *)malloc(bytes);
		if (!h_a[s] || !h_b[s] || !h_c[s])
			return 1;
		for (i = 0; i < n; i++) {
			h_a[s][i] = (float)((i + s) % 1000) * 0.5f;
			h_b[s][i] = (float)((i + 2 * s) % 997) * 0.25f;
		}
		CHECK(cudaMalloc(&d_a[s], bytes));
		CHECK(cudaMalloc(&d_b[s], bytes));
		CHECK(cudaMalloc(&d_c[s], bytes));
		CHECK(cudaStreamCreate(&st[s]));
		CHECK(cudaEventCreate(&ev[s]));
	}
	CHECK(cudaEventCreate(&t0));
	CHECK(cudaEventCreate(&t1));

	printf("DPTRS");
	for (s = 0; s < NSTREAMS; s++)
		printf(" da%d=%p db%d=%p dc%d=%p", s, (void *)d_a[s], s,
		       (void *)d_b[s], s, (void *)d_c[s]);
	printf("\n");
	printf("HPTRS");
	for (s = 0; s < NSTREAMS; s++)
		printf(" ha%d=%p hb%d=%p hc%d=%p", s, (void *)h_a[s], s,
		       (void *)h_b[s], s, (void *)h_c[s]);
	printf("\n");

	CHECK(cudaEventRecord(t0));

	for (s = 0; s < NSTREAMS; s++) {
		CHECK(cudaMemcpyAsync(d_a[s], h_a[s], bytes,
				      cudaMemcpyHostToDevice, st[s]));
		CHECK(cudaMemcpyAsync(d_b[s], h_b[s], bytes,
				      cudaMemcpyHostToDevice, st[s]));
		vadd<<<grid, 256, 0, st[s]>>>(d_a[s], d_b[s], d_c[s], n);
		CHECK(cudaGetLastError());
		CHECK(cudaEventRecord(ev[s], st[s]));
	}

	CHECK(cudaStreamWaitEvent(st[1], ev[0], 0));
	vadd_into<<<grid, 256, 0, st[1]>>>(d_c[1], d_c[0], n);
	CHECK(cudaGetLastError());
	CHECK(cudaEventRecord(ev[1], st[1]));

	CHECK(cudaStreamWaitEvent(st[2], ev[1], 0));
	vadd_into<<<grid, 256, 0, st[2]>>>(d_c[2], d_c[1], n);
	CHECK(cudaGetLastError());

	for (s = 0; s < NSTREAMS; s++)
		CHECK(cudaMemcpyAsync(h_c[s], d_c[s], bytes,
				      cudaMemcpyDeviceToHost, st[s]));
	CHECK(cudaEventRecord(t1, st[2]));

	for (s = 0; s < NSTREAMS; s++)
		CHECK(cudaStreamSynchronize(st[s]));
	CHECK(cudaEventElapsedTime(&ms, t0, t1));

	for (s = 0; s < NSTREAMS; s++) {
		int b = 0;
		float exp0[8], got0[8];

		for (i = 0; i < n; i++) {
			float c0 = h_a[0][i] + h_b[0][i];
			float c1 = h_a[1][i] + h_b[1][i] + c0;
			float c2 = h_a[2][i] + h_b[2][i] + c1;
			float want = (s == 0) ? c0 : (s == 1) ? c1 : c2;

			if (i < 8) {
				exp0[i] = want;
				got0[i] = h_c[s][i];
			}
			if (h_c[s][i] != want)
				b++;
		}
		bad += b;
		printf("BUF s=%d bad=%d\n", s, b);
		printf("FIRST s=%d exp=", s);
		for (i = 0; i < 8; i++)
			printf("%.4f ", exp0[i]);
		printf(" got=");
		for (i = 0; i < 8; i++)
			printf("%.4f ", got0[i]);
		printf("\n");
	}

	printf("STREAMS3 n=%d bad=%d\n", n, bad);
	printf("TIMING ms=%.3f\n", ms);

	if (bad != 0) {
		printf("STATUS FAIL\n");
		return 1;
	}
	printf("STATUS OK\n");
	return 0;
}