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daedalus-fourier/tests/bench_h264_primitives.c
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claude-noether 989818c2e6 bench: H.264 primitive bench now measures both substrates + comparison table
Closes task #166 (re-measure R-bands on post-buffer-pool dispatch path).

Now that all H.264 hot-path primitives have QPU shaders and the
dispatch overhead has been hammered down (tasks #160 buffer pool,
#161 persistent command buffer), bench_h264_primitives no longer
measures one column.  Two passes — CPU NEON and QPU V3D7 compute —
with a side-by-side per-kernel comparison and ratio.

Headline result on hertz (Pi 5 V3D 7.1, 30 iters x 5 warmup):

  kernel             CPU ns/op  QPU ns/op  winner
  IDCT 4x4 luma          10.79       2.47  QPU 4.36x
  IDCT 8x8 luma          29.69       9.23  QPU 3.22x
  Deblock luma_v         17.58      10.21  QPU 1.72x
  Deblock luma_h         38.41       9.98  QPU 3.85x
  qpel mc20 (8x8)        28.24       9.66  QPU 2.92x
  qpel mc02 (8x8)        16.96      20.54  CPU 1.21x
  qpel mc22 (8x8)        71.58       9.64  QPU 7.43x

  1080p worst-case sum (IDCT4 + deblock luma + qpel mc22):
    CPU NEON only:  5.57 ms
    QPU only:       1.30 ms   (CPU/QPU sum ratio = 4.30x)

Reverses PR #10's verdict (which had CPU NEON 4x faster than QPU
for IDCT-only) — the buffer-pool + persistent-cmdbuf wins land
hard.  Only qpel mc02 still shows CPU ahead, marginally (single-
axis vertical filter, row-strided memory pattern unfriendly to the
WG layout — left as a follow-up for cycle-9-style targeted tuning).

Substrate decree (2026-05-23) stays in force as policy — these
numbers retroactively justify it.

Also tightens test_api_h264's startup recipe print: the stale
"(CPU)" / "(CPU, no QPU H shader yet)" / "(CPU, bS=4 set)" labels
next to deblock_lh, deblock_cv, deblock_ch and deblock_*_intra
are now wrong since PRs #28, #29, #35 (those kernels are on QPU).
2026-05-25 20:42:39 +02:00

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/* SPDX-License-Identifier: BSD-2-Clause */
/* CLOCK_MONOTONIC under -std=c11 -CMAKE_C_EXTENSIONS=OFF. */
#define _POSIX_C_SOURCE 200809L
/*
* bench_h264_primitives — latency baseline for the H.264 primitive
* library landed across PRs #9#35.
*
* Each kernel is exercised at a representative per-frame N for 1080p
* (8160 MBs); the per-kernel total + ns/op + ms/frame are reported,
* once per substrate (CPU NEON, QPU V3D7 compute). The QPU column
* appears only when the host has a usable Vulkan device. When both
* columns exist a CPU/QPU ratio is printed; that's the per-kernel
* data the QPU-substrate decree (2026-05-23) deliberately overrides
* but which is still useful to track over time as dispatch overhead
* shrinks (buffer pool, persistent cmdbuf, dmabuf import — tasks 160-162).
*
* NOT a ctest — produces wall-time numbers, doesn't pass/fail.
*
* Invoke: ./build/bench_h264_primitives [iters [warmup]]
* (default iters = 50, warmup = 5)
*/
#include "daedalus.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
static uint64_t xs64_state = 0xfeedface5a5a5a5aULL;
static uint64_t xs64(void) {
uint64_t x = xs64_state;
x ^= x << 13; x ^= x >> 7; x ^= x << 17;
return xs64_state = x;
}
static double now_ms(void) {
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return ts.tv_sec * 1000.0 + ts.tv_nsec / 1.0e6;
}
/* Per-1080p-frame counts (8160 MBs at 1920x1088). */
#define MBS_1080P 8160
/* Standard benchmark loop. fn() is called n times per iteration. */
typedef void (*bench_fn)(void);
static double bench_ns(const char *name, int iters, int warmup,
int ops_per_iter, bench_fn fn)
{
for (int i = 0; i < warmup; i++) fn();
double t0 = now_ms();
for (int i = 0; i < iters; i++) fn();
double t1 = now_ms();
double total_ms = (t1 - t0);
double ns_per_op = (total_ms * 1e6) / ((double) iters * ops_per_iter);
printf(" %-32s %10.2f ns/op (%d iters x %d ops)\n",
name, ns_per_op, iters, ops_per_iter);
return ns_per_op;
}
/* ---- Per-kernel scaffolding. Each section sets up the buffers +
* meta, then defines a static fn() that calls the corresponding
* dispatch with a representative N. The substrate is read from the
* global g_sub so the same fn() can be re-driven with CPU then QPU. */
static daedalus_ctx *ctx;
static daedalus_substrate g_sub = DAEDALUS_SUBSTRATE_CPU;
/* --- IDCT 4x4 luma: N = 16 blocks per MB. Bench with 1024 blocks
* per call (64 MBs worth). Per-MB the dispatch overhead is the
* same regardless of N — we want ns per block. */
static int16_t idct4_coeffs[1024 * 16];
static daedalus_h264_block_meta idct4_meta[1024];
static uint8_t idct_dst[64 * 4 * 16 * 16]; /* 64 MB-rows × ... */
static void bench_idct4(void) {
daedalus_dispatch_h264_idct4(ctx, g_sub,
idct_dst, 64*16, idct4_coeffs, 1024, idct4_meta);
}
/* --- IDCT 8x8 luma: 256 8x8 blocks per call. */
static int16_t idct8_coeffs[256 * 64];
static daedalus_h264_block_meta idct8_meta[256];
static void bench_idct8(void) {
daedalus_dispatch_h264_idct8(ctx, g_sub,
idct_dst, 64*16, idct8_coeffs, 256, idct8_meta);
}
/* --- Deblock luma_v (cycle 8 baseline; M3 path). */
static daedalus_h264_deblock_meta deblock_meta[256];
static uint8_t deblock_dst[256 * 16 * 16];
static void bench_deblock_v(void) {
daedalus_dispatch_h264_deblock_luma_v(ctx, g_sub,
deblock_dst, 16, 256, deblock_meta);
}
static void bench_deblock_h(void) {
daedalus_dispatch_h264_deblock_luma_h(ctx, g_sub,
deblock_dst, 16, 256, deblock_meta);
}
/* --- qpel mc20 + mc02 + mc22 (the H/V/HV anchors). */
static uint8_t qpel_src[256 * 16 * 16];
static uint8_t qpel_dst[256 * 16 * 16];
static daedalus_h264_qpel_meta qpel_meta[256];
static void bench_qpel_mc20(void) {
daedalus_dispatch_h264_qpel_mc20(ctx, g_sub,
qpel_dst, qpel_src, 16, 256, qpel_meta);
}
static void bench_qpel_mc02(void) {
daedalus_dispatch_h264_qpel_mc02(ctx, g_sub,
qpel_dst, qpel_src, 16, 256, qpel_meta);
}
static void bench_qpel_mc22(void) {
daedalus_dispatch_h264_qpel_mc22(ctx, g_sub,
qpel_dst, qpel_src, 16, 256, qpel_meta);
}
/* ---- One row of bench output:
* - kernel name + N
* - CPU ns/op
* - QPU ns/op (or "n/a" if Vulkan absent)
* - CPU/QPU ratio (>1 means QPU wins; <1 means CPU wins) */
struct row {
const char *name;
int n_per_call;
bench_fn fn;
double cpu_ns;
double qpu_ns; /* -1 if not measured */
int frame_n; /* count per 1080p frame */
};
static struct row rows[] = {
{"IDCT 4x4 luma", 1024, bench_idct4, 0, -1, MBS_1080P * 16},
{"IDCT 8x8 luma", 256, bench_idct8, 0, -1, MBS_1080P * 4},
{"Deblock luma_v", 256, bench_deblock_v, 0, -1, MBS_1080P * 4},
{"Deblock luma_h", 256, bench_deblock_h, 0, -1, MBS_1080P * 4},
{"qpel mc20 (8x8)", 256, bench_qpel_mc20, 0, -1, MBS_1080P * 4},
{"qpel mc02 (8x8)", 256, bench_qpel_mc02, 0, -1, MBS_1080P * 4},
{"qpel mc22 (8x8)", 256, bench_qpel_mc22, 0, -1, MBS_1080P * 4},
};
#define N_ROWS ((int)(sizeof(rows)/sizeof(rows[0])))
int main(int argc, char **argv)
{
int iters = argc > 1 ? atoi(argv[1]) : 50;
int warmup = argc > 2 ? atoi(argv[2]) : 5;
ctx = daedalus_ctx_create();
if (!ctx) {
fprintf(stderr, "ctx create failed (Vulkan?)\n");
return 1;
}
int has_qpu = daedalus_ctx_has_qpu(ctx);
/* Pre-fill all input buffers with random data so the NEON inner
* loops see realistic memory access patterns. */
for (size_t i = 0; i < sizeof(idct4_coeffs)/2; i++)
idct4_coeffs[i] = (int16_t)((int)(xs64() % 1024) - 512);
for (size_t i = 0; i < sizeof(idct8_coeffs)/2; i++)
idct8_coeffs[i] = (int16_t)((int)(xs64() % 1024) - 512);
for (size_t i = 0; i < sizeof(qpel_src); i++) qpel_src[i] = (uint8_t)(xs64() & 0xff);
/* IDCT meta. */
for (size_t i = 0; i < 1024; i++)
idct4_meta[i].dst_off = (uint32_t)((i / 16) * 64 + (i % 16) * 4);
for (size_t i = 0; i < 256; i++)
idct8_meta[i].dst_off = (uint32_t)((i / 8) * 64 + (i % 8) * 8);
/* Deblock meta: edge offsets within 256 16x16 tiles. */
for (size_t i = 0; i < 256; i++) {
deblock_meta[i].dst_off = (uint32_t)(i * 256 + 4 * 16);
deblock_meta[i].alpha = 30;
deblock_meta[i].beta = 10;
for (int s = 0; s < 4; s++) deblock_meta[i].tc0[s] = (int8_t)(s + 1);
}
/* qpel meta. */
for (size_t i = 0; i < 256; i++) {
qpel_meta[i].src_off = (uint32_t)(i * 256 + 3 * 16 + 3);
qpel_meta[i].dst_off = (uint32_t)(i * 256 + 3 * 16 + 3);
}
printf("bench_h264_primitives: %d iters (%d warmup)\n", iters, warmup);
printf(" ctx has_qpu=%d (CPU pass always runs; QPU pass skipped without Vulkan)\n\n", has_qpu);
/* Pass 1: CPU NEON. */
g_sub = DAEDALUS_SUBSTRATE_CPU;
printf("== CPU NEON ==\n");
for (int i = 0; i < N_ROWS; i++)
rows[i].cpu_ns = bench_ns(rows[i].name, iters, warmup, rows[i].n_per_call, rows[i].fn);
/* Pass 2: QPU compute (if available). */
if (has_qpu) {
g_sub = DAEDALUS_SUBSTRATE_QPU;
printf("\n== QPU V3D7 compute ==\n");
for (int i = 0; i < N_ROWS; i++)
rows[i].qpu_ns = bench_ns(rows[i].name, iters, warmup, rows[i].n_per_call, rows[i].fn);
}
/* Summary table — both substrates side by side. */
printf("\n== Per-kernel comparison ==\n");
printf(" %-24s %12s %12s %8s %7s\n",
"kernel", "CPU ns/op", "QPU ns/op", "winner", "ms/frame");
for (int i = 0; i < N_ROWS; i++) {
double cpu_ms = rows[i].cpu_ns * rows[i].frame_n / 1e6;
double qpu_ms = rows[i].qpu_ns > 0 ? rows[i].qpu_ns * rows[i].frame_n / 1e6 : -1;
const char *winner;
char ratio[16];
if (rows[i].qpu_ns <= 0) {
winner = "CPU"; /* QPU n/a */
snprintf(ratio, sizeof(ratio), "n/a");
} else if (rows[i].cpu_ns < rows[i].qpu_ns) {
winner = "CPU";
snprintf(ratio, sizeof(ratio), "%.2fx", rows[i].qpu_ns / rows[i].cpu_ns);
} else {
winner = "QPU";
snprintf(ratio, sizeof(ratio), "%.2fx", rows[i].cpu_ns / rows[i].qpu_ns);
}
char qpu_field[16];
if (rows[i].qpu_ns > 0) snprintf(qpu_field, sizeof(qpu_field), "%.2f", rows[i].qpu_ns);
else snprintf(qpu_field, sizeof(qpu_field), "n/a");
char ms_field[24];
if (qpu_ms > 0)
snprintf(ms_field, sizeof(ms_field), "%.2f/%.2f", cpu_ms, qpu_ms);
else
snprintf(ms_field, sizeof(ms_field), "%.2f/n/a", cpu_ms);
printf(" %-24s %12.2f %12s %3s %s %s\n",
rows[i].name, rows[i].cpu_ns, qpu_field, winner, ratio, ms_field);
}
/* Per-frame budget summary at 1080p (8160 MBs). */
double cpu_idct4 = rows[0].cpu_ns * MBS_1080P * 16 / 1e6;
double cpu_debl = (rows[2].cpu_ns + rows[3].cpu_ns) * MBS_1080P * 4 / 1e6;
double cpu_mc = rows[6].cpu_ns * MBS_1080P * 4 / 1e6; /* mc22 worst-case */
double cpu_sum = cpu_idct4 + cpu_debl + cpu_mc;
printf("\n== Projected 1080p worst-case (CPU NEON only) ==\n");
printf(" IDCT 4x4 + deblock luma + qpel mc22: %.2f ms (30fps deadline 33.33)\n", cpu_sum);
printf(" Margin: %+.2f ms\n", 33.33 - cpu_sum);
if (has_qpu) {
double qpu_idct4 = rows[0].qpu_ns * MBS_1080P * 16 / 1e6;
double qpu_debl = (rows[2].qpu_ns + rows[3].qpu_ns) * MBS_1080P * 4 / 1e6;
double qpu_mc = rows[6].qpu_ns * MBS_1080P * 4 / 1e6;
double qpu_sum = qpu_idct4 + qpu_debl + qpu_mc;
printf("\n== Projected 1080p worst-case (QPU V3D7 compute only) ==\n");
printf(" IDCT 4x4 + deblock luma + qpel mc22: %.2f ms (30fps deadline 33.33)\n", qpu_sum);
printf(" Margin: %+.2f ms\n", 33.33 - qpu_sum);
printf("\n CPU vs QPU sum ratio: %.2fx (>1 means QPU wins)\n",
qpu_sum > 0 ? cpu_sum / qpu_sum : 0.0);
}
printf("\n(NOT included: chroma deblock, chroma IDCT, intra prediction,\n");
printf(" CABAC/CAVLC entropy. These bench numbers are a budget LOWER\n");
printf(" bound; the real decode stack adds 20-40%% on top.\n");
printf(" Per-kernel substrate decisions belong in daedalus_core.c recipe\n");
printf(" table; the QPU substrate decree (2026-05-23) keeps everything\n");
printf(" on QPU regardless of these numbers as a policy choice.)\n");
daedalus_ctx_destroy(ctx);
return 0;
}