Hexagon HVX (tests/tcg/hexagon) histogram test

Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>

tests/tcg/hexagon/hvx_histogram.c

@@ -0,0 +1,88 @@
+/*
+ *  Copyright(c) 2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include "hvx_histogram_row.h"
+
+const int vector_len = 128;
+const int width = 275;
+const int height = 20;
+const int stride = (width + vector_len - 1) & -vector_len;
+
+int err;
+
+static uint8_t input[height][stride] __attribute__((aligned(128))) = {
+#include "hvx_histogram_input.h"
+};
+
+static int result[256] __attribute__((aligned(128)));
+static int expect[256] __attribute__((aligned(128)));
+
+static void check(void)
+{
+    for (int i = 0; i < 256; i++) {
+        int res = result[i];
+        int exp = expect[i];
+        if (res != exp) {
+            printf("ERROR at %3d: 0x%04x != 0x%04x\n",
+                   i, res, exp);
+            err++;
+        }
+    }
+}
+
+static void ref_histogram(uint8_t *src, int stride, int width, int height,
+                          int *hist)
+{
+    for (int i = 0; i < 256; i++) {
+        hist[i] = 0;
+    }
+
+    for (int i = 0; i < height; i++) {
+        for (int j = 0; j < width; j++) {
+            hist[src[i * stride + j]]++;
+        }
+    }
+}
+
+static void hvx_histogram(uint8_t *src, int stride, int width, int height,
+                          int *hist)
+{
+    int n = 8192 / width;
+
+    for (int i = 0; i < 256; i++) {
+        hist[i] = 0;
+    }
+
+    for (int i = 0; i < height; i += n) {
+        int k = height - i > n ? n : height - i;
+        hvx_histogram_row(src, stride, width, k, hist);
+        src += n * stride;
+    }
+}
+
+int main()
+{
+    ref_histogram(&input[0][0], stride, width, height, expect);
+    hvx_histogram(&input[0][0], stride, width, height, result);
+    check();
+
+    puts(err ? "FAIL" : "PASS");
+    return err ? 1 : 0;
+}