add some code

managed_components/espressif__dl_fft/base/dl_fft_base.c

@@ -0,0 +1,92 @@
+#include "dl_fft_base.h"
+
+bool dl_is_power_of_two(int x)
+{
+    return (x != 0) && ((x & (x - 1)) == 0);
+}
+
+int dl_power_of_two(uint32_t n)
+{
+    int pos = 0;
+    if (n >= 1 << 16) {
+        n >>= 16;
+        pos += 16;
+    }
+    if (n >= 1 << 8) {
+        n >>= 8;
+        pos += 8;
+    }
+    if (n >= 1 << 4) {
+        n >>= 4;
+        pos += 4;
+    }
+    if (n >= 1 << 2) {
+        n >>= 2;
+        pos += 2;
+    }
+    if (n >= 1 << 1) {
+        pos += 1;
+    }
+    return pos;
+}
+
+float *dl_short_to_float(const int16_t *x, int len, int exponent, float *y)
+{
+    float scale = powf(2, exponent);
+    // printf("scale: %f\n", scale);
+    for (int i = 0; i < len; i++) {
+        y[i] = scale * x[i];
+    }
+    return y;
+}
+
+int16_t dl_array_max_q_s16(const int16_t *x, int size)
+{
+    int16_t max = 0;
+    for (int i = 1; i < size; i++) {
+        if (x[i] > max) {
+            max = x[i];
+        } else if (-x[i] > max) {
+            max = -x[i];
+        }
+    }
+
+    if (max == 0) {
+        return 1;
+    }
+
+    int16_t k = 2;
+    while (max > 1) {
+        k++;
+        max = max >> 1;
+    }
+
+    return k;
+}
+
+int dl_array_max_q_f32(const float *x, int size, float eps)
+{
+    float max = 0;
+    for (int i = 1; i < size; i++) {
+        if (x[i] > max) {
+            max = x[i];
+        } else if (-x[i] > max) {
+            max = -x[i];
+        }
+    }
+    int max_int = ceilf(max + eps);
+
+    return dl_power_of_two(max_int);
+}
+
+int dl_float_to_short(const float *x, int len, int16_t *y, int out_exponent)
+{
+    int exponent = out_exponent - dl_array_max_q_f32(x, len, 1e-8);
+    float scale = powf(2, exponent);
+
+    for (int i = 0; i < len; i++) {
+        y[i] = (int16_t)roundf(x[i] * scale);
+    }
+
+    return -exponent;
+}