DMIC: Add min/max, ceil divide, find number, and normalize utils

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>
iganakov · May 7, 2018 · ea5f722 · ea5f722
1 parent 8848856
commit ea5f722
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diff --git a/src/include/sof/math/numbers.h b/src/include/sof/math/numbers.h
@@ -33,6 +33,29 @@
 #ifndef NUMBERS_H
 #define NUMBERS_H
 
+#include <stdint.h>
+
+#define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+
 int gcd(int a, int b); /* Calculate greatest common divisor for a and b */
 
+/* Divide function that returns ceil() of quotient */
+int ceil_divide(int a, int b);
+
+/* Find indices of equal values in a vector of integer values */
+int find_equal_int16(int16_t idx[], int16_t vec[], int n, int vec_length,
+	int max_results);
+
+/* Return the smallest value found in a vector */
+int16_t find_min_int16(int16_t vec[], int vec_length);
+
+/* Return the largest absolute value found in a vector */
+int32_t find_max_abs_int32(int32_t vec[], int vec_length);
+
+/* Count the left shift amount to normalize a 32 bit signed integer value
+ * without causing overflow. Input value 0 will result to 31.
+ */
+int norm_int32(int32_t val);
+
 #endif /* NUMBERS_H */
diff --git a/src/math/numbers.c b/src/math/numbers.c
@@ -36,6 +36,7 @@
  */
 
 #include <sof/math/numbers.h>
+#include <sof/audio/format.h>
 
 int gcd(int a, int b)
 {
@@ -47,3 +48,98 @@ int gcd(int a, int b)
 	}
 	return a;
 }
+
+/* This is a divide function that returns ceil of the quotient.
+ * E.g. ceil_divide(9, 3) returns 3, ceil_divide(10, 3) returns 4.
+ */
+int ceil_divide(int a, int b)
+{
+	int c;
+
+	c = a / b;
+	if (c * b < a)
+		c++;
+
+	return c;
+}
+
+/* This function searches from vec[] (of length vec_length) integer values
+ * of n. The indexes to equal values is returned in idx[]. The function
+ * returns the number of found matches. The max_results should be set to
+ * 0 (or negative) or vec_length get all the matches. The max_result can be set
+ * to 1 to receive only the first match in ascending order. It avoids need
+ * for an array for idx.
+ */
+int find_equal_int16(int16_t idx[], int16_t vec[], int n, int vec_length,
+	int max_results)
+{
+	int nresults = 0;
+	int i;
+
+	for (i = 0; i < vec_length; i++) {
+		if (vec[i] == n) {
+			idx[nresults++] = i;
+			if (nresults == max_results)
+				break;
+		}
+	}
+
+	return nresults;
+}
+
+/* Return the smallest value found in the vector */
+int16_t find_min_int16(int16_t vec[], int vec_length)
+{
+	int i;
+	int min = vec[0];
+
+	for (i = 1; i < vec_length; i++)
+		min = (vec[i] < min) ? vec[i] : min;
+
+	return min;
+}
+
+/* Return the largest absolute value found in the vector. Note that
+ * smallest negative value need to be saturated to preset as int32_t.
+ */
+int32_t find_max_abs_int32(int32_t vec[], int vec_length)
+{
+	int i;
+	int64_t amax = (vec[0] > 0) ? vec[0] : -vec[0];
+
+	for (i = 1; i < vec_length; i++) {
+		amax = (vec[i] > amax) ? vec[i] : amax;
+		amax = (-vec[i] > amax) ? -vec[i] : amax;
+	}
+
+	return SATP_INT32(amax); /* Amax is always a positive value */
+}
+
+/* Count the left shift amount to normalize a 32 bit signed integer value
+ * without causing overflow. Input value 0 will result to 31.
+ */
+int norm_int32(int32_t val)
+{
+	int s;
+	int32_t n;
+
+	if (!val)
+		return 31;
+
+	if (val > 0) {
+		n = val << 1;
+		s = 0;
+		while (n > 0) {
+			n = n << 1;
+			s++;
+		}
+	} else {
+		n = val << 1;
+		s = 0;
+		while (n < 0) {
+			n = n << 1;
+			s++;
+		}
+	}
+	return s;
+}