mat

diff --git a/mat.c b/mat.c
new file mode 100644 (file)
index 0000000..41970a6
--- /dev/null
+++ b/mat.c
@@ -0,0 +1,155 @@
+#include"stdio.h"
+#include"stdlib.h"
+#include"stdint.h"
+#include"string.h"
+#include"assert.h"
+
+typedef struct buf_s buf_t;
+typedef struct mat_s mat_t;
+
+struct buf_s
+{
+       int  refs;
+       int  n;
+       int  data[0];
+};
+
+struct mat_s
+{
+       int    i;
+       int    j;
+       int    n;
+       buf_t* b;
+};
+
+buf_t* buf_alloc(int n)
+{
+       assert(n > 0);
+
+       buf_t* b = malloc(sizeof(buf_t) + sizeof(int) * n * n);
+       assert(b);
+
+       b->refs = 1;
+       b->n    = n;
+       return b;
+}
+
+void buf_free(buf_t* b)
+{
+       if (b && 0 == --b->refs)
+               free(b);
+}
+
+mat_t* mat_alloc(int i, int j, int n, buf_t* b)
+{
+       mat_t* m = malloc(sizeof(mat_t));
+       assert(m);
+
+       m->i = i;
+       m->j = j;
+       m->n = n;
+
+       if (!b) {
+               b = buf_alloc(n);
+               assert(b);
+       }
+       m->b = b;
+       return m;
+}
+
+void mat_free(mat_t* m)
+{
+       if (m) {
+               buf_free(m->b);
+               free(m);
+       }
+}
+
+void mat_mul(mat_t* m, mat_t* m0, mat_t* m1)
+{
+       assert(m0->n == m1->n);
+       assert(m->n  == m0->n);
+
+       assert(m0->b);
+       assert(m1->b);
+       assert(m->b);
+
+       int i;
+       int j;
+       int k;
+       int n = m->n;
+
+       for (i = 0; i < n; i++) {
+               for (j = 0; j < n; j++) {
+
+                       int sum = 0;
+                       for (k  = 0; k < n; k++) {
+
+                               int ik = (i + m0->i) * m0->b->n + (k + m0->j);
+                               int kj = (k + m1->i) * m1->b->n + (j + m1->j);
+
+                               sum += m0->b->data[ik] * m1->b->data[kj];
+                       }
+
+                       int ij  = (i + m->i) * m->b->n + (j + m->j);
+
+                       m->b->data[ij] = sum;
+               }
+       }
+}
+
+void mat_print(mat_t* m)
+{
+       assert(m && m->b);
+
+       int i;
+       int j;
+
+       printf("m: %p, i: %d, j: %d, n: %d, m->b->n: %d, m->b: %p\n",
+                       m, m->i, m->j, m->n, m->b->n, m->b);
+
+       for (i = 0; i < m->n; i++) {
+               for (j = 0; j < m->n; j++) {
+
+                       int ij = (i + m->i) * m->b->n + (j + m->j);
+
+                       printf("%8d ", m->b->data[ij]);
+               }
+               printf("\n");
+       }
+       printf("\n");
+}
+
+int main()
+{
+       int a[4] = {1, 2, 3, 4};
+
+       mat_t* m0 = mat_alloc(0, 0, 2, NULL); 
+       mat_t* m1 = mat_alloc(0, 0, 2, NULL);
+       mat_t* m  = mat_alloc(0, 0, 2, NULL);
+
+       memcpy(m0->b->data, a, sizeof(int) * 4);
+       memcpy(m1->b->data, a, sizeof(int) * 4);
+
+       mat_mul(m, m0, m1);
+
+       mat_print(m0);
+       mat_print(m1);
+       mat_print(m);
+       return 0;
+}
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