add likely reproducer for flame/blis#514

recipe/debug_blis.c

@@ -0,0 +1,36 @@
+#include <blis.h>
+
+#include <assert.h>
+#include <math.h>
+
+int main(int argc, char** argv)
+{
+    double M[5][3] = {{ 0, 1, 2},
+                      { 3, 4, 5},
+                      { 6, 7, 8},
+                      { 9,10,11},
+                      {12,13,14}};
+    double C[5][5];
+    int m = 5, n = 5, k = 3;
+    double one = 1.0, zero = 0.0;
+
+    for (int i = 0;i < m;i++)
+    for (int j = 0;j < n;j++)
+        C[i][j] = NAN;
+
+    bli_dgemm(BLIS_NO_TRANSPOSE, BLIS_TRANSPOSE, m, n, k,
+               &one, &M[0][0], 3, 1,
+                     &M[0][0], 3, 1,
+              &zero, &C[0][0], 5, 1);
+
+    for (int i = 0;i < m;i++)
+    for (int j = 0;j < n;j++)
+    {
+        double ref = 0;
+        for (int p = 0;p < k;p++)
+            ref += M[i][p]*M[j][p];
+        assert(fabs(ref - C[i][j]) < 1e-14);
+    }
+
+    return 0;
+}