Workaround for a problem in gcc-4.1.0 when used with -O2

diff --git a/lib/pathplan/route.c b/lib/pathplan/route.c
index 80892fdb648f15117a83a5a0358e6a0f71e0fc25..cdfc6411f98e82acec7f9e9d6139ab8084efb95f 100644 (file)
--- a/lib/pathplan/route.c
+++ b/lib/pathplan/route.c
@@ -262,7 +262,21 @@ static int mkspline(Ppoint_t * inps, int inpn, tna_t * tnas, Ppoint_t ev0,
        x[0] += dot(tnas[i].a[0], tmp);
        x[1] += dot(tnas[i].a[1], tmp);
     }
+#if 0
     det01 = c[0][0] * c[1][1] - c[1][0] * c[0][1];
+#else
+    /* workaround for problem with:
+     *         gcc (GCC) 4.1.0 20051212 (Red Hat 4.1.0-0.7)
+     *
+     * the problem is a NAN from the subtraction which 
+     * shows up as a SIGFPE a few lines down when
+     * det01 is used as the denominator in a division 
+     */
+    det01 = c[0][0] * c[1][1];
+    d01 = c[1][0] * c[0][1];
+    if (ABS(d01) > 1e-6)
+       det01 -= d01;
+#endif
     det0X = c[0][0] * x[1] - c[0][1] * x[0];
     detX1 = x[0] * c[1][1] - x[1] * c[0][1];
     if (ABS(det01) >= 1e-6) {