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authorGravatar xleroy <xleroy@fca1b0fc-160b-0410-b1d3-a4f43f01ea2e>2010-02-17 13:24:48 +0000
committerGravatar xleroy <xleroy@fca1b0fc-160b-0410-b1d3-a4f43f01ea2e>2010-02-17 13:24:48 +0000
commit6f3a9afdda5c02dc84522fc8604addb7e5c8d7df (patch)
tree9b73d1072a2bd168ca04a7441a91d0b341ea0c0f /test/cminor/mainfft.c
parentf6bdc196c093d413c900e38e894682b7b70d4483 (diff)
Moved test harness C files here
git-svn-id: https://yquem.inria.fr/compcert/svn/compcert/trunk@1251 fca1b0fc-160b-0410-b1d3-a4f43f01ea2e
Diffstat (limited to 'test/cminor/mainfft.c')
-rw-r--r--test/cminor/mainfft.c72
1 files changed, 72 insertions, 0 deletions
diff --git a/test/cminor/mainfft.c b/test/cminor/mainfft.c
new file mode 100644
index 0000000..ce75062
--- /dev/null
+++ b/test/cminor/mainfft.c
@@ -0,0 +1,72 @@
+#undef DEBUG
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define PI 3.14159265358979323846
+
+extern void dfft(double * xr, double * xi, int np);
+
+double * xr, * xi;
+
+#ifdef DEBUG
+void trace()
+{
+ int i;
+ for (i=0; i<=15; i++) printf("%d %g %g\n",i,xr[i],xi[i]);
+ printf("-----------\n");
+}
+void print_int(int n) { printf("%d\n", n); }
+void print_float(double x) { printf("%g\n", x); }
+#endif
+
+int main(int argc, char ** argv)
+{
+ int n, np, npm, n2, i, j;
+ double enp, t, y, z, zr, zi, zm, a;
+ double * pxr, * pxi;
+
+ if (argc >= 2) n = atoi(argv[1]); else n = 12;
+ np = 1 << n;
+ enp = np;
+ npm = np / 2 - 1;
+ t = PI / enp;
+ xr = calloc(np, sizeof(double));
+ xi = calloc(np, sizeof(double));
+ pxr = xr;
+ pxi = xi;
+ *pxr = (enp - 1.0) * 0.5;
+ *pxi = 0.0;
+ n2 = np / 2;
+ *(pxr+n2) = -0.5;
+ *(pxi+n2) = 0.0;
+ for (i = 1; i <= npm; i++) {
+ j = np - i;
+ *(pxr+i) = -0.5;
+ *(pxr+j) = -0.5;
+ z = t * (double)i;
+ y = -0.5*(cos(z)/sin(z));
+ *(pxi+i) = y;
+ *(pxi+j) = -y;
+ }
+#ifdef DEBUG
+ trace();
+#endif
+ dfft(xr,xi,np);
+#ifdef DEBUG
+ trace();
+#endif
+ zr = 0.0;
+ zi = 0.0;
+ npm = np-1;
+ for (i = 0; i <= npm; i++ ) {
+ a = fabs(pxr[i] - i);
+ if (zr < a) zr = a;
+ a = fabs(pxi[i]);
+ if (zi < a) zi = a;
+ }
+ zm = zr;
+ if (zr < zi) zm = zi;
+ printf("%d points, error %g\n", np, zm);
+ return 0;
+}