1 files changed, 25 insertions, 0 deletions
diff --git a/src/test/java/com/seaofnodes/simple/progs/floatToInteger.c b/src/test/java/com/seaofnodes/simple/progs/floatToInteger.c
new file mode 100644
index 00000000..cf9390d8
--- /dev/null
+++ b/src/test/java/com/seaofnodes/simple/progs/floatToInteger.c
@@ -0,0 +1,25 @@
+#include <stdint.h>
+#include <math.h>
+#include <stdio.h>
+
+extern int64_t float_to_int(double);
+extern int64_t float_to_u8(double);
+
+int main(void) {
+    double values[] = {0.0,-0.0,6.92,-6.92,0.99,-0.99,255.75,-257.75,
+        0x1p63,0x1.fffffffffffffp62,-0x1p63,-0x1.0000000000001p63,
+        INFINITY,-INFINITY,NAN,-NAN};
+    for( unsigned i=0; i<sizeof(values)/sizeof(values[0]); i++ ) {
+        double x=values[i];
+        int64_t expected=isnan(x) ? 0 : x>=0x1p63 ? INT64_MAX
+            : x<=-0x1p63 ? INT64_MIN : (int64_t)x;
+        int64_t actual=float_to_int(x), narrow=float_to_u8(x);
+        if( actual!=expected || narrow!=(expected&255) ) {
+            fprintf(stderr,"conversion of %g: got %lld / %lld, expected %lld / %lld\n",
+                    x,(long long)actual,(long long)narrow,
+                    (long long)expected,(long long)(expected&255));
+            return 1;
+        }
+    }
+    return 0;
+}