aboutsummaryrefslogtreecommitdiff
path: root/lib/fixsfti.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/fixsfti.c')
-rw-r--r--lib/fixsfti.c45
1 files changed, 45 insertions, 0 deletions
diff --git a/lib/fixsfti.c b/lib/fixsfti.c
new file mode 100644
index 000000000000..95992fe3f48e
--- /dev/null
+++ b/lib/fixsfti.c
@@ -0,0 +1,45 @@
+/* ===-- fixsfti.c - Implement __fixsfti -----------------------------------===
+ *
+ * The LLVM Compiler Infrastructure
+ *
+ * This file is distributed under the University of Illinois Open Source
+ * License. See LICENSE.TXT for details.
+ *
+ * ===----------------------------------------------------------------------===
+ *
+ * This file implements __fixsfti for the compiler_rt library.
+ *
+ * ===----------------------------------------------------------------------===
+ */
+
+#if __x86_64
+
+#include "int_lib.h"
+
+/* Returns: convert a to a signed long long, rounding toward zero. */
+
+/* Assumption: float is a IEEE 32 bit floating point type
+ * su_int is a 32 bit integral type
+ * value in float is representable in ti_int (no range checking performed)
+ */
+
+/* seee eeee emmm mmmm mmmm mmmm mmmm mmmm */
+
+ti_int
+__fixsfti(float a)
+{
+ float_bits fb;
+ fb.f = a;
+ int e = ((fb.u & 0x7F800000) >> 23) - 127;
+ if (e < 0)
+ return 0;
+ ti_int s = (si_int)(fb.u & 0x80000000) >> 31;
+ ti_int r = (fb.u & 0x007FFFFF) | 0x00800000;
+ if (e > 23)
+ r <<= (e - 23);
+ else
+ r >>= (23 - e);
+ return (r ^ s) - s;
+}
+
+#endif