summaryrefslogtreecommitdiff
path: root/lib/fixxfdi.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/fixxfdi.c')
-rw-r--r--lib/fixxfdi.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/lib/fixxfdi.c b/lib/fixxfdi.c
new file mode 100644
index 000000000..2a7d20814
--- /dev/null
+++ b/lib/fixxfdi.c
@@ -0,0 +1,41 @@
+//===-- fixxfdi.c - Implement __fixxfdi -----------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __fixxfdi for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#if !_ARCH_PPC
+
+#include "int_lib.h"
+
+// Returns: convert a to a signed long long, rounding toward zero.
+
+// Assumption: long double is an intel 80 bit floating point type padded with 6 bytes
+// su_int is a 32 bit integral type
+// value in long double is representable in di_int (no range checking performed)
+
+// gggg gggg gggg gggg gggg gggg gggg gggg | gggg gggg gggg gggg seee eeee eeee eeee |
+// 1mmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
+
+di_int
+__fixxfdi(long double a)
+{
+ long_double_bits fb;
+ fb.f = a;
+ int e = (fb.u.high.low & 0x00007FFF) - 16383;
+ if (e < 0)
+ return 0;
+ di_int s = -(si_int)((fb.u.high.low & 0x00008000) >> 15);
+ di_int r = fb.u.low.all;
+ r = (du_int)r >> (63 - e);
+ return (r ^ s) - s;
+}
+
+#endif