Initial import of compiler-rt.

 -

llvm-svn: 74292

1 files changed, 41 insertions, 0 deletions

diff --git a/compiler-rt/lib/fixdfdi.c b/compiler-rt/lib/fixdfdi.c
new file mode 100644
index 00000000000..87368b7e5a0
--- /dev/null
+++ b/compiler-rt/lib/fixdfdi.c
@@ -0,0 +1,41 @@
+//===-- fixdfdi.c - Implement __fixdfdi -----------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __fixdfdi for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+
+// Returns: convert a to a signed long long, rounding toward zero.
+
+// Assumption: double is a IEEE 64 bit floating point type 
+//             su_int is a 32 bit integral type
+//             value in double is representable in di_int (no range checking performed)
+
+// seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
+
+di_int
+__fixdfdi(double a)
+{
+    double_bits fb;
+    fb.f = a;
+    int e = ((fb.u.high & 0x7FF00000) >> 20) - 1023;
+    if (e < 0)
+        return 0;
+    di_int s = (si_int)(fb.u.high & 0x80000000) >> 31;
+    dwords r;
+    r.high = (fb.u.high & 0x000FFFFF) | 0x00100000;
+    r.low = fb.u.low;
+    if (e > 52)
+        r.all <<= (e - 52);
+    else
+        r.all >>= (52 - e);
+    return (r.all ^ s) - s;
+}