From b3a6901e66f55b35aa9e01bcb24134e6a65ea004 Mon Sep 17 00:00:00 2001
From: Daniel Dunbar <daniel@zuster.org>
Date: Fri, 26 Jun 2009 16:47:03 +0000
Subject: Initial import of compiler-rt.  -

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@74292 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/fixunsdfsi.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 lib/fixunsdfsi.c

(limited to 'lib/fixunsdfsi.c')

diff --git a/lib/fixunsdfsi.c b/lib/fixunsdfsi.c
new file mode 100644
index 000000000..383a35efe
--- /dev/null
+++ b/lib/fixunsdfsi.c
@@ -0,0 +1,39 @@
+//===-- fixunsdfsi.c - Implement __fixunsdfsi -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __fixunsdfsi for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "int_lib.h"
+
+// Returns: convert a to a unsigned int, rounding toward zero.
+//          Negative values all become 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 su_int or is negative 
+//                 (no range checking performed)
+
+// seee eeee eeee mmmm mmmm mmmm mmmm mmmm | mmmm mmmm mmmm mmmm mmmm mmmm mmmm mmmm
+
+su_int
+__fixunsdfsi(double a)
+{
+    double_bits fb;
+    fb.f = a;
+    int e = ((fb.u.high & 0x7FF00000) >> 20) - 1023;
+    if (e < 0 || (fb.u.high & 0x80000000))
+        return 0;
+    return (
+                0x80000000u                      |
+                ((fb.u.high & 0x000FFFFF) << 11) |
+                (fb.u.low >> 21)
+           ) >> (31 - e);
+}
-- 
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