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authorDaniel Dunbar <daniel@zuster.org>2009-06-26 16:47:03 +0000
committerDaniel Dunbar <daniel@zuster.org>2009-06-26 16:47:03 +0000
commitb3a6901e66f55b35aa9e01bcb24134e6a65ea004 (patch)
tree4d57d73575ea3f7e30bf430920d6e96fa2a369c1 /lib/fixxfti.c
parent8cbe163cba77c772621f89ddb33793ac170b1fa2 (diff)
downloadcompiler-rt-b3a6901e66f55b35aa9e01bcb24134e6a65ea004.tar.gz
Initial import of compiler-rt.
- git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@74292 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/fixxfti.c')
-rw-r--r--lib/fixxfti.c44
1 files changed, 44 insertions, 0 deletions
diff --git a/lib/fixxfti.c b/lib/fixxfti.c
new file mode 100644
index 000000000..d9cb3eaf0
--- /dev/null
+++ b/lib/fixxfti.c
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+//===-- fixxfti.c - Implement __fixxfti -----------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements __fixxfti for the compiler_rt library.
+//
+//===----------------------------------------------------------------------===//
+
+#if __x86_64
+
+#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 ti_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
+
+ti_int
+__fixxfti(long double a)
+{
+ long_double_bits fb;
+ fb.f = a;
+ int e = (fb.u.high.low & 0x00007FFF) - 16383;
+ if (e < 0)
+ return 0;
+ ti_int s = -(si_int)((fb.u.high.low & 0x00008000) >> 15);
+ ti_int r = fb.u.low.all;
+ if (e > 63)
+ r <<= (e - 63);
+ else
+ r >>= (63 - e);
+ return (r ^ s) - s;
+}
+
+#endif