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authorDimitry Andric <dim@FreeBSD.org>2015-01-07 19:55:37 +0000
committerDimitry Andric <dim@FreeBSD.org>2015-01-07 19:55:37 +0000
commitca9211ecdede9bdedb812b2243a4abdb8dacd1b9 (patch)
tree9b19e801150082c33e9152275829a6ce90614b55 /lib/builtins/floatsitf.c
parent8ef50bf3d1c287b5013c3168de77a462dfce3495 (diff)
downloadsrc-ca9211ecdede9bdedb812b2243a4abdb8dacd1b9.tar.gz
src-ca9211ecdede9bdedb812b2243a4abdb8dacd1b9.zip
Import compiler-rt trunk r224034.vendor/compiler-rt/compiler-rt-r224034
Notes
Notes: svn path=/vendor/compiler-rt/dist/; revision=276789 svn path=/vendor/compiler-rt/compiler-rt-r224034/; revision=276790; tag=vendor/compiler-rt/compiler-rt-r224034
Diffstat (limited to 'lib/builtins/floatsitf.c')
-rw-r--r--lib/builtins/floatsitf.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/lib/builtins/floatsitf.c b/lib/builtins/floatsitf.c
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+//===-- lib/floatsitf.c - integer -> quad-precision conversion ----*- C -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements integer to quad-precision conversion for the
+// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
+// mode.
+//
+//===----------------------------------------------------------------------===//
+
+#define QUAD_PRECISION
+#include "fp_lib.h"
+
+#if defined(CRT_HAS_128BIT) && defined(CRT_LDBL_128BIT)
+COMPILER_RT_ABI fp_t __floatsitf(int a) {
+
+ const int aWidth = sizeof a * CHAR_BIT;
+
+ // Handle zero as a special case to protect clz
+ if (a == 0)
+ return fromRep(0);
+
+ // All other cases begin by extracting the sign and absolute value of a
+ rep_t sign = 0;
+ unsigned aAbs = (unsigned)a;
+ if (a < 0) {
+ sign = signBit;
+ aAbs += 0x80000000;
+ }
+
+ // Exponent of (fp_t)a is the width of abs(a).
+ const int exponent = (aWidth - 1) - __builtin_clz(a);
+ rep_t result;
+
+ // Shift a into the significand field and clear the implicit bit. Extra
+ // cast to unsigned int is necessary to get the correct behavior for
+ // the input INT_MIN.
+ const int shift = significandBits - exponent;
+ result = (rep_t)aAbs << shift ^ implicitBit;
+
+ // Insert the exponent
+ result += (rep_t)(exponent + exponentBias) << significandBits;
+ // Insert the sign bit and return
+ return fromRep(result | sign);
+}
+
+#endif