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author | Dimitry Andric <dim@FreeBSD.org> | 2015-01-07 19:55:37 +0000 |
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committer | Dimitry Andric <dim@FreeBSD.org> | 2015-01-07 19:55:37 +0000 |
commit | ca9211ecdede9bdedb812b2243a4abdb8dacd1b9 (patch) | |
tree | 9b19e801150082c33e9152275829a6ce90614b55 /lib/builtins/floatsidf.c | |
parent | 8ef50bf3d1c287b5013c3168de77a462dfce3495 (diff) | |
download | src-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/floatsidf.c')
-rw-r--r-- | lib/builtins/floatsidf.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/lib/builtins/floatsidf.c b/lib/builtins/floatsidf.c new file mode 100644 index 000000000000..1cf99b782a60 --- /dev/null +++ b/lib/builtins/floatsidf.c @@ -0,0 +1,53 @@ +//===-- lib/floatsidf.c - integer -> double-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 double-precision conversion for the +// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even +// mode. +// +//===----------------------------------------------------------------------===// + +#define DOUBLE_PRECISION +#include "fp_lib.h" + +#include "int_lib.h" + +ARM_EABI_FNALIAS(i2d, floatsidf) + +COMPILER_RT_ABI fp_t +__floatsidf(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; + if (a < 0) { + sign = signBit; + a = -a; + } + + // 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)(unsigned int)a << shift ^ implicitBit; + + // Insert the exponent + result += (rep_t)(exponent + exponentBias) << significandBits; + // Insert the sign bit and return + return fromRep(result | sign); +} |