diff options
Diffstat (limited to 'compiler-rt/lib/builtins/floatunditf.c')
-rw-r--r-- | compiler-rt/lib/builtins/floatunditf.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/compiler-rt/lib/builtins/floatunditf.c b/compiler-rt/lib/builtins/floatunditf.c new file mode 100644 index 000000000000..8d310851e179 --- /dev/null +++ b/compiler-rt/lib/builtins/floatunditf.c @@ -0,0 +1,40 @@ +//===-- lib/floatunditf.c - uint -> quad-precision conversion -----*- C -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file implements du_int 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 __floatunditf(du_int a) { + + const int aWidth = sizeof a * CHAR_BIT; + + // Handle zero as a special case to protect clz + if (a == 0) + return fromRep(0); + + // Exponent of (fp_t)a is the width of abs(a). + const int exponent = (aWidth - 1) - __builtin_clzll(a); + rep_t result; + + // Shift a into the significand field and clear the implicit bit. + const int shift = significandBits - exponent; + result = (rep_t)a << shift ^ implicitBit; + + // Insert the exponent + result += (rep_t)(exponent + exponentBias) << significandBits; + return fromRep(result); +} + +#endif |