From b6d4e2e3a87eb3c9a6dec0ad21d4c1dec545c137 Mon Sep 17 00:00:00 2001 From: Stephen Canon Date: Sat, 3 Jul 2010 00:56:03 +0000 Subject: Renamed unsigned->float routines to match GCC convention git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@107554 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/floatunsisf.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 lib/floatunsisf.c (limited to 'lib/floatunsisf.c') diff --git a/lib/floatunsisf.c b/lib/floatunsisf.c new file mode 100644 index 00000000..31c06443 --- /dev/null +++ b/lib/floatunsisf.c @@ -0,0 +1,45 @@ +//===-- lib/floatunsisf.c - uint -> single-precision conversion ---*- C -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements unsigned integer to single-precision conversion for the +// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even +// mode. +// +//===----------------------------------------------------------------------===// + +#define SINGLE_PRECISION +#include "fp_lib.h" + +fp_t __floatunsisf(unsigned 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_clz(a); + rep_t result; + + // Shift a into the significand field, rounding if it is a right-shift + if (exponent <= significandBits) { + const int shift = significandBits - exponent; + result = (rep_t)a << shift ^ implicitBit; + } else { + const int shift = exponent - significandBits; + result = (rep_t)a >> shift ^ implicitBit; + rep_t round = (rep_t)a << (typeWidth - shift); + if (round > signBit) result++; + if (round == signBit) result += result & 1; + } + + // Insert the exponent + result += (rep_t)(exponent + exponentBias) << significandBits; + return fromRep(result); +} -- cgit v1.2.3