From 53aa4fda49f94920139300227786ac47c393f1ce Mon Sep 17 00:00:00 2001 From: Alexey Samsonov Date: Fri, 14 Feb 2014 09:20:33 +0000 Subject: Move original compiler-rt functions (libgcc replacement) to lib/builtins directory git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@201393 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/builtins/floatunsidf.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 lib/builtins/floatunsidf.c (limited to 'lib/builtins/floatunsidf.c') diff --git a/lib/builtins/floatunsidf.c b/lib/builtins/floatunsidf.c new file mode 100644 index 000000000..ba6c2cfd2 --- /dev/null +++ b/lib/builtins/floatunsidf.c @@ -0,0 +1,41 @@ +//===-- lib/floatunsidf.c - uint -> 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 unsigned 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(ui2d, floatunsidf) + +fp_t __floatunsidf(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 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); +} -- cgit v1.2.3