.file "libm_frexp_4.s"// Copyright (C) 2000, 2001, Intel Corporation// All rights reserved.//// Contributed 2/2/2000 by John Harrison, Ted Kubaska, Bob Norin, Shane Story,// and Ping Tak Peter Tang of the Computational Software Lab, Intel Corporation.//// Redistribution and use in source and binary forms, with or without// modification, are permitted provided that the following conditions are// met://// * Redistributions of source code must retain the above copyright// notice, this list of conditions and the following disclaimer.//// * Redistributions in binary form must reproduce the above copyright// notice, this list of conditions and the following disclaimer in the// documentation and/or other materials provided with the distribution.//// * The name of Intel Corporation may not be used to endorse or promote// products derived from this software without specific prior written// permission.//// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.//// Intel Corporation is the author of this code, and requests that all// problem reports or change requests be submitted to it directly at// http://developer.intel.com/opensource.//// History//==============================================================// 2/02/00: Initial version// 3/20/00: Improved speed// 6/01/00: Fixed bug when x a double-extended denormal// 12/08/00 Corrected label on .endp//// API//==============================================================// double frexp(double x, int* y)// double __libm_frexp_4(double x, int* y)//   where int* y is a 32-bit integer//// Overview of operation//==============================================================// break a floating point x number into fraction and an exponent// The fraction is returned as a double// The exponent is returned as an integer pointed to by y//    This is a true (not a biased exponent) but 0fffe is subtracted//    as a bias instead of 0xffff. This is because the fraction returned//    is between 0.5 and 1.0, not the expected IEEE range.//// The fraction is 0.5 <= fraction < 1.0//// Registers used//==============================================================//// general registers:// r14  exponent bias for x negative// r15  exponent bias for x positive// r16  signexp of x// r17  exponent mask// r18  exponent of x// r19  exponent result// r20  signexp of 2^64// r32  on input contains the 64-bit IEEE double that is in f8// r33  on input pointer to 32-bit integer for exponent//// predicate registers:// p6   set if x is Nan, zero, or infinity// p7   set if x negative// p8   set if x positive// p9   set if x double-extended denormal//// floating-point registers:// f8  input, output// f9  normalized x// f10 signexp for significand result for x positive// f11 signexp for significand result for x negative// f12 2^64#include "libm_support.h".align 32.global __libm_frexp_4#.section .text.proc  __libm_frexp_4#.align 32__libm_frexp_4:// Set signexp for significand result for x>0// If x is a NaN, zero, or infinity, return it.// Put 0 in the int pointer.// x NAN, ZERO, INFINITY?// Set signexp for significand result for x<0{ .mfi(p0)    mov         r15 = 0x0fffe(p0)    fclass.m.unc p6,p0 = f8, 0xe7(p0)    mov         r14 = 0x2fffe}// Form signexp of 2^64 in case x double-extended denormal// Save the normalized value of input in f9// The normalization also sets fault flags and takes faults if necessary{ .mfi(p0)    mov         r20 = 0x1003f(p0)    fnorm       f9 = f8        nop.i 999 ;;}// Move signexp for significand result for x>0 to FP reg// Form 2^64 in case x double-extended denormal{ .mmi(p0)    setf.exp    f10 = r15(p0)    setf.exp    f12 = r20        nop.i 999 ;;}// Move signexp for significand result for x<0 to FP reg// If x NAN, ZERO, INFINITY, set *y=0 as a 32-bit integer, and exit{ .mmb(p0)    setf.exp    f11 = r14(p6)    st4         [r33] = r0(p6)    br.ret.spnt b0 ;;}// Form exponent mask// p7 if x<0, else p8{ .mfi(p0)    mov         r17 = 0x1ffff(p0)    fcmp.lt.unc p7,p8 = f8,f0        nop.i 999 ;;}// Test for fnorm(x) denormal, means x double-extended denormal{ .mfi        nop.m 999(p0)    fclass.m.unc p9,p0 = f9, 0x0b        nop.i 999 ;;}// If x double-extended denormal add 64 to exponent bias for scaling// If x double-extended denormal multiply x * 2^64 which is normal{ .mfi(p9)    add         r15 = 64, r15(p9)    fmpy        f9 = f9, f12        nop.i 999 ;;}// true exponent stored to int pointer// the bias is treated as 0xfffe instead of// normal 0xffff because we want the significand// to be in the range <=0.5 sig < 1.0// Store the value of the exponent at the pointer in r33// If x>0 form significand result{ .mfi        nop.m 999(p8)    fmerge.se   f8 = f10,f9        nop.i 999  ;;}// Get signexp of normalized x// If x<0 form significand result{ .mfi(p0)    getf.exp    r16 = f9(p7)    fmerge.se   f8 = f11,f9        nop.i 999  ;;}// Get exp of normalized x// Subtract off bias to get true exponent of x{ .mmi(p0)    and         r18 = r17,r16 ;;(p0)    sub         r19 = r18,r15        nop.i 999  ;;}// Store int y as a 32-bit integer// Make the value a double{ .mfb(p0)    st4         [r33] = r19(p0)    fnorm.d     f8 = f8(p0)    br.ret.sptk b0 ;;}.endp __libm_frexp_4ASM_SIZE_DIRECTIVE(__libm_frexp_4)strong_alias(__libm_frexp_4, _GI___libm_frexp_4)