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We stopped adding "Contributed by" or similar lines in sources in 2012 in favour of git logs and keeping the Contributors section of the glibc manual up to date. Removing these lines makes the license header a bit more consistent across files and also removes the possibility of error in attribution when license blocks or files are copied across since the contributed-by lines don't actually reflect reality in those cases. Move all "Contributed by" and similar lines (Written by, Test by, etc.) into a new file CONTRIBUTED-BY to retain record of these contributions. These contributors are also mentioned in manual/contrib.texi, so we just maintain this additional record as a courtesy to the earlier developers. The following scripts were used to filter a list of files to edit in place and to clean up the CONTRIBUTED-BY file respectively. These were not added to the glibc sources because they're not expected to be of any use in future given that this is a one time task: https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02 Reviewed-by: Carlos O'Donell <carlos@redhat.com>
198 lines
5.9 KiB
ArmAsm
198 lines
5.9 KiB
ArmAsm
.file "libm_frexp_4.s"
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// Copyright (C) 2000, 2001, Intel Corporation
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// All rights reserved.
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//
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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//
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// * Redistributions in binary form must reproduce the above copyright
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// notice, this list of conditions and the following disclaimer in the
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// documentation and/or other materials provided with the distribution.
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//
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// * The name of Intel Corporation may not be used to endorse or promote
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// products derived from this software without specific prior written
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// permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS
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// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
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// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
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// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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// Intel Corporation is the author of this code, and requests that all
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// problem reports or change requests be submitted to it directly at
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// http://developer.intel.com/opensource.
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//
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// History
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//==============================================================
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// 2/02/00: Initial version
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// 3/20/00: Improved speed
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// 6/01/00: Fixed bug when x a double-extended denormal
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// 12/08/00 Corrected label on .endp
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//
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// API
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//==============================================================
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// double frexp(double x, int* y)
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// double __libm_frexp_4(double x, int* y)
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// where int* y is a 32-bit integer
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//
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// Overview of operation
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//==============================================================
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// break a floating point x number into fraction and an exponent
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// The fraction is returned as a double
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// The exponent is returned as an integer pointed to by y
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// This is a true (not a biased exponent) but 0fffe is subtracted
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// as a bias instead of 0xffff. This is because the fraction returned
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// is between 0.5 and 1.0, not the expected IEEE range.
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//
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// The fraction is 0.5 <= fraction < 1.0
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//
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// Registers used
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//==============================================================
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//
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// general registers:
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// r14 exponent bias for x negative
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// r15 exponent bias for x positive
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// r16 signexp of x
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// r17 exponent mask
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// r18 exponent of x
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// r19 exponent result
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// r20 signexp of 2^64
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// r32 on input contains the 64-bit IEEE double that is in f8
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// r33 on input pointer to 32-bit integer for exponent
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//
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// predicate registers:
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// p6 set if x is Nan, zero, or infinity
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// p7 set if x negative
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// p8 set if x positive
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// p9 set if x double-extended denormal
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//
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// floating-point registers:
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// f8 input, output
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// f9 normalized x
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// f10 signexp for significand result for x positive
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// f11 signexp for significand result for x negative
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// f12 2^64
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#include "libm_support.h"
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.align 32
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.global __libm_frexp_4#
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.section .text
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.proc __libm_frexp_4#
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.align 32
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__libm_frexp_4:
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// Set signexp for significand result for x>0
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// If x is a NaN, zero, or infinity, return it.
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// Put 0 in the int pointer.
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// x NAN, ZERO, INFINITY?
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// Set signexp for significand result for x<0
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{ .mfi
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(p0) mov r15 = 0x0fffe
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(p0) fclass.m.unc p6,p0 = f8, 0xe7
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(p0) mov r14 = 0x2fffe
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}
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// Form signexp of 2^64 in case x double-extended denormal
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// Save the normalized value of input in f9
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// The normalization also sets fault flags and takes faults if necessary
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{ .mfi
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(p0) mov r20 = 0x1003f
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(p0) fnorm f9 = f8
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nop.i 999 ;;
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}
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// Move signexp for significand result for x>0 to FP reg
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// Form 2^64 in case x double-extended denormal
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{ .mmi
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(p0) setf.exp f10 = r15
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(p0) setf.exp f12 = r20
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nop.i 999 ;;
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}
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// Move signexp for significand result for x<0 to FP reg
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// If x NAN, ZERO, INFINITY, set *y=0 as a 32-bit integer, and exit
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{ .mmb
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(p0) setf.exp f11 = r14
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(p6) st4 [r33] = r0
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(p6) br.ret.spnt b0 ;;
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}
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// Form exponent mask
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// p7 if x<0, else p8
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{ .mfi
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(p0) mov r17 = 0x1ffff
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(p0) fcmp.lt.unc p7,p8 = f8,f0
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nop.i 999 ;;
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}
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// Test for fnorm(x) denormal, means x double-extended denormal
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{ .mfi
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nop.m 999
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(p0) fclass.m.unc p9,p0 = f9, 0x0b
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nop.i 999 ;;
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}
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// If x double-extended denormal add 64 to exponent bias for scaling
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// If x double-extended denormal multiply x * 2^64 which is normal
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{ .mfi
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(p9) add r15 = 64, r15
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(p9) fmpy f9 = f9, f12
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nop.i 999 ;;
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}
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// true exponent stored to int pointer
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// the bias is treated as 0xfffe instead of
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// normal 0xffff because we want the significand
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// to be in the range <=0.5 sig < 1.0
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// Store the value of the exponent at the pointer in r33
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// If x>0 form significand result
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{ .mfi
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nop.m 999
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(p8) fmerge.se f8 = f10,f9
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nop.i 999 ;;
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}
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// Get signexp of normalized x
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// If x<0 form significand result
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{ .mfi
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(p0) getf.exp r16 = f9
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(p7) fmerge.se f8 = f11,f9
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nop.i 999 ;;
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}
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// Get exp of normalized x
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// Subtract off bias to get true exponent of x
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{ .mmi
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(p0) and r18 = r17,r16 ;;
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(p0) sub r19 = r18,r15
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nop.i 999 ;;
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}
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// Store int y as a 32-bit integer
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// Make the value a double
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{ .mfb
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(p0) st4 [r33] = r19
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(p0) fnorm.d f8 = f8
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(p0) br.ret.sptk b0 ;;
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}
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.endp __libm_frexp_4
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ASM_SIZE_DIRECTIVE(__libm_frexp_4)
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strong_alias(__libm_frexp_4, _GI___libm_frexp_4)
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