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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>
800 lines
22 KiB
ArmAsm
800 lines
22 KiB
ArmAsm
.file "exp.s"
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// Copyright (c) 2000 - 2005, 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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// 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://www.intel.com/software/products/opensource/libraries/num.htm.
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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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// 3/07/00 exp(inf) = inf but now does NOT call error support
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// exp(-inf) = 0 but now does NOT call error support
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// 4/04/00 Unwind support added
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// 8/15/00 Bundle added after call to __libm_error_support to properly
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// set [the previously overwritten] GR_Parameter_RESULT.
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// 11/30/00 Reworked to shorten main path, widen main path to include all
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// args in normal range, and add quick exit for 0, nan, inf.
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// 12/05/00 Loaded constants earlier with setf to save 2 cycles.
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// 02/05/02 Corrected uninitialize predicate in POSSIBLE_UNDERFLOW path
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// 05/20/02 Cleaned up namespace and sf0 syntax
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// 09/07/02 Force inexact flag
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// 11/15/02 Split underflow path into zero/nonzero; eliminated fma in main path
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// 05/30/03 Set inexact flag on unmasked overflow/underflow
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// 03/31/05 Reformatted delimiters between data tables
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// API
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//==============================================================
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// double exp(double)
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// Overview of operation
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//==============================================================
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// Take the input x. w is "how many log2/128 in x?"
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// w = x * 128/log2
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// n = int(w)
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// x = n log2/128 + r + delta
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// n = 128M + index_1 + 2^4 index_2
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// x = M log2 + (log2/128) index_1 + (log2/8) index_2 + r + delta
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// exp(x) = 2^M 2^(index_1/128) 2^(index_2/8) exp(r) exp(delta)
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// Construct 2^M
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// Get 2^(index_1/128) from table_1;
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// Get 2^(index_2/8) from table_2;
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// Calculate exp(r) by 5th order polynomial
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// r = x - n (log2/128)_high
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// delta = - n (log2/128)_low
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// Calculate exp(delta) as 1 + delta
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// Special values
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//==============================================================
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// exp(+0) = 1.0
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// exp(-0) = 1.0
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// exp(+qnan) = +qnan
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// exp(-qnan) = -qnan
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// exp(+snan) = +qnan
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// exp(-snan) = -qnan
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// exp(-inf) = +0
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// exp(+inf) = +inf
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// Overflow and Underflow
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//=======================
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// exp(x) = largest double normal when
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// x = 709.7827 = 0x40862e42fefa39ef
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// exp(x) = smallest double normal when
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// x = -708.396 = 0xc086232bdd7abcd2
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// exp(x) = largest round-to-nearest single zero when
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// x = -745.1332 = 0xc0874910d52d3052
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// Registers used
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//==============================================================
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// Floating Point registers used:
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// f8, input, output
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// f6 -> f15, f32 -> f49
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// General registers used:
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// r14 -> r40
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// Predicate registers used:
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// p6 -> p15
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// Assembly macros
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//==============================================================
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rRshf = r14
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rAD_TB1 = r15
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rAD_T1 = r15
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rAD_TB2 = r16
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rAD_T2 = r16
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rAD_P = r17
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rN = r18
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rIndex_1 = r19
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rIndex_2_16 = r20
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rM = r21
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rBiased_M = r21
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rIndex_1_16 = r21
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rSig_inv_ln2 = r22
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rExp_bias = r23
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rExp_mask = r24
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rTmp = r25
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rRshf_2to56 = r26
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rGt_ln = r27
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rExp_2tom56 = r28
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GR_SAVE_B0 = r33
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GR_SAVE_PFS = r34
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GR_SAVE_GP = r35
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GR_SAVE_SP = r36
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GR_Parameter_X = r37
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GR_Parameter_Y = r38
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GR_Parameter_RESULT = r39
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GR_Parameter_TAG = r40
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FR_X = f10
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FR_Y = f1
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FR_RESULT = f8
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fRSHF_2TO56 = f6
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fINV_LN2_2TO63 = f7
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fW_2TO56_RSH = f9
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f2TOM56 = f11
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fP5 = f12
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fP54 = f12
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fP5432 = f12
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fP4 = f13
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fP3 = f14
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fP32 = f14
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fP2 = f15
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fP = f15
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fLn2_by_128_hi = f33
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fLn2_by_128_lo = f34
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fRSHF = f35
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fNfloat = f36
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fNormX = f37
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fR = f38
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fF = f39
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fRsq = f40
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f2M = f41
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fS1 = f42
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fT1 = f42
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fS2 = f43
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fT2 = f43
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fS = f43
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fWre_urm_f8 = f44
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fFtz_urm_f8 = f44
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fMIN_DBL_OFLOW_ARG = f45
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fMAX_DBL_ZERO_ARG = f46
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fMAX_DBL_NORM_ARG = f47
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fMIN_DBL_NORM_ARG = f48
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fGt_pln = f49
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fTmp = f49
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// Data tables
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//==============================================================
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RODATA
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.align 16
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// ************* DO NOT CHANGE ORDER OF THESE TABLES ********************
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// double-extended 1/ln(2)
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// 3fff b8aa 3b29 5c17 f0bb be87fed0691d3e88
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// 3fff b8aa 3b29 5c17 f0bc
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// For speed the significand will be loaded directly with a movl and setf.sig
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// and the exponent will be bias+63 instead of bias+0. Thus subsequent
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// computations need to scale appropriately.
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// The constant 128/ln(2) is needed for the computation of w. This is also
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// obtained by scaling the computations.
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//
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// Two shifting constants are loaded directly with movl and setf.d.
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// 1. fRSHF_2TO56 = 1.1000..00 * 2^(63-7)
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// This constant is added to x*1/ln2 to shift the integer part of
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// x*128/ln2 into the rightmost bits of the significand.
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// The result of this fma is fW_2TO56_RSH.
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// 2. fRSHF = 1.1000..00 * 2^(63)
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// This constant is subtracted from fW_2TO56_RSH * 2^(-56) to give
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// the integer part of w, n, as a floating-point number.
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// The result of this fms is fNfloat.
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LOCAL_OBJECT_START(exp_table_1)
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data8 0x40862e42fefa39f0 // smallest dbl overflow arg, +709.7827
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data8 0xc0874910d52d3052 // largest arg for rnd-to-nearest 0 result, -745.133
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data8 0x40862e42fefa39ef // largest dbl arg to give normal dbl result, +709.7827
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data8 0xc086232bdd7abcd2 // smallest dbl arg to give normal dbl result, -708.396
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data8 0xb17217f7d1cf79ab , 0x00003ff7 // ln2/128 hi
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data8 0xc9e3b39803f2f6af , 0x00003fb7 // ln2/128 lo
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//
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// Table 1 is 2^(index_1/128) where
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// index_1 goes from 0 to 15
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//
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data8 0x8000000000000000 , 0x00003FFF
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data8 0x80B1ED4FD999AB6C , 0x00003FFF
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data8 0x8164D1F3BC030773 , 0x00003FFF
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data8 0x8218AF4373FC25EC , 0x00003FFF
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data8 0x82CD8698AC2BA1D7 , 0x00003FFF
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data8 0x8383594EEFB6EE37 , 0x00003FFF
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data8 0x843A28C3ACDE4046 , 0x00003FFF
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data8 0x84F1F656379C1A29 , 0x00003FFF
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data8 0x85AAC367CC487B15 , 0x00003FFF
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data8 0x8664915B923FBA04 , 0x00003FFF
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data8 0x871F61969E8D1010 , 0x00003FFF
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data8 0x87DB357FF698D792 , 0x00003FFF
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data8 0x88980E8092DA8527 , 0x00003FFF
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data8 0x8955EE03618E5FDD , 0x00003FFF
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data8 0x8A14D575496EFD9A , 0x00003FFF
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data8 0x8AD4C6452C728924 , 0x00003FFF
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LOCAL_OBJECT_END(exp_table_1)
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// Table 2 is 2^(index_1/8) where
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// index_2 goes from 0 to 7
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LOCAL_OBJECT_START(exp_table_2)
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data8 0x8000000000000000 , 0x00003FFF
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data8 0x8B95C1E3EA8BD6E7 , 0x00003FFF
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data8 0x9837F0518DB8A96F , 0x00003FFF
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data8 0xA5FED6A9B15138EA , 0x00003FFF
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data8 0xB504F333F9DE6484 , 0x00003FFF
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data8 0xC5672A115506DADD , 0x00003FFF
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data8 0xD744FCCAD69D6AF4 , 0x00003FFF
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data8 0xEAC0C6E7DD24392F , 0x00003FFF
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LOCAL_OBJECT_END(exp_table_2)
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LOCAL_OBJECT_START(exp_p_table)
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data8 0x3f8111116da21757 //P5
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data8 0x3fa55555d787761c //P4
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data8 0x3fc5555555555414 //P3
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data8 0x3fdffffffffffd6a //P2
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LOCAL_OBJECT_END(exp_p_table)
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.section .text
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GLOBAL_IEEE754_ENTRY(exp)
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{ .mlx
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nop.m 0
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movl rSig_inv_ln2 = 0xb8aa3b295c17f0bc // significand of 1/ln2
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}
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{ .mlx
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addl rAD_TB1 = @ltoff(exp_table_1), gp
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movl rRshf_2to56 = 0x4768000000000000 // 1.10000 2^(63+56)
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}
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;;
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{ .mfi
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ld8 rAD_TB1 = [rAD_TB1]
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fclass.m p8,p0 = f8,0x07 // Test for x=0
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mov rExp_mask = 0x1ffff
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}
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{ .mfi
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mov rExp_bias = 0xffff
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fnorm.s1 fNormX = f8
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mov rExp_2tom56 = 0xffff-56
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}
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;;
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// Form two constants we need
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// 1/ln2 * 2^63 to compute w = x * 1/ln2 * 128
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// 1.1000..000 * 2^(63+63-7) to right shift int(w) into the significand
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{ .mfi
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setf.sig fINV_LN2_2TO63 = rSig_inv_ln2 // form 1/ln2 * 2^63
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fclass.m p9,p0 = f8,0x22 // Test for x=-inf
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nop.i 0
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}
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{ .mlx
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setf.d fRSHF_2TO56 = rRshf_2to56 // Form const 1.100 * 2^(63+56)
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movl rRshf = 0x43e8000000000000 // 1.10000 2^63 for right shift
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}
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;;
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{ .mfi
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ldfpd fMIN_DBL_OFLOW_ARG, fMAX_DBL_ZERO_ARG = [rAD_TB1],16
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fclass.m p10,p0 = f8,0x1e1 // Test for x=+inf, nan, NaT
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nop.i 0
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}
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{ .mfb
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setf.exp f2TOM56 = rExp_2tom56 // form 2^-56 for scaling Nfloat
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(p9) fma.d.s0 f8 = f0,f0,f0 // quick exit for x=-inf
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(p9) br.ret.spnt b0
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}
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;;
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{ .mfi
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ldfpd fMAX_DBL_NORM_ARG, fMIN_DBL_NORM_ARG = [rAD_TB1],16
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nop.f 0
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nop.i 0
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}
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{ .mfb
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setf.d fRSHF = rRshf // Form right shift const 1.100 * 2^63
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(p8) fma.d.s0 f8 = f1,f1,f0 // quick exit for x=0
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(p8) br.ret.spnt b0
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}
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;;
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{ .mfb
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ldfe fLn2_by_128_hi = [rAD_TB1],16
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(p10) fma.d.s0 f8 = f8,f8,f0 // Result if x=+inf, nan, NaT
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(p10) br.ret.spnt b0 // quick exit for x=+inf, nan, NaT
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}
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;;
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{ .mfi
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ldfe fLn2_by_128_lo = [rAD_TB1],16
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fcmp.eq.s0 p6,p0 = f8, f0 // Dummy to set D
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nop.i 0
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}
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;;
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// After that last load, rAD_TB1 points to the beginning of table 1
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// W = X * Inv_log2_by_128
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// By adding 1.10...0*2^63 we shift and get round_int(W) in significand.
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// We actually add 1.10...0*2^56 to X * Inv_log2 to do the same thing.
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{ .mfi
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nop.m 0
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fma.s1 fW_2TO56_RSH = fNormX, fINV_LN2_2TO63, fRSHF_2TO56
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nop.i 0
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}
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;;
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// Divide arguments into the following categories:
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// Certain Underflow p11 - -inf < x <= MAX_DBL_ZERO_ARG
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// Possible Underflow p13 - MAX_DBL_ZERO_ARG < x < MIN_DBL_NORM_ARG
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// Certain Safe - MIN_DBL_NORM_ARG <= x <= MAX_DBL_NORM_ARG
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// Possible Overflow p14 - MAX_DBL_NORM_ARG < x < MIN_DBL_OFLOW_ARG
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// Certain Overflow p15 - MIN_DBL_OFLOW_ARG <= x < +inf
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//
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// If the input is really a double arg, then there will never be
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// "Possible Overflow" arguments.
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//
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{ .mfi
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add rAD_TB2 = 0x100, rAD_TB1
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fcmp.ge.s1 p15,p0 = fNormX,fMIN_DBL_OFLOW_ARG
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nop.i 0
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}
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;;
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{ .mfi
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add rAD_P = 0x80, rAD_TB2
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fcmp.le.s1 p11,p0 = fNormX,fMAX_DBL_ZERO_ARG
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nop.i 0
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}
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;;
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{ .mfb
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ldfpd fP5, fP4 = [rAD_P] ,16
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fcmp.gt.s1 p14,p0 = fNormX,fMAX_DBL_NORM_ARG
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(p15) br.cond.spnt EXP_CERTAIN_OVERFLOW
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}
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;;
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// Nfloat = round_int(W)
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// The signficand of fW_2TO56_RSH contains the rounded integer part of W,
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// as a twos complement number in the lower bits (that is, it may be negative).
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// That twos complement number (called N) is put into rN.
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// Since fW_2TO56_RSH is scaled by 2^56, it must be multiplied by 2^-56
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// before the shift constant 1.10000 * 2^63 is subtracted to yield fNfloat.
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// Thus, fNfloat contains the floating point version of N
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{ .mfb
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ldfpd fP3, fP2 = [rAD_P]
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fms.s1 fNfloat = fW_2TO56_RSH, f2TOM56, fRSHF
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(p11) br.cond.spnt EXP_CERTAIN_UNDERFLOW
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}
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;;
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{ .mfi
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getf.sig rN = fW_2TO56_RSH
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nop.f 0
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nop.i 0
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}
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;;
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// rIndex_1 has index_1
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// rIndex_2_16 has index_2 * 16
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// rBiased_M has M
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// rIndex_1_16 has index_1 * 16
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// rM has true M
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// r = x - Nfloat * ln2_by_128_hi
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// f = 1 - Nfloat * ln2_by_128_lo
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{ .mfi
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and rIndex_1 = 0x0f, rN
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fnma.s1 fR = fNfloat, fLn2_by_128_hi, fNormX
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shr rM = rN, 0x7
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}
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{ .mfi
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and rIndex_2_16 = 0x70, rN
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fnma.s1 fF = fNfloat, fLn2_by_128_lo, f1
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nop.i 0
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}
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;;
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// rAD_T1 has address of T1
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// rAD_T2 has address if T2
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{ .mmi
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add rBiased_M = rExp_bias, rM
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add rAD_T2 = rAD_TB2, rIndex_2_16
|
|
shladd rAD_T1 = rIndex_1, 4, rAD_TB1
|
|
}
|
|
;;
|
|
|
|
// Create Scale = 2^M
|
|
{ .mmi
|
|
setf.exp f2M = rBiased_M
|
|
ldfe fT2 = [rAD_T2]
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
// Load T1 and T2
|
|
{ .mfi
|
|
ldfe fT1 = [rAD_T1]
|
|
fmpy.s0 fTmp = fLn2_by_128_lo, fLn2_by_128_lo // Force inexact
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fma.s1 fRsq = fR, fR, f0
|
|
nop.i 0
|
|
}
|
|
{ .mfi
|
|
nop.m 0
|
|
fma.s1 fP54 = fR, fP5, fP4
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fcmp.lt.s1 p13,p0 = fNormX,fMIN_DBL_NORM_ARG
|
|
nop.i 0
|
|
}
|
|
{ .mfi
|
|
nop.m 0
|
|
fma.s1 fP32 = fR, fP3, fP2
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fma.s1 fP5432 = fRsq, fP54, fP32
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fma.s1 fS1 = f2M,fT1,f0
|
|
nop.i 0
|
|
}
|
|
{ .mfi
|
|
nop.m 0
|
|
fma.s1 fS2 = fF,fT2,f0
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fma.s1 fP = fRsq, fP5432, fR
|
|
nop.i 0
|
|
}
|
|
{ .mfi
|
|
nop.m 0
|
|
fma.s1 fS = fS1,fS2,f0
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mbb
|
|
nop.m 0
|
|
(p13) br.cond.spnt EXP_POSSIBLE_UNDERFLOW
|
|
(p14) br.cond.spnt EXP_POSSIBLE_OVERFLOW
|
|
}
|
|
;;
|
|
|
|
{ .mfb
|
|
nop.m 0
|
|
fma.d.s0 f8 = fS, fP, fS
|
|
br.ret.sptk b0 // Normal path exit
|
|
}
|
|
;;
|
|
|
|
|
|
EXP_POSSIBLE_OVERFLOW:
|
|
|
|
// Here if fMAX_DBL_NORM_ARG < x < fMIN_DBL_OFLOW_ARG
|
|
// This cannot happen if input is a double, only if input higher precision.
|
|
// Overflow is a possibility, not a certainty.
|
|
|
|
// Recompute result using status field 2 with user's rounding mode,
|
|
// and wre set. If result is larger than largest double, then we have
|
|
// overflow
|
|
|
|
{ .mfi
|
|
mov rGt_ln = 0x103ff // Exponent for largest dbl + 1 ulp
|
|
fsetc.s2 0x7F,0x42 // Get user's round mode, set wre
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
setf.exp fGt_pln = rGt_ln // Create largest double + 1 ulp
|
|
fma.d.s2 fWre_urm_f8 = fS, fP, fS // Result with wre set
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fsetc.s2 0x7F,0x40 // Turn off wre in sf2
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fcmp.ge.s1 p6, p0 = fWre_urm_f8, fGt_pln // Test for overflow
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfb
|
|
nop.m 0
|
|
nop.f 0
|
|
(p6) br.cond.spnt EXP_CERTAIN_OVERFLOW // Branch if overflow
|
|
}
|
|
;;
|
|
|
|
{ .mfb
|
|
nop.m 0
|
|
fma.d.s0 f8 = fS, fP, fS
|
|
br.ret.sptk b0 // Exit if really no overflow
|
|
}
|
|
;;
|
|
|
|
EXP_CERTAIN_OVERFLOW:
|
|
{ .mmi
|
|
sub rTmp = rExp_mask, r0, 1
|
|
;;
|
|
setf.exp fTmp = rTmp
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
alloc r32=ar.pfs,1,4,4,0
|
|
fmerge.s FR_X = f8,f8
|
|
nop.i 0
|
|
}
|
|
{ .mfb
|
|
mov GR_Parameter_TAG = 14
|
|
fma.d.s0 FR_RESULT = fTmp, fTmp, fTmp // Set I,O and +INF result
|
|
br.cond.sptk __libm_error_region
|
|
}
|
|
;;
|
|
|
|
EXP_POSSIBLE_UNDERFLOW:
|
|
|
|
// Here if fMAX_DBL_ZERO_ARG < x < fMIN_DBL_NORM_ARG
|
|
// Underflow is a possibility, not a certainty
|
|
|
|
// We define an underflow when the answer with
|
|
// ftz set
|
|
// is zero (tiny numbers become zero)
|
|
|
|
// Notice (from below) that if we have an unlimited exponent range,
|
|
// then there is an extra machine number E between the largest denormal and
|
|
// the smallest normal.
|
|
|
|
// So if with unbounded exponent we round to E or below, then we are
|
|
// tiny and underflow has occurred.
|
|
|
|
// But notice that you can be in a situation where we are tiny, namely
|
|
// rounded to E, but when the exponent is bounded we round to smallest
|
|
// normal. So the answer can be the smallest normal with underflow.
|
|
|
|
// E
|
|
// -----+--------------------+--------------------+-----
|
|
// | | |
|
|
// 1.1...10 2^-3fff 1.1...11 2^-3fff 1.0...00 2^-3ffe
|
|
// 0.1...11 2^-3ffe (biased, 1)
|
|
// largest dn smallest normal
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fsetc.s2 0x7F,0x41 // Get user's round mode, set ftz
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fma.d.s2 fFtz_urm_f8 = fS, fP, fS // Result with ftz set
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fsetc.s2 0x7F,0x40 // Turn off ftz in sf2
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fcmp.eq.s1 p6, p7 = fFtz_urm_f8, f0 // Test for underflow
|
|
nop.i 0
|
|
}
|
|
{ .mfi
|
|
nop.m 0
|
|
fma.d.s0 f8 = fS, fP, fS // Compute result, set I, maybe U
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mbb
|
|
nop.m 0
|
|
(p6) br.cond.spnt EXP_UNDERFLOW_COMMON // Branch if really underflow
|
|
(p7) br.ret.sptk b0 // Exit if really no underflow
|
|
}
|
|
;;
|
|
|
|
EXP_CERTAIN_UNDERFLOW:
|
|
// Here if x < fMAX_DBL_ZERO_ARG
|
|
// Result will be zero (or smallest denorm if round to +inf) with I, U set
|
|
{ .mmi
|
|
mov rTmp = 1
|
|
;;
|
|
setf.exp fTmp = rTmp // Form small normal
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfi
|
|
nop.m 0
|
|
fmerge.se fTmp = fTmp, fLn2_by_128_lo // Small with signif lsb 1
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfb
|
|
nop.m 0
|
|
fma.d.s0 f8 = fTmp, fTmp, f0 // Set I,U, tiny (+0.0) result
|
|
br.cond.sptk EXP_UNDERFLOW_COMMON
|
|
}
|
|
;;
|
|
|
|
EXP_UNDERFLOW_COMMON:
|
|
// Determine if underflow result is zero or nonzero
|
|
{ .mfi
|
|
alloc r32=ar.pfs,1,4,4,0
|
|
fcmp.eq.s1 p6, p0 = f8, f0
|
|
nop.i 0
|
|
}
|
|
;;
|
|
|
|
{ .mfb
|
|
nop.m 0
|
|
fmerge.s FR_X = fNormX,fNormX
|
|
(p6) br.cond.spnt EXP_UNDERFLOW_ZERO
|
|
}
|
|
;;
|
|
|
|
EXP_UNDERFLOW_NONZERO:
|
|
// Here if x < fMIN_DBL_NORM_ARG and result nonzero;
|
|
// I, U are set
|
|
{ .mfb
|
|
mov GR_Parameter_TAG = 15
|
|
nop.f 0 // FR_RESULT already set
|
|
br.cond.sptk __libm_error_region
|
|
}
|
|
;;
|
|
|
|
EXP_UNDERFLOW_ZERO:
|
|
// Here if x < fMIN_DBL_NORM_ARG and result zero;
|
|
// I, U are set
|
|
{ .mfb
|
|
mov GR_Parameter_TAG = 15
|
|
nop.f 0 // FR_RESULT already set
|
|
br.cond.sptk __libm_error_region
|
|
}
|
|
;;
|
|
|
|
GLOBAL_IEEE754_END(exp)
|
|
libm_alias_double_other (__exp, exp)
|
|
#ifdef SHARED
|
|
.symver exp,exp@@GLIBC_2.29
|
|
.weak __exp_compat
|
|
.set __exp_compat,__exp
|
|
.symver __exp_compat,exp@GLIBC_2.2
|
|
#endif
|
|
|
|
|
|
LOCAL_LIBM_ENTRY(__libm_error_region)
|
|
.prologue
|
|
{ .mfi
|
|
add GR_Parameter_Y=-32,sp // Parameter 2 value
|
|
nop.f 0
|
|
.save ar.pfs,GR_SAVE_PFS
|
|
mov GR_SAVE_PFS=ar.pfs // Save ar.pfs
|
|
}
|
|
{ .mfi
|
|
.fframe 64
|
|
add sp=-64,sp // Create new stack
|
|
nop.f 0
|
|
mov GR_SAVE_GP=gp // Save gp
|
|
};;
|
|
{ .mmi
|
|
stfd [GR_Parameter_Y] = FR_Y,16 // STORE Parameter 2 on stack
|
|
add GR_Parameter_X = 16,sp // Parameter 1 address
|
|
.save b0, GR_SAVE_B0
|
|
mov GR_SAVE_B0=b0 // Save b0
|
|
};;
|
|
.body
|
|
{ .mib
|
|
stfd [GR_Parameter_X] = FR_X // STORE Parameter 1 on stack
|
|
add GR_Parameter_RESULT = 0,GR_Parameter_Y // Parameter 3 address
|
|
nop.b 0
|
|
}
|
|
{ .mib
|
|
stfd [GR_Parameter_Y] = FR_RESULT // STORE Parameter 3 on stack
|
|
add GR_Parameter_Y = -16,GR_Parameter_Y
|
|
br.call.sptk b0=__libm_error_support# // Call error handling function
|
|
};;
|
|
{ .mmi
|
|
add GR_Parameter_RESULT = 48,sp
|
|
nop.m 0
|
|
nop.i 0
|
|
};;
|
|
{ .mmi
|
|
ldfd f8 = [GR_Parameter_RESULT] // Get return result off stack
|
|
.restore sp
|
|
add sp = 64,sp // Restore stack pointer
|
|
mov b0 = GR_SAVE_B0 // Restore return address
|
|
};;
|
|
{ .mib
|
|
mov gp = GR_SAVE_GP // Restore gp
|
|
mov ar.pfs = GR_SAVE_PFS // Restore ar.pfs
|
|
br.ret.sptk b0 // Return
|
|
};;
|
|
|
|
LOCAL_LIBM_END(__libm_error_region)
|
|
.type __libm_error_support#,@function
|
|
.global __libm_error_support#
|