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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>
450 lines
11 KiB
ArmAsm
450 lines
11 KiB
ArmAsm
.file "libm_scalblnf.s"
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// Copyright (c) 2001 - 2003, 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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// 08/03/01 Initial version
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// 08/23/01 Corrected error tag number
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// 02/06/02 Corrected to handle 32- or 64-bit integers
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// 05/20/02 Cleaned up namespace and sf0 syntax
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// 02/10/03 Reordered header: .section, .global, .proc, .align
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// 08/25/03 Improved performance
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//
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// API
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//==============================================================
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// float __libm_scalblnf (float x, long int n, int long_int_type)
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// input floating point f8 and long int n (r33)
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// input long_int_type = 0 if long int defined as 32 bits, = 1 if 64 bits
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// output floating point f8
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//
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// Returns x* 2**n using an fma and detects overflow
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// and underflow.
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//
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//
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// Strategy:
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// Compute biased exponent of result exp_Result = N + exp_X
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// Break into ranges:
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// exp_Result > 0x1007e -> Certain overflow
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// exp_Result = 0x1007e -> Possible overflow
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// 0x0ff81 <= exp_Result < 0x1007e -> No over/underflow (main path)
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// 0x0ff81 - 23 <= exp_Result < 0x0ff81 -> Possible underflow
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// exp_Result < 0x0ff81 - 23 -> Certain underflow
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FR_Big = f6
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FR_NBig = f7
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FR_Floating_X = f8
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FR_Result = f8
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FR_Result2 = f9
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FR_Result3 = f10
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FR_Norm_X = f11
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FR_Two_N = f12
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GR_neg_ov_limit= r14
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GR_N_Biased = r15
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GR_Big = r16
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GR_NBig = r17
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GR_exp_Result = r18
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GR_pos_ov_limit= r19
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GR_Bias = r20
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GR_N_as_int = r21
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GR_signexp_X = r22
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GR_exp_X = r23
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GR_exp_mask = r24
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GR_max_exp = r25
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GR_min_exp = r26
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GR_min_den_exp = r27
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GR_SAVE_B0 = r32
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GR_SAVE_GP = r33
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GR_SAVE_PFS = r34
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GR_Parameter_X = r35
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GR_Parameter_Y = r36
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GR_Parameter_RESULT = r37
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GR_Tag = r38
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.section .text
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GLOBAL_LIBM_ENTRY(__libm_scalblnf)
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//
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// Is x NAN, INF, ZERO, +-?
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// Build the exponent Bias
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//
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{ .mfi
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getf.exp GR_signexp_X = FR_Floating_X // Get signexp of x
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fclass.m p6,p0 = FR_Floating_X, 0xe7 // @snan | @qnan | @inf | @zero
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mov GR_Bias = 0x0ffff
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}
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//
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// Normalize x
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// Is long integer type 32 bits?
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//
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{ .mfi
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mov GR_Big = 35000 // If N this big then certain overflow
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fnorm.s1 FR_Norm_X = FR_Floating_X
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cmp.eq p8,p9 = r34,r0
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}
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;;
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// Sign extend N if long int is 32 bits
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{ .mfi
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(p9) mov GR_N_as_int = r33 // Copy N if long int is 64 bits
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fclass.m p9,p0 = FR_Floating_X, 0x0b // Test for x=unorm
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(p8) sxt4 GR_N_as_int = r33 // Sign extend N if long int is 32 bits
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}
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{ .mfi
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mov GR_NBig = -35000 // If N this small then certain underflow
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nop.f 0
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mov GR_max_exp = 0x1007e // Exponent of maximum float
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}
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;;
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// Create biased exponent for 2**N
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{ .mfi
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add GR_N_Biased = GR_Bias,GR_N_as_int
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nop.f 0
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cmp.ge p7, p0 = GR_N_as_int, GR_Big // Certain overflow?
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}
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{ .mib
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cmp.le p8, p0 = GR_N_as_int, GR_NBig // Certain underflow?
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mov GR_min_exp = 0x0ff81 // Exponent of minimum float
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(p9) br.cond.spnt SCALBNF_UNORM // Branch if x=unorm
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}
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;;
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SCALBNF_COMMON:
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// Main path continues. Also return here from x=unorm path.
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// Create 2**N
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.pred.rel "mutex",p7,p8
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{ .mfi
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setf.exp FR_Two_N = GR_N_Biased
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nop.f 0
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(p7) mov GR_N_as_int = GR_Big // Limit max N
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}
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{ .mfi
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(p8) mov GR_N_as_int = GR_NBig // Limit min N
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nop.f 0
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(p8) cmp.eq p7,p0 = r0,r0 // Set p7 if |N| big
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}
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;;
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//
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// Create biased exponent for 2**N for N big
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// Is N zero?
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//
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{ .mfi
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(p7) add GR_N_Biased = GR_Bias,GR_N_as_int
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nop.f 0
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cmp.eq.or p6,p0 = r33,r0
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}
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{ .mfi
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mov GR_pos_ov_limit = 0x1007f // Exponent for positive overflow
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nop.f 0
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mov GR_exp_mask = 0x1ffff // Exponent mask
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}
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;;
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//
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// Create 2**N for N big
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// Return x when N = 0 or X = Nan, Inf, Zero
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//
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{ .mfi
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(p7) setf.exp FR_Two_N = GR_N_Biased
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nop.f 0
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mov GR_min_den_exp = 0x0ff81 - 23 // Exponent of min denorm float
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}
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{ .mfb
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and GR_exp_X = GR_exp_mask, GR_signexp_X
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(p6) fma.s.s0 FR_Result = FR_Floating_X, f1, f0
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(p6) br.ret.spnt b0
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}
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;;
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//
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// Raise Denormal operand flag with compare
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// Compute biased result exponent
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//
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{ .mfi
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add GR_exp_Result = GR_exp_X, GR_N_as_int
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fcmp.ge.s0 p0,p11 = FR_Floating_X,f0
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mov GR_neg_ov_limit = 0x3007f // Exponent for negative overflow
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}
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;;
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//
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// Do final operation
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//
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{ .mfi
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cmp.lt p7,p6 = GR_exp_Result, GR_max_exp // Test no overflow
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fma.s.s0 FR_Result = FR_Two_N,FR_Norm_X,f0
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cmp.lt p9,p0 = GR_exp_Result, GR_min_den_exp // Test sure underflow
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}
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{ .mfb
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nop.m 0
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nop.f 0
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(p9) br.cond.spnt SCALBNF_UNDERFLOW // Branch if certain underflow
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}
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;;
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{ .mib
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(p6) cmp.gt.unc p6,p8 = GR_exp_Result, GR_max_exp // Test sure overflow
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(p7) cmp.ge.unc p7,p9 = GR_exp_Result, GR_min_exp // Test no over/underflow
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(p7) br.ret.sptk b0 // Return from main path
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}
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;;
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{ .bbb
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(p6) br.cond.spnt SCALBNF_OVERFLOW // Branch if certain overflow
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(p8) br.cond.spnt SCALBNF_POSSIBLE_OVERFLOW // Branch if possible overflow
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(p9) br.cond.spnt SCALBNF_POSSIBLE_UNDERFLOW // Branch if possible underflow
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}
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;;
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// Here if possible underflow.
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// Resulting exponent: 0x0ff81-23 <= exp_Result < 0x0ff81
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SCALBNF_POSSIBLE_UNDERFLOW:
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//
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// Here if possible overflow.
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// Resulting exponent: 0x1007e = exp_Result
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SCALBNF_POSSIBLE_OVERFLOW:
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// Set up necessary status fields
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//
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// S0 user supplied status
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// S2 user supplied status + WRE + TD (Overflows)
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// S3 user supplied status + FZ + TD (Underflows)
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//
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{ .mfi
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nop.m 0
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fsetc.s3 0x7F,0x41
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nop.i 0
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}
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{ .mfi
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nop.m 0
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fsetc.s2 0x7F,0x42
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nop.i 0
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}
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;;
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//
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// Do final operation with s2 and s3
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//
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{ .mfi
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setf.exp FR_NBig = GR_neg_ov_limit
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fma.s.s3 FR_Result3 = FR_Two_N,FR_Norm_X,f0
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nop.i 0
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}
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{ .mfi
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setf.exp FR_Big = GR_pos_ov_limit
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fma.s.s2 FR_Result2 = FR_Two_N,FR_Norm_X,f0
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nop.i 0
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}
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;;
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// Check for overflow or underflow.
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// Restore s3
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// Restore s2
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//
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{ .mfi
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nop.m 0
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fsetc.s3 0x7F,0x40
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nop.i 0
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}
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{ .mfi
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nop.m 0
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fsetc.s2 0x7F,0x40
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nop.i 0
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}
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;;
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//
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// Is the result zero?
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//
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{ .mfi
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nop.m 0
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fclass.m p6, p0 = FR_Result3, 0x007
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nop.i 0
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}
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{ .mfi
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nop.m 0
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fcmp.ge.s1 p7, p8 = FR_Result2 , FR_Big
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nop.i 0
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}
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;;
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//
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// Detect masked underflow - Tiny + Inexact Only
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//
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{ .mfi
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nop.m 0
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(p6) fcmp.neq.unc.s1 p6, p0 = FR_Result , FR_Result2
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nop.i 0
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}
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;;
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//
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// Is result bigger the allowed range?
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// Branch out for underflow
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//
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{ .mfb
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nop.m 0
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(p8) fcmp.le.unc.s1 p9, p10 = FR_Result2 , FR_NBig
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(p6) br.cond.spnt SCALBNF_UNDERFLOW
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}
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;;
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//
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// Branch out for overflow
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//
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{ .bbb
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(p7) br.cond.spnt SCALBNF_OVERFLOW
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(p9) br.cond.spnt SCALBNF_OVERFLOW
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br.ret.sptk b0 // Return from main path.
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}
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;;
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// Here if result overflows
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SCALBNF_OVERFLOW:
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{ .mib
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alloc r32=ar.pfs,3,0,4,0
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addl GR_Tag = 205, r0 // Set error tag for overflow
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br.cond.sptk __libm_error_region // Call error support for overflow
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}
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;;
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// Here if result underflows
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SCALBNF_UNDERFLOW:
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{ .mib
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alloc r32=ar.pfs,3,0,4,0
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addl GR_Tag = 206, r0 // Set error tag for underflow
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br.cond.sptk __libm_error_region // Call error support for underflow
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}
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;;
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// Here if x=unorm
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SCALBNF_UNORM:
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{ .mib
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getf.exp GR_signexp_X = FR_Norm_X // Get signexp of normalized x
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nop.i 0
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br.cond.sptk SCALBNF_COMMON // Return to main path
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}
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;;
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GLOBAL_LIBM_END(__libm_scalblnf)
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LOCAL_LIBM_ENTRY(__libm_error_region)
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//
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// Get stack address of N
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//
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.prologue
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{ .mfi
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add GR_Parameter_Y=-32,sp
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nop.f 0
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.save ar.pfs,GR_SAVE_PFS
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mov GR_SAVE_PFS=ar.pfs
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}
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//
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// Adjust sp
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//
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{ .mfi
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.fframe 64
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add sp=-64,sp
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nop.f 0
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mov GR_SAVE_GP=gp
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};;
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//
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// Store N on stack in correct position
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// Locate the address of x on stack
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//
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{ .mmi
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st8 [GR_Parameter_Y] = GR_N_as_int,16
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add GR_Parameter_X = 16,sp
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.save b0, GR_SAVE_B0
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mov GR_SAVE_B0=b0
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};;
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//
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// Store x on the stack.
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// Get address for result on stack.
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//
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.body
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{ .mib
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stfs [GR_Parameter_X] = FR_Norm_X
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add GR_Parameter_RESULT = 0,GR_Parameter_Y
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nop.b 0
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}
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{ .mib
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stfs [GR_Parameter_Y] = FR_Result
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add GR_Parameter_Y = -16,GR_Parameter_Y
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br.call.sptk b0=__libm_error_support#
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};;
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//
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// Get location of result on stack
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//
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{ .mmi
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add GR_Parameter_RESULT = 48,sp
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nop.m 0
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nop.i 0
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};;
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//
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// Get the new result
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//
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{ .mmi
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ldfs FR_Result = [GR_Parameter_RESULT]
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.restore sp
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add sp = 64,sp
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mov b0 = GR_SAVE_B0
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};;
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//
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// Restore gp, ar.pfs and return
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//
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{ .mib
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mov gp = GR_SAVE_GP
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mov ar.pfs = GR_SAVE_PFS
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br.ret.sptk b0
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};;
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LOCAL_LIBM_END(__libm_error_region)
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.type __libm_error_support#,@function
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.global __libm_error_support#
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