30891f35fa
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>
234 lines
6.9 KiB
ArmAsm
234 lines
6.9 KiB
ArmAsm
.file "roundf.s"
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// Copyright (c) 2000 - 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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// 10/25/00 Initial version
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// 06/14/01 Changed cmp to an equivalent form
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// 05/20/02 Cleaned up namespace and sf0 syntax
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// 01/20/03 Improved performance and reduced code size
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// 04/18/03 Eliminate possible WAW dependency warning
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// 09/03/03 Improved performance
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//==============================================================
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// API
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//==============================================================
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// float roundf(float x)
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//==============================================================
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// general input registers:
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// r14 - r18
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rSignexp = r14
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rExp = r15
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rExpMask = r16
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rBigexp = r17
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rExpHalf = r18
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// floating-point registers:
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// f8 - f13
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fXtruncInt = f9
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fNormX = f10
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fHalf = f11
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fInc = f12
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fRem = f13
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// predicate registers used:
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// p6 - p10
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// Overview of operation
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//==============================================================
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// float roundf(float x)
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// Return an integer value (represented as a float) that is x
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// rounded to nearest integer, halfway cases rounded away from
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// zero.
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// if x>0 result = trunc(x+0.5)
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// if x<0 result = trunc(x-0.5)
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//
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//==============================================================
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// double_extended
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// if the exponent is > 1003e => 3F(true) = 63(decimal)
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// we have a significand of 64 bits 1.63-bits.
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// If we multiply by 2^63, we no longer have a fractional part
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// So input is an integer value already.
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// double
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// if the exponent is >= 10033 => 34(true) = 52(decimal)
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// 34 + 3ff = 433
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// we have a significand of 53 bits 1.52-bits. (implicit 1)
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// If we multiply by 2^52, we no longer have a fractional part
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// So input is an integer value already.
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// single
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// if the exponent is > 10016 => 17(true) = 23(decimal)
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// we have a significand of 24 bits 1.23-bits. (implicit 1)
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// If we multiply by 2^23, we no longer have a fractional part
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// So input is an integer value already.
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.section .text
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GLOBAL_LIBM_ENTRY(__roundf)
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{ .mfi
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getf.exp rSignexp = f8 // Get signexp, recompute if unorm
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fcvt.fx.trunc.s1 fXtruncInt = f8 // Convert to int in significand
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addl rBigexp = 0x10016, r0 // Set exponent at which is integer
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}
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{ .mfi
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mov rExpHalf = 0x0FFFE // Form sign and exponent of 0.5
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fnorm.s1 fNormX = f8 // Normalize input
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mov rExpMask = 0x1FFFF // Form exponent mask
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}
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;;
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{ .mfi
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setf.exp fHalf = rExpHalf // Form 0.5
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fclass.m p7,p0 = f8, 0x0b // Test x unorm
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nop.i 0
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}
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;;
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{ .mfb
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nop.m 0
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fclass.m p6,p0 = f8, 0x1e3 // Test x natval, nan, inf
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(p7) br.cond.spnt ROUND_UNORM // Branch if x unorm
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}
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;;
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ROUND_COMMON:
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// Return here from ROUND_UNORM
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{ .mfb
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nop.m 0
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fcmp.lt.s1 p8,p9 = f8, f0 // Test if x < 0
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(p6) br.cond.spnt ROUND_SPECIAL // Exit if x natval, nan, inf
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}
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;;
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{ .mfi
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nop.m 0
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fcvt.xf f8 = fXtruncInt // Pre-Result if 0.5 <= |x| < 2^23
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nop.i 0
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}
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;;
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{ .mfi
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and rExp = rSignexp, rExpMask // Get biased exponent
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fmerge.s fInc = fNormX, f1 // Form increment if |rem| >= 0.5
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nop.i 0
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}
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;;
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{ .mmi
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cmp.lt p6,p0 = rExp, rExpHalf // Is |x| < 0.5?
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cmp.ge p7,p0 = rExp, rBigexp // Is |x| >= 2^23?
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cmp.lt p10,p0 = rExp, rExpHalf // Is |x| < 0.5?
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}
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;;
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// We must correct result if |x| < 0.5, or |x| >= 2^23
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.pred.rel "mutex",p6,p7
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{ .mfi
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nop.m 0
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(p6) fmerge.s f8 = fNormX, f0 // If |x| < 0.5, result sgn(x)*0
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nop.i 0
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}
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{ .mfb
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(p7) cmp.eq p10,p0 = r0, r0 // Also turn on p10 if |x| >= 2^23
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(p7) fma.s.s0 f8 = fNormX, f1, f0 // If |x| >= 2^23, result x
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(p10) br.ret.spnt b0 // Exit |x| < 0.5 or |x| >= 2^23
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}
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;;
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// Here if 0.5 <= |x| < 2^23
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{ .mfi
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nop.m 0
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(p9) fms.s1 fRem = fNormX, f1, f8 // Get remainder = x - trunc(x)
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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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(p8) fms.s1 fRem = f8, f1, fNormX // Get remainder = trunc(x) - x
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nop.i 0
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}
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;;
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{ .mfi
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nop.m 0
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fcmp.ge.s1 p9,p0 = fRem, fHalf // Test |rem| >= 0.5
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nop.i 0
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}
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;;
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// If x < 0 and remainder <= -0.5, then subtract 1 from result
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// If x > 0 and remainder >= +0.5, then add 1 to result
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{ .mfb
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nop.m 0
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(p9) fma.s.s0 f8 = f8, f1, fInc
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br.ret.sptk b0
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}
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;;
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ROUND_SPECIAL:
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// Here if x natval, nan, inf
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{ .mfb
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nop.m 0
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fma.s.s0 f8 = f8, f1, f0
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br.ret.sptk b0
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}
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;;
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ROUND_UNORM:
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// Here if x unorm
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{ .mfi
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getf.exp rSignexp = fNormX // Get signexp, recompute if unorm
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fcmp.eq.s0 p7,p0 = f8, f0 // Dummy op to set denormal flag
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nop.i 0
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}
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{ .mfb
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nop.m 0
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fcvt.fx.trunc.s1 fXtruncInt = fNormX // Convert to int in significand
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br.cond.sptk ROUND_COMMON // Return to main path
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}
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;;
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GLOBAL_LIBM_END(__roundf)
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libm_alias_float (__round, round)
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