glibc/sysdeps/ia64/fpu/s_logbl.S
Siddhesh Poyarekar 30891f35fa Remove "Contributed by" lines
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>
2021-09-03 22:06:44 +05:30

282 lines
8.2 KiB
ArmAsm

.file "logbl.s"
// Copyright (c) 2000 - 2003, Intel Corporation
// All rights reserved.
//
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// * The name of Intel Corporation may not be used to endorse or promote
// products derived from this software without specific prior written
// permission.
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Intel Corporation is the author of this code, and requests that all
// problem reports or change requests be submitted to it directly at
// http://www.intel.com/software/products/opensource/libraries/num.htm.
//
// History
//==============================================================
// 02/02/00 Initial version
// 02/16/00 Modified to conform to C9X
// 03/16/00 Improved speed
// 04/04/00 Unwind support added
// 05/30/00 Fixed bug when x double-extended denormal
// 08/15/00 Bundle added after call to __libm_error_support to properly
// set [the previously overwritten] GR_Parameter_RESULT.
// 05/20/02 Cleaned up namespace and sf0 syntax
// 01/20/03 Improved performance
//
// API
//==============================================================
// long double logbl( long double x );
//
// Overview of operation
//==============================================================
// The logbl function extracts the exponent of x as an integer in
// floating-point format.
// logbl computes log2 of x as a long double
//
// logbl is similar to ilogbl but differs in the following ways:
// +-inf
// ilogbl: returns INT_MAX
// logbl: returns +inf
// Nan returns FP_LOGBNAN (which is either INT_MAX or INT_MIN)
// ilogbl: returns INT_MAX (7fffffff)
// logbl: returns QNAN (quietized SNAN)
// 0 returns FP_ILOGB0 (which is either INT_MIN or -INT_MAX)
// ilogbl: returns -INT_MAX (80000001)
// logbl: returns -inf, raises the divide-by-zero exception,
// and calls libm_error_support to set domain error
//
// Registers used
//==============================================================
// general registers used:
// r26 -> r38
// r35 -> r38 used as parameters to error path
//
// predicate registers used:
// p6, p7, p8
// floating-point registers used:
// f9, f10, f11
// f8, input
rExpBias = r26
rExpMask = r27
rSignexp_x = r28
rExp_x = r29
rTrueExp_x = r30
rExp_2to64 = r31
GR_SAVE_PFS = r32
GR_SAVE_B0 = r33
GR_SAVE_GP = r34
GR_Parameter_X = r35
GR_Parameter_Y = r36
GR_Parameter_RESULT = r37
GR_Parameter_TAG = r38
fExp_in_signif = f9
fNorm_x = f10
fFloat_Exp = f10
f2to64 = f11
.section .text
GLOBAL_LIBM_ENTRY(logbl)
// X NORMAL
// TrueExp_x = exp(f8) - 0xffff
// sig = TrueExp_x
// f8 = convert_to_fp (sig))
{ .mfi
getf.exp rSignexp_x = f8
fclass.m p8,p0 = f8, 0x0b // Test for x unorm
mov rExpBias = 0xffff // Exponent bias
}
{ .mfi
nop.m 0
fnorm.s1 fNorm_x = f8
mov rExpMask = 0x1ffff // Exponent mask
}
;;
// Form signexp of 2^64 in case need to scale denormal
{ .mfb
mov rExp_2to64 = 0x1003f
fclass.m p6,p0 = f8, 0x1e3 // Test x natval, nan, inf
(p8) br.cond.spnt LOGB_DENORM // Branch if x unorm
}
;;
LOGB_COMMON:
// Return here from LOGB_DENORM
{ .mfi
and rExp_x = rSignexp_x, rExpMask // Get biased exponent
fclass.m p7,p0 = f8, 0x07 // Test x zero
nop.i 0
}
;;
// X NAN or INFINITY, return f8 * f8
{ .mfb
sub rTrueExp_x = rExp_x, rExpBias // Get true exponent
(p6) fma.s0 f8= f8,f8,f0 // Result if x natval, nan, inf
(p6) br.ret.spnt b0 // Exit if x natval, nan, inf
}
;;
{ .mib
setf.sig fExp_in_signif = rTrueExp_x // Exponent as integer in fp
nop.i 999
(p7) br.cond.spnt LOGB_ZERO
}
;;
// Result can be represented in less than 24 bits, so no precision completer
// is needed.
{ .mfb
nop.m 0
fcvt.xf f8 = fExp_in_signif
br.ret.sptk b0 // Exit main path, 0 < |x| < inf
}
;;
LOGB_DENORM:
// Form 2^64 in case need to scale denormal
// Check to see if double-extended denormal
{ .mfi
setf.exp f2to64 = rExp_2to64
fclass.m p8,p0 = fNorm_x, 0x0b
nop.i 0
}
;;
{ .mfi
nop.m 0
fcmp.eq.s0 p7,p0 = f8, f0 // Dummy op to set denormal flag
nop.i 0
}
;;
// If double-extended denormal add 64 to exponent bias for scaling
// If double-extended denormal form x * 2^64 which is normal
{ .mfi
(p8) add rExpBias = 64, rExpBias
(p8) fmpy.s1 fNorm_x = fNorm_x, f2to64
nop.i 0
}
;;
// Logic is the same as normal path but use normalized input
{ .mib
getf.exp rSignexp_x = fNorm_x
nop.i 0
br.cond.sptk LOGB_COMMON // Return to main path
}
;;
LOGB_ZERO:
// Here if x zero
// f10 = -|f8|
// f9 = 1.0/f10 = -1.0/|f8| = -inf
{ .mmf
alloc r32=ar.pfs,1,2,4,0
mov GR_Parameter_TAG = 150 // Error code
fmerge.ns f10 = f0,f8
}
;;
{ .mfb
nop.m 0
frcpa.s0 f9,p6 = f1,f10 // Produce -inf, Z flag
br.cond.sptk __libm_error_region // Call error support
}
;;
GLOBAL_LIBM_END(logbl)
libm_alias_ldouble_other (logb, logb)
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
stfe [GR_Parameter_Y] = f0,16 // 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
stfe [GR_Parameter_X] = f8 // STORE Parameter 1 on stack
add GR_Parameter_RESULT = 0,GR_Parameter_Y // Parameter 3 address
nop.b 0
}
{ .mib
stfe [GR_Parameter_Y] = f9 // 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
ldfe 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
};;
LOCAL_LIBM_END(__libm_error_region)
.type __libm_error_support#,@function
.global __libm_error_support#