glibc/sysdeps/ia64/fpu/e_remainderf.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

608 lines
12 KiB
ArmAsm

.file "remainderf.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
// 03/02/00 New algorithm
// 04/04/00 Unwind support added
// 07/21/00 Fixed quotient=2^{24*m+23} bug
// 08/15/00 Bundle added after call to __libm_error_support to properly
// set [the previously overwritten] GR_Parameter_RESULT.
// 11/29/00 Set FR_Y to f9
// 05/20/02 Cleaned up namespace and sf0 syntax
// 02/10/03 Reordered header: .section, .global, .proc, .align
//
// API
//====================================================================
// float remainderf(float,float);
//
// Overview of operation
//====================================================================
// remainder(a,b)=a-i*b,
// where i is an integer such that, if b!=0 and a is finite,
// |a/b-i|<=1/2. If |a/b-i|=1/2, i is even.
//
// Algorithm
//====================================================================
// a). eliminate special cases
// b). if |a/b|<0.25 (first quotient estimate), return a
// c). use single precision divide algorithm to get quotient q
// rounded to 24 bits of precision
// d). calculate partial remainders (using both q and q-ulp);
// select one and RZ(a/b) based on the sign of |a|-|b|*q
// e). if the exponent difference (exponent(a)-exponent(b))
// is less than 24 (quotient estimate<2^{24}-2), use RZ(a/b)
// and sticky bits to round to integer; exit loop and
// calculate final remainder
// f). if exponent(a)-exponent(b)>=24, select new value of a as
// the partial remainder calculated using RZ(a/b);
// repeat from c).
//
// Special cases
//====================================================================
// a=+/- Inf, or b=+/-0: return NaN, call libm_error_support
// a=NaN or b=NaN: return NaN
//
// Registers used
//====================================================================
// Predicate registers: p6-p12
// General registers: r2,r3,r28,r29,r32 (ar.pfs), r33-r39
// Floating point registers: f6-f15
//
GR_SAVE_B0 = r33
GR_SAVE_PFS = r34
GR_SAVE_GP = r35
GR_SAVE_SP = r36
GR_Parameter_X = r37
GR_Parameter_Y = r38
GR_Parameter_RESULT = r39
GR_Parameter_TAG = r40
FR_X = f10
FR_Y = f9
FR_RESULT = f8
.section .text
GLOBAL_IEEE754_ENTRY(remainderf)
// inputs in f8, f9
// result in f8
{ .mfi
alloc r32=ar.pfs,1,4,4,0
// f13=|a|
fmerge.s f13=f0,f8
nop.i 0
}
{.mfi
nop.m 0
// f14=|b|
fmerge.s f14=f0,f9
nop.i 0;;
}
{.mlx
nop.m 0
// r2=2^{24}-2
movl r3=0x4b7ffffe;;
}
// Y +-NAN, +-inf, +-0? p11
{ .mfi
nop.m 999
fclass.m.unc p11,p0 = f9, 0xe7
nop.i 999
}
// qnan snan inf norm unorm 0 -+
// 1 1 1 0 0 0 11
// e 3
// X +-NAN, +-inf, ? p9
{ .mfi
nop.m 999
fclass.m.unc p9,p0 = f8, 0xe3
nop.i 999;;
}
{.mfi
nop.m 0
mov f15=f0
nop.i 0
}
{ .mfi
// set p7=1
cmp.eq.unc p7,p0=r0,r0
// Step (1)
// y0 = 1 / b in f10
frcpa.s1 f10,p6=f13,f14
nop.i 0;;
}
{.bbb
(p9) br.cond.spnt FREM_X_NAN_INF
(p11) br.cond.spnt FREM_Y_NAN_INF_ZERO
nop.b 0
} {.mfi
nop.m 0
// set D flag if a (f8) is denormal
fnma.s0 f6=f8,f1,f8
nop.i 0;;
}
.align 32
remloop24:
{ .mfi
// f12=2^{24}-2
setf.s f12=r3
// Step (2)
// q0 = a * y0 in f15
(p6) fma.s1 f15=f13,f10,f0
nop.i 0
}
{ .mfi
nop.m 0
// Step (3)
// e0 = 1 - b * y0 in f7
(p6) fnma.s1 f7=f14,f10,f1
nop.i 0;;
}
{.mlx
nop.m 0
// r2=1.25*2^{-24}
movl r2=0x33a00000;;
}
{ .mfi
nop.m 0
// Step (4)
// q1 = q0 + e0 * q0 in f6
(p6) fma.s1 f6=f7,f15,f15
nop.i 0
}
{ .mfi
nop.m 0
// Step (5)
// e1 = e0 * e0 in f7
(p6) fma.s1 f7=f7,f7,f0
nop.i 0;;
}
{.mii
(p7) getf.exp r29=f15
(p7) mov r28=0xfffd
nop.i 0;;
}
{ .mfi
// f15=1.25*2^{-24}
setf.s f15=r2
// Step (6)
// q2 = q1 + e1 * q1 in f6
(p6) fma.s1 f6=f7,f6,f6
nop.i 0
}
{ .mfi
mov r2=0x3e7
// Step (7)
// e2 = e1 * e1 in f7
(p6) fma.s1 f7=f7,f7,f0
nop.i 0;;
}
{.mmi
// q<1/4 ? (i.e. expon< -2)
(p7) cmp.gt.unc p7,p0=r28,r29
nop.m 0
// r2=0x3e7000000
shl r2=r2,24;;
}
{.mfb
// r2=0x3e7000001
add r2=1,r2
// if |a/b|<1/4, set D flag before returning
(p7) fma.s.s0 f9=f9,f0,f8
nop.b 0;;
}
{.mfb
nop.m 0
// can be combined with bundle above if sign of 0 or
// FTZ enabled are not important
(p7) fmerge.s f8=f8,f9
// return if |a|<4*|b| (estimated quotient < 1/4)
(p7) br.ret.spnt b0;;
}
{.mfi
nop.m 0
// set f8 to current a value | sign
fmerge.s f8=f8,f13
// r2=2^{-24}+2^{-48} (double prec.)
shl r2=r2,28;;
}
{ .mfi
// r29= -32+bias
mov r29=0xffdf
// Step (8)
// q3 = q2 + e2 * q2 in f6
(p6) fma.d.s1 f6=f7,f6,f6
nop.i 0;;
}
{ .mfi
nop.m 0
// Step (9)
// q = q3 in f11
(p6) fma.s.s1 f11=f6,f1,f0
nop.i 0;;
}
{.mfi
// f7=2^{-24}
setf.d f7=r2
// last step ? (q3<2^{24}-2 --> q<2^{24})
fcmp.lt.unc.s1 p0,p12=f6,f12
nop.i 0
} {.mfi
// f12=2^{-32}
setf.exp f12=r29
nop.f 0
nop.i 0;;
}
{.mfi
nop.m 0
// r=a-b*q
fnma.s1 f6=f14,f11,f13
nop.i 0
}
{.mfi
nop.m 0
// q'=q-q*(1.25*2^{-24}) (q'=q-ulp)
fnma.s.s1 f15=f11,f15,f11
nop.i 0;;
}
{.mfi
nop.m 0
// r2=a-b*q'
fnma.s1 f13=f14,f15,f13
nop.i 0;;
}
{.mfi
nop.m 0
// r>0 iff q=RZ(a/b) and inexact
fcmp.gt.unc.s1 p8,p0=f6,f0
nop.i 0
}
{.mfi
nop.m 0
// r<0 iff q'=RZ(a/b) and inexact
fcmp.lt.unc.s1 p9,p10=f6,f0
nop.i 0;;
}
.pred.rel "mutex",p8,p9
{.mfi
nop.m 0
// (p8) Q=q+(last iteration ? sticky bits:0)
// i.e. Q=q+q*x (x=2^{-32} or 0)
(p8) fma.s1 f11=f11,f12,f11
nop.i 0
}
{.mfi
nop.m 0
// (p9) Q=q'+(last iteration ? sticky bits:0)
// i.e. Q=q'+q'*x (x=2^{-24} or 0: if expon. difference=23, want to round back to q)
(p9) fma.s1 f11=f15,f7,f15
nop.i 0;;
}
{.mfb
nop.m 0
// (p9) set r=r2 (new a, if not last iteration)
// (p10) new a =r
(p10) mov f13=f6
(p12) br.cond.sptk remloop24;;
}
// last iteration
{.mfi
nop.m 0
// set f9=|b|*sgn(a)
fmerge.s f9=f8,f9
nop.i 0
}
{.mfi
nop.m 0
// round to integer
fcvt.fx.s1 f11=f11
nop.i 0;;
}
{.mfi
nop.m 0
// save sign of a
fmerge.s f7=f8,f8
nop.i 0
}
{.mfi
nop.m 0
// normalize
fcvt.xf f11=f11
nop.i 0;;
}
{.mfi
nop.m 0
// This can be removed if sign of 0 is not important
// get remainder using sf1
fnma.s.s1 f12=f9,f11,f8
nop.i 0
}
{.mfi
nop.m 0
// get remainder
fnma.s.s0 f8=f9,f11,f8
nop.i 0;;
}
{.mfi
nop.m 0
// f12=0?
// This can be removed if sign of 0 is not important
fcmp.eq.unc.s1 p8,p0=f12,f0
nop.i 0;;
}
{.mfb
nop.m 0
// if f8=0, set sign correctly
// This can be removed if sign of 0 is not important
(p8) fmerge.s f8=f7,f8
// return
br.ret.sptk b0;;
}
FREM_X_NAN_INF:
// Y zero ?
{.mfi
nop.m 0
fma.s1 f10=f9,f1,f0
nop.i 0;;
}
{.mfi
nop.m 0
fcmp.eq.unc.s1 p11,p0=f10,f0
nop.i 0;;
}
{.mib
nop.m 0
nop.i 0
// if Y zero
(p11) br.cond.spnt FREM_Y_ZERO;;
}
// X infinity? Return QNAN indefinite
{ .mfi
nop.m 999
fclass.m.unc p8,p0 = f8, 0x23
nop.i 999
}
// X infinity? Return QNAN indefinite
{ .mfi
nop.m 999
fclass.m.unc p11,p0 = f8, 0x23
nop.i 999;;
}
// Y NaN ?
{.mfi
nop.m 999
(p8) fclass.m.unc p0,p8=f9,0xc3
nop.i 0;;
}
{.mfi
nop.m 999
// also set Denormal flag if necessary
(p8) fma.s0 f9=f9,f1,f0
nop.i 0
}
{ .mfi
nop.m 999
(p8) frcpa.s0 f8,p7 = f8,f8
nop.i 999 ;;
}
{.mfi
nop.m 999
(p11) mov f10=f8
nop.i 0
}
{ .mfi
nop.m 999
(p8) fma.s.s0 f8=f8,f1,f0
nop.i 0 ;;
}
{ .mfb
nop.m 999
frcpa.s0 f8,p7=f8,f9
(p11) br.cond.spnt EXP_ERROR_RETURN;;
}
{ .mib
nop.m 0
nop.i 0
br.ret.spnt b0 ;;
}
FREM_Y_NAN_INF_ZERO:
// Y INF
{ .mfi
nop.m 999
fclass.m.unc p7,p0 = f9, 0x23
nop.i 999 ;;
}
{ .mfb
nop.m 999
(p7) fma.s.s0 f8=f8,f1,f0
(p7) br.ret.spnt b0 ;;
}
// Y NAN?
{ .mfi
nop.m 999
fclass.m.unc p9,p0 = f9, 0xc3
nop.i 999 ;;
}
{ .mfb
nop.m 999
(p9) fma.s.s0 f8=f9,f1,f0
(p9) br.ret.spnt b0 ;;
}
FREM_Y_ZERO:
// Y zero? Must be zero at this point
// because it is the only choice left.
// Return QNAN indefinite
// X NAN?
{ .mfi
nop.m 999
fclass.m.unc p9,p10 = f8, 0xc3
nop.i 999 ;;
}
{ .mfi
nop.m 999
(p10) fclass.nm p9,p10 = f8, 0xff
nop.i 999 ;;
}
{.mfi
nop.m 999
(p9) frcpa.s0 f11,p7=f8,f0
nop.i 0;;
}
{ .mfi
nop.m 999
(p10) frcpa.s0 f11,p7 = f0,f0
nop.i 999;;
}
{ .mfi
nop.m 999
fmerge.s f10 = f8, f8
nop.i 999
}
{ .mfi
nop.m 999
fma.s.s0 f8=f11,f1,f0
nop.i 999
}
EXP_ERROR_RETURN:
{ .mib
mov GR_Parameter_TAG = 125
nop.i 999
br.sptk __libm_error_region;;
}
GLOBAL_IEEE754_END(remainderf)
libm_alias_float_other (__remainder, remainder)
weak_alias (__remainderf, dremf)
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
stfs [GR_Parameter_Y] = FR_Y,16 // Save 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
stfs [GR_Parameter_X] = FR_X // Store Parameter 1 on stack
add GR_Parameter_RESULT = 0,GR_Parameter_Y
nop.b 0 // Parameter 3 address
}
{ .mib
stfs [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
nop.m 0
nop.m 0
add GR_Parameter_RESULT = 48,sp
};;
{ .mmi
ldfs 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#