glibc/sysdeps/ia64/fpu/e_exp.S
Andreas Jaeger aeb25823d8 Update.
2002-06-05  Brian Youmans <3diff@gnu.org>

	* sysdeps/ia64/fpu/e_acos.S: Added text of Intel license.
	* sysdeps/ia64/fpu/e_acosf.S: Likewise.
	* sysdeps/ia64/fpu/e_acosl.S: Likewise.
	* sysdeps/ia64/fpu/e_asin.S: Likewise.
	* sysdeps/ia64/fpu/e_asinf.S: Likewise.
	* sysdeps/ia64/fpu/e_asinl.S: Likewise.
	* sysdeps/ia64/fpu/e_atan2.S: Likewise.
	* sysdeps/ia64/fpu/e_atan2f.S: Likewise.
	* sysdeps/ia64/fpu/e_cosh.S: Likewise.
	* sysdeps/ia64/fpu/e_coshf.S: Likewise.
	* sysdeps/ia64/fpu/e_coshl.S: Likewise.
	* sysdeps/ia64/fpu/e_exp.S: Likewise.
	* sysdeps/ia64/fpu/e_expf.S: Likewise.
	* sysdeps/ia64/fpu/e_fmod.S: Likewise.
	* sysdeps/ia64/fpu/e_fmodf.S: Likewise.
	* sysdeps/ia64/fpu/e_fmodl.S: Likewise.
	* sysdeps/ia64/fpu/e_hypot.S: Likewise.
	* sysdeps/ia64/fpu/e_hypotf.S: Likewise.
	* sysdeps/ia64/fpu/e_hypotl.S: Likewise.
	* sysdeps/ia64/fpu/e_log.S: Likewise.
	* sysdeps/ia64/fpu/e_logf.S: Likewise.
	* sysdeps/ia64/fpu/e_pow.S: Likewise.
	* sysdeps/ia64/fpu/e_powf.S: Likewise.
	* sysdeps/ia64/fpu/e_powl.S: Likewise.
	* sysdeps/ia64/fpu/e_remainder.S: Likewise.
	* sysdeps/ia64/fpu/e_remainderf.S: Likewise.
	* sysdeps/ia64/fpu/e_remainderl.S: Likewise.
	* sysdeps/ia64/fpu/e_scalb.S: Likewise.
	* sysdeps/ia64/fpu/e_scalbf.S: Likewise.
	* sysdeps/ia64/fpu/e_scalbl.S: Likewise.
	* sysdeps/ia64/fpu/e_sinh.S: Likewise.
	* sysdeps/ia64/fpu/e_sinhf.S: Likewise.
	* sysdeps/ia64/fpu/e_sinhl.S: Likewise.
	* sysdeps/ia64/fpu/e_sqrt.S: Likewise.
	* sysdeps/ia64/fpu/e_sqrtf.S: Likewise.
	* sysdeps/ia64/fpu/e_sqrtl.S: Likewise.
	* sysdeps/ia64/fpu/libm_atan2_req.S: Likewise.
	* sysdeps/ia64/fpu/libm_error.c: Likewise.
	* sysdeps/ia64/fpu/libm_frexp4.S: Likewise.
	* sysdeps/ia64/fpu/libm_frexp4f.S: Likewise.
	* sysdeps/ia64/fpu/s_frexpl.c: Likewise.
	* sysdeps/ia64/fpu/s_ilogb.S: Likewise.
	* sysdeps/ia64/fpu/s_ilogbf.S: Likewise.
	* sysdeps/ia64/fpu/s_ilogbl.S: Likewise.
	* sysdeps/ia64/fpu/s_ldexp.S: Likewise.
	* sysdeps/ia64/fpu/s_ldexpf.S: Likewise.
	* sysdeps/ia64/fpu/s_ldexpl.S: Likewise.
	* sysdeps/ia64/fpu/s_log1p.S: Likewise.
	* sysdeps/ia64/fpu/s_log1pf.S: Likewise.
	* sysdeps/ia64/fpu/s_log1pl.S: Likewise.
	* sysdeps/ia64/fpu/s_logb.S: Likewise.
	* sysdeps/ia64/fpu/s_logbf.S: Likewise.
	* sysdeps/ia64/fpu/s_logbl.S: Likewise.
	* sysdeps/ia64/fpu/s_modf.S: Likewise.
	* sysdeps/ia64/fpu/s_modff.S: Likewise.
	* sysdeps/ia64/fpu/s_modfl.S: Likewise.
	* sysdeps/ia64/fpu/s_nearbyint.S: Likewise.
	* sysdeps/ia64/fpu/s_nearbyintf.S: Likewise.
	* sysdeps/ia64/fpu/s_nearbyintl.S: Likewise.
	* sysdeps/ia64/fpu/s_rint.S: Likewise.
	* sysdeps/ia64/fpu/s_rintf.S: Likewise.
	* sysdeps/ia64/fpu/s_rintl.S: Likewise.
	* sysdeps/ia64/fpu/s_round.S: Likewise.
	* sysdeps/ia64/fpu/s_roundf.S: Likewise.
	* sysdeps/ia64/fpu/s_roundl.S: Likewise.
	* sysdeps/ia64/fpu/s_scalbn.S: Likewise.
	* sysdeps/ia64/fpu/s_scalbnf.S: Likewise.
	* sysdeps/ia64/fpu/s_scalbnl.S: Likewise.
	* sysdeps/ia64/fpu/s_significand.S: Likewise.
	* sysdeps/ia64/fpu/s_significandf.S: Likewise.
	* sysdeps/ia64/fpu/s_significandl.S: Likewise.
	* sysdeps/ia64/fpu/s_tan.S: Likewise.
	* sysdeps/ia64/fpu/s_tanf.S: Likewise.
	* sysdeps/ia64/fpu/s_tanl.S: Likewise.
	* sysdeps/ia64/fpu/s_trunc.S: Likewise.
	* sysdeps/ia64/fpu/s_truncf.S: Likewise.
	* sysdeps/ia64/fpu/s_truncl.S: Likewise.
	* sysdeps/ieee754/dbl-64/doasin.c: Changed copyright notice to
	reflect IBM donation of math library to FSF
	* sysdeps/ieee754/dbl-64/dosincos.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_asin.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_atan2.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_exp.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_log.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_pow.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_remainder.c: Likewise.
	* sysdeps/ieee754/dbl-64/e_sqrt.c: Likewise.
	* sysdeps/ieee754/dbl-64/halfulp.c: Likewise.
	* sysdeps/ieee754/dbl-64/mpa.c: Likewise.
	* sysdeps/ieee754/dbl-64/mpatan.c: Likewise.
	* sysdeps/ieee754/dbl-64/mpatan2.c: Likewise.
	* sysdeps/ieee754/dbl-64/mpexp.c: Likewise.
	* sysdeps/ieee754/dbl-64/mplog.c: Likewise.
	* sysdeps/ieee754/dbl-64/mpsqrt.c: Likewise.
	* sysdeps/ieee754/dbl-64/mptan.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_atan.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_sin.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_tan.c: Likewise.
	* sysdeps/ieee754/dbl-64/sincos32.c: Likewise.
	* sysdeps/ieee754/dbl-64/slowexp.c: Likewise.
	* sysdeps/ieee754/dbl-64/slowpow.c: Likewise.
	* sysdeps/gnu/netinet/udp.h: Added BSD copying permission notice
	* sysdeps/vax/__longjmp.c: Likewise.
	* sysdeps/vax/setjmp.c: Likewise.
	* libio/filedoalloc.c: Fixed BSD copying permission notice to
	remove advertising clause
	* sysdeps/vax/htonl.s: Likewise.
	* sysdeps/vax/htons.s: Likewise.
	* libio/wfiledoalloc.c: Likewise.
	* stdlib/random.c: Likewise.
	* stdlib/random_r.c: Likewise.
	* sysdeps/mach/sys/reboot.h: Likewise.
	* inet/getnameinfo.c: Deleted advertising clause from Inner Net License
	* sysdeps/posix/getaddrinfo.c: Likewise.
	* sunrpc/des_impl.c: Updated license permission notice to Lesser
	GPL and corrected pointer to point to the correct license.
2002-07-06 06:36:39 +00:00

829 lines
22 KiB
ArmAsm

.file "exp.s"
// Copyright (C) 2000, 2001, Intel Corporation
// All rights reserved.
//
// Contributed 2/2/2000 by John Harrison, Ted Kubaska, Bob Norin, Shane Story,
// and Ping Tak Peter Tang of the Computational Software Lab, Intel Corporation.
//
// 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://developer.intel.com/opensource.
//
// History
//==============================================================
// 2/02/00 Initial version
// 3/07/00 exp(inf) = inf but now does NOT call error support
// exp(-inf) = 0 but now does NOT call error support
// 4/04/00 Unwind support added
// 8/15/00 Bundle added after call to __libm_error_support to properly
// set [the previously overwritten] GR_Parameter_RESULT.
// 11/30/00 Reworked to shorten main path, widen main path to include all
// args in normal range, and add quick exit for 0, nan, inf.
// 12/05/00 Loaded constants earlier with setf to save 2 cycles.
// API
//==============================================================
// double exp(double)
// Overview of operation
//==============================================================
// Take the input x. w is "how many log2/128 in x?"
// w = x * 128/log2
// n = int(w)
// x = n log2/128 + r + delta
// n = 128M + index_1 + 2^4 index_2
// x = M log2 + (log2/128) index_1 + (log2/8) index_2 + r + delta
// exp(x) = 2^M 2^(index_1/128) 2^(index_2/8) exp(r) exp(delta)
// Construct 2^M
// Get 2^(index_1/128) from table_1;
// Get 2^(index_2/8) from table_2;
// Calculate exp(r) by series
// r = x - n (log2/128)_high
// delta = - n (log2/128)_low
// Calculate exp(delta) as 1 + delta
// Special values
//==============================================================
// exp(+0) = 1.0
// exp(-0) = 1.0
// exp(+qnan) = +qnan
// exp(-qnan) = -qnan
// exp(+snan) = +qnan
// exp(-snan) = -qnan
// exp(-inf) = +0
// exp(+inf) = +inf
// Overfow and Underfow
//=======================
// exp(-x) = smallest double normal when
// x = -708.396 = c086232bdd7abcd2
// exp(x) = largest double normal when
// x = 709.7827 = 40862e42fefa39ef
// Registers used
//==============================================================
// Floating Point registers used:
// f8, input
// f9 -> f15, f32 -> f60
// General registers used:
// r32 -> r60
// Predicate registers used:
// p6 -> p15
#include "libm_support.h"
// Assembly macros
//==============================================================
exp_GR_rshf = r33
EXP_AD_TB1 = r34
EXP_AD_TB2 = r35
EXP_AD_P = r36
exp_GR_N = r37
exp_GR_index_1 = r38
exp_GR_index_2_16 = r39
exp_GR_biased_M = r40
exp_GR_index_1_16 = r41
EXP_AD_T1 = r42
EXP_AD_T2 = r43
exp_GR_sig_inv_ln2 = r44
exp_GR_17ones = r45
exp_GR_one = r46
exp_TB1_size = r47
exp_TB2_size = r48
exp_GR_rshf_2to56 = r49
exp_GR_gt_ln = r50
exp_GR_exp_2tom56 = r51
exp_GR_17ones_m1 = r52
GR_SAVE_B0 = r53
GR_SAVE_PFS = r54
GR_SAVE_GP = r55
GR_SAVE_SP = r56
GR_Parameter_X = r57
GR_Parameter_Y = r58
GR_Parameter_RESULT = r59
GR_Parameter_TAG = r60
FR_X = f10
FR_Y = f1
FR_RESULT = f8
EXP_RSHF_2TO56 = f6
EXP_INV_LN2_2TO63 = f7
EXP_W_2TO56_RSH = f9
EXP_2TOM56 = f11
exp_P4 = f12
exp_P3 = f13
exp_P2 = f14
exp_P1 = f15
exp_ln2_by_128_hi = f33
exp_ln2_by_128_lo = f34
EXP_RSHF = f35
EXP_Nfloat = f36
exp_W = f37
exp_r = f38
exp_f = f39
exp_rsq = f40
exp_rcube = f41
EXP_2M = f42
exp_S1 = f43
exp_T1 = f44
EXP_MIN_DBL_OFLOW_ARG = f45
EXP_MAX_DBL_ZERO_ARG = f46
EXP_MAX_DBL_NORM_ARG = f47
EXP_MAX_DBL_UFLOW_ARG = f48
EXP_MIN_DBL_NORM_ARG = f49
exp_rP4pP3 = f50
exp_P_lo = f51
exp_P_hi = f52
exp_P = f53
exp_S = f54
EXP_NORM_f8 = f56
exp_wre_urm_f8 = f57
exp_ftz_urm_f8 = f57
exp_gt_pln = f58
exp_S2 = f59
exp_T2 = f60
// Data tables
//==============================================================
#ifdef _LIBC
.rodata
#else
.data
#endif
.align 16
// ************* DO NOT CHANGE ORDER OF THESE TABLES ********************
// double-extended 1/ln(2)
// 3fff b8aa 3b29 5c17 f0bb be87fed0691d3e88
// 3fff b8aa 3b29 5c17 f0bc
// For speed the significand will be loaded directly with a movl and setf.sig
// and the exponent will be bias+63 instead of bias+0. Thus subsequent
// computations need to scale appropriately.
// The constant 128/ln(2) is needed for the computation of w. This is also
// obtained by scaling the computations.
//
// Two shifting constants are loaded directly with movl and setf.d.
// 1. EXP_RSHF_2TO56 = 1.1000..00 * 2^(63-7)
// This constant is added to x*1/ln2 to shift the integer part of
// x*128/ln2 into the rightmost bits of the significand.
// The result of this fma is EXP_W_2TO56_RSH.
// 2. EXP_RSHF = 1.1000..00 * 2^(63)
// This constant is subtracted from EXP_W_2TO56_RSH * 2^(-56) to give
// the integer part of w, n, as a floating-point number.
// The result of this fms is EXP_Nfloat.
exp_table_1:
ASM_TYPE_DIRECTIVE(exp_table_1,@object)
data8 0x40862e42fefa39f0 // smallest dbl overflow arg
data8 0xc0874c0000000000 // approx largest arg for zero result
data8 0x40862e42fefa39ef // largest dbl arg to give normal dbl result
data8 0xc086232bdd7abcd3 // largest dbl underflow arg
data8 0xc086232bdd7abcd2 // smallest dbl arg to give normal dbl result
data8 0x0 // pad
data8 0xb17217f7d1cf79ab , 0x00003ff7 // ln2/128 hi
data8 0xc9e3b39803f2f6af , 0x00003fb7 // ln2/128 lo
// Table 1 is 2^(index_1/128) where
// index_1 goes from 0 to 15
data8 0x8000000000000000 , 0x00003FFF
data8 0x80B1ED4FD999AB6C , 0x00003FFF
data8 0x8164D1F3BC030773 , 0x00003FFF
data8 0x8218AF4373FC25EC , 0x00003FFF
data8 0x82CD8698AC2BA1D7 , 0x00003FFF
data8 0x8383594EEFB6EE37 , 0x00003FFF
data8 0x843A28C3ACDE4046 , 0x00003FFF
data8 0x84F1F656379C1A29 , 0x00003FFF
data8 0x85AAC367CC487B15 , 0x00003FFF
data8 0x8664915B923FBA04 , 0x00003FFF
data8 0x871F61969E8D1010 , 0x00003FFF
data8 0x87DB357FF698D792 , 0x00003FFF
data8 0x88980E8092DA8527 , 0x00003FFF
data8 0x8955EE03618E5FDD , 0x00003FFF
data8 0x8A14D575496EFD9A , 0x00003FFF
data8 0x8AD4C6452C728924 , 0x00003FFF
ASM_SIZE_DIRECTIVE(exp_table_1)
// Table 2 is 2^(index_1/8) where
// index_2 goes from 0 to 7
exp_table_2:
ASM_TYPE_DIRECTIVE(exp_table_2,@object)
data8 0x8000000000000000 , 0x00003FFF
data8 0x8B95C1E3EA8BD6E7 , 0x00003FFF
data8 0x9837F0518DB8A96F , 0x00003FFF
data8 0xA5FED6A9B15138EA , 0x00003FFF
data8 0xB504F333F9DE6484 , 0x00003FFF
data8 0xC5672A115506DADD , 0x00003FFF
data8 0xD744FCCAD69D6AF4 , 0x00003FFF
data8 0xEAC0C6E7DD24392F , 0x00003FFF
ASM_SIZE_DIRECTIVE (exp_table_2)
exp_p_table:
ASM_TYPE_DIRECTIVE(exp_p_table,@object)
data8 0x3f8111116da21757 //P_4
data8 0x3fa55555d787761c //P_3
data8 0x3fc5555555555414 //P_2
data8 0x3fdffffffffffd6a //P_1
ASM_SIZE_DIRECTIVE(exp_p_table)
.align 32
.global exp#
.section .text
.proc exp#
.align 32
exp:
#ifdef _LIBC
.global __ieee754_exp#
__ieee754_exp:
#endif
{ .mlx
alloc r32=ar.pfs,1,24,4,0
movl exp_GR_sig_inv_ln2 = 0xb8aa3b295c17f0bc // significand of 1/ln2
}
{ .mlx
addl EXP_AD_TB1 = @ltoff(exp_table_1), gp
movl exp_GR_rshf_2to56 = 0x4768000000000000 ;; // 1.10000 2^(63+56)
}
;;
// We do this fnorm right at the beginning to take any enabled
// faults and to normalize any input unnormals so that SWA is not taken.
{ .mfi
ld8 EXP_AD_TB1 = [EXP_AD_TB1]
fclass.m p8,p0 = f8,0x07 // Test for x=0
mov exp_GR_17ones = 0x1FFFF
}
{ .mfi
mov exp_TB1_size = 0x100
fnorm EXP_NORM_f8 = f8
mov exp_GR_exp_2tom56 = 0xffff-56
}
;;
// Form two constants we need
// 1/ln2 * 2^63 to compute w = x * 1/ln2 * 128
// 1.1000..000 * 2^(63+63-7) to right shift int(w) into the significand
{ .mmf
setf.sig EXP_INV_LN2_2TO63 = exp_GR_sig_inv_ln2 // form 1/ln2 * 2^63
setf.d EXP_RSHF_2TO56 = exp_GR_rshf_2to56 // Form const 1.100 * 2^(63+56)
fclass.m p9,p0 = f8,0x22 // Test for x=-inf
}
;;
{ .mlx
setf.exp EXP_2TOM56 = exp_GR_exp_2tom56 // form 2^-56 for scaling Nfloat
movl exp_GR_rshf = 0x43e8000000000000 // 1.10000 2^63 for right shift
}
{ .mfb
mov exp_TB2_size = 0x80
(p8) fma.d f8 = f1,f1,f0 // quick exit for x=0
(p8) br.ret.spnt b0
;;
}
{ .mfi
ldfpd EXP_MIN_DBL_OFLOW_ARG, EXP_MAX_DBL_ZERO_ARG = [EXP_AD_TB1],16
fclass.m p10,p0 = f8,0x21 // Test for x=+inf
nop.i 999
}
{ .mfb
nop.m 999
(p9) fma.d f8 = f0,f0,f0 // quick exit for x=-inf
(p9) br.ret.spnt b0
;;
}
{ .mmf
ldfpd EXP_MAX_DBL_NORM_ARG, EXP_MAX_DBL_UFLOW_ARG = [EXP_AD_TB1],16
setf.d EXP_RSHF = exp_GR_rshf // Form right shift const 1.100 * 2^63
fclass.m p11,p0 = f8,0xc3 // Test for x=nan
;;
}
{ .mfb
ldfd EXP_MIN_DBL_NORM_ARG = [EXP_AD_TB1],16
nop.f 999
(p10) br.ret.spnt b0 // quick exit for x=+inf
;;
}
{ .mfi
ldfe exp_ln2_by_128_hi = [EXP_AD_TB1],16
nop.f 999
nop.i 999
;;
}
{ .mfb
ldfe exp_ln2_by_128_lo = [EXP_AD_TB1],16
(p11) fmerge.s f8 = EXP_NORM_f8, EXP_NORM_f8
(p11) br.ret.spnt b0 // quick exit for x=nan
;;
}
// After that last load, EXP_AD_TB1 points to the beginning of table 1
// W = X * Inv_log2_by_128
// By adding 1.10...0*2^63 we shift and get round_int(W) in significand.
// We actually add 1.10...0*2^56 to X * Inv_log2 to do the same thing.
{ .mfi
nop.m 999
fma.s1 EXP_W_2TO56_RSH = EXP_NORM_f8, EXP_INV_LN2_2TO63, EXP_RSHF_2TO56
nop.i 999
;;
}
// Divide arguments into the following categories:
// Certain Underflow/zero p11 - -inf < x <= MAX_DBL_ZERO_ARG
// Certain Underflow p12 - MAX_DBL_ZERO_ARG < x <= MAX_DBL_UFLOW_ARG
// Possible Underflow p13 - MAX_DBL_UFLOW_ARG < x < MIN_DBL_NORM_ARG
// Certain Safe - MIN_DBL_NORM_ARG <= x <= MAX_DBL_NORM_ARG
// Possible Overflow p14 - MAX_DBL_NORM_ARG < x < MIN_DBL_OFLOW_ARG
// Certain Overflow p15 - MIN_DBL_OFLOW_ARG <= x < +inf
//
// If the input is really a double arg, then there will never be "Possible
// Underflow" or "Possible Overflow" arguments.
//
{ .mfi
add EXP_AD_TB2 = exp_TB1_size, EXP_AD_TB1
fcmp.ge.s1 p15,p14 = EXP_NORM_f8,EXP_MIN_DBL_OFLOW_ARG
nop.i 999
;;
}
{ .mfi
add EXP_AD_P = exp_TB2_size, EXP_AD_TB2
fcmp.le.s1 p11,p12 = EXP_NORM_f8,EXP_MAX_DBL_ZERO_ARG
nop.i 999
;;
}
{ .mfb
ldfpd exp_P4, exp_P3 = [EXP_AD_P] ,16
(p14) fcmp.gt.unc.s1 p14,p0 = EXP_NORM_f8,EXP_MAX_DBL_NORM_ARG
(p15) br.cond.spnt L(EXP_CERTAIN_OVERFLOW)
;;
}
// Nfloat = round_int(W)
// The signficand of EXP_W_2TO56_RSH contains the rounded integer part of W,
// as a twos complement number in the lower bits (that is, it may be negative).
// That twos complement number (called N) is put into exp_GR_N.
// Since EXP_W_2TO56_RSH is scaled by 2^56, it must be multiplied by 2^-56
// before the shift constant 1.10000 * 2^63 is subtracted to yield EXP_Nfloat.
// Thus, EXP_Nfloat contains the floating point version of N
{ .mfi
nop.m 999
(p12) fcmp.le.unc p12,p0 = EXP_NORM_f8,EXP_MAX_DBL_UFLOW_ARG
nop.i 999
}
{ .mfb
ldfpd exp_P2, exp_P1 = [EXP_AD_P]
fms.s1 EXP_Nfloat = EXP_W_2TO56_RSH, EXP_2TOM56, EXP_RSHF
(p11) br.cond.spnt L(EXP_CERTAIN_UNDERFLOW_ZERO)
;;
}
{ .mfi
getf.sig exp_GR_N = EXP_W_2TO56_RSH
(p13) fcmp.lt.unc p13,p0 = EXP_NORM_f8,EXP_MIN_DBL_NORM_ARG
nop.i 999
;;
}
// exp_GR_index_1 has index_1
// exp_GR_index_2_16 has index_2 * 16
// exp_GR_biased_M has M
// exp_GR_index_1_16 has index_1 * 16
// r2 has true M
{ .mfi
and exp_GR_index_1 = 0x0f, exp_GR_N
fnma.s1 exp_r = EXP_Nfloat, exp_ln2_by_128_hi, EXP_NORM_f8
shr r2 = exp_GR_N, 0x7
}
{ .mfi
and exp_GR_index_2_16 = 0x70, exp_GR_N
fnma.s1 exp_f = EXP_Nfloat, exp_ln2_by_128_lo, f1
nop.i 999
;;
}
// EXP_AD_T1 has address of T1
// EXP_AD_T2 has address if T2
{ .mmi
addl exp_GR_biased_M = 0xffff, r2
add EXP_AD_T2 = EXP_AD_TB2, exp_GR_index_2_16
shladd EXP_AD_T1 = exp_GR_index_1, 4, EXP_AD_TB1
;;
}
// Create Scale = 2^M
// r = x - Nfloat * ln2_by_128_hi
// f = 1 - Nfloat * ln2_by_128_lo
{ .mmi
setf.exp EXP_2M = exp_GR_biased_M
ldfe exp_T2 = [EXP_AD_T2]
nop.i 999
;;
}
// Load T1 and T2
{ .mfi
ldfe exp_T1 = [EXP_AD_T1]
nop.f 999
nop.i 999
;;
}
{ .mfi
nop.m 999
fma.s1 exp_rsq = exp_r, exp_r, f0
nop.i 999
}
{ .mfi
nop.m 999
fma.s1 exp_rP4pP3 = exp_r, exp_P4, exp_P3
nop.i 999
;;
}
{ .mfi
nop.m 999
fma.s1 exp_rcube = exp_r, exp_rsq, f0
nop.i 999
}
{ .mfi
nop.m 999
fma.s1 exp_P_lo = exp_r, exp_rP4pP3, exp_P2
nop.i 999
;;
}
{ .mfi
nop.m 999
fma.s1 exp_P_hi = exp_rsq, exp_P1, exp_r
nop.i 999
}
{ .mfi
nop.m 999
fma.s1 exp_S2 = exp_f,exp_T2,f0
nop.i 999
;;
}
{ .mfi
nop.m 999
fma.s1 exp_S1 = EXP_2M,exp_T1,f0
nop.i 999
;;
}
{ .mfi
nop.m 999
fma.s1 exp_P = exp_rcube, exp_P_lo, exp_P_hi
nop.i 999
;;
}
{ .mfi
nop.m 999
fma.s1 exp_S = exp_S1,exp_S2,f0
nop.i 999
;;
}
{ .bbb
(p12) br.cond.spnt L(EXP_CERTAIN_UNDERFLOW)
(p13) br.cond.spnt L(EXP_POSSIBLE_UNDERFLOW)
(p14) br.cond.spnt L(EXP_POSSIBLE_OVERFLOW)
;;
}
{ .mfb
nop.m 999
fma.d f8 = exp_S, exp_P, exp_S
br.ret.sptk b0 ;; // Normal path exit
}
L(EXP_POSSIBLE_OVERFLOW):
// We got an answer. EXP_MAX_DBL_NORM_ARG < x < EXP_MIN_DBL_OFLOW_ARG
// overflow is a possibility, not a certainty
{ .mfi
nop.m 999
fsetc.s2 0x7F,0x42
nop.i 999 ;;
}
{ .mfi
nop.m 999
fma.d.s2 exp_wre_urm_f8 = exp_S, exp_P, exp_S
nop.i 999 ;;
}
// We define an overflow when the answer with
// WRE set
// user-defined rounding mode
// is ldn +1
// Is the exponent 1 more than the largest double?
// If so, go to ERROR RETURN, else get the answer and
// leave.
// Largest double is 7FE (biased double)
// 7FE - 3FF + FFFF = 103FE
// Create + largest_double_plus_ulp
// Create - largest_double_plus_ulp
// Calculate answer with WRE set.
// Cases when answer is ldn+1 are as follows:
// ldn ldn+1
// --+----------|----------+------------
// |
// +inf +inf -inf
// RN RN
// RZ
{ .mfi
nop.m 999
fsetc.s2 0x7F,0x40
mov exp_GR_gt_ln = 0x103ff ;;
}
{ .mfi
setf.exp exp_gt_pln = exp_GR_gt_ln
nop.f 999
nop.i 999 ;;
}
{ .mfi
nop.m 999
fcmp.ge.unc.s1 p6, p0 = exp_wre_urm_f8, exp_gt_pln
nop.i 999 ;;
}
{ .mfb
nop.m 999
nop.f 999
(p6) br.cond.spnt L(EXP_CERTAIN_OVERFLOW) ;; // Branch if really overflow
}
{ .mfb
nop.m 999
fma.d f8 = exp_S, exp_P, exp_S
br.ret.sptk b0 ;; // Exit if really no overflow
}
L(EXP_CERTAIN_OVERFLOW):
{ .mmi
sub exp_GR_17ones_m1 = exp_GR_17ones, r0, 1 ;;
setf.exp f9 = exp_GR_17ones_m1
nop.i 999 ;;
}
{ .mfi
nop.m 999
fmerge.s FR_X = f8,f8
nop.i 999
}
{ .mfb
mov GR_Parameter_TAG = 14
fma.d FR_RESULT = f9, f9, f0 // Set I,O and +INF result
br.cond.sptk __libm_error_region ;;
}
L(EXP_POSSIBLE_UNDERFLOW):
// We got an answer. EXP_MAX_DBL_UFLOW_ARG < x < EXP_MIN_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 999
fsetc.s2 0x7F,0x41
nop.i 999 ;;
}
{ .mfi
nop.m 999
fma.d.s2 exp_ftz_urm_f8 = exp_S, exp_P, exp_S
nop.i 999 ;;
}
{ .mfi
nop.m 999
fsetc.s2 0x7F,0x40
nop.i 999 ;;
}
{ .mfi
nop.m 999
fcmp.eq.unc.s1 p6, p0 = exp_ftz_urm_f8, f0
nop.i 999 ;;
}
{ .mfb
nop.m 999
nop.f 999
(p6) br.cond.spnt L(EXP_CERTAIN_UNDERFLOW) ;; // Branch if really underflow
}
{ .mfb
nop.m 999
fma.d f8 = exp_S, exp_P, exp_S
br.ret.sptk b0 ;; // Exit if really no underflow
}
L(EXP_CERTAIN_UNDERFLOW):
{ .mfi
nop.m 999
fmerge.s FR_X = f8,f8
nop.i 999
}
{ .mfb
mov GR_Parameter_TAG = 15
fma.d FR_RESULT = exp_S, exp_P, exp_S // Set I,U and tiny result
br.cond.sptk __libm_error_region ;;
}
L(EXP_CERTAIN_UNDERFLOW_ZERO):
{ .mmi
mov exp_GR_one = 1 ;;
setf.exp f9 = exp_GR_one
nop.i 999 ;;
}
{ .mfi
nop.m 999
fmerge.s FR_X = f8,f8
nop.i 999
}
{ .mfb
mov GR_Parameter_TAG = 15
fma.d FR_RESULT = f9, f9, f0 // Set I,U and tiny (+0.0) result
br.cond.sptk __libm_error_region ;;
}
.endp exp
ASM_SIZE_DIRECTIVE(exp)
.proc __libm_error_region
__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
nop.m 0
nop.m 0
add GR_Parameter_RESULT = 48,sp
};;
{ .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
};;
.endp __libm_error_region
ASM_SIZE_DIRECTIVE(__libm_error_region)
.type __libm_error_support#,@function
.global __libm_error_support#