path: root/sysdeps/ia64/fpu/e_exp.S

.file "exp.s"


// Copyright (c) 2000 - 2003, Intel Corporation
// All rights reserved.
//
// Contributed 2000 by the Intel Numerics Group, 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://www.intel.com/software/products/opensource/libraries/num.htm.
//
// 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.
// 02/05/02 Corrected uninitialize predicate in POSSIBLE_UNDERFLOW path
// 05/20/02 Cleaned up namespace and sf0 syntax
// 09/07/02 Force inexact flag
// 11/15/02 Split underflow path into zero/nonzero; eliminated fma in main path
// 05/30/03 Set inexact flag on unmasked overflow/underflow

// 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 5th order polynomial
//          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

// Overflow and Underflow
//=======================
// exp(x) = largest double normal when
//     x = 709.7827 = 0x40862e42fefa39ef

// exp(x) = smallest double normal when
//     x = -708.396 = 0xc086232bdd7abcd2

// exp(x) = largest round-to-nearest single zero when
//     x = -745.1332 = 0xc0874910d52d3052


// Registers used
//==============================================================
// Floating Point registers used:
// f8, input, output
// f6 -> f15,  f32 -> f49

// General registers used:
// r14 -> r40

// Predicate registers used:
// p6 -> p15

// Assembly macros
//==============================================================

rRshf                 = r14
rAD_TB1               = r15
rAD_T1                = r15
rAD_TB2               = r16
rAD_T2                = r16
rAD_P                 = r17
rN                    = r18
rIndex_1              = r19
rIndex_2_16           = r20
rM                    = r21
rBiased_M             = r21
rIndex_1_16           = r21
rSig_inv_ln2          = r22
rExp_bias             = r23
rExp_mask             = r24
rTmp                  = r25
rRshf_2to56           = r26
rGt_ln                = r27
rExp_2tom56           = r28


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                  = f1
FR_RESULT             = f8

fRSHF_2TO56           = f6
fINV_LN2_2TO63        = f7
fW_2TO56_RSH          = f9
f2TOM56               = f11
fP5                   = f12
fP54                  = f12
fP5432                = f12
fP4                   = f13
fP3                   = f14
fP32                  = f14
fP2                   = f15
fP                    = f15

fLn2_by_128_hi        = f33
fLn2_by_128_lo        = f34

fRSHF                 = f35
fNfloat               = f36
fNormX                = f37
fR                    = f38
fF                    = f39

fRsq                  = f40
f2M                   = f41
fS1                   = f42
fT1                   = f42
fS2                   = f43
fT2                   = f43
fS                    = f43
fWre_urm_f8           = f44
fFtz_urm_f8           = f44

fMIN_DBL_OFLOW_ARG    = f45
fMAX_DBL_ZERO_ARG     = f46
fMAX_DBL_NORM_ARG     = f47
fMIN_DBL_NORM_ARG     = f48
fGt_pln               = f49
fTmp                  = f49


// Data tables
//==============================================================

RODATA
.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. fRSHF_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 fW_2TO56_RSH.
//   2. fRSHF       = 1.1000..00 * 2^(63)
//        This constant is subtracted from fW_2TO56_RSH * 2^(-56) to give
//        the integer part of w, n, as a floating-point number.
//        The result of this fms is fNfloat.


LOCAL_OBJECT_START(exp_table_1)
data8 0x40862e42fefa39f0 // smallest dbl overflow arg, +709.7827
data8 0xc0874910d52d3052 // largest arg for rnd-to-nearest 0 result, -745.133
data8 0x40862e42fefa39ef // largest dbl arg to give normal dbl result, +709.7827
data8 0xc086232bdd7abcd2 // smallest dbl arg to give normal dbl result, -708.396
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
LOCAL_OBJECT_END(exp_table_1)

// Table 2 is 2^(index_1/8) where
// index_2 goes from 0 to 7
LOCAL_OBJECT_START(exp_table_2)
data8 0x8000000000000000 , 0x00003FFF
data8 0x8B95C1E3EA8BD6E7 , 0x00003FFF
data8 0x9837F0518DB8A96F , 0x00003FFF
data8 0xA5FED6A9B15138EA , 0x00003FFF
data8 0xB504F333F9DE6484 , 0x00003FFF
data8 0xC5672A115506DADD , 0x00003FFF
data8 0xD744FCCAD69D6AF4 , 0x00003FFF
data8 0xEAC0C6E7DD24392F , 0x00003FFF
LOCAL_OBJECT_END(exp_table_2)


LOCAL_OBJECT_START(exp_p_table)
data8 0x3f8111116da21757 //P5
data8 0x3fa55555d787761c //P4
data8 0x3fc5555555555414 //P3
data8 0x3fdffffffffffd6a //P2
LOCAL_OBJECT_END(exp_p_table)


.section .text
GLOBAL_IEEE754_ENTRY(exp)

{ .mlx
      nop.m           0
      movl            rSig_inv_ln2 = 0xb8aa3b295c17f0bc  // significand of 1/ln2
}
{ .mlx
      addl            rAD_TB1    = @ltoff(exp_table_1), gp
      movl            rRshf_2to56 = 0x4768000000000000   // 1.10000 2^(63+56)
}
;;

{ .mfi
      ld8             rAD_TB1    = [rAD_TB1]
      fclass.m        p8,p0 = f8,0x07  // Test for x=0
      mov             rExp_mask = 0x1ffff
}
{ .mfi
      mov             rExp_bias = 0xffff
      fnorm.s1        fNormX   = f8
      mov             rExp_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

{ .mfi
      setf.sig        fINV_LN2_2TO63 = rSig_inv_ln2 // form 1/ln2 * 2^63
      fclass.m        p9,p0 = f8,0x22  // Test for x=-inf
      nop.i           0
}
{ .mlx
      setf.d          fRSHF_2TO56 = rRshf_2to56 // Form const 1.100 * 2^(63+56)
      movl            rRshf = 0x43e8000000000000 // 1.10000 2^63 for right shift
}
;;

{ .mfi
      ldfpd           fMIN_DBL_OFLOW_ARG, fMAX_DBL_ZERO_ARG = [rAD_TB1],16
      fclass.m        p10,p0 = f8,0x1e1  // Test for x=+inf, nan, NaT
      nop.i           0
}
{ .mfb
      setf.exp        f2TOM56 = rExp_2tom56 // form 2^-56 for scaling Nfloat
(p9)  fma.d.s0        f8 = f0,f0,f0           // quick exit for x=-inf
(p9)  br.ret.spnt     b0
}
;;

{ .mfi
      ldfpd           fMAX_DBL_NORM_ARG, fMIN_DBL_NORM_ARG = [rAD_TB1],16
      nop.f           0
      nop.i           0
}
{ .mfb
      setf.d          fRSHF = rRshf // Form right shift const 1.100 * 2^63
(p8)  fma.d.s0        f8 = f1,f1,f0           // quick exit for x=0
(p8)  br.ret.spnt     b0
}
;;

{ .mfb
      ldfe            fLn2_by_128_hi  = [rAD_TB1],16
(p10) fma.d.s0        f8 = f8,f8,f0  // Result if x=+inf, nan, NaT
(p10) br.ret.spnt     b0               // quick exit for x=+inf, nan, NaT
}
;;

{ .mfi
      ldfe            fLn2_by_128_lo  = [rAD_TB1],16
      fcmp.eq.s0      p6,p0 = f8, f0       // Dummy to set D
      nop.i           0
}
;;

// After that last load, rAD_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           0
      fma.s1          fW_2TO56_RSH  = fNormX, fINV_LN2_2TO63, fRSHF_2TO56
      nop.i           0
}
;;

// Divide arguments into the following categories:
//  Certain Underflow       p11 - -inf < x <= MAX_DBL_ZERO_ARG
//  Possible Underflow      p13 - MAX_DBL_ZERO_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 Overflow" arguments.
//

{ .mfi
      add             rAD_TB2 = 0x100, rAD_TB1
      fcmp.ge.s1      p15,p0 = fNormX,fMIN_DBL_OFLOW_ARG
      nop.i           0
}
;;

{ .mfi
      add             rAD_P = 0x80, rAD_TB2
      fcmp.le.s1      p11,p0 = fNormX,fMAX_DBL_ZERO_ARG
      nop.i           0
}
;;

{ .mfb
      ldfpd           fP5, fP4  = [rAD_P] ,16
      fcmp.gt.s1      p14,p0 = fNormX,fMAX_DBL_NORM_ARG
(p15) br.cond.spnt    EXP_CERTAIN_OVERFLOW
}
;;

// Nfloat = round_int(W)
// The signficand of fW_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 rN.

// Since fW_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 fNfloat.
// Thus, fNfloat contains the floating point version of N

{ .mfb
      ldfpd           fP3, fP2  = [rAD_P]
      fms.s1          fNfloat = fW_2TO56_RSH, f2TOM56, fRSHF
(p11) br.cond.spnt    EXP_CERTAIN_UNDERFLOW
}
;;

{ .mfi
      getf.sig        rN        = fW_2TO56_RSH
      nop.f           0
      nop.i           0
}
;;

// rIndex_1 has index_1
// rIndex_2_16 has index_2 * 16
// rBiased_M has M
// rIndex_1_16 has index_1 * 16

// rM has true M
// r = x - Nfloat * ln2_by_128_hi
// f = 1 - Nfloat * ln2_by_128_lo
{ .mfi
      and             rIndex_1 = 0x0f, rN
      fnma.s1         fR   = fNfloat, fLn2_by_128_hi, fNormX
      shr             rM = rN,  0x7
}
{ .mfi
      and             rIndex_2_16 = 0x70, rN
      fnma.s1         fF   = fNfloat, fLn2_by_128_lo, f1
      nop.i           0
}
;;

// rAD_T1 has address of T1
// rAD_T2 has address if T2

{ .mmi
      add             rBiased_M = rExp_bias, rM
      add             rAD_T2 = rAD_TB2, rIndex_2_16
      shladd          rAD_T1 = rIndex_1, 4, rAD_TB1
}
;;

// Create Scale = 2^M
{ .mmi
      setf.exp        f2M = rBiased_M
      ldfe            fT2  = [rAD_T2]
      nop.i           0
}
;;

// Load T1 and T2
{ .mfi
      ldfe            fT1  = [rAD_T1]
      fmpy.s0         fTmp = fLn2_by_128_lo, fLn2_by_128_lo // Force inexact
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fma.s1          fRsq = fR, fR, f0
      nop.i           0
}
{ .mfi
      nop.m           0
      fma.s1          fP54 = fR, fP5, fP4
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fcmp.lt.s1      p13,p0 = fNormX,fMIN_DBL_NORM_ARG
      nop.i           0
}
{ .mfi
      nop.m           0
      fma.s1          fP32 = fR, fP3, fP2
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fma.s1          fP5432  = fRsq, fP54, fP32
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fma.s1          fS1  = f2M,fT1,f0
      nop.i           0
}
{ .mfi
      nop.m           0
      fma.s1          fS2  = fF,fT2,f0
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fma.s1          fP     = fRsq, fP5432, fR
      nop.i           0
}
{ .mfi
      nop.m           0
      fma.s1          fS   = fS1,fS2,f0
      nop.i           0
}
;;

{ .mbb
      nop.m           0
(p13) br.cond.spnt    EXP_POSSIBLE_UNDERFLOW
(p14) br.cond.spnt    EXP_POSSIBLE_OVERFLOW
}
;;

{ .mfb
      nop.m           0
      fma.d.s0        f8 = fS, fP, fS
      br.ret.sptk     b0                  // Normal path exit
}
;;


EXP_POSSIBLE_OVERFLOW:

// Here if fMAX_DBL_NORM_ARG < x < fMIN_DBL_OFLOW_ARG
// This cannot happen if input is a double, only if input higher precision.
// Overflow is a possibility, not a certainty.

// Recompute result using status field 2 with user's rounding mode,
// and wre set.  If result is larger than largest double, then we have
// overflow

{ .mfi
      mov             rGt_ln  = 0x103ff // Exponent for largest dbl + 1 ulp
      fsetc.s2        0x7F,0x42         // Get user's round mode, set wre
      nop.i           0
}
;;

{ .mfi
      setf.exp        fGt_pln = rGt_ln  // Create largest double + 1 ulp
      fma.d.s2        fWre_urm_f8 = fS, fP, fS    // Result with wre set
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fsetc.s2        0x7F,0x40                   // Turn off wre in sf2
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fcmp.ge.s1      p6, p0 =  fWre_urm_f8, fGt_pln // Test for overflow
      nop.i           0
}
;;

{ .mfb
      nop.m           0
      nop.f           0
(p6)  br.cond.spnt    EXP_CERTAIN_OVERFLOW // Branch if overflow
}
;;

{ .mfb
      nop.m           0
      fma.d.s0        f8 = fS, fP, fS
      br.ret.sptk     b0                     // Exit if really no overflow
}
;;

EXP_CERTAIN_OVERFLOW:
{ .mmi
      sub             rTmp = rExp_mask, r0, 1
;;
      setf.exp        fTmp = rTmp
      nop.i           0
}
;;

{ .mfi
      alloc           r32=ar.pfs,1,4,4,0
      fmerge.s        FR_X = f8,f8
      nop.i           0
}
{ .mfb
      mov             GR_Parameter_TAG = 14
      fma.d.s0        FR_RESULT = fTmp, fTmp, fTmp    // Set I,O and +INF result
      br.cond.sptk    __libm_error_region
}
;;

EXP_POSSIBLE_UNDERFLOW:

// Here if fMAX_DBL_ZERO_ARG < x < fMIN_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           0
      fsetc.s2        0x7F,0x41                // Get user's round mode, set ftz
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fma.d.s2        fFtz_urm_f8 = fS, fP, fS // Result with ftz set
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fsetc.s2        0x7F,0x40                // Turn off ftz in sf2
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fcmp.eq.s1      p6, p7 = fFtz_urm_f8, f0 // Test for underflow
      nop.i           0
}
{ .mfi
      nop.m           0
      fma.d.s0        f8 = fS, fP, fS          // Compute result, set I, maybe U
      nop.i           0
}
;;

{ .mbb
      nop.m           0
(p6)  br.cond.spnt    EXP_UNDERFLOW_COMMON     // Branch if really underflow
(p7)  br.ret.sptk     b0                       // Exit if really no underflow
}
;;

EXP_CERTAIN_UNDERFLOW:
// Here if  x < fMAX_DBL_ZERO_ARG
// Result will be zero (or smallest denorm if round to +inf) with I, U set
{ .mmi
      mov             rTmp = 1
;;
      setf.exp        fTmp = rTmp               // Form small normal
      nop.i           0
}
;;

{ .mfi
      nop.m           0
      fmerge.se       fTmp = fTmp, fLn2_by_128_lo // Small with signif lsb 1
      nop.i           0
}
;;
      
{ .mfb
      nop.m           0
      fma.d.s0        f8 = fTmp, fTmp, f0 // Set I,U, tiny (+0.0) result
      br.cond.sptk    EXP_UNDERFLOW_COMMON
}
;;

EXP_UNDERFLOW_COMMON:
// Determine if underflow result is zero or nonzero
{ .mfi
      alloc           r32=ar.pfs,1,4,4,0
      fcmp.eq.s1      p6, p0 =  f8, f0
      nop.i           0
}
;;

{ .mfb
      nop.m           0
      fmerge.s        FR_X = fNormX,fNormX
(p6)  br.cond.spnt    EXP_UNDERFLOW_ZERO
}
;;

EXP_UNDERFLOW_NONZERO:
// Here if  x < fMIN_DBL_NORM_ARG and result nonzero;
// I, U are set
{ .mfb
      mov             GR_Parameter_TAG = 15
      nop.f           0                         // FR_RESULT already set
      br.cond.sptk    __libm_error_region
}
;;

EXP_UNDERFLOW_ZERO:
// Here if x < fMIN_DBL_NORM_ARG and result zero;
// I, U are set
{ .mfb
      mov             GR_Parameter_TAG = 15
      nop.f           0                         // FR_RESULT already set
      br.cond.sptk    __libm_error_region
}
;;

GLOBAL_IEEE754_END(exp)


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
        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
        add   GR_Parameter_RESULT = 48,sp
        nop.m 0
        nop.i 0
};;
{ .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
};;

LOCAL_LIBM_END(__libm_error_region)
.type   __libm_error_support#,@function
.global __libm_error_support#