.file "exp_m1.s"

// Copyright (c) 2000 - 2005, 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

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// 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

// 04/04/00 Unwind support added

// 08/15/00 Bundle added after call to __libm_error_support to properly

//          set [the previously overwritten] GR_Parameter_RESULT.

// 07/07/01 Improved speed of all paths

// 05/20/02 Cleaned up namespace and sf0 syntax

// 11/20/02 Improved speed, algorithm based on exp

// 03/31/05 Reformatted delimiters between data tables

// API

//==============================================================

// double expm1(double)

// Overview of operation

//==============================================================

// 1. Inputs of Nan, Inf, Zero, NatVal handled with special paths

//

// 2. |x| < 2^-60

//    Result = x, computed by x + x*x to handle appropriate flags and rounding

//

// 3. 2^-60 <= |x| < 2^-2

//    Result determined by 13th order Taylor series polynomial

//    expm1f(x) = x + Q2*x^2 + ... + Q13*x^13

//

// 4. x < -48.0

//    Here we know result is essentially -1 + eps, where eps only affects

//    rounded result.  Set I.

//

// 5. x >= 709.7827

//    Result overflows.  Set I, O, and call error support

//

// 6. 2^-2 <= x < 709.7827  or  -48.0 <= x < -2^-2

//    This is the main path.  The algorithm is described below:

// 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 by 5th order polynomial

//          r = x - n (log2/128)_high

//          delta = - n (log2/128)_low

//       Calculate exp(delta) as 1 + delta

// Special values

//==============================================================

// expm1(+0)    = +0.0

// expm1(-0)    = -0.0

// expm1(+qnan) = +qnan

// expm1(-qnan) = -qnan

// expm1(+snan) = +qnan

// expm1(-snan) = -qnan

// expm1(-inf)  = -1.0

// expm1(+inf)  = +inf

// Overflow and Underflow

//=======================

// expm1(x) = largest double normal when

//     x = 709.7827 = 40862e42fefa39ef

//

// Underflow is handled as described in case 2 above.

// Registers used

//==============================================================

// Floating Point registers used:

// f8, input

// f9 -> f15,  f32 -> f75

// 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_Ln2_lo             = r17

rAD_P                  = r17

rN                     = r18

rIndex_1               = r19

rIndex_2_16            = r20

rM                     = r21

rBiased_M              = r21

rIndex_1_16            = r22

rSignexp_x             = r23

rExp_x                 = r24

rSig_inv_ln2           = r25

rAD_Q1                 = r26

rAD_Q2                 = r27

rTmp                   = r27

rExp_bias              = r28

rExp_mask              = r29

rRshf_2to56            = r30

rGt_ln                 = r31

rExp_2tom56            = r31

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                   = f50

fP5432                 = f50

fP4                    = f13

fP3                    = f14

fP32                   = f14

fP2                    = f15

fLn2_by_128_hi         = f33

fLn2_by_128_lo         = f34

fRSHF                  = f35

fNfloat                = f36

fW                     = f37

fR                     = f38

fF                     = f39

fRsq                   = f40

fRcube                 = f41

f2M                    = f42

fS1                    = f43

fT1                    = f44

fMIN_DBL_OFLOW_ARG     = f45

fMAX_DBL_MINUS_1_ARG   = f46

fMAX_DBL_NORM_ARG      = f47

fP_lo                  = f51

fP_hi                  = f52

fP                     = f53

fS                     = f54

fNormX                 = f56

fWre_urm_f8            = f57

fGt_pln                = f58

fTmp                   = f58

fS2                    = f59

fT2                    = f60

fSm1                   = f61

fXsq                   = f62

fX6                    = f63

fX4                    = f63

fQ7                    = f64

fQ76                   = f64

fQ7654                 = f64

fQ765432               = f64

fQ6                    = f65

fQ5                    = f66

fQ54                   = f66

fQ4                    = f67

fQ3                    = f68

fQ32                   = f68

fQ2                    = f69

fQD                    = f70

fQDC                   = f70

fQDCBA                 = f70

fQDCBA98               = f70

fQDCBA98765432         = f70

fQC                    = f71

fQB                    = f72

fQBA                   = f72

fQA                    = f73

fQ9                    = f74

fQ98                   = f74

fQ8                    = f75

// 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

data8 0xc048000000000000 // approx largest arg for minus one result

data8 0x40862e42fefa39ef // largest 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

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)

LOCAL_OBJECT_START(exp_Q1_table)

data8 0x3de6124613a86d09 // QD = 1/13!

data8 0x3e21eed8eff8d898 // QC = 1/12!

data8 0x3ec71de3a556c734 // Q9 = 1/9!

data8 0x3efa01a01a01a01a // Q8 = 1/8!

data8 0x8888888888888889,0x3ff8 // Q5 = 1/5!

data8 0xaaaaaaaaaaaaaaab,0x3ffc // Q3 = 1/3!

data8 0x0,0x0            // Pad to avoid bank conflicts

LOCAL_OBJECT_END(exp_Q1_table)

LOCAL_OBJECT_START(exp_Q2_table)

data8 0x3e5ae64567f544e4 // QB = 1/11!

data8 0x3e927e4fb7789f5c // QA = 1/10!

data8 0x3f2a01a01a01a01a // Q7 = 1/7!

data8 0x3f56c16c16c16c17 // Q6 = 1/6!

data8 0xaaaaaaaaaaaaaaab,0x3ffa // Q4 = 1/4!

data8 0x8000000000000000,0x3ffe // Q2 = 1/2!

LOCAL_OBJECT_END(exp_Q2_table)

.section .text

GLOBAL_IEEE754_ENTRY(expm1)

{ .mlx

      getf.exp        rSignexp_x = f8  // Must recompute if x unorm

      movl            rSig_inv_ln2 = 0xb8aa3b295c17f0bc  // signif of 1/ln2

}

{ .mlx

      addl            rAD_TB1    = @ltoff(exp_Table_1), gp

      movl            rRshf_2to56 = 0x4768000000000000   // 1.10000 2^(63+56)

}

;;

// We do this fnorm right at the beginning to normalize

// any input unnormals so that SWA is not taken.

{ .mfi

      ld8             rAD_TB1    = [rAD_TB1]

      fclass.m        p6,p0 = f8,0x0b  // Test for x=unorm

      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        p8,p0 = f8,0x07  // Test for x=0

      nop.i           0

}

{ .mlx

      setf.d          fRSHF_2TO56 = rRshf_2to56 // Form 1.100 * 2^(63+56)

      movl            rRshf = 0x43e8000000000000   // 1.10000 2^63 for rshift

}

;;

{ .mfi

      setf.exp        f2TOM56 = rExp_2tom56 // form 2^-56 for scaling Nfloat

      fclass.m        p9,p0 = f8,0x22  // Test for x=-inf

      add             rAD_TB2 = 0x140, rAD_TB1 // Point to Table 2

}

{ .mib

      add             rAD_Q1 = 0x1e0, rAD_TB1 // Point to Q table for small path

      add             rAD_Ln2_lo = 0x30, rAD_TB1 // Point to ln2_by_128_lo

(p6)  br.cond.spnt    EXPM1_UNORM // Branch if x unorm

}

;;

EXPM1_COMMON:

{ .mfi

      ldfpd           fMIN_DBL_OFLOW_ARG, fMAX_DBL_MINUS_1_ARG = [rAD_TB1],16

      fclass.m        p10,p0 = f8,0x1e1  // Test for x=+inf, NaN, NaT

      add             rAD_Q2 = 0x50, rAD_Q1   // Point to Q table for small path

}

{ .mfb

      nop.m           0

      nop.f           0

(p8)  br.ret.spnt     b0                        // Exit for x=0, return x

}

;;

{ .mfi

      ldfd            fMAX_DBL_NORM_ARG = [rAD_TB1],16

      nop.f           0

      and             rExp_x = rExp_mask, rSignexp_x // Biased exponent of x

}

{ .mfb

      setf.d          fRSHF = rRshf // Form right shift const 1.100 * 2^63

(p9)  fms.d.s0        f8 = f0,f0,f1            // quick exit for x=-inf

(p9)  br.ret.spnt     b0

}

;;

{ .mfi

      ldfpd           fQD, fQC = [rAD_Q1], 16  // Load coeff for small path

      nop.f           0

      sub             rExp_x = rExp_x, rExp_bias // True exponent of x

}

{ .mfb

      ldfpd           fQB, fQA = [rAD_Q2], 16  // Load coeff for small path

(p10) fma.d.s0        f8 = f8, f1, f0          // For x=+inf, NaN, NaT

(p10) br.ret.spnt     b0                       // Exit for x=+inf, NaN, NaT

}

;;

{ .mfi

      ldfpd           fQ9, fQ8 = [rAD_Q1], 16  // Load coeff for small path

      fma.s1          fXsq = fNormX, fNormX, f0  // x*x for small path

      cmp.gt          p7, p8 = -2, rExp_x      // Test |x| < 2^(-2)

}

{ .mfi

      ldfpd           fQ7, fQ6 = [rAD_Q2], 16  // Load coeff for small path

      nop.f           0

      nop.i           0

}

;;

{ .mfi

      ldfe            fQ5 = [rAD_Q1], 16       // Load coeff for small path

      nop.f           0

      nop.i           0

}

{ .mib

      ldfe            fQ4 = [rAD_Q2], 16       // Load coeff for small path

(p7)  cmp.gt.unc      p6, p7 = -60, rExp_x     // Test |x| < 2^(-60)

(p7)  br.cond.spnt    EXPM1_SMALL              // Branch if 2^-60 <= |x| < 2^-2

}

;;

// 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

      ldfe            fLn2_by_128_hi  = [rAD_TB1],32

      fma.s1          fW_2TO56_RSH  = fNormX, fINV_LN2_2TO63, fRSHF_2TO56

      nop.i           0

}

{ .mfb

      ldfe            fLn2_by_128_lo  = [rAD_Ln2_lo]

(p6)  fma.d.s0        f8 = f8, f8, f8 // If x < 2^-60, result=x+x*x

(p6)  br.ret.spnt     b0              // Exit if x < 2^-60

}

;;

// Divide arguments into the following categories:

//  Certain minus one       p11 - -inf < x <= MAX_DBL_MINUS_1_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.

//

// After that last load, rAD_TB1 points to the beginning of table 1

{ .mfi

      nop.m           0

      fcmp.ge.s1      p15,p14 = fNormX,fMIN_DBL_OFLOW_ARG

      nop.i           0

}

;;

{ .mfi

      add             rAD_P = 0x80, rAD_TB2

      fcmp.le.s1      p11,p0 = fNormX,fMAX_DBL_MINUS_1_ARG

      nop.i           0

}

;;

{ .mfb

      ldfpd           fP5, fP4  = [rAD_P] ,16

(p14) fcmp.gt.unc.s1  p14,p0 = fNormX,fMAX_DBL_NORM_ARG

(p15) br.cond.spnt    EXPM1_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    EXPM1_CERTAIN_MINUS_ONE

}

;;

{ .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

// 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

// Load T1 and T2

{ .mmi

      setf.exp        f2M = rBiased_M

      ldfe            fT2  = [rAD_T2]

      nop.i           0

}

;;

{ .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          fP54 = fR, fP5, fP4

      nop.i           0

}

{ .mfi

      nop.m           0

      fma.s1          fP32 = fR, fP3, fP2

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fRsq = fR, fR, f0

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fP5432  = fRsq, fP54, fP32

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fS2  = fF,fT2,f0

      nop.i           0

}

{ .mfi

      nop.m           0

      fma.s1          fS1  = f2M,fT1,f0

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fP = fRsq, fP5432, fR

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fms.s1          fSm1 = fS1,fS2,f1    // S - 1.0

      nop.i           0

}

{ .mfb

      nop.m           0

      fma.s1          fS   = fS1,fS2,f0

(p14) br.cond.spnt    EXPM1_POSSIBLE_OVERFLOW

}

;;

{ .mfb

      nop.m           0

      fma.d.s0        f8 = fS, fP, fSm1

      br.ret.sptk     b0                // Normal path exit

}

;;

// Here if 2^-60 <= |x| <2^-2

// Compute 13th order polynomial

EXPM1_SMALL:

{ .mmf

      ldfe            fQ3 = [rAD_Q1], 16

      ldfe            fQ2 = [rAD_Q2], 16

      fma.s1          fX4 = fXsq, fXsq, f0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fQDC = fQD, fNormX, fQC

      nop.i           0

}

{ .mfi

      nop.m           0

      fma.s1          fQBA = fQB, fNormX, fQA

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fQ98 = fQ9, fNormX, fQ8

      nop.i           0

}

{ .mfi

      nop.m           0

      fma.s1          fQ76= fQ7, fNormX, fQ6

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fQ54 = fQ5, fNormX, fQ4

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fX6 = fX4, fXsq, f0

      nop.i           0

}

{ .mfi

      nop.m           0

      fma.s1          fQ32= fQ3, fNormX, fQ2

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fQDCBA = fQDC, fXsq, fQBA

      nop.i           0

}

{ .mfi

      nop.m           0

      fma.s1          fQ7654 = fQ76, fXsq, fQ54

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fQDCBA98 = fQDCBA, fXsq, fQ98

      nop.i           0

}

{ .mfi

      nop.m           0

      fma.s1          fQ765432 = fQ7654, fXsq, fQ32

      nop.i           0

}

;;

{ .mfi

      nop.m           0

      fma.s1          fQDCBA98765432 = fQDCBA98, fX6, fQ765432

      nop.i           0

}

;;

{ .mfb

      nop.m           0

      fma.d.s0        f8 = fQDCBA98765432, fXsq, fNormX

      br.ret.sptk     b0                   // Exit small branch

}

;;

EXPM1_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, fSm1  // 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    EXPM1_CERTAIN_OVERFLOW // Branch if overflow

}

;;

{ .mfb

      nop.m           0

      fma.d.s0        f8 = fS, fP, fSm1

      br.ret.sptk     b0                     // Exit if really no overflow

}

;;

EXPM1_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 = 41

      fma.d.s0        FR_RESULT = fTmp, fTmp, f0    // Set I,O and +INF result

      br.cond.sptk    __libm_error_region

}

;;

// Here if x unorm

EXPM1_UNORM:

{ .mfb

      getf.exp        rSignexp_x = fNormX    // Must recompute if x unorm

      fcmp.eq.s0      p6, p0 = f8, f0        // Set D flag

      br.cond.sptk    EXPM1_COMMON

}

;;

// here if result will be -1 and inexact, x <= -48.0

EXPM1_CERTAIN_MINUS_ONE:

{ .mmi

      mov             rTmp = 1

;;

      setf.exp        fTmp = rTmp

      nop.i           0

}

;;

{ .mfb

      nop.m           0

      fms.d.s0        FR_RESULT = fTmp, fTmp, f1 // Set I, rounded -1+eps result

      br.ret.sptk     b0

}

;;

GLOBAL_IEEE754_END(expm1)

libm_alias_double_other (__expm1, expm1)

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