.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#