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797 lines
22 KiB
797 lines
22 KiB
.file "exp.s"
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// Copyright (c) 2000, 2001, Intel Corporation
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// All rights reserved.
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//
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// Contributed 2/2/2000 by John Harrison, Ted Kubaska, Bob Norin, Shane Story,
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// and Ping Tak Peter Tang of the Computational Software Lab, Intel Corporation.
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//
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// WARRANTY DISCLAIMER
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTEL OR ITS
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// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
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// OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING
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// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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//
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// Intel Corporation is the author of this code, and requests that all
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// problem reports or change requests be submitted to it directly at
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// http://developer.intel.com/opensource.
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//
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// History
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//==============================================================
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// 2/02/00 Initial version
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// 3/07/00 exp(inf) = inf but now does NOT call error support
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// exp(-inf) = 0 but now does NOT call error support
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// 4/04/00 Unwind support added
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// 8/15/00 Bundle added after call to __libm_error_support to properly
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// set [the previously overwritten] GR_Parameter_RESULT.
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// 11/30/00 Reworked to shorten main path, widen main path to include all
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// args in normal range, and add quick exit for 0, nan, inf.
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// 12/05/00 Loaded constants earlier with setf to save 2 cycles.
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// API
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//==============================================================
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// double exp(double)
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// Overview of operation
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//==============================================================
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// Take the input x. w is "how many log2/128 in x?"
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// w = x * 128/log2
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// n = int(w)
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// x = n log2/128 + r + delta
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// n = 128M + index_1 + 2^4 index_2
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// x = M log2 + (log2/128) index_1 + (log2/8) index_2 + r + delta
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// exp(x) = 2^M 2^(index_1/128) 2^(index_2/8) exp(r) exp(delta)
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// Construct 2^M
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// Get 2^(index_1/128) from table_1;
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// Get 2^(index_2/8) from table_2;
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// Calculate exp(r) by series
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// r = x - n (log2/128)_high
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// delta = - n (log2/128)_low
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// Calculate exp(delta) as 1 + delta
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// Special values
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//==============================================================
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// exp(+0) = 1.0
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// exp(-0) = 1.0
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// exp(+qnan) = +qnan
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// exp(-qnan) = -qnan
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// exp(+snan) = +qnan
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// exp(-snan) = -qnan
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// exp(-inf) = +0
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// exp(+inf) = +inf
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// Overfow and Underfow
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//=======================
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// exp(-x) = smallest double normal when
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// x = -708.396 = c086232bdd7abcd2
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// exp(x) = largest double normal when
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// x = 709.7827 = 40862e42fefa39ef
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// Registers used
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//==============================================================
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// Floating Point registers used:
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// f8, input
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// f9 -> f15, f32 -> f60
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// General registers used:
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// r32 -> r60
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// Predicate registers used:
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// p6 -> p15
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// Assembly macros
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//==============================================================
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exp_GR_rshf = r33
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EXP_AD_TB1 = r34
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EXP_AD_TB2 = r35
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EXP_AD_P = r36
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exp_GR_N = r37
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exp_GR_index_1 = r38
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exp_GR_index_2_16 = r39
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exp_GR_biased_M = r40
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exp_GR_index_1_16 = r41
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EXP_AD_T1 = r42
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EXP_AD_T2 = r43
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exp_GR_sig_inv_ln2 = r44
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exp_GR_17ones = r45
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exp_GR_one = r46
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exp_TB1_size = r47
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exp_TB2_size = r48
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exp_GR_rshf_2to56 = r49
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exp_GR_gt_ln = r50
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exp_GR_exp_2tom56 = r51
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exp_GR_17ones_m1 = r52
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GR_SAVE_B0 = r53
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GR_SAVE_PFS = r54
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GR_SAVE_GP = r55
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GR_SAVE_SP = r56
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GR_Parameter_X = r57
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GR_Parameter_Y = r58
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GR_Parameter_RESULT = r59
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GR_Parameter_TAG = r60
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FR_X = f10
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FR_Y = f1
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FR_RESULT = f8
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EXP_RSHF_2TO56 = f6
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EXP_INV_LN2_2TO63 = f7
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EXP_W_2TO56_RSH = f9
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EXP_2TOM56 = f11
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exp_P4 = f12
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exp_P3 = f13
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exp_P2 = f14
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exp_P1 = f15
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exp_ln2_by_128_hi = f33
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exp_ln2_by_128_lo = f34
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EXP_RSHF = f35
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EXP_Nfloat = f36
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exp_W = f37
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exp_r = f38
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exp_f = f39
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exp_rsq = f40
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exp_rcube = f41
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EXP_2M = f42
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exp_S1 = f43
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exp_T1 = f44
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EXP_MIN_DBL_OFLOW_ARG = f45
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EXP_MAX_DBL_ZERO_ARG = f46
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EXP_MAX_DBL_NORM_ARG = f47
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EXP_MAX_DBL_UFLOW_ARG = f48
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EXP_MIN_DBL_NORM_ARG = f49
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exp_rP4pP3 = f50
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exp_P_lo = f51
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exp_P_hi = f52
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exp_P = f53
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exp_S = f54
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EXP_NORM_f8 = f56
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exp_wre_urm_f8 = f57
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exp_ftz_urm_f8 = f57
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exp_gt_pln = f58
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exp_S2 = f59
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exp_T2 = f60
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// Data tables
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//==============================================================
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.data
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.align 16
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// ************* DO NOT CHANGE ORDER OF THESE TABLES ********************
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// double-extended 1/ln(2)
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// 3fff b8aa 3b29 5c17 f0bb be87fed0691d3e88
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// 3fff b8aa 3b29 5c17 f0bc
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// For speed the significand will be loaded directly with a movl and setf.sig
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// and the exponent will be bias+63 instead of bias+0. Thus subsequent
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// computations need to scale appropriately.
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// The constant 128/ln(2) is needed for the computation of w. This is also
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// obtained by scaling the computations.
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//
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// Two shifting constants are loaded directly with movl and setf.d.
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// 1. EXP_RSHF_2TO56 = 1.1000..00 * 2^(63-7)
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// This constant is added to x*1/ln2 to shift the integer part of
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// x*128/ln2 into the rightmost bits of the significand.
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// The result of this fma is EXP_W_2TO56_RSH.
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// 2. EXP_RSHF = 1.1000..00 * 2^(63)
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// This constant is subtracted from EXP_W_2TO56_RSH * 2^(-56) to give
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// the integer part of w, n, as a floating-point number.
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// The result of this fms is EXP_Nfloat.
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exp_table_1:
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data8 0x40862e42fefa39f0 // smallest dbl overflow arg
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data8 0xc0874c0000000000 // approx largest arg for zero result
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data8 0x40862e42fefa39ef // largest dbl arg to give normal dbl result
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data8 0xc086232bdd7abcd3 // largest dbl underflow arg
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data8 0xc086232bdd7abcd2 // smallest dbl arg to give normal dbl result
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data8 0x0 // pad
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data8 0xb17217f7d1cf79ab , 0x00003ff7 // ln2/128 hi
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data8 0xc9e3b39803f2f6af , 0x00003fb7 // ln2/128 lo
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// Table 1 is 2^(index_1/128) where
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// index_1 goes from 0 to 15
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data8 0x8000000000000000 , 0x00003FFF
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data8 0x80B1ED4FD999AB6C , 0x00003FFF
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data8 0x8164D1F3BC030773 , 0x00003FFF
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data8 0x8218AF4373FC25EC , 0x00003FFF
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data8 0x82CD8698AC2BA1D7 , 0x00003FFF
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data8 0x8383594EEFB6EE37 , 0x00003FFF
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data8 0x843A28C3ACDE4046 , 0x00003FFF
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data8 0x84F1F656379C1A29 , 0x00003FFF
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data8 0x85AAC367CC487B15 , 0x00003FFF
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data8 0x8664915B923FBA04 , 0x00003FFF
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data8 0x871F61969E8D1010 , 0x00003FFF
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data8 0x87DB357FF698D792 , 0x00003FFF
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data8 0x88980E8092DA8527 , 0x00003FFF
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data8 0x8955EE03618E5FDD , 0x00003FFF
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data8 0x8A14D575496EFD9A , 0x00003FFF
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data8 0x8AD4C6452C728924 , 0x00003FFF
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// Table 2 is 2^(index_1/8) where
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// index_2 goes from 0 to 7
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exp_table_2:
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data8 0x8000000000000000 , 0x00003FFF
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data8 0x8B95C1E3EA8BD6E7 , 0x00003FFF
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data8 0x9837F0518DB8A96F , 0x00003FFF
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data8 0xA5FED6A9B15138EA , 0x00003FFF
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data8 0xB504F333F9DE6484 , 0x00003FFF
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data8 0xC5672A115506DADD , 0x00003FFF
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data8 0xD744FCCAD69D6AF4 , 0x00003FFF
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data8 0xEAC0C6E7DD24392F , 0x00003FFF
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exp_p_table:
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data8 0x3f8111116da21757 //P_4
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data8 0x3fa55555d787761c //P_3
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data8 0x3fc5555555555414 //P_2
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data8 0x3fdffffffffffd6a //P_1
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.align 32
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.global exp#
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.section .text
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.proc exp#
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.align 32
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exp:
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{ .mlx
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alloc r32=ar.pfs,1,24,4,0
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movl exp_GR_sig_inv_ln2 = 0xb8aa3b295c17f0bc // significand of 1/ln2
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}
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{ .mlx
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addl EXP_AD_TB1 = @ltoff(exp_table_1), gp
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movl exp_GR_rshf_2to56 = 0x4768000000000000 ;; // 1.10000 2^(63+56)
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}
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;;
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// We do this fnorm right at the beginning to take any enabled
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// faults and to normalize any input unnormals so that SWA is not taken.
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{ .mfi
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ld8 EXP_AD_TB1 = [EXP_AD_TB1]
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fclass.m p8,p0 = f8,0x07 // Test for x=0
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mov exp_GR_17ones = 0x1FFFF
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}
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{ .mfi
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mov exp_TB1_size = 0x100
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fnorm EXP_NORM_f8 = f8
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mov exp_GR_exp_2tom56 = 0xffff-56
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}
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;;
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// Form two constants we need
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// 1/ln2 * 2^63 to compute w = x * 1/ln2 * 128
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// 1.1000..000 * 2^(63+63-7) to right shift int(w) into the significand
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{ .mmf
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setf.sig EXP_INV_LN2_2TO63 = exp_GR_sig_inv_ln2 // form 1/ln2 * 2^63
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setf.d EXP_RSHF_2TO56 = exp_GR_rshf_2to56 // Form const 1.100 * 2^(63+56)
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fclass.m p9,p0 = f8,0x22 // Test for x=-inf
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}
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;;
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{ .mlx
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setf.exp EXP_2TOM56 = exp_GR_exp_2tom56 // form 2^-56 for scaling Nfloat
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movl exp_GR_rshf = 0x43e8000000000000 // 1.10000 2^63 for right shift
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}
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{ .mfb
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mov exp_TB2_size = 0x80
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(p8) fma.d f8 = f1,f1,f0 // quick exit for x=0
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(p8) br.ret.spnt b0
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;;
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}
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{ .mfi
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ldfpd EXP_MIN_DBL_OFLOW_ARG, EXP_MAX_DBL_ZERO_ARG = [EXP_AD_TB1],16
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fclass.m p10,p0 = f8,0x21 // Test for x=+inf
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nop.i 999
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}
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{ .mfb
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nop.m 999
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(p9) fma.d f8 = f0,f0,f0 // quick exit for x=-inf
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(p9) br.ret.spnt b0
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;;
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}
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{ .mmf
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ldfpd EXP_MAX_DBL_NORM_ARG, EXP_MAX_DBL_UFLOW_ARG = [EXP_AD_TB1],16
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setf.d EXP_RSHF = exp_GR_rshf // Form right shift const 1.100 * 2^63
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fclass.m p11,p0 = f8,0xc3 // Test for x=nan
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;;
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}
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{ .mfb
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ldfd EXP_MIN_DBL_NORM_ARG = [EXP_AD_TB1],16
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nop.f 999
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(p10) br.ret.spnt b0 // quick exit for x=+inf
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;;
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}
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{ .mfi
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ldfe exp_ln2_by_128_hi = [EXP_AD_TB1],16
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nop.f 999
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nop.i 999
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;;
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}
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{ .mfb
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ldfe exp_ln2_by_128_lo = [EXP_AD_TB1],16
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(p11) fmerge.s f8 = EXP_NORM_f8, EXP_NORM_f8
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(p11) br.ret.spnt b0 // quick exit for x=nan
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;;
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}
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// After that last load, EXP_AD_TB1 points to the beginning of table 1
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// W = X * Inv_log2_by_128
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// By adding 1.10...0*2^63 we shift and get round_int(W) in significand.
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// We actually add 1.10...0*2^56 to X * Inv_log2 to do the same thing.
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{ .mfi
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nop.m 999
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fma.s1 EXP_W_2TO56_RSH = EXP_NORM_f8, EXP_INV_LN2_2TO63, EXP_RSHF_2TO56
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nop.i 999
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;;
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}
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// Divide arguments into the following categories:
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// Certain Underflow/zero p11 - -inf < x <= MAX_DBL_ZERO_ARG
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// Certain Underflow p12 - MAX_DBL_ZERO_ARG < x <= MAX_DBL_UFLOW_ARG
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// Possible Underflow p13 - MAX_DBL_UFLOW_ARG < x < MIN_DBL_NORM_ARG
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// Certain Safe - MIN_DBL_NORM_ARG <= x <= MAX_DBL_NORM_ARG
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// Possible Overflow p14 - MAX_DBL_NORM_ARG < x < MIN_DBL_OFLOW_ARG
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// Certain Overflow p15 - MIN_DBL_OFLOW_ARG <= x < +inf
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//
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// If the input is really a double arg, then there will never be "Possible
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// Underflow" or "Possible Overflow" arguments.
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//
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{ .mfi
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add EXP_AD_TB2 = exp_TB1_size, EXP_AD_TB1
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fcmp.ge.s1 p15,p14 = EXP_NORM_f8,EXP_MIN_DBL_OFLOW_ARG
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nop.i 999
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;;
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}
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{ .mfi
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add EXP_AD_P = exp_TB2_size, EXP_AD_TB2
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fcmp.le.s1 p11,p12 = EXP_NORM_f8,EXP_MAX_DBL_ZERO_ARG
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nop.i 999
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;;
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}
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{ .mfb
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ldfpd exp_P4, exp_P3 = [EXP_AD_P] ,16
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(p14) fcmp.gt.unc.s1 p14,p0 = EXP_NORM_f8,EXP_MAX_DBL_NORM_ARG
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(p15) br.cond.spnt EXP_CERTAIN_OVERFLOW
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;;
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}
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// Nfloat = round_int(W)
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// The signficand of EXP_W_2TO56_RSH contains the rounded integer part of W,
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// as a twos complement number in the lower bits (that is, it may be negative).
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// That twos complement number (called N) is put into exp_GR_N.
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// Since EXP_W_2TO56_RSH is scaled by 2^56, it must be multiplied by 2^-56
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// before the shift constant 1.10000 * 2^63 is subtracted to yield EXP_Nfloat.
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// Thus, EXP_Nfloat contains the floating point version of N
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{ .mfi
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nop.m 999
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(p12) fcmp.le.unc p12,p0 = EXP_NORM_f8,EXP_MAX_DBL_UFLOW_ARG
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nop.i 999
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}
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{ .mfb
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ldfpd exp_P2, exp_P1 = [EXP_AD_P]
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fms.s1 EXP_Nfloat = EXP_W_2TO56_RSH, EXP_2TOM56, EXP_RSHF
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(p11) br.cond.spnt EXP_CERTAIN_UNDERFLOW_ZERO
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;;
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}
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{ .mfi
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getf.sig exp_GR_N = EXP_W_2TO56_RSH
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(p13) fcmp.lt.unc p13,p0 = EXP_NORM_f8,EXP_MIN_DBL_NORM_ARG
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nop.i 999
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;;
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}
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// exp_GR_index_1 has index_1
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// exp_GR_index_2_16 has index_2 * 16
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// exp_GR_biased_M has M
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// exp_GR_index_1_16 has index_1 * 16
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// r2 has true M
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{ .mfi
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and exp_GR_index_1 = 0x0f, exp_GR_N
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fnma.s1 exp_r = EXP_Nfloat, exp_ln2_by_128_hi, EXP_NORM_f8
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shr r2 = exp_GR_N, 0x7
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}
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{ .mfi
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and exp_GR_index_2_16 = 0x70, exp_GR_N
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fnma.s1 exp_f = EXP_Nfloat, exp_ln2_by_128_lo, f1
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nop.i 999
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;;
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}
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// EXP_AD_T1 has address of T1
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// EXP_AD_T2 has address if T2
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{ .mmi
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addl exp_GR_biased_M = 0xffff, r2
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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 EXP_CERTAIN_UNDERFLOW
|
|
(p13) br.cond.spnt EXP_POSSIBLE_UNDERFLOW
|
|
(p14) br.cond.spnt EXP_POSSIBLE_OVERFLOW
|
|
;;
|
|
}
|
|
|
|
|
|
{ .mfb
|
|
nop.m 999
|
|
fma.d f8 = exp_S, exp_P, exp_S
|
|
br.ret.sptk b0 ;; // Normal path exit
|
|
}
|
|
|
|
|
|
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 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
|
|
}
|
|
|
|
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 ;;
|
|
}
|
|
|
|
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 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
|
|
}
|
|
|
|
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 ;;
|
|
}
|
|
|
|
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
|
|
|
|
|
|
.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
|
|
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
|
|
.type __libm_error_support#,@function
|
|
.global __libm_error_support#
|