| .file "modf.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 |
| //============================================================== |
| // 02/02/00 Initial version |
| // 04/04/00 Improved speed, corrected result for NaN input |
| // 12/22/00 Fixed so inexact flag is never set, and invalid is not set for |
| // qnans nor for inputs larger than 2^63. |
| // 05/20/02 Cleaned up namespace and sf0 syntax |
| // 02/10/03 Reordered header: .section, .global, .proc, .align |
| // |
| // API |
| //============================================================== |
| // double modf(double x, double *iptr) |
| // break a floating point x number into fraction and an exponent |
| // |
| // input floating point f8, address in r33 |
| // output floating point f8 (x fraction), and *iptr (x integral part) |
| // |
| // OVERVIEW |
| //============================================================== |
| // |
| // NO FRACTIONAL PART: HUGE |
| // If |
| // for double-extended |
| // If the true exponent is greater than or equal 63 |
| // 1003e ==> 1003e -ffff = 3f = 63(dec) |
| // for double |
| // If the true exponent is greater than or equal 52 |
| // 10033 -ffff = 34 = 52(dec) |
| // for single |
| // If the true exponent is greater than or equal 23 |
| // 10016 -ffff = 17 = 23(dec) |
| // then |
| // we are already an integer (p9 true) |
| |
| // NO INTEGER PART: SMALL |
| // Is f8 exponent less than register bias (that is, is it |
| // less than 1). If it is, get the right sign of |
| // zero and store this in iptr. |
| |
| // CALCULATION: NOT HUGE, NOT SMALL |
| // To get the integer part |
| // Take the floating-point input and truncate |
| // then convert this integer to fp Call it MODF_INTEGER_PART |
| |
| // Subtract MODF_INTEGER_PART from MODF_NORM_F8 to get fraction part |
| // Then put fraction part in f8 |
| // put integer part MODF_INTEGER_PART into *iptr |
| |
| // Registers used |
| //============================================================== |
| |
| // predicate registers used: |
| // p6 - p13 |
| |
| // 0xFFFF 0x10033 |
| // -----------------------+-----------------+------------- |
| // SMALL | NORMAL | HUGE |
| // p11 --------------->|<----- p12 ----->| <-------------- p9 |
| // p10 --------------------------------->| |
| // p13 --------------------------------------------------->| |
| // |
| |
| // floating-point registers used: |
| MODF_NORM_F8 = f9 |
| MODF_FRACTION_PART = f10 |
| MODF_INTEGER_PART = f11 |
| MODF_INT_INTEGER_PART = f12 |
| |
| |
| // general registers used |
| modf_signexp = r14 |
| modf_GR_no_frac = r15 |
| modf_GR_FFFF = r16 |
| modf_17_ones = r17 |
| modf_exp = r18 |
| // r33 = iptr |
| |
| |
| .section .text |
| GLOBAL_LIBM_ENTRY(modf) |
| |
| // Main path is p9, p11, p8 FALSE and p12 TRUE |
| |
| // Assume input is normalized and get signexp |
| // Normalize input just in case |
| // Form exponent bias |
| { .mfi |
| getf.exp modf_signexp = f8 |
| fnorm.s0 MODF_NORM_F8 = f8 |
| addl modf_GR_FFFF = 0xffff, r0 |
| } |
| // Get integer part of input |
| // Form exponent mask |
| { .mfi |
| nop.m 999 |
| fcvt.fx.trunc.s1 MODF_INT_INTEGER_PART = f8 |
| mov modf_17_ones = 0x1ffff ;; |
| } |
| |
| // Is x nan or inf? |
| // qnan snan inf norm unorm 0 -+ |
| // 1 1 1 0 0 0 11 = 0xe3 NAN_INF |
| // Form biased exponent where input only has an integer part |
| { .mfi |
| nop.m 999 |
| fclass.m.unc p6,p13 = f8, 0xe3 |
| addl modf_GR_no_frac = 0x10033, r0 ;; |
| } |
| |
| // Mask to get exponent |
| // Is x unnorm? |
| // qnan snan inf norm unorm 0 -+ |
| // 0 0 0 0 1 0 11 = 0x0b UNORM |
| // Set p13 to indicate calculation path, else p6 if nan or inf |
| { .mfi |
| and modf_exp = modf_17_ones, modf_signexp |
| fclass.m.unc p8,p0 = f8, 0x0b |
| nop.i 999 ;; |
| } |
| |
| // p11 <== SMALL, no integer part, fraction is everyting |
| // p9 <== HUGE, no fraction part, integer is everything |
| // p12 <== NORMAL, fraction part and integer part |
| { .mii |
| (p13) cmp.lt.unc p11,p10 = modf_exp, modf_GR_FFFF |
| nop.i 999 |
| nop.i 999 ;; |
| } |
| |
| // Is x inf? p6 if inf, p7 if nan |
| { .mfb |
| (p10) cmp.ge.unc p9,p12 = modf_exp, modf_GR_no_frac |
| (p6) fclass.m.unc p6,p7 = f8, 0x23 |
| (p8) br.cond.spnt MODF_DENORM ;; |
| } |
| |
| MODF_COMMON: |
| // For HUGE set fraction to signed 0 |
| { .mfi |
| nop.m 999 |
| (p9) fmerge.s f8 = f8,f0 |
| nop.i 999 |
| } |
| // For HUGE set integer part to normalized input |
| { .mfi |
| nop.m 999 |
| (p9) fnorm.d.s0 MODF_INTEGER_PART = MODF_NORM_F8 |
| nop.i 999 ;; |
| } |
| |
| // For SMALL set fraction to normalized input, integer part to signed 0 |
| { .mfi |
| nop.m 999 |
| (p11) fmerge.s MODF_INTEGER_PART = f8,f0 |
| nop.i 999 |
| } |
| { .mfi |
| nop.m 999 |
| (p11) fnorm.d.s0 f8 = MODF_NORM_F8 |
| nop.i 999 ;; |
| } |
| |
| // For NORMAL float the integer part |
| { .mfi |
| nop.m 999 |
| (p12) fcvt.xf MODF_INTEGER_PART = MODF_INT_INTEGER_PART |
| nop.i 999 ;; |
| } |
| |
| // If x inf set integer part to INF, fraction to signed 0 |
| { .mfi |
| (p6) stfd [r33] = MODF_NORM_F8 |
| (p6) fmerge.s f8 = f8,f0 |
| nop.i 999 ;; |
| } |
| |
| // If x nan set integer and fraction parts to NaN (quietized) |
| { .mfi |
| (p7) stfd [r33] = MODF_NORM_F8 |
| (p7) fmerge.s f8 = MODF_NORM_F8, MODF_NORM_F8 |
| nop.i 999 ;; |
| } |
| |
| { .mmi |
| (p9) stfd [r33] = MODF_INTEGER_PART |
| nop.m 999 |
| nop.i 999 ;; |
| } |
| |
| // For NORMAL compute fraction part |
| { .mfi |
| (p11) stfd [r33] = MODF_INTEGER_PART |
| (p12) fms.d.s0 f8 = MODF_NORM_F8,f1, MODF_INTEGER_PART |
| nop.i 999 ;; |
| } |
| |
| // For NORMAL test if fraction part is zero; if so append correct sign |
| { .mfi |
| nop.m 999 |
| (p12) fcmp.eq.unc.s0 p7,p0 = MODF_NORM_F8, MODF_INTEGER_PART |
| nop.i 999 ;; |
| } |
| |
| { .mfi |
| (p12) stfd [r33] = MODF_INTEGER_PART |
| nop.f 999 |
| nop.i 999 ;; |
| } |
| |
| // For NORMAL if fraction part is zero append sign of input |
| { .mfb |
| nop.m 999 |
| (p7) fmerge.s f8 = MODF_NORM_F8, f0 |
| br.ret.sptk b0 ;; |
| } |
| |
| MODF_DENORM: |
| // If x unorm get signexp from normalized input |
| // If x unorm get integer part from normalized input |
| { .mfi |
| getf.exp modf_signexp = MODF_NORM_F8 |
| fcvt.fx.trunc.s1 MODF_INT_INTEGER_PART = MODF_NORM_F8 |
| nop.i 999 ;; |
| } |
| |
| // If x unorm mask to get exponent |
| { .mmi |
| and modf_exp = modf_17_ones, modf_signexp ;; |
| cmp.lt.unc p11,p10 = modf_exp, modf_GR_FFFF |
| nop.i 999 ;; |
| } |
| |
| { .mfb |
| (p10) cmp.ge.unc p9,p12 = modf_exp, modf_GR_no_frac |
| nop.f 999 |
| br.cond.spnt MODF_COMMON ;; |
| } |
| |
| GLOBAL_LIBM_END(modf) |
