| .file "fdim.s" |
| |
| |
| // Copyright (c) 2001 - 2003, Intel Corporation |
| // All rights reserved. |
| // |
| // Contributed 2001 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 |
| //============================================================== |
| // 06/08/01 Initial version |
| // 08/23/01 Corrected error tag number |
| // 05/20/02 Cleaned up namespace and sf0 syntax |
| // 01/28/03 Improved performance |
| // |
| // API |
| //============================================================== |
| // double fdim( double x, double y ); |
| // input floating point f8, f9 |
| // output floating point f8 |
| // |
| // |
| // Overview of operation |
| //============================================================== |
| // fdim determines the positive difference between the arguments |
| // Result = x - y if x > y |
| // = +0 if x <= y |
| // |
| // Error support is called if x-y overflows for x > y |
| // |
| |
| // Registers used |
| //============================================================== |
| // General purpose registers: r14, r32 - r39 |
| |
| rExpBig = r14 |
| |
| // r36-39 parameters for libm_error_support |
| GR_SAVE_B0 = r33 |
| GR_SAVE_GP = r34 |
| GR_SAVE_PFS = r35 |
| |
| GR_Parameter_X = r36 |
| GR_Parameter_Y = r37 |
| GR_Parameter_RESULT = r38 |
| GR_Parameter_TAG = r39 |
| |
| // Floating-point registers: f8 - f12 |
| |
| f_tmp_result = f10 |
| fBig = f11 |
| fNormX = f12 |
| |
| // Predicate registers: p6 - p10 |
| |
| |
| .section .text |
| GLOBAL_LIBM_ENTRY(fdim) |
| |
| { .mfi |
| mov rExpBig = 0x103ff // Exponent to indicate overflow |
| fcmp.le.s1 p6,p7 = f8, f9 // Is x <= y? |
| nop.i 0 |
| } |
| { .mfi |
| nop.m 0 |
| fnorm.s1 fNormX = f8 // Save x |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| setf.exp fBig = rExpBig // Constant to test for overflow |
| fcmp.eq.s0 p8,p0 = f8, f9 // Dummy op to set Denormal or Invalid |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| fclass.m p9,p10 = f8, 0x1e3 // Test for x natval, nan, inf |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| (p6) fmerge.s f8 = f0, f0 // Result is +0 if x <= y |
| nop.i 0 |
| } |
| { .mfi |
| nop.m 0 |
| (p7) fms.d.s0 f8 = f8, f1, f9 // Result is x - y if x > y |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| (p10) fclass.m p9,p10 = f9, 0x1e3 // Test for y natval, nan, inf |
| nop.i 0 |
| } |
| ;; |
| |
| { .mfi |
| nop.m 0 |
| (p10) fcmp.ge.s1 p8,p0 = f8, fBig // Test result for overflow |
| nop.i 0 |
| } |
| ;; |
| |
| { .mbb |
| (p9) cmp.ne p8,p0 = r0,r0 // Clear p8 if x or y natval,nan,inf |
| (p8) br.cond.spnt FDIM_OVERFLOW // Branch if result overflows |
| br.ret.sptk b0 // Normal return |
| } |
| ;; |
| |
| |
| // Here if result will overflow |
| FDIM_OVERFLOW: |
| { .mfi |
| alloc r32=ar.pfs,2,2,4,0 |
| fms.d.s0 f_tmp_result = f8,f1,f9 // Normalize result force overflow |
| nop.i 0 |
| } |
| { .mfb |
| mov GR_Parameter_TAG = 196 // Error code |
| nop.f 0 |
| br.cond.sptk __libm_error_region // Branch to error code |
| } |
| ;; |
| |
| GLOBAL_LIBM_END(fdim) |
| |
| |
| LOCAL_LIBM_ENTRY(__libm_error_region) |
| // Call error support to report possible range error |
| .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] = f9,16 // 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] = fNormX // STORE Parameter 1 on stack |
| add GR_Parameter_RESULT = 0,GR_Parameter_Y // Parameter 3 address |
| nop.b 0 |
| } |
| { .mib |
| stfd [GR_Parameter_Y] = f_tmp_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# |
| |
