?? s_ceilf.s
字號:
.file "ceilf.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// 06/13/00 Improved speed// 06/27/00 Eliminated incorrect invalid flag setting// 05/20/02 Cleaned up namespace and sf0 syntax// 01/28/03 Improved performance//==============================================================// API//==============================================================// float ceilf(float x)//==============================================================// general input registers:// r14 - r19rSignexp = r14rExp = r15rExpMask = r16rBigexp = r17rM1 = r18rSignexpM1 = r19// floating-point registers:// f8 - f13fXInt = f9fNormX = f10fTmp = f11fAdj = f12fPreResult = f13// predicate registers used:// p6 - p10// Overview of operation//==============================================================// float ceilf(float x)// Return an integer value (represented as a float) that is the smallest// value not less than x// This is x rounded toward +infinity to an integral value.// Inexact is set if x != ceilf(x)//==============================================================// double_extended// if the exponent is > 1003e => 3F(true) = 63(decimal)// we have a significand of 64 bits 1.63-bits.// If we multiply by 2^63, we no longer have a fractional part// So input is an integer value already.// double// if the exponent is >= 10033 => 34(true) = 52(decimal)// 34 + 3ff = 433// we have a significand of 53 bits 1.52-bits. (implicit 1)// If we multiply by 2^52, we no longer have a fractional part// So input is an integer value already.// single// if the exponent is > 10016 => 17(true) = 23(decimal)// we have a significand of 24 bits 1.23-bits. (implicit 1)// If we multiply by 2^23, we no longer have a fractional part// So input is an integer value already..section .textGLOBAL_LIBM_ENTRY(ceilf){ .mfi getf.exp rSignexp = f8 // Get signexp, recompute if unorm fclass.m p7,p0 = f8, 0x0b // Test x unorm addl rBigexp = 0x10016, r0 // Set exponent at which is integer}{ .mfi mov rM1 = -1 // Set all ones fcvt.fx.trunc.s1 fXInt = f8 // Convert to int in significand mov rExpMask = 0x1FFFF // Form exponent mask};;{ .mfi mov rSignexpM1 = 0x2FFFF // Form signexp of -1 fcmp.lt.s1 p8,p9 = f8, f0 // Test x < 0 nop.i 0}{ .mfb setf.sig fTmp = rM1 // Make const for setting inexact fnorm.s1 fNormX = f8 // Normalize input(p7) br.cond.spnt CEIL_UNORM // Branch if x unorm};;CEIL_COMMON:// Return here from CEIL_UNORM{ .mfi nop.m 0 fclass.m p6,p0 = f8, 0x1e7 // Test x natval, nan, inf, 0 nop.i 0};;.pred.rel "mutex",p8,p9{ .mfi nop.m 0(p8) fma.s1 fAdj = f0, f0, f0 // If x < 0, adjustment is 0 nop.i 0}{ .mfi nop.m 0(p9) fma.s1 fAdj = f1, f1, f0 // If x > 0, adjustment is +1 nop.i 0};;{ .mfi nop.m 0 fcvt.xf fPreResult = fXInt // trunc(x) nop.i 0}{ .mfb nop.m 0(p6) fma.s.s0 f8 = f8, f1, f0 // Result if x natval, nan, inf, 0(p6) br.ret.spnt b0 // Exit if x natval, nan, inf, 0};;{ .mmi and rExp = rSignexp, rExpMask // Get biased exponent;; cmp.ge p7,p6 = rExp, rBigexp // Is |x| >= 2^23?(p8) cmp.lt.unc p10,p0 = rSignexp, rSignexpM1 // Is -1 < x < 0?};;// If -1 < x < 0, we turn off p6 and compute result as -0{ .mfi(p10) cmp.ne p6,p0 = r0,r0(p10) fmerge.s f8 = fNormX, f0 nop.i 0};;.pred.rel "mutex",p6,p7{ .mfi nop.m 0(p6) fma.s.s0 f8 = fPreResult, f1, fAdj // Result if !int, |x| < 2^23 nop.i 0}{ .mfi nop.m 0(p7) fma.s.s0 f8 = fNormX, f1, f0 // Result, if |x| >= 2^23(p10) cmp.eq p6,p0 = r0,r0 // If -1 < x < 0, turn on p6 again};;{ .mfi nop.m 0(p6) fcmp.eq.unc.s1 p8, p9 = fPreResult, fNormX // Is trunc(x) = x ? nop.i 0};;{ .mfi nop.m 0(p9) fmpy.s0 fTmp = fTmp, fTmp // Dummy to set inexact nop.i 0}{ .mfb nop.m 0(p8) fma.s.s0 f8 = fNormX, f1, f0 // If x int, result normalized x br.ret.sptk b0 // Exit main path, 0 < |x| < 2^23};;CEIL_UNORM:// Here if x unorm{ .mfb getf.exp rSignexp = fNormX // Get signexp, recompute if unorm fcmp.eq.s0 p7,p0 = f8, f0 // Dummy op to set denormal flag br.cond.sptk CEIL_COMMON // Return to main path};;GLOBAL_LIBM_END(ceilf)
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -