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kernel/linux-imx6_3.14.28/arch/ia64/lib/idiv64.S 2.03 KB
6b13f685e   김민수   BSP 최초 추가
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  /*
   * Copyright (C) 1999-2000 Hewlett-Packard Co
   * Copyright (C) 1999-2000 David Mosberger-Tang <davidm@hpl.hp.com>
   *
   * 64-bit integer division.
   *
   * This code is based on the application note entitled "Divide, Square Root
   * and Remainder Algorithms for the IA-64 Architecture".  This document
   * is available as Intel document number 248725-002 or via the web at
   * http://developer.intel.com/software/opensource/numerics/
   *
   * For more details on the theory behind these algorithms, see "IA-64
   * and Elementary Functions" by Peter Markstein; HP Professional Books
   * (http://www.hp.com/go/retailbooks/)
   */
  
  #include <asm/asmmacro.h>
  
  #ifdef MODULO
  # define OP	mod
  #else
  # define OP	div
  #endif
  
  #ifdef UNSIGNED
  # define SGN	u
  # define INT_TO_FP(a,b)	fcvt.xuf.s1 a=b
  # define FP_TO_INT(a,b)	fcvt.fxu.trunc.s1 a=b
  #else
  # define SGN
  # define INT_TO_FP(a,b)	fcvt.xf a=b
  # define FP_TO_INT(a,b)	fcvt.fx.trunc.s1 a=b
  #endif
  
  #define PASTE1(a,b)	a##b
  #define PASTE(a,b)	PASTE1(a,b)
  #define NAME		PASTE(PASTE(__,SGN),PASTE(OP,di3))
  
  GLOBAL_ENTRY(NAME)
  	.regstk 2,0,0,0
  	// Transfer inputs to FP registers.
  	setf.sig f8 = in0
  	setf.sig f9 = in1
  	;;
  	// Convert the inputs to FP, to avoid FP software-assist faults.
  	INT_TO_FP(f8, f8)
  	INT_TO_FP(f9, f9)
  	;;
  	frcpa.s1 f11, p6 = f8, f9	// y0 = frcpa(b)
  	;;
  (p6)	fmpy.s1 f7 = f8, f11		// q0 = a*y0
  (p6)	fnma.s1 f6 = f9, f11, f1	// e0 = -b*y0 + 1
  	;;
  (p6)	fma.s1 f10 = f7, f6, f7		// q1 = q0*e0 + q0
  (p6)	fmpy.s1 f7 = f6, f6		// e1 = e0*e0
  	;;
  #ifdef MODULO
  	sub in1 = r0, in1		// in1 = -b
  #endif
  (p6)	fma.s1 f10 = f10, f7, f10	// q2 = q1*e1 + q1
  (p6)	fma.s1 f6 = f11, f6, f11	// y1 = y0*e0 + y0
  	;;
  (p6)	fma.s1 f6 = f6, f7, f6		// y2 = y1*e1 + y1
  (p6)	fnma.s1 f7 = f9, f10, f8	// r = -b*q2 + a
  	;;
  #ifdef MODULO
  	setf.sig f8 = in0		// f8 = a
  	setf.sig f9 = in1		// f9 = -b
  #endif
  (p6)	fma.s1 f11 = f7, f6, f10	// q3 = r*y2 + q2
  	;;
  	FP_TO_INT(f11, f11)		// q = trunc(q3)
  	;;
  #ifdef MODULO
  	xma.l f11 = f11, f9, f8		// r = q*(-b) + a
  	;;
  #endif
  	getf.sig r8 = f11		// transfer result to result register
  	br.ret.sptk.many rp
  END(NAME)