| /* |
| * Copyright (C) 2000 Hewlett-Packard Co |
| * Copyright (C) 2000 David Mosberger-Tang <davidm@hpl.hp.com> |
| * |
| * 32-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 EXTEND zxt4 |
| # 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 EXTEND sxt4 |
| # 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,si3)) |
| |
| GLOBAL_ENTRY(NAME) |
| .regstk 2,0,0,0 |
| // Transfer inputs to FP registers. |
| mov r2 = 0xffdd // r2 = -34 + 65535 (fp reg format bias) |
| EXTEND in0 = in0 // in0 = a |
| EXTEND in1 = in1 // in1 = b |
| ;; |
| setf.sig f8 = in0 |
| setf.sig f9 = in1 |
| #ifdef MODULO |
| sub in1 = r0, in1 // in1 = -b |
| #endif |
| ;; |
| // Convert the inputs to FP, to avoid FP software-assist faults. |
| INT_TO_FP(f8, f8) |
| INT_TO_FP(f9, f9) |
| ;; |
| setf.exp f7 = r2 // f7 = 2^-34 |
| frcpa.s1 f6, p6 = f8, f9 // y0 = frcpa(b) |
| ;; |
| (p6) fmpy.s1 f8 = f8, f6 // q0 = a*y0 |
| (p6) fnma.s1 f6 = f9, f6, f1 // e0 = -b*y0 + 1 |
| ;; |
| #ifdef MODULO |
| setf.sig f9 = in1 // f9 = -b |
| #endif |
| (p6) fma.s1 f8 = f6, f8, f8 // q1 = e0*q0 + q0 |
| (p6) fma.s1 f6 = f6, f6, f7 // e1 = e0*e0 + 2^-34 |
| ;; |
| #ifdef MODULO |
| setf.sig f7 = in0 |
| #endif |
| (p6) fma.s1 f6 = f6, f8, f8 // q2 = e1*q1 + q1 |
| ;; |
| FP_TO_INT(f6, f6) // q = trunc(q2) |
| ;; |
| #ifdef MODULO |
| xma.l f6 = f6, f9, f7 // r = q*(-b) + a |
| ;; |
| #endif |
| getf.sig r8 = f6 // transfer result to result register |
| br.ret.sptk.many rp |
| END(NAME) |