udivsi3.S revision 1.10
1 /* $NetBSD: udivsi3.S,v 1.10 2011/07/14 09:48:04 mrg Exp $ */ 2 3 /*- 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * William Jolitz. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)udivsi3.s 5.1 (Berkeley) 5/15/90 35 */ 36 37 #include <machine/asm.h> 38 #if defined(LIBC_SCCS) 39 RCSID("$NetBSD: udivsi3.S,v 1.10 2011/07/14 09:48:04 mrg Exp $") 40 #endif 41 42 /* 43 * IMPOTANT: This function is special. 44 * 45 * This function is an auxiliary function that is referenced by the 46 * code generated by gcc for integer division. But gcc does NOT treat 47 * a call to this function as an ordinary function call w.r.t. the set 48 * of register this call clobbers. See the definition of "udivsi3_i1" 49 * in gcc/config/sh/sh.md. 50 * 51 * Any call to this function MUST NOT clobber any registers besides r4 52 * and r0, where the result is returned. At the time of the call the 53 * r4 contains the first argument, so we are only left with r0, and we 54 * cannot do anything meaningful using only one register. The 55 * consequences are: 56 * 57 * . this function cannot have _PROF_PROLOGUE 58 * . this function cannot be called via PLT 59 */ 60 61 62 #ifdef __ELF__ 63 .hidden __udivsi3 64 #endif 65 66 67 /* r0 <= r4 / r5 */ 68 NENTRY(__udivsi3) 69 tst r5, r5 70 bt div_by_zero 71 72 mov #0, r0 73 div0u 74 #define DIVSTEP rotcl r4; div1 r5, r0 75 /* repeat 32 times */ 76 DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; 77 DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; 78 DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; 79 DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; DIVSTEP; 80 #undef DIVSTEP 81 rotcl r4 82 83 rts 84 mov r4, r0 85 86 div_by_zero: 87 #ifdef _KERNEL 88 rts 89 mov #0, r0 90 #else 91 mov.l r14, @-r15 92 sts.l pr, @-r15 93 mov r15, r14 94 95 mov.l L_raise, r1 96 #ifdef PIC 97 1: bsrf r1 98 #else 99 jsr @r1 100 #endif 101 mov #8, r4 /* delay slot. 8 <- SIGFPE. */ 102 mov #0, r0 103 104 lds.l @r15+, pr 105 rts 106 mov.l @r15+, r14 107 108 .align 2 109 L_raise: 110 #ifdef PIC 111 .long _C_LABEL(raise)-(1b+4) 112 #else 113 .long _C_LABEL(raise) 114 #endif 115 #endif 116
Indexes created Wed Oct 01 19:09:53 GMT 2025