101baa056SKyle Moffett/* 201baa056SKyle Moffett * This code was copied from arch/powerpc/kernel/misc_32.S in the Linux 301baa056SKyle Moffett * kernel sources (commit 85e2efbb1db9a18d218006706d6e4fbeb0216213, also 401baa056SKyle Moffett * known as 2.6.38-rc5). The source file copyrights are as follows: 501baa056SKyle Moffett * 601baa056SKyle Moffett * (C) Copyright 1995-1996 Gary Thomas (gdt@linuxppc.org) 701baa056SKyle Moffett * 801baa056SKyle Moffett * Largely rewritten by Cort Dougan (cort@cs.nmt.edu) 901baa056SKyle Moffett * and Paul Mackerras. 1001baa056SKyle Moffett * 11*1a459660SWolfgang Denk * SPDX-License-Identifier: GPL-2.0+ 1201baa056SKyle Moffett */ 1301baa056SKyle Moffett 1401baa056SKyle Moffett#include <ppc_asm.tmpl> 1501baa056SKyle Moffett#include <ppc_defs.h> 1601baa056SKyle Moffett#include <config.h> 1701baa056SKyle Moffett 1801baa056SKyle Moffett/* 1901baa056SKyle Moffett * Extended precision shifts. 2001baa056SKyle Moffett * 2101baa056SKyle Moffett * Updated to be valid for shift counts from 0 to 63 inclusive. 2201baa056SKyle Moffett * -- Gabriel 2301baa056SKyle Moffett * 2401baa056SKyle Moffett * R3/R4 has 64 bit value 2501baa056SKyle Moffett * R5 has shift count 2601baa056SKyle Moffett * result in R3/R4 2701baa056SKyle Moffett * 2801baa056SKyle Moffett * ashrdi3: arithmetic right shift (sign propagation) 2901baa056SKyle Moffett * lshrdi3: logical right shift 3001baa056SKyle Moffett * ashldi3: left shift 3101baa056SKyle Moffett */ 3201baa056SKyle Moffett .globl __ashrdi3 3301baa056SKyle Moffett__ashrdi3: 3401baa056SKyle Moffett subfic r6,r5,32 3501baa056SKyle Moffett srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count 3601baa056SKyle Moffett addi r7,r5,32 # could be xori, or addi with -32 3701baa056SKyle Moffett slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count) 3801baa056SKyle Moffett rlwinm r8,r7,0,32 # t3 = (count < 32) ? 32 : 0 3901baa056SKyle Moffett sraw r7,r3,r7 # t2 = MSW >> (count-32) 4001baa056SKyle Moffett or r4,r4,r6 # LSW |= t1 4101baa056SKyle Moffett slw r7,r7,r8 # t2 = (count < 32) ? 0 : t2 4201baa056SKyle Moffett sraw r3,r3,r5 # MSW = MSW >> count 4301baa056SKyle Moffett or r4,r4,r7 # LSW |= t2 4401baa056SKyle Moffett blr 45