/* * This code was copied from arch/powerpc/kernel/misc_32.S in the Linux * kernel sources (commit 85e2efbb1db9a18d218006706d6e4fbeb0216213, also * known as 2.6.38-rc5). The source file copyrights are as follows: * * (C) Copyright 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Largely rewritten by Cort Dougan (cort@cs.nmt.edu) * and Paul Mackerras. * * SPDX-License-Identifier: GPL-2.0+ */ #include #include #include /* * Extended precision shifts. * * Updated to be valid for shift counts from 0 to 63 inclusive. * -- Gabriel * * R3/R4 has 64 bit value * R5 has shift count * result in R3/R4 * * ashrdi3: arithmetic right shift (sign propagation) * lshrdi3: logical right shift * ashldi3: left shift */ .globl __ashrdi3 __ashrdi3: subfic r6,r5,32 srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count addi r7,r5,32 # could be xori, or addi with -32 slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count) rlwinm r8,r7,0,32 # t3 = (count < 32) ? 32 : 0 sraw r7,r3,r7 # t2 = MSW >> (count-32) or r4,r4,r6 # LSW |= t1 slw r7,r7,r8 # t2 = (count < 32) ? 0 : t2 sraw r3,r3,r5 # MSW = MSW >> count or r4,r4,r7 # LSW |= t2 blr