# *****************************************************************
#
#               The Compcert verified compiler
#
#           Xavier Leroy, INRIA Paris-Rocquencourt
#
# Copyright (c) 2013 Institut National de Recherche en Informatique et
#  en Automatique.
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# *********************************************************************

# Helper functions for 64-bit integer arithmetic.  PowerPC version.

        .text

# Shift right unsigned
	
        .balign 16
        .globl __i64_shr
__i64_shr:
# On PowerPC, shift instructions with amount mod 64 >= 32 return 0
# lo = (lo >> amount) | (hi << (32 - amount)) | (hi >> (amount - 32))
# hi = hi >> amount
# if 0 <= amount < 32:
#    (amount - 32) mod 64 >= 32, hence hi >> (amount - 32) == 0
# if 32 <= amount < 64:
#    hi >> amount == 0
#    (32 - amount) mod 64 >= 32, hence hi << (32 - amount) == 0
        andi. r5, r5, 63        # take amount modulo 64
        subfic r6, r5, 32       # r6 = 32 - amount
        addi r7, r5, -32        # r7 = amount - 32
        srw r4, r4, r5
        slw r0, r3, r6
        or r4, r4, r0
        srw r0, r3, r7
        or r4, r4, r0
        srw r3, r3, r5
        blr
        .type __i64_shr, @function
        .size __i64_shr, .-__i64_shr