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#------------------------------------------------------------------------------
#*
#* Copyright (c) 2009 - 2012, Intel Corporation. All rights reserved.<BR>
#* This program and the accompanying materials
#* are licensed and made available under the terms and conditions of the BSD License
#* which accompanies this distribution. The full text of the license may be found at
#* http://opensource.org/licenses/bsd-license.php
#*
#* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
#* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#*
#*
#------------------------------------------------------------------------------
#
# Initializes floating point units for requirement of UEFI specification.
#
# This function initializes floating-point control word to 0x037F (all exceptions
# masked,double-extended-precision, round-to-nearest) and multimedia-extensions control word
# (if supported) to 0x1F80 (all exceptions masked, round-to-nearest, flush to zero
# for masked underflow).
#
ASM_GLOBAL ASM_PFX(InitializeFloatingPointUnits)
ASM_PFX(InitializeFloatingPointUnits):
#
# Initialize floating point units
#
finit
#
# Float control word initial value:
# all exceptions masked, double-precision, round-to-nearest
#
pushq $0x037F
lea (%rsp), %rax
fldcw (%rax)
popq %rax
#
# Set OSFXSR bit 9 in CR4
#
movq %cr4, %rax
or $0x200, %rax
movq %rax, %cr4
#
# Multimedia-extensions control word:
# all exceptions masked, round-to-nearest, flush to zero for masked underflow
#
pushq $0x01F80
lea (%rsp), %rax
ldmxcsr (%rax)
popq %rax
ret
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