;------------------------------------------------------------------------------ ; Return the current FPU rounding mode. ; ; MASM implementation of the flt_rounds function from NetBSD. ; ; Copyright (c) 2010, Intel Corporation. All rights reserved.
; 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. ; ;------------------------------------------------------------------------------ .code ;_map BYTE 1 ; round to nearest ; BYTE 3 ; round to negative infinity ; BYTE 2 ; round to positive infinity ; BYTE 0 ; round to zero ;------------------------------------------------------------------------------ ; int ; EFIAPI ; fpu_rmode( void ); ; ; VC++ always creates space for 4 parameters on the stack, whether they are ; used or not. We use one for temporary storage since the only variant of ; fnstcw saves to memory, NOT a register. ;------------------------------------------------------------------------------ internal_FPU_rmode PROC fnstcw [rsp + 8] ; save 16-bit FPU Control Word mov eax, [rsp + 8] ; get the saved FPU Control Word shr eax, 10 and rax, 3 ; index is only the LSB two bits in RAX ret ; Return rounding mode in RAX internal_FPU_rmode ENDP END