1;------------------------------------------------------------------------------ 2; Return the current FPU rounding mode. 3; 4; MASM implementation of the flt_rounds function from NetBSD. 5; 6; Copyright (c) 2010, Intel Corporation. All rights reserved.<BR> 7; This program and the accompanying materials 8; are licensed and made available under the terms and conditions of the BSD License 9; which accompanies this distribution. The full text of the license may be found at 10; http://opensource.org/licenses/bsd-license.php. 11; 12; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 13; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 14; 15;------------------------------------------------------------------------------ 16 17 .code 18 19;_map BYTE 1 ; round to nearest 20; BYTE 3 ; round to negative infinity 21; BYTE 2 ; round to positive infinity 22; BYTE 0 ; round to zero 23 24;------------------------------------------------------------------------------ 25; int 26; EFIAPI 27; fpu_rmode( void ); 28; 29; VC++ always creates space for 4 parameters on the stack, whether they are 30; used or not. We use one for temporary storage since the only variant of 31; fnstcw saves to memory, NOT a register. 32;------------------------------------------------------------------------------ 33internal_FPU_rmode PROC 34 fnstcw [rsp + 8] ; save 16-bit FPU Control Word 35 mov eax, [rsp + 8] ; get the saved FPU Control Word 36 shr eax, 10 37 and rax, 3 ; index is only the LSB two bits in RAX 38 ret ; Return rounding mode in RAX 39internal_FPU_rmode ENDP 40 41 END 42