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2aa62f2b | 1 | ;------------------------------------------------------------------------------\r |
2 | ; Return the current FPU rounding mode.\r | |
3 | ;\r | |
4 | ; MASM implementation of the flt_rounds function from NetBSD.\r | |
5 | ;\r | |
6 | ; Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>\r | |
7 | ; This program and the accompanying materials\r | |
8 | ; are licensed and made available under the terms and conditions of the BSD License\r | |
9 | ; which accompanies this distribution. The full text of the license may be found at\r | |
10 | ; http://opensource.org/licenses/bsd-license.php.\r | |
11 | ;\r | |
12 | ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r | |
13 | ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
14 | ;\r | |
15 | ;------------------------------------------------------------------------------\r | |
16 | \r | |
17 | .code\r | |
18 | \r | |
19 | ;_map BYTE 1 ; round to nearest\r | |
20 | ; BYTE 3 ; round to negative infinity\r | |
21 | ; BYTE 2 ; round to positive infinity\r | |
22 | ; BYTE 0 ; round to zero\r | |
23 | \r | |
24 | ;------------------------------------------------------------------------------\r | |
25 | ; int\r | |
26 | ; EFIAPI\r | |
27 | ; fpu_rmode( void );\r | |
28 | ;\r | |
29 | ; VC++ always creates space for 4 parameters on the stack, whether they are\r | |
30 | ; used or not. We use one for temporary storage since the only variant of\r | |
31 | ; fnstcw saves to memory, NOT a register.\r | |
32 | ;------------------------------------------------------------------------------\r | |
33 | internal_FPU_rmode PROC\r | |
34 | fnstcw [rsp + 8] ; save 16-bit FPU Control Word\r | |
35 | mov eax, [rsp + 8] ; get the saved FPU Control Word\r | |
36 | shr eax, 10\r | |
37 | and rax, 3 ; index is only the LSB two bits in RAX\r | |
38 | ret ; Return rounding mode in RAX\r | |
39 | internal_FPU_rmode ENDP\r | |
40 | \r | |
41 | END\r |