lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* Macros to test for CPU features on ARM. Generic ARM version. |
| 2 | Copyright (C) 2012-2015 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library. If not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #ifndef _ARM_ARM_FEATURES_H |
| 20 | #define _ARM_ARM_FEATURES_H 1 |
| 21 | |
| 22 | /* An OS-specific arm-features.h file should define ARM_HAVE_VFP to |
| 23 | an appropriate expression for testing at runtime whether the VFP |
| 24 | hardware is present. We'll then redefine it to a constant if we |
| 25 | know at compile time that we can assume VFP. */ |
| 26 | |
| 27 | #ifndef __SOFTFP__ |
| 28 | /* The compiler is generating VFP instructions, so we're already |
| 29 | assuming the hardware exists. */ |
| 30 | # undef ARM_HAVE_VFP |
| 31 | # define ARM_HAVE_VFP 1 |
| 32 | #endif |
| 33 | |
| 34 | /* An OS-specific arm-features.h file may define ARM_ASSUME_NO_IWMMXT |
| 35 | to indicate at compile time that iWMMXt hardware is never present |
| 36 | at runtime (or that we never care about its state) and so need not |
| 37 | be checked for. */ |
| 38 | |
| 39 | /* A more-specific arm-features.h file may define ARM_ALWAYS_BX to indicate |
| 40 | that instructions using pc as a destination register must never be used, |
| 41 | so a "bx" (or "blx") instruction is always required. */ |
| 42 | |
| 43 | /* The log2 of the minimum alignment required for an address that |
| 44 | is the target of a computed branch (i.e. a "bx" instruction). |
| 45 | A more-specific arm-features.h file may define this to set a more |
| 46 | stringent requirement. |
| 47 | |
| 48 | Using this only makes sense for code in ARM mode (where instructions |
| 49 | always have a fixed size of four bytes), or for Thumb-mode code that is |
| 50 | specifically aligning all the related branch targets to match (since |
| 51 | Thumb instructions might be either two or four bytes). */ |
| 52 | #ifndef ARM_BX_ALIGN_LOG2 |
| 53 | # define ARM_BX_ALIGN_LOG2 2 |
| 54 | #endif |
| 55 | |
| 56 | /* An OS-specific arm-features.h file may define ARM_NO_INDEX_REGISTER to |
| 57 | indicate that the two-register addressing modes must never be used. */ |
| 58 | |
| 59 | #endif /* arm-features.h */ |