1 /* Macros to test for CPU features on ARM. Generic ARM version. 2 Copyright (C) 2012-2025 Free Software Foundation, Inc. 3 4 The GNU C Library is free software; you can redistribute it and/or 5 modify it under the terms of the GNU Lesser General Public 6 License as published by the Free Software Foundation; either 7 version 2.1 of the License, or (at your option) any later version. 8 9 The GNU C Library is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public 15 License along with the GNU C Library. If not, see 16 <https://www.gnu.org/licenses/>. */ 17 18 #ifndef _ARM_ARM_FEATURES_H 19 #define _ARM_ARM_FEATURES_H 1 20 21 /* An OS-specific arm-features.h file should define ARM_HAVE_VFP to 22 an appropriate expression for testing at runtime whether the VFP 23 hardware is present. We'll then redefine it to a constant if we 24 know at compile time that we can assume VFP. */ 25 26 #ifndef __SOFTFP__ 27 /* The compiler is generating VFP instructions, so we're already 28 assuming the hardware exists. */ 29 # undef ARM_HAVE_VFP 30 # define ARM_HAVE_VFP 1 31 #endif 32 33 /* An OS-specific arm-features.h file may define ARM_ASSUME_NO_IWMMXT 34 to indicate at compile time that iWMMXt hardware is never present 35 at runtime (or that we never care about its state) and so need not 36 be checked for. */ 37 38 /* A more-specific arm-features.h file may define ARM_ALWAYS_BX to indicate 39 that instructions using pc as a destination register must never be used, 40 so a "bx" (or "blx") instruction is always required. */ 41 42 /* The log2 of the minimum alignment required for an address that 43 is the target of a computed branch (i.e. a "bx" instruction). 44 A more-specific arm-features.h file may define this to set a more 45 stringent requirement. 46 47 Using this only makes sense for code in ARM mode (where instructions 48 always have a fixed size of four bytes), or for Thumb-mode code that is 49 specifically aligning all the related branch targets to match (since 50 Thumb instructions might be either two or four bytes). */ 51 #ifndef ARM_BX_ALIGN_LOG2 52 # define ARM_BX_ALIGN_LOG2 2 53 #endif 54 55 /* An OS-specific arm-features.h file may define ARM_NO_INDEX_REGISTER to 56 indicate that the two-register addressing modes must never be used. */ 57 58 #endif /* arm-features.h */ 59