arm.opt revision 1.10
1; Options for the ARM port of the compiler. 2 3; Copyright (C) 2005-2019 Free Software Foundation, Inc. 4; 5; This file is part of GCC. 6; 7; GCC is free software; you can redistribute it and/or modify it under 8; the terms of the GNU General Public License as published by the Free 9; Software Foundation; either version 3, or (at your option) any later 10; version. 11; 12; GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13; WARRANTY; without even the implied warranty of MERCHANTABILITY or 14; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15; for more details. 16; 17; You should have received a copy of the GNU General Public License 18; along with GCC; see the file COPYING3. If not see 19; <http://www.gnu.org/licenses/>. 20 21HeaderInclude 22config/arm/arm-opts.h 23 24TargetSave 25const char *x_arm_arch_string 26 27TargetSave 28const char *x_arm_cpu_string 29 30TargetSave 31const char *x_arm_tune_string 32 33Enum 34Name(tls_type) Type(enum arm_tls_type) 35TLS dialect to use: 36 37EnumValue 38Enum(tls_type) String(gnu) Value(TLS_GNU) 39 40EnumValue 41Enum(tls_type) String(gnu2) Value(TLS_GNU2) 42 43mabi= 44Target RejectNegative Joined Enum(arm_abi_type) Var(arm_abi) Init(ARM_DEFAULT_ABI) 45Specify an ABI. 46 47Enum 48Name(arm_abi_type) Type(enum arm_abi_type) 49Known ARM ABIs (for use with the -mabi= option): 50 51EnumValue 52Enum(arm_abi_type) String(apcs-gnu) Value(ARM_ABI_APCS) 53 54EnumValue 55Enum(arm_abi_type) String(atpcs) Value(ARM_ABI_ATPCS) 56 57EnumValue 58Enum(arm_abi_type) String(aapcs) Value(ARM_ABI_AAPCS) 59 60EnumValue 61Enum(arm_abi_type) String(iwmmxt) Value(ARM_ABI_IWMMXT) 62 63EnumValue 64Enum(arm_abi_type) String(aapcs-linux) Value(ARM_ABI_AAPCS_LINUX) 65 66mabort-on-noreturn 67Target Report Mask(ABORT_NORETURN) 68Generate a call to abort if a noreturn function returns. 69 70mapcs 71Target RejectNegative Mask(APCS_FRAME) Undocumented 72 73mapcs-frame 74Target Report Mask(APCS_FRAME) 75Generate APCS conformant stack frames. 76 77mapcs-reentrant 78Target Report Mask(APCS_REENT) 79Generate re-entrant, PIC code. 80 81mapcs-stack-check 82Target Report Mask(APCS_STACK) Undocumented 83 84march= 85Target RejectNegative Negative(march=) ToLower Joined Var(arm_arch_string) 86Specify the name of the target architecture. 87 88; Other arm_arch values are loaded from arm-tables.opt 89; but that is a generated file and this is an odd-one-out. 90EnumValue 91Enum(arm_arch) String(native) Value(-1) DriverOnly 92 93marm 94Target Report RejectNegative Negative(mthumb) InverseMask(THUMB) 95Generate code in 32 bit ARM state. 96 97mbig-endian 98Target Report RejectNegative Negative(mlittle-endian) Mask(BIG_END) 99Assume target CPU is configured as big endian. 100 101mcallee-super-interworking 102Target Report Mask(CALLEE_INTERWORKING) 103Thumb: Assume non-static functions may be called from ARM code. 104 105mcaller-super-interworking 106Target Report Mask(CALLER_INTERWORKING) 107Thumb: Assume function pointers may go to non-Thumb aware code. 108 109mcpu= 110Target RejectNegative Negative(mcpu=) ToLower Joined Var(arm_cpu_string) 111Specify the name of the target CPU. 112 113mfloat-abi= 114Target RejectNegative Joined Enum(float_abi_type) Var(arm_float_abi) Init(TARGET_DEFAULT_FLOAT_ABI) 115Specify if floating point hardware should be used. 116 117mcmse 118Target RejectNegative Var(use_cmse) 119Specify that the compiler should target secure code as per ARMv8-M Security Extensions. 120 121Enum 122Name(float_abi_type) Type(enum float_abi_type) 123Known floating-point ABIs (for use with the -mfloat-abi= option): 124 125EnumValue 126Enum(float_abi_type) String(soft) Value(ARM_FLOAT_ABI_SOFT) 127 128EnumValue 129Enum(float_abi_type) String(softfp) Value(ARM_FLOAT_ABI_SOFTFP) 130 131EnumValue 132Enum(float_abi_type) String(hard) Value(ARM_FLOAT_ABI_HARD) 133 134mflip-thumb 135Target Report Var(TARGET_FLIP_THUMB) Undocumented 136Switch ARM/Thumb modes on alternating functions for compiler testing. 137 138mfp16-format= 139Target RejectNegative Joined Enum(arm_fp16_format_type) Var(arm_fp16_format) Init(ARM_FP16_FORMAT_NONE) 140Specify the __fp16 floating-point format. 141 142Enum 143Name(arm_fp16_format_type) Type(enum arm_fp16_format_type) 144Known __fp16 formats (for use with the -mfp16-format= option): 145 146EnumValue 147Enum(arm_fp16_format_type) String(none) Value(ARM_FP16_FORMAT_NONE) 148 149EnumValue 150Enum(arm_fp16_format_type) String(ieee) Value(ARM_FP16_FORMAT_IEEE) 151 152EnumValue 153Enum(arm_fp16_format_type) String(alternative) Value(ARM_FP16_FORMAT_ALTERNATIVE) 154 155mfpu= 156Target RejectNegative Joined Enum(arm_fpu) Var(arm_fpu_index) Init(TARGET_FPU_auto) Save 157Specify the name of the target floating point hardware/format. 158 159mhard-float 160Target RejectNegative Alias(mfloat-abi=, hard) Undocumented 161 162mlittle-endian 163Target Report RejectNegative Negative(mbig-endian) InverseMask(BIG_END) 164Assume target CPU is configured as little endian. 165 166mlong-calls 167Target Report Mask(LONG_CALLS) 168Generate call insns as indirect calls, if necessary. 169 170mpic-data-is-text-relative 171Target Report Var(arm_pic_data_is_text_relative) Init(TARGET_DEFAULT_PIC_DATA_IS_TEXT_RELATIVE) 172Assume data segments are relative to text segment. 173 174mpic-register= 175Target RejectNegative Joined Var(arm_pic_register_string) 176Specify the register to be used for PIC addressing. 177 178mpoke-function-name 179Target Report Mask(POKE_FUNCTION_NAME) 180Store function names in object code. 181 182msched-prolog 183Target Report Mask(SCHED_PROLOG) 184Permit scheduling of a function's prologue sequence. 185 186msingle-pic-base 187Target Report Mask(SINGLE_PIC_BASE) 188Do not load the PIC register in function prologues. 189 190msoft-float 191Target RejectNegative Alias(mfloat-abi=, soft) Undocumented 192 193mstructure-size-boundary= 194Target RejectNegative Joined UInteger Var(arm_structure_size_boundary) Init(DEFAULT_STRUCTURE_SIZE_BOUNDARY) 195Specify the minimum bit alignment of structures. (Deprecated). 196 197mthumb 198Target Report RejectNegative Negative(marm) Mask(THUMB) Save 199Generate code for Thumb state. 200 201mthumb-interwork 202Target Report Mask(INTERWORK) 203Support calls between Thumb and ARM instruction sets. 204 205mtls-dialect= 206Target RejectNegative Joined Enum(tls_type) Var(target_tls_dialect) Init(TLS_GNU) 207Specify thread local storage scheme. 208 209mtp= 210Target RejectNegative Joined Enum(arm_tp_type) Var(target_thread_pointer) Init(TP_AUTO) 211Specify how to access the thread pointer. 212 213Enum 214Name(arm_tp_type) Type(enum arm_tp_type) 215Valid arguments to -mtp=: 216 217EnumValue 218Enum(arm_tp_type) String(soft) Value(TP_SOFT) 219 220EnumValue 221Enum(arm_tp_type) String(auto) Value(TP_AUTO) 222 223EnumValue 224Enum(arm_tp_type) String(cp15) Value(TP_CP15) 225 226mtpcs-frame 227Target Report Mask(TPCS_FRAME) 228Thumb: Generate (non-leaf) stack frames even if not needed. 229 230mtpcs-leaf-frame 231Target Report Mask(TPCS_LEAF_FRAME) 232Thumb: Generate (leaf) stack frames even if not needed. 233 234mtune= 235Target RejectNegative Negative(mtune=) ToLower Joined Var(arm_tune_string) 236Tune code for the given processor. 237 238mprint-tune-info 239Target Report RejectNegative Var(print_tune_info) Init(0) 240Print CPU tuning information as comment in assembler file. This is 241an option used only for regression testing of the compiler and not 242intended for ordinary use in compiling code. 243 244; Other processor_type values are loaded from arm-tables.opt 245; but that is a generated file and this is an odd-one-out. 246EnumValue 247Enum(processor_type) String(native) Value(-1) DriverOnly 248 249mvectorize-with-neon-quad 250Target Report RejectNegative InverseMask(NEON_VECTORIZE_DOUBLE) 251Use Neon quad-word (rather than double-word) registers for vectorization. 252 253mvectorize-with-neon-double 254Target Report RejectNegative Mask(NEON_VECTORIZE_DOUBLE) 255Use Neon double-word (rather than quad-word) registers for vectorization. 256 257mverbose-cost-dump 258Common Undocumented Var(arm_verbose_cost) Init(0) 259Enable more verbose RTX cost dumps during debug. For GCC developers use only. 260 261mword-relocations 262Target Report Var(target_word_relocations) Init(TARGET_DEFAULT_WORD_RELOCATIONS) 263Only generate absolute relocations on word sized values. 264 265mrestrict-it 266Target Report Var(arm_restrict_it) Init(2) Save 267Generate IT blocks appropriate for ARMv8. 268 269mfix-cortex-m3-ldrd 270Target Report Var(fix_cm3_ldrd) Init(2) 271Avoid overlapping destination and address registers on LDRD instructions 272that may trigger Cortex-M3 errata. 273 274munaligned-access 275Target Report Var(unaligned_access) Init(2) Save 276Enable unaligned word and halfword accesses to packed data. 277 278mneon-for-64bits 279Target Report RejectNegative Var(use_neon_for_64bits) Init(0) 280Use Neon to perform 64-bits operations rather than core registers. 281 282mslow-flash-data 283Target Report Var(target_slow_flash_data) Init(0) 284Assume loading data from flash is slower than fetching instructions. 285 286masm-syntax-unified 287Target Report Var(inline_asm_unified) Init(0) Save 288Assume unified syntax for inline assembly code. 289 290mpure-code 291Target Report Var(target_pure_code) Init(0) 292Do not allow constant data to be placed in code sections. 293 294mbe8 295Target Report RejectNegative Negative(mbe32) Mask(BE8) 296When linking for big-endian targets, generate a BE8 format image. 297 298mbe32 299Target Report RejectNegative Negative(mbe8) InverseMask(BE8) 300When linking for big-endian targets, generate a legacy BE32 format image. 301 302mbranch-cost= 303Target RejectNegative Joined UInteger Var(arm_branch_cost) Init(-1) 304Cost to assume for a branch insn. 305 306mgeneral-regs-only 307Target Report RejectNegative Mask(GENERAL_REGS_ONLY) Save 308Generate code which uses the core registers only (r0-r14). 309