; Options for the ATMEL AVR port of the compiler.
; Copyright (C) 2005-2020 Free Software Foundation, Inc.
;
; This file is part of GCC.
;
; GCC is free software; you can redistribute it and/or modify it under
; the terms of the GNU General Public License as published by the Free
; Software Foundation; either version 3, or (at your option) any later
; version.
;
; GCC is distributed in the hope that it will be useful, but WITHOUT ANY
; WARRANTY; without even the implied warranty of MERCHANTABILITY or
; FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
; for more details.
;
; You should have received a copy of the GNU General Public License
; along with GCC; see the file COPYING3. If not see
; <http://www.gnu.org/licenses/>.
mcall-prologues
Target Report Mask(CALL_PROLOGUES)
Use subroutines for function prologues and epilogues.
mmcu=
Target RejectNegative Joined Var(avr_mmcu) MissingArgError(missing device or architecture after %qs)
-mmcu=MCU Select the target MCU.
mgas-isr-prologues
Target Report Var(avr_gasisr_prologues) UInteger Init(0)
Allow usage of __gcc_isr pseudo instructions in ISR prologues and epilogues.
mn-flash=
Target RejectNegative Joined Var(avr_n_flash) UInteger Init(-1)
Set the number of 64 KiB flash segments.
mskip-bug
Target Report Mask(SKIP_BUG)
Indicate presence of a processor erratum.
mrmw
Target Report Mask(RMW)
Enable Read-Modify-Write (RMW) instructions support/use.
mdeb
Target Report Undocumented Mask(ALL_DEBUG)
mlog=
Target RejectNegative Joined Undocumented Var(avr_log_details)
mshort-calls
Target Report RejectNegative Mask(SHORT_CALLS)
Use RJMP / RCALL even though CALL / JMP are available.
mint8
Target Report Mask(INT8)
Use an 8-bit 'int' type.
mno-interrupts
Target Report RejectNegative Mask(NO_INTERRUPTS)
Change the stack pointer without disabling interrupts.
mbranch-cost=
Target Report Joined RejectNegative UInteger Var(avr_branch_cost) Init(0)
Set the branch costs for conditional branch instructions. Reasonable values are small, non-negative integers. The default branch cost is 0.
mmain-is-OS_task
Target Report Mask(MAIN_IS_OS_TASK)
Treat main as if it had attribute OS_task.
morder1
Target Report Undocumented Mask(ORDER_1)
morder2
Target Report Undocumented Mask(ORDER_2)
mtiny-stack
Target Report Mask(TINY_STACK)
Change only the low 8 bits of the stack pointer.
mrelax
Target Report
Relax branches.
mpmem-wrap-around
Target Report
Make the linker relaxation machine assume that a program counter wrap-around occurs.
maccumulate-args
Target Report Mask(ACCUMULATE_OUTGOING_ARGS)
Accumulate outgoing function arguments and acquire/release the needed stack space for outgoing function arguments in function prologue/epilogue. Without this option, outgoing arguments are pushed before calling a function and popped afterwards. This option can lead to reduced code size for functions that call many functions that get their arguments on the stack like, for example printf.
mstrict-X
Target Report Var(avr_strict_X) Init(0)
When accessing RAM, use X as imposed by the hardware, i.e. just use pre-decrement, post-increment and indirect addressing with the X register. Without this option, the compiler may assume that there is an addressing mode X+const similar to Y+const and Z+const and emit instructions to emulate such an addressing mode for X.
;; For rationale behind -msp8 see explanation in avr.h.
msp8
Target Report RejectNegative Var(avr_sp8) Init(0)
The device has no SPH special function register. This option will be overridden by the compiler driver with the correct setting if presence/absence of SPH can be deduced from -mmcu=MCU.
Waddr-space-convert
Warning C Report Var(avr_warn_addr_space_convert) Init(0)
Warn if the address space of an address is changed.
Wmisspelled-isr
Warning C C++ Report Var(avr_warn_misspelled_isr) Init(1)
Warn if the ISR is misspelled, i.e. without __vector prefix. Enabled by default.
mfract-convert-truncate
Target Report Mask(FRACT_CONV_TRUNC)
Allow to use truncation instead of rounding towards zero for fractional fixed-point types.
mabsdata
Target Report Mask(ABSDATA)
Assume that all data in static storage can be accessed by LDS / STS. This option is only useful for reduced Tiny devices.
mdouble=
Target Report Joined RejectNegative Var(avr_double) Init(0) Enum(avr_bits_e)
-mdouble=<BITS> Use <BITS> bits wide double type.
mlong-double=
Target Report Joined RejectNegative Var(avr_long_double) Init(0) Enum(avr_bits_e)
-mlong-double=<BITS> Use <BITS> bits wide long double type.
nodevicelib
Driver Target Report RejectNegative
Do not link against the device-specific library lib<MCU>.a.
nodevicespecs
Driver Target Report RejectNegative
Do not use the device-specific specs file device-specs/specs-<MCU>.
Enum
Name(avr_bits_e) Type(int)
Available BITS selections:
EnumValue
Enum(avr_bits_e) String(32) Value(32)
EnumValue
Enum(avr_bits_e) String(64) Value(64)