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   gcc    ( 1 )

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Параметры подробно (Options detail)

RISC-V

These command-line options are defined for RISC-V targets:

       -mbranch-cost=n
           Set the cost of branches to roughly n instructions.

       -mplt
       -mno-plt
           When generating PIC code, do or don't allow the use of PLTs.
           Ignored for non-PIC.  The default is -mplt.

       -mabi=ABI-string
           Specify integer and floating-point calling convention.  ABI-
           string contains two parts: the size of integer types and the
           registers used for floating-point types.  For example
           -march=rv64ifd -mabi=lp64d means that long and pointers are
           64-bit (implicitly defining int to be 32-bit), and that
           floating-point values up to 64 bits wide are passed in F
           registers.  Contrast this with -march=rv64ifd -mabi=lp64f,
           which still allows the compiler to generate code that uses
           the F and D extensions but only allows floating-point values
           up to 32 bits long to be passed in registers; or
           -march=rv64ifd -mabi=lp64, in which no floating-point
           arguments will be passed in registers.

           The default for this argument is system dependent, users who
           want a specific calling convention should specify one
           explicitly.  The valid calling conventions are: ilp32,
           ilp32f, ilp32d, lp64, lp64f, and lp64d.  Some calling
           conventions are impossible to implement on some ISAs: for
           example, -march=rv32if -mabi=ilp32d is invalid because the
           ABI requires 64-bit values be passed in F registers, but F
           registers are only 32 bits wide.  There is also the ilp32e
           ABI that can only be used with the rv32e architecture.  This
           ABI is not well specified at present, and is subject to
           change.

       -mfdiv
       -mno-fdiv
           Do or don't use hardware floating-point divide and square
           root instructions.  This requires the F or D extensions for
           floating-point registers.  The default is to use them if the
           specified architecture has these instructions.

       -mdiv
       -mno-div
           Do or don't use hardware instructions for integer division.
           This requires the M extension.  The default is to use them if
           the specified architecture has these instructions.

       -march=ISA-string
           Generate code for given RISC-V ISA (e.g. rv64im).  ISA
           strings must be lower-case.  Examples include rv64i, rv32g,
           rv32e, and rv32imaf.

       -mtune=processor-string
           Optimize the output for the given processor, specified by
           microarchitecture name.  Permissible values for this option
           are: rocket, sifive-3-series, sifive-5-series,
           sifive-7-series, and size.

           When -mtune= is not specified, the default is rocket.

           The size choice is not intended for use by end-users.  This
           is used when -Os is specified.  It overrides the instruction
           cost info provided by -mtune=, but does not override the
           pipeline info.  This helps reduce code size while still
           giving good performance.

       -mpreferred-stack-boundary=num
           Attempt to keep the stack boundary aligned to a 2 raised to
           num byte boundary.  If -mpreferred-stack-boundary is not
           specified, the default is 4 (16 bytes or 128-bits).

           Warning: If you use this switch, then you must build all
           modules with the same value, including any libraries.  This
           includes the system libraries and startup modules.

       -msmall-data-limit=n
           Put global and static data smaller than n bytes into a
           special section (on some targets).

       -msave-restore
       -mno-save-restore
           Do or don't use smaller but slower prologue and epilogue code
           that uses library function calls.  The default is to use fast
           inline prologues and epilogues.

       -mstrict-align
       -mno-strict-align
           Do not or do generate unaligned memory accesses.  The default
           is set depending on whether the processor we are optimizing
           for supports fast unaligned access or not.

       -mcmodel=medlow
           Generate code for the medium-low code model. The program and
           its statically defined symbols must lie within a single 2 GiB
           address range and must lie between absolute addresses -2 GiB
           and +2 GiB. Programs can be statically or dynamically linked.
           This is the default code model.

       -mcmodel=medany
           Generate code for the medium-any code model. The program and
           its statically defined symbols must be within any single 2
           GiB address range. Programs can be statically or dynamically
           linked.

       -mexplicit-relocs
       -mno-exlicit-relocs
           Use or do not use assembler relocation operators when dealing
           with symbolic addresses.  The alternative is to use assembler
           macros instead, which may limit optimization.

       -mrelax
       -mno-relax
           Take advantage of linker relaxations to reduce the number of
           instructions required to materialize symbol addresses. The
           default is to take advantage of linker relaxations.

       -memit-attribute
       -mno-emit-attribute
           Emit (do not emit) RISC-V attribute to record extra
           information into ELF objects.  This feature requires at least
           binutils 2.32.