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LLVM-MC(1) User Commands LLVM-MC(1)


llvm-mc - manual page for llvm-mc 11


OVERVIEW: llvm machine code playground

USAGE: llvm-mc [options] <input file>


Color Options:

--color - Use colors in output (default=autodetect)

General options:

-I=<directory> - Directory of include files

--aarch64-neon-syntax=<value> - Choose style of NEON code to emit from AArch64 backend:

- Emit generic NEON assembly
- Emit Apple-style NEON assembly

--amdgpu-bypass-slow-div - Skip 64-bit divide for dynamic 32-bit values

--amdgpu-disable-loop-alignment - Do not align and prefetch loops

--amdgpu-disable-power-sched - Disable scheduling to minimize mAI power bursts

--amdgpu-dpp-combine - Enable DPP combiner

--amdgpu-dump-hsa-metadata - Dump AMDGPU HSA Metadata

--amdgpu-enable-global-sgpr-addr - Enable use of SGPR regs for GLOBAL LOAD/STORE instructions

--amdgpu-enable-merge-m0 - Merge and hoist M0 initializations

--amdgpu-promote-alloca-to-vector-limit=<uint> - Maximum byte size to consider promote alloca to vector

--amdgpu-reserve-vgpr-for-sgpr-spill - Allocates one VGPR for future SGPR Spill

--amdgpu-sdwa-peephole - Enable SDWA peepholer

--amdgpu-verify-hsa-metadata - Verify AMDGPU HSA Metadata

--amdgpu-vgpr-index-mode - Use GPR indexing mode instead of movrel for vector indexing

--arch=<string> - Target arch to assemble for, see -version for available targets

--arm-add-build-attributes -

--arm-implicit-it=<value> - Allow conditional instructions outdside of an IT block

- Accept in both ISAs, emit implicit ITs in Thumb
- Warn in ARM, reject in Thumb
- Accept in ARM, reject in Thumb
- Warn in ARM, emit implicit ITs in Thumb

--asm-show-inst - Emit internal instruction representation to assembly file

Action to perform:

--as-lex - Lex tokens from a .s file

--assemble - Assemble a .s file (default)

--disassemble - Disassemble strings of hex bytes

--mdis - Marked up disassembly of strings of hex bytes

for promoted counters only

--atomic-first-counter - Use atomic fetch add for first counter in a function (usually the entry counter)

--bounds-checking-single-trap - Use one trap block per function

--cfg-hide-deoptimize-paths -

--cfg-hide-unreachable-paths -

--compress-debug-sections=<value> - Choose DWARF debug sections compression:

- No compression
- Use zlib compression
- Use zlib-gnu compression (deprecated)

--cost-kind=<value> - Target cost kind

- Reciprocal throughput
- Instruction latency
- Code size

--cvp-dont-add-nowrap-flags -

--debugify-level=<value> - Kind of debug info to add

- Locations only
- Locations and Variables

--debugify-quiet - Suppress verbose debugify output

--defsym=<string> - Defines a symbol to be an integer constant

--disable-promote-alloca-to-lds - Disable promote alloca to LDS

--disable-promote-alloca-to-vector - Disable promote alloca to vector

--do-counter-promotion - Do counter register promotion

--dwarf-version=<int> - Dwarf version

--dwarf64 - Generate debugging info in the 64-bit DWARF format

--emscripten-cxx-exceptions-allowed=<string> - The list of function names in which Emscripten-style exception handling is enabled (see emscripten EMSCRIPTEN_CATCHING_ALLOWED options)

--enable-cse-in-irtranslator - Should enable CSE in irtranslator

--enable-cse-in-legalizer - Should enable CSE in Legalizer

--enable-emscripten-cxx-exceptions - WebAssembly Emscripten-style exception handling

--enable-emscripten-sjlj - WebAssembly Emscripten-style setjmp/longjmp handling

--enable-gvn-hoist - Enable the GVN hoisting pass (default = off)

--enable-gvn-memdep -

--enable-gvn-sink - Enable the GVN sinking pass (default = off)

--enable-load-in-loop-pre -

--enable-load-pre -

--enable-loop-simplifycfg-term-folding -

--enable-name-compression - Enable name/filename string compression

--fatal-warnings - Treat warnings as errors

--fdebug-compilation-dir=<string> - Specifies the debug info's compilation dir

--fdebug-prefix-map=<= separated key-value pairs> - Map file source paths in debug info

--filetype=<value> - Choose an output file type:

- Emit an assembly ('.s') file
- Don't emit anything (for timing purposes)
- Emit a native object ('.o') file

-g - Generate dwarf debugging info for assembly source files

The default size is 8.

--hash-based-counter-split - Rename counter variable of a comdat function based on cfg hash

--hot-cold-split - Enable hot-cold splitting pass

--import-all-index - Import all external functions in index.

--incremental-linker-compatible - When used with filetype=obj, emit an object file which can be used with an incremental linker

--instcombine-code-sinking - Enable code sinking

--instcombine-guard-widening-window=<uint> - How wide an instruction window to bypass looking for another guard

--instcombine-max-iterations=<uint> - Limit the maximum number of instruction combining iterations

--instcombine-max-num-phis=<uint> - Maximum number phis to handle in intptr/ptrint folding

--instcombine-maxarray-size=<uint> - Maximum array size considered when doing a combine

--instcombine-negator-enabled - Should we attempt to sink negations?

--instcombine-negator-max-depth=<uint> - What is the maximal lookup depth when trying to check for viability of negation sinking.

--instrprof-atomic-counter-update-all - Make all profile counter updates atomic (for testing only)

--internalize-public-api-file=<filename> - A file containing list of symbol names to preserve

--internalize-public-api-list=<list> - A list of symbol names to preserve

--iterative-counter-promotion - Allow counter promotion across the whole loop nest.

--large-code-model - Create cfi directives that assume the code might be more than 2gb away

--lto-embed-bitcode - Embed LLVM bitcode in object files produced by LTO

--lto-pass-remarks-filter=<regex> - Only record optimization remarks from passes whose names match the given regular expression

--lto-pass-remarks-format=<format> - The format used for serializing remarks (default: YAML)

--lto-pass-remarks-output=<filename> - Output filename for pass remarks

--main-file-name=<string> - Specifies the name we should consider the input file

--masm-integers - Enable binary and hex masm integers (0b110 and 0ABCh)

--matrix-default-layout=<value> - Sets the default matrix layout

- Use column-major layout
- Use row-major layout

--mattr=<a1,+a2,-a3,...> - Target specific attributes (-mattr=help for details)

--max-counter-promotions=<int> - Max number of allowed counter promotions

--max-counter-promotions-per-loop=<uint> - Max number counter promotions per loop to avoid increasing register pressure too much

--mc-relax-all - When used with filetype=obj, relax all fixups in the emitted object file

--mcpu=<cpu-name> - Target a specific cpu type (-mcpu=help for details)

--memop-size-large=<uint> - Set large value thresthold in memory intrinsic size profiling. Value of 0 disables the large value profiling.

--memop-size-range=<string> - Set the range of size in memory intrinsic calls to be profiled precisely, in a format of <start_val>:<end_val>

--merror-missing-parenthesis - Error for missing parenthesis around predicate registers

--merror-noncontigious-register - Error for register names that aren't contigious

--mhvx - Enable Hexagon Vector eXtensions

--mhvx=<value> - Enable Hexagon Vector eXtensions

- Build for HVX v60
- Build for HVX v62
- Build for HVX v65
- Build for HVX v66
- Build for HVX v67

--mips-compact-branches=<value> - MIPS Specific: Compact branch policy.

- Do not use compact branches if possible.
- Use compact branches where appropriate (default).
- Always use compact branches if possible.

--mips16-constant-islands - Enable mips16 constant islands.

--mips16-hard-float - Enable mips16 hard float.

--mir-strip-debugify-only - Should mir-strip-debug only strip debug info from debugified modules by default

--mno-compound - Disable looking for compound instructions for Hexagon

--mno-fixup - Disable fixing up resolved relocations for Hexagon

--mno-ldc1-sdc1 - Expand double precision loads and stores to their single precision counterparts

--mno-pairing - Disable looking for duplex instructions for Hexagon

--mwarn-missing-parenthesis - Warn for missing parenthesis around predicate registers

--mwarn-noncontigious-register - Warn for register names that arent contigious

--mwarn-sign-mismatch - Warn for mismatching a signed and unsigned value

-n - Don't assume assembly file starts in the text section

--no-deprecated-warn - Suppress all deprecated warnings

--no-discriminators - Disable generation of discriminator information.

--no-exec-stack - File doesn't need an exec stack

--no-warn - Suppress all warnings

--nvptx-sched4reg - NVPTX Specific: schedule for register pressue

-o=<filename> - Output filename

--output-asm-variant=<uint> - Syntax variant to use for output printing

--poison-checking-function-local - Check that returns are non-poison (for testing)

--position-independent - Position independent

--preserve-comments - Preserve Comments in outputted assembly

--print-imm-hex - Prefer hex format for immediate values

--r600-ir-structurize - Use StructurizeCFG IR pass

--rdf-dump -

--rdf-limit=<uint> -

--relax-relocations - Emit R_X86_64_GOTPCRELX instead of R_X86_64_GOTPCREL

--runtime-counter-relocation - Enable relocating counters at runtime.

--safepoint-ir-verifier-print-only -

--sample-profile-check-record-coverage=<N> - Emit a warning if less than N% of records in the input profile are matched to the IR.

--sample-profile-check-sample-coverage=<N> - Emit a warning if less than N% of samples in the input profile are matched to the IR.

--sample-profile-max-propagate-iterations=<uint> - Maximum number of iterations to go through when propagating sample block/edge weights through the CFG.

--save-temp-labels - Don't discard temporary labels

--show-encoding - Show instruction encodings

--show-inst - Show internal instruction representation

--show-inst-operands - Show instructions operands as parsed

speculative counter promotion
update can be further/iteratively promoted into an acyclic region.

--split-dwarf-file=<filename> - DWO output filename

--summary-file=<string> - The summary file to use for function importing.

--tail-predication=<value> - MVE tail-predication options

- Don't tail-predicate loops
- Enable tail-predication, but not for reduction loops
- Enable tail-predication, including reduction loops
- Enable tail-predication, but not for reduction loops, and force this which might be unsafe
- Enable tail-predication, including reduction loops, and force this which might be unsafe

--threads=<int> -

--triple=<string> - Target triple to assemble for, see -version for available targets

--verify-region-info - Verify region info (time consuming)

--vp-counters-per-site=<number> - The average number of profile counters allocated per value profiling site.

--vp-static-alloc - Do static counter allocation for value profiler

jcc indicates conditional jumps fused indicates fused conditional jumps jmp indicates direct unconditional jumps call indicates direct and indirect calls ret indicates rets indirect indicates indirect unconditional jumps

--x86-align-branch-boundary=<uint> - Control how the assembler should align branches with NOP. If the boundary's size is not 0, it should be a power of 2 and no less than 32. Branches will be aligned to prevent from being across or against the boundary of specified size. The default value 0 does not align branches.

May break assumptions about labels corresponding to particular instructions, and should be used with caution.

--x86-pad-max-prefix-size=<uint> - Maximum number of prefixes to use for padding

Generic Options:

--help - Display available options (--help-hidden for more)

--help-list - Display list of available options (--help-list-hidden for more)

--version - Display the version of this program

Polly Options: Configure the polly loop optimizer

--polly - Enable the polly optimizer (only at -O3)

--polly-2nd-level-tiling - Enable a 2nd level loop of loop tiling

--polly-ast-print-accesses - Print memory access functions

--polly-context=<isl parameter set> - Provide additional constraints on the context parameters

--polly-dce-precise-steps=<int> - The number of precise steps between two approximating iterations. (A value of -1 schedules another approximation stage before the actual dead code elimination.

--polly-delicm-max-ops=<int> - Maximum number of isl operations to invest for lifetime analysis; 0=no limit

--polly-detect-full-functions - Allow the detection of full functions

--polly-dump-after - Dump module after Polly transformations into a file suffixed with "-after"

--polly-dump-after-file=<string> - Dump module after Polly transformations to the given file

--polly-dump-before - Dump module before Polly transformations into a file suffixed with "-before"

--polly-dump-before-file=<string> - Dump module before Polly transformations to the given file

--polly-enable-simplify - Simplify SCoP after optimizations

--polly-ignore-func=<string> - Ignore functions that match a regex. Multiple regexes can be comma separated. Scop detection will ignore all functions that match ANY of the regexes provided.

--polly-isl-arg=<argument> - Option passed to ISL

--polly-on-isl-error-abort - Abort if an isl error is encountered

--polly-only-func=<string> - Only run on functions that match a regex. Multiple regexes can be comma separated. Scop detection will run on all functions that match ANY of the regexes provided.

--polly-only-region=<identifier> - Only run on certain regions (The provided identifier must appear in the name of the region's entry block

--polly-only-scop-detection - Only run scop detection, but no other optimizations

--polly-optimized-scops - Polly - Dump polyhedral description of Scops optimized with the isl scheduling optimizer and the set of post-scheduling transformations is applied on the schedule tree

--polly-parallel - Generate thread parallel code (isl codegen only)

--polly-parallel-force - Force generation of thread parallel code ignoring any cost model

--polly-pattern-matching-based-opts - Perform optimizations based on pattern matching

--polly-process-unprofitable - Process scops that are unlikely to benefit from Polly optimizations.

--polly-register-tiling - Enable register tiling

--polly-report - Print information about the activities of Polly

--polly-show - Highlight the code regions that will be optimized in a (CFG BBs and LLVM-IR instructions)

--polly-show-only - Highlight the code regions that will be optimized in a (CFG only BBs)

--polly-stmt-granularity=<value> - Algorithm to use for splitting basic blocks into multiple statements

- One statement per basic block
- Scalar independence heuristic
- Store-level granularity

--polly-target=<value> - The hardware to target

- generate CPU code

--polly-tiling - Enable loop tiling

--polly-vectorizer=<value> - Select the vectorization strategy

- No Vectorization
- Polly internal vectorizer
- Strip-mine outer loops for the loop-vectorizer to trigger
January 2021 llvm-mc 11