This topic provides you with a reference to all the compiler options
and some linker control options.
All other options are supported on both IA-32 and Itanium-based systems.
| Option |
Description |
Default |
-0f_check
IA-32 only |
Avoids the incorrect decoding of certain 0f
instructions for code targeted at older processors.
|
OFF |
| -A- |
Disables all predefined macros.
|
OFF |
-[no]align
IA-32 only |
Analyze and reorder memory layout for variables and arrays. |
OFF |
| -Aname[(value)] |
Associates a symbol name with the specified
sequence of value. Equivalent to an #assert preprocessing directive.
|
OFF |
|
-ansi |
Select strict ANSI C/C++ conformance dialect. |
OFF |
|
-ansi_alias[-] |
-ansi_alias directs the compiler to assume the
following:
- Arrays are not accessed out of bounds.
- Pointers are not cast to non-pointer types, and vice-versa.
- References to objects of two different scalar types
cannot alias. For example, an object of type int
cannot alias with an object of type float, or
an object of type float cannot alias with an object
of type double.
If your program satisfies the above conditions, setting the -ansi_alias
flag will help the compiler better optimize the program. However, if your
program does not satisfy one of the above conditions, the -ansi_alias
flag may lead the compiler to generate incorrect code. |
OFF |
|
-ax{M|i|K|W}
IA-32 only |
Generates specialized code for processor-specific codes M,
i, K, W
while also generating generic IA-32 code.
- M = Intel®
Pentium®
processors with MMX(TM) technology
- i = Intel Pentium Pro and
Intel Pentium II processors
- K = Intel Pentium III processors
- W = Intel Pentium 4 processors,
Intel®
Xeon(TM) processors, and Intel®
Pentium®
M processors
|
OFF |
| -C |
Places comments in preprocessed source output.
|
OFF |
| -c |
Stops the compilation process after an object file has been generated.
The compiler generates an object file for each C or C++ source file or
preprocessed source file. Also takes an assembler file and invokes the
assembler to generate an object file.
|
OFF |
| -c99[-] |
Enables [disables] C99 support for C programs.
|
ON |
| -complex_limited_range |
This option causes the compiler to use the highest performance formulations
of complex arithmetic operations, which may not produce acceptable results
for input values near the top or bottom of the legal range. Without this
option, the compiler users a better formulation of complex arithmetic
operations which produces acceptable results for the full range of input
values, at some loss in performance. |
OFF |
| -dM |
Output macro definitions in effect after preprocessing (use with -E). |
OFF |
| -Dname[=value] |
Defines a macro name and associates
it with the specified value. Equivalent
to a #define preprocessor directive.
|
OFF |
| -dryrun |
Show driver tool commands but do not execute tools. |
OFF |
|
-dynamic-linkerfilename |
Selects a dynamic linker (filename)
other than the default. |
OFF |
|
-E |
Stops the compilation process after the C or C++ source files have been
preprocessed, and writes the results to stdout.
|
OFF |
| -EP |
Preprocess to stdout omitting #line directives.
|
OFF |
| -falias |
Assume aliasing in program. |
ON |
| -fcode-asm |
Produce assemblable file with optional code annotations. Requires -S. |
OFF |
| -fno-alias |
Assume no aliasing in program. |
OFF |
| -ffnalias |
Assume aliasing within functions |
ON |
| -fno-fnalias |
Assume no aliasing within functions, but assume aliasing across calls. |
OFF |
| -fno-rtti |
Disable RTTI support. |
OFF |
| -f[no]verbose-asm |
Produce assemblable file with compiler comments. |
ON |
|
-fnsplit[-]
Itanium-based
systems only |
Enables [disables] function splitting. Default is ON with -prof_use.
To disable function splitting when you use -prof_use,
also specify -fnsplit-. |
OFF |
|
-fp
IA-32 only |
Disable using the EBP register as general purpose register.
|
OFF |
| -fpic, -fPIC |
Generate position independent code. |
OFF |
-fp_port
IA-32 only |
Round fp results at assignments and casts. Some speed impact. |
OFF |
-fr32
Itanium-based
systems only |
Use only lower 32 floating-point registers. |
OFF |
| -fshort-enums |
Allocate as many bytes as needed for enumerated types. |
OFF |
| -fsource-asm |
Produce assemblable file with optional code annotations. Requires -S. |
OFF |
| -fsyntax-only |
Same as -syntax. |
OFF |
-ftz[-]
Itanium-based
systems only |
Flushes denormal results to zero. The option is turned ON with -O3.
|
OFF |
| -funsigned-char |
Change default char type to unsigned. |
OFF |
| -funsigned-bitfields |
Change default bitfield type to unsigned. |
OFF |
| -g |
Generates symbolic debugging information in the object code for use
by source-level debuggers.
|
OFF |
| -H |
Print "include" file order and continue compilation. |
OFF |
| -help |
Prints compiler options summary. |
OFF |
| -idirafterdir |
Add directory (dir) to the second include
file search path (after -I). |
OFF |
| -Idirectory |
Specifies an additional directory to
search for include files.
|
OFF |
| -i_dynamic |
Link Intel provided libraries dynamically. |
OFF |
| -inline_debug_info |
Preserve the source position of inlined code instead of assigning the
call-site source position to inlined code. |
OFF |
| -ip |
Enables interprocedural optimizations for single file compilation.
|
OFF |
-IPF_fma[-]
Itanium-based
systems only |
Enable [disable] the combining of floating-point multiplies and add/subtract
operations.
|
OFF |
-IPF_fltacc[-]
Itanium-based
systems only |
Enable [disable] optimizations that affect floating-point accuracy.
|
OFF |
-IPF_flt_eval_method0
Itanium-based
systems only |
Floating-point operands evaluated to the precision indicated by the
program.
|
OFF |
-IPF_fp_speculationmode
Itanium-based
systems only |
Enable floating-point speculations with the following mode
conditions:
- fast - speculate floating-point
operations
- safe - speculate only when
safe
- strict - same as off
- off - disables speculation
of floating-point operations
|
OFF |
| -ip_no_inlining |
Disables inlining that would result from the -ip
interprocedural optimization, but has no effect on other interprocedural
optimizations.
|
OFF |
-ip_no_pinlining
IA-32 only |
Disable partial inlining. Requires -ip or -ipo. |
OFF |
| -ipo |
Enables interprocedural optimizations across files.
|
OFF |
| -ipo_c |
Generates a multifile object file (ipo_out.o)
that can be used in further link steps.
|
OFF |
| -ipo_obj |
Forces the compiler to create real object files when used with -ipo.
|
OFF |
| -ipo_S |
Generates a multifile assemblable file named ipo_out.s
that can be used in further link steps.
|
OFF |
-ivdep_parallel
Itanium-based
systems only |
This option indicates there is absolutely no loop-carried memory dependency
in the loop where IVDEP directive is specified.
|
OFF |
| -Kc++ |
Compile all source or unrecognized file types as C++ source files. |
ON
(for icpc/ecpc) |
-Knopic, -KNOPIC
Itanium-based
systems only |
Don't generate position independent code. |
OFF |
| -KPIC, -Kpic |
Generate position independent code. |
OFF for IA-32
ON for Itanium-based systems |
| -Ldirectory |
Instruct linker to search directory
for libraries.
|
OFF |
-long_double
IA-32 only |
Changes the default size of the long double data type from 64 to 80
bits.
|
OFF |
| -M |
Generates makefile dependency lines for each source file, based on
the #include lines found in the source file. |
OFF |
-march=cpu
IA-32 only |
Generate code excusively for a given cpu.
Values for cpu are:
- pentiumpro - Pentium® Pro and Pentium
II processor instructions.
- pentiumii - MMX(TM) instructions.
- pentiumiii - Streaming SIMD
extensions.
- pentium4 - Pentium 4 instructions.
|
OFF |
| -mcpu=cpu |
Optimize for a specific cpu.
For IA-32, cpu values are:
- pentium - Optimize for Pentium
processor.
- pentiumpro - Optimize for
Pentium Pro, Pentium II and Pentium III processors.
- pentium4 - Optimize for Pentium
4 processor (Default).
For Itanium-based Systems, cpu values are:
- itanium - Optimize for Itanium
processor.
- itanium2 - Optimize for Itanium
2 processor (Default).
|
ON
pentium
on IA-32
itanium2
on Itanium-based
Systems |
| -MD |
Preprocess and compile. Generate output file (.d
extension) containing dependency information. |
OFF |
| -MFfile |
Generate makefile dependency information in file.
Must specify -M or -MM. |
OFF |
| -MG |
Similar to -M, but treats missing header files
as generated files. |
OFF |
| -MM |
Similar to -M, but does not include system
header files. |
OFF |
| -MMD |
Similar to -MD, but does not include system
header files. |
OFF |
| -MX |
Generate dependency file (.o.dep extension)
containing information used for the Intel wb tool. |
OFF |
| -mp |
Favors conformance to the ANSI C and IEEE 754 standards for floating-point
arithmetic. |
OFF |
| -mp1 |
Improve floating-point precision (speed impact is less than -mp).
|
OFF |
| -mrelax |
Pass -relax to the linker. |
ON |
| -mno-relax |
Do not pass -relax to the linker. |
OFF |
-mserialize-volatile
Itanium-based
systems only |
Impose strict memory access ordering for volatile data object references. |
OFF |
-mno-serialize-volatile
Itanium-based
systems only |
The compiler may suppress both run-time and compile-time memory access
ordering for volatile data object references. Specifically, the .rel/.acq completers will not be issued on referencing
loads and stores. |
OFF |
| -nobss_init |
Places variables that are initialized with zeroes in the DATA section.
Disables placement of zero-initialized variables in BSS (use DATA).
|
OFF |
| -no_cpprt |
Do not link in C++ run-time libraries. |
OFF |
| -nodefaultlibs |
Do not use standard libraries when linking. |
|
| -nolib_inline |
Disables inline expansion of standard library functions.
|
OFF |
| -nostartfiles |
Do not use standard startup files when linking. |
OFF |
| -nostdlib |
Do not use standard libraries and startup files when linking. |
OFF |
| -O |
Same as -O1 on IA-32. Same as -O2
on Itanium-based systems. |
OFF |
| -O0 |
Disables optimizations.
|
OFF |
| -O1 |
Enable optimizations. Optimizes for speed. For Itanium compiler, -O1 turns off software pipelining to reduce code size.
|
ON |
| -O2 |
Same as -O1 on IA-32. Same as -O
on Itanium-based systems.
|
OFF |
| -O3 |
Enable -O2 plus more aggressive optimizations
that may increase the compilation time. Impact on performance is application
dependent, some applications may not see a performance improvement.
|
OFF |
|
-Obn |
Controls the compiler's inline expansion. The amount of inline expansion
performed varies with the value of n as
follows:
- 0: Disables inlining.
- 1: Enables (default) inlining
of functions declared with the __inline keyword.
Also enables inlining according to the C++ language.
- 2: Enables inlining of any
function. However, the compiler decides which functions to inline.
Enables interprocedural optimizations and has the same effect as -ip.
|
ON |
|
-ofile |
Name output file. |
OFF |
| -openmp |
Enables the parallelizer to generate multi-threaded code based on the
OpenMP* directives. The -openmp option only works
at an optimization level of -O2 (the default)
or higher.
|
OFF |
| -openmp_report{0|1|2} |
Controls the OpenMP parallelizer's diagnostic levels.
|
ON
-openmp_report1 |
| -openmp_stubs |
Enables OpenMP programs to compile in sequential mode. The OpenMP directives
are ignored and a stub OpenMP library is linked sequentially. |
OFF |
| -opt_report |
Generates an optimization report directed to stderr, unless -opt_report_file
is specified. |
OFF |
| -opt_report_filefilename |
Specifies the filename for the optimization
report. It is not necessary to invoke -opt_report
when this option is specified. |
OFF |
| -opt_report_levellevel |
Specifies the verbosity level of the
output. Valid level arguments:
If a level is not specified, min
is used by default. |
OFF |
| -opt_report_phasename |
Specifies the compilation name for which
reports are generated. The option can be used multiple times in the same
compilation to get output from multiple phases.
Valid name arguments:
- ipo: Interprocedural Optimizer
- hlo: High Level Optimizer
- ilo: Intermediate Language
Scalar Optimizer
- ecg: Code Generator
- omp: OpenMP*
- all: All phases
|
OFF |
| -opt_report_routinesubstring |
Specifies a routine substring. Reports
from all routines with names that include substring
as part of the name are generated. By default, reports for all routines
are generated. |
OFF |
| -opt_report_help |
Displays all possible settings for -opt_report_phase.
No compilation is performed. |
OFF |
| -P, -F |
Stops the compilation process after C or C++ source files have been
preprocessed and writes the results to files named according to the compiler's
default file-naming conventions.
|
OFF |
| -parallel |
Detects parallel loops capable of being executed safely in parallel
and automatically generates multithreaded code for these loops. |
OFF |
| -par_report{0|1|2|3} |
Controls the auto-parallelizer's diagnostic levels 0, 1, 2, or 3 as
follows:
- -par_report0: no diagnostic
information is displayed.
- -par_report1: indicates loops
successfully auto-parallelized (default).
- -par_report2: loops successfully
and unsccessfully auto-parallelized.
- -par_report3: same as 2 plus
additional information about any proven or assumed dependences inhibiting
auto-parallelization.
|
OFF |
| -par_threshold[n] |
Sets a threshold for the auto-parallelization of loops based on the
probability of profitable execution of the loop in parallel, n=0
to 100. This option is used for loops whose computation work volume cannot
be determined at compile time.
- -par_threshold0: loops get
auto-parallelized regardless of computation work volume.
- -par_threshold100: loops
get auto-parallelized only if profitable parallel execution is almost
certain.
|
OFF |
-pc32
IA-32 only |
Set internal FPU precision to 24-bit significand. |
OFF |
-pc64
IA-32 only |
Set internal FPU precision to 53-bit significand. |
OFF |
-pc80
IA-32 only |
Set internal FPU precision to 64-bit significand. |
ON |
-prec_div
IA-32 only |
Disables the floating point division-to-multiplication optimization.
Improves precision of floating-point divides.
|
OFF |
| -prof_dir dirname |
Specify the directory (dirname) to hold
profile information (*.dyn, *.dpi).
|
OFF |
| -prof_file filename |
Specify the filename for profiling summary
file.
|
OFF |
| -prof_gen[x] |
Instruments the program to prepare for instrumented execution and also
creates a new static profile information file (.spi
). With the x qualifier, extra information is
gathered.
|
OFF |
| -prof_use |
Uses dynamic feedback information.
|
OFF |
| -Qinstall dir |
Sets dir as root of compiler installation.
|
OFF |
| -Qlocation,tool,path |
Sets path as the location of the tool
specified by tool .
|
OFF |
| -Qoption,tool,list |
Passes an argument list to another tool in the compilation sequence, such as the
assembler or linker.
|
OFF |
| -qp, -p |
Compile and link for function profiling with UNIX* prof
tool |
OFF |
-rcd
IA-32 only |
Disables changing of the FPU rounding control. Enables fast float-to-int
conversions.
|
OFF |
| -[no]restrict |
Enables/disables pointer disambiguation with the
restrict qualifier. |
OFF |
| -S |
Generates assemblable files with .s suffix,
then stops the compilation.
|
OFF |
| -shared |
Produce a shared object. |
OFF |
-size_lp64
Itanium-based
systems only |
Assume 64-bit size for long and pointer types. |
OFF |
-sox[-]
IA-32 only |
Enables [disables] the saving of compiler options and version information
in the executable file. |
-sox- |
| -static |
Prevents linking with shared libraries. |
OFF |
| -std=c99 |
Enable C99 support for C programs. |
ON |
| -syntax |
Checks the syntax of a program and stops the compilation process after
the C or C++ source files and preprocessed source files have been parsed.
Generates no code and produces no output files. Warnings and messages
appear on stderr.
|
OFF |
-tpp1
Itanium-based
systems only |
Target optimization to the Itanium processor. |
OFF |
-tpp2
Itanium-based
systems only |
Target optimization to the Itanium®
2 processor. Generated code is compatible with the Itanium processor. |
ON |
|
-tpp5
IA-32 only |
Targets the optimizations to the Pentium processor.
|
OFF |
-tpp6
IA-32 only |
Targets the optimizations to the Pentium Pro, Pentium II and Pentium
III processors.
|
OFF |
-tpp7
IA-32 only |
Tunes code to favor the Pentium 4 and Intel®
Xeon(TM) processor.
|
ON |
| -Uname |
Suppresses any definition of a macro name.
Equivalent to a #undef preprocessing directive.
|
OFF |
-unroll0
Itanium-based
systems only |
Disable loop unrolling.
|
OFF |
-unroll[n]
IA-32 only |
Set maximum number of times to unroll loops. Omit n to use default heuristics.
Use n =0 to disable loop unroller.
|
OFF |
|
-use_asm |
Produce objects through assembler. |
OFF |
|
-use_msasm
IA-32 only |
Accept the Microsoft* MASM-style inlined assembly format instead of
GNU-style. |
OFF |
|
-u symbol |
Pretend the symbol is undefined. |
OFF |
|
-V |
Display compiler version information. |
OFF |
|
-v |
Show driver tool commands and execute tools. |
|
|
-vec_report[n]
IA-32 only |
Controls the amount of vectorizer diagnostic information.
- n = 0 no diagnostic information
- n = 1 indicates vectorized
loops (DEFAULT)
- n = 2 indicates vectorized/non-vectorized
loops
- n = 3 indicates vectorized/non-vectorized
loops and prohibiting data dependence information
- n = 4 indicates non-vectorized
loops
- n = 5 indicates non-vectorized
loops and prohibiting data
|
ON
-vec_report1 |
| -w |
Disable all warnings. |
OFF |
|
-Wall |
Enable all warnings. |
OFF |
|
-wn |
Control diagnostics.
- n = 0 displays errors (same
as -w)
- n = 1 displays warnings and
errors (DEFAULT)
- n = 2 displays remarks, warnings,
and errors
|
ON
-w1 |
| -wdL1[,L2,...] |
Disables diagnostics L1 through LN.
|
OFF |
| -weL1[,L2,...] |
Changes severity of diagnostics L1 through
LN to error.
|
OFF |
|
-Werror |
Force warnings to be reported as errors. |
OFF |
|
-wnn |
Limits the number of errors displayed prior to aborting compilation
to n.
|
ON
-wn100 |
| -wrL1[,L2,...] |
Changes the severity of diagnostics L1
through LN to remark.
|
OFF |
| -wwL1[,L2,...] |
Changes severity of diagnostics L1 through
LN to warning.
|
OFF |
|
-Wl,o1[,o2,...] |
Pass options o1, o2,
etc. to the linker for processing. |
OFF |
|
-xtype |
All source files found subsequent to -xtype
will be recognized as one of the following types:
- c - C source file
- c++ - C++ source file
- c-header - C header file
- cpp-output - C preprocessed
file
- assembler - assemblable file
- assembler-with-cpp - Assemblable
file that needs to be preprocessed.
- none - Disable recognition
and revert to file extension.
|
OFF |
|
-X |
Removes the standard directories from the list of directories to be
searched for include files.
|
OFF |
| -Xa |
Select extended ANSI C dialect. |
ON |
| -Xc |
Select strict ANSI conformance dialect. |
OFF |
-x{M|i|K|W}
IA-32 only |
Generates specialized code for processor-specific codes M,
i, K, W.
- M = Intel®
Pentium®
processors with MMX(TM) technology
- i = Intel Pentium Pro and
Intel Pentium II processors
- K = Intel Pentium III processors
- W = Intel Pentium 4 processors,
Intel Xeon processors, and Intel Pentium M processors
|
OFF |
| -Xlinker val |
Pass val directly to the linker for
processing. |
OFF |
| -Zp{1|2|4|8|16} |
Specifies the strictest alignment constraint for structure and union
types as one of the following: 1, 2, 4, 8, or 16 bytes.
|
ON
-Zp16 |