Intel 8.0 Linux Compiler Option List
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Performance
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-O1 enable optimizations (DEFAULT),optimizes for speed. for Itanium compiler, -O1 turns off software pipelining to reduce code size.
-O2 same as -O1 on IA-32. Same as -O on Itanium-based systems.
-O3 enable -O2 plus more aggressive optimizations that may increase the compilation time and may not improve
performance for all programs
-O0 disable optimizations
-O same as -O1
-fast enable -O3 -ipo -static
-Ob<n> control inline expansion:
n=0 disables inlining
n=1 inline functions declared with __inline, and perform C++ inlining
n=2 inline any function, at the compiler's discretion (same as -Qip)
-falias assume aliasing in program (DEFAULT)
-fno-alias assume no aliasing in program
-ffnalias assume aliasing within functions (DEFAULT)
-fno-fnalias assume no aliasing within functions, but assume aliasing across
calls
-nolib_inline disable inline expansion of intrinsic functions
-mp maintain floating point precision (disables some optimizations)
-mp1 improve floating-point precision (speed impact is less than -mp)
-fp disable using EBP as general purpose register
-prec_div improve precision of floating-point divides (some speed impact)
-fp_port round fp results at assignments & casts (some speed impact)
-fpstkchk enable fp stack checking after every function/procedure call
-pc32 set internal FPU precision to 24 bit significand
-pc64 set internal FPU precision to 53 bit significand
-pc80 set internal FPU precision to 64 bit significand (DEFAULT)
-rcd rounding mode to enable fast float-to-int conversions
-tpp5 optimize for Pentium(R) processor
-tpp6 optimize for Pentium(R) Pro, Pentium(R) II and Pentium(R) III processors
-tpp7 optimize for Pentium(R) 4 processor (DEFAULT)
-mcpu=<cpu> optimize for a specific cpu
pentium - optimize for Pentium(R) processor
pentiumpro - optimize for Pentium(R) Pro, Pentium(R) II and Pentium(R)
III processors
pentium4 - optimize for Pentium(R) 4 processor (DEFAULT)
-ax<codes> generate code specialized for processors specified by <codes>
while also generating generic IA-32 code. <codes> includes
one or more of the following characters:
K Intel Pentium III and compatible Intel processors
W Intel Pentium 4 and compatible Intel processors
N Intel Pentium 4 and compatible Intel processors
P Intel processors code-named Prescott
B Intel Pentium M and compatible Intel processors
-x<codes> generate specialized code to run exclusively on processors
indicated by <codes> as described above.
-march=<cpu> generate code excusively for a given <cpu>
pentiumpro - Pentium(R) Pro and Pentium(R) II processor instructions
pentiumii - MMX(TM)instructions
pentiumiii - streaming SIMD extensions
pentium4 - Pentium(R) 4 New Instructions
Advanced Performance
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Enable and specify the scope of Interprocedural (IP) Optimizations:
-ip enable single-file IP optimizations (within files)
-ipo enable multi-file IP optimizations (between files)
-ipo_c generate a multi-file object file (ipo_out.o)
-ipo_S generate a multi-file assembly file (ipo_out.s)
Modify the behavior of IP:
-ip_no_inlining disable full and partial inlining (requires -ip or -ipo)
-ip_no_pinlining disable partial inlining (requires -ip or -ipo)
-ipo_obj force generation of real object files (requires -ipo)
Other Advanced Performance Options:
-unroll[n] set maximum number of times to unroll loops. Omit n to use
default heuristics. Use n=0 to disable loop unroller.
-unroll [n] set maximum number of times to unroll loops. Omit n to use
default heuristics. Use n=0 to disable loop unroller.
-prof_dir <d> specify directory for profiling output files (*.dyn and *.dpi)
-prof_file <f> specify file name for profiling summary file
-prof_gen[x] instrument program for profiling; with the x qualifier, extra
information is gathered
-prof_use enable use of profiling information during optimization
-qp compile and link for function profiling with UNIX gprof tool
-p same as -qp
-prefetch[-] enable(DEFAULT)/disable prefetch insertion
-vec_report[n] control amount of vectorizer diagnostic information:
n=0 no diagnostic information
n=1 indicate vectorized loops (DEFAULT)
n=2 indicate vectorized/non-vectorized loops
n=3 indicate vectorized/non-vectorized loops and prohibiting
data dependence information
n=4 indicate non-vectorized loops
n=5 indicate non-vectorized loops and prohibiting data
dependence information
-opt_report generate an optimization report to stderr
-opt_report_file<file> specify the filename for the generated report
-opt_report_level[level] specify the level of report verbosity (min|med|max)
-opt_report_phase<name> specify the phase that reports are generated against
-opt_report_routine<name> reports on routines containing the given name
-opt_report_help display the optimization phases available for
reporting
-tcheck generate instrumentation to detect multi-threading bugs
(requires Intel(R) Threading Tools; cannot be used with
compiler alone)
-openmp enable the compiler to generate multi-threaded code
based on the OpenMP directives
-openmp_profile link with instrumented OpenMP runtime library to
generate OpenMP profiling information for use with the
OpenMP component of the VTune(TM) Performance Analyzer
-openmp_stubs enables the user to compile OpenMP programs in
sequential mode. The openmp directives are ignored and
a stub OpenMP library is linked (sequential)
-openmp_report{0|1|2} control the OpenMP parallelizer diagnostic level
-parallel enable the auto-parallelizer to generate multi-threaded
code for loops that can be safely executed in parallel
-par_report{0|1|2|3} control the auto-parallelizer diagnostic level
-par_threshold[n] set threshold for the auto-parallelization of loops
where n is an integer from 0 to 100
-alias_args[-] enable(DEFAULT)/disable C/C++ rule that function
arguments may be aliased; when disabling the rule, the
user asserts that this is safe
-ansi_alias[-] enable/disable(DEFAULT) use of ANSI aliasing rules in
optimizations; user asserts that the program adheres to
these rules
-complex_limited_range[-] enable/disable(DEFAULT) the use of the basic
algebraic expansions of some complex arithmetic
operations. This can allow for some performance
improvement in programs which use a lot of complex
arithmetic at the loss of some exponent range.
Portability flags for SPEC CPU2000:
-Dalloca=_alloca Replace occurrences of alloca() with _alloca.
-DLINUX_i386 Linux Intel system, use "long long" as 64bit variable.
-DHAS_ERRLIST Prog env provides specification for "sys_errlist[]".
-DSPEC_CPU2000_LINUX_I386 Enable the code changes for porting to Linux on i386 architecture to be utilized
-DUSG Specify that the programming environment is like System V Unix systems
-DSPEC_CPU2000_NEED_BOOL Use SPEC provided definition of the boolean type.
-DPSEC_CPU2000_GLIBC22 Compatibility with 2.2 & later versions of glibc
-DSYS_IS_USG Specifies that the operating system is USG compliant.
-DSYS_HAS_TIME_PROTO Do not explicitly declare time().
-DSYS_HAS_SIGNAL_PROTO Do not explicitly #include <signal.h>
-DSYS_HAS_IOCTL_PROTO Do not explicitly declare ioctl().
-DSYS_HAS_ANSI System is ANSI compliant.
-DSYS_HAS_CALLOC_PROTO Do not explicitly declare calloc().