Description of compiler flags for Intel C++ Compiler 8.0
--------------------------------------------------------
Portability flags:
-Dalloca=_alloca so as to use the built-in optimized alloc
/Fn 176.gcc uses alloca and this options tells
the linker to pre-allocate n bytes of stack.
The default amount of stack allocated is not
enough and 176.gcc crashes with a run-time
error
-DNT_i386 Specifies that it is a Windows NT Intel
processor-based system which makes the compiler
use "long long" as the 64-bit variable that
186.crafty needs.
-DSPEC_CPU2000_NTOS This enables the code changes for porting to
Windows get included.
-DPERLDLL On Windows, we need a perl.exe instead of a
perl.exe and perl.dll. This pre-define ensures
that the changes necessary to get a single,
UNIX-style executable without getting the
indirect calls that can cause a 10% performance
degradation. This allows the Windows-based
executable to be as close as possible to
the Unix-based one.
/MT Use the static multi-threaded library else
it will not compile.
-DSYS_HAS_CALLOC_PROTO These two pre-defines tell of the existence
-DSYS_HAS_MALLOC_PROTO of malloc and calloc prototypes.
Optimization Flags:
-O2
Optimizes for speed. The -O2 option has the same effect as specifying
the following options: -Og, -Oi, -Ot, -Oy, -Ob1, -Gf, -Gs, and -Gy.
This options defaults to ON.
-O3
Optimizes for speed. Enables high-level optimization. This level does
not guarantee higher performance. Using this option may increase the
compilation time. Impact on performance is application dependent, some
applications may not see a performance improvement.
-Oa[-]
Assume [not assume] no aliasing
-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
-Qip.
Default n=1.
-Og
Enables global optimizations. Default ON.
-Ot
Enables all speed optimizations. Overrides -Os
-Oi[-]
Enables/disables inline expansion of intrinsic functions. Default Enabled.
-Ow[-]
Assume[not assume] no aliasing within functions, but assume aliasing
across calls.
-Oy[-]
Enables [disables] the use of the EBP register in optimizations. When
you disable with -Oy-, the EBP register is used as frame pointer.
Default Enabled.
-Gf
Enables string-pooling optimization. Default ON.
-Gs[n]
Disables stack-checking for routines with n or more bytes of local
variables and compiler temporaries. Default: n=4096
-Gy
Packages functions to enable linker optimization. Default ON.
-Qax{K|W|N}
Generates specialized code for processor specific codes
K, W, N while also generating generic IA-32 code.
K = Intel Pentium III and compatible Intel processors
W = Intel Pentium 4 and compatible Intel processors
N = Intel Pentium 4 and compatible Intel processors. These options also enable
advanced data layout and code restructuring optimizations to improve memory
accesses for Intel processors.
-Qx{K|W|N}
Generate specialized code to run exclusively on processors
supporting the extensions indicated by <codes> as
described above.
-Qip
Enables single-file interprocedural optimizations within a file.
Same as -Ob2.
-Qipo
multi-file ip optimizations that includes:
- inline function expansion
- interprocedural constant propagation
- monitoring module-level static variables
- dead code elimination
- propagation of function characteristics
- passing arguments in registers
- loop-invariant code motion
-Qprof_gen
Instruments the program for profiling: to get the execution
count of each basic block.
-Qprof_use
Enables the use of profiling dynamic feedback information
during optimization. Turns on -Qfnsplit.
-Qrcd
Enables[disables] fast conversions of floating-point to
integer conversions. This option does not guarantee that
any particular rounding mode will be used.
-Qansi_alias[-]
-Qansi_alias directs the compiler to assume[not 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 -Qansi_alias
flag will help the compiler better optimize the program. However, if your
program does not satisfy one of the above conditions, the -Qansi_alias
flag may lead the compiler to generate incorrect code.
-GR[-]
Enables[disables] C++ Run Time Type Information (RTTI).
-GX[-]
Enables[disables] C++ Exception Handling.
-fast
Maximize speed across the entire program. Turns on -O3 and -Qipo.
-Qfp_port
round fp results at assignments & casts (some speed impact)
-Qprefetch
Enable prefetch insertion. Default ON.
-Qunroll[n]
Specifies the maximum number of times to unroll a loop. n=0 disables
loop unrolling.
-Qoption,tool,optlist
-Qoption passes an option specified by optlist to a tool, where
optlist is a comma-separated list of options.
tool Description
------------------------------------
cpp Specifies the compiler front-end preprocessor
c Specifies the C++ compiler
asm Specifies the assembler
link Specifies the linker
oplist Indicates one or more valid argument strings for the
designated program. If the argument is a command-line
option, you must include the hyphen. If the argument
contains a space or tab character, you must enclose the
entire argument in quotation characters (""). You must
separate multiple arguments with commas
-Qoption can be used with the -Qipo flag to refine IPO. The valid options
that can be used for this purpose are:
-ip_args_in_regs=0
Disables the passing of arguments in registers.
-ip_ninl_max_stats=n
Sets the valid max number of intermediate
language statements for a function that is
expanded in line. The number n is a positive
integer. The number of intermediate language
statements usually exceeds the actual number of
source language statements. The default value
for n is 230. The compiler uses a larger limit
for user inline functions.
-ip_ninl_min_stats=n
Sets the valid min number of intermediate
language statements for a function that is
expanded in line. The number n is a positive
integer. The default values for
ip_ninl_min_stats are:
IA-32 compiler: ip_ninl_min_stats = 7
-ip_ninl_max_total_stats=n
Sets the maximum increase in size of a function,
measured in intermediate language statements,
due to inlining. n is a positive integer whose
default value is 2000.
shlW32M.lib:
MicroQuill SmartHeap Library available from
http://www.microquill.com/
-Zp{1|2|4|8|16}
Specifies the strictest alignment constraint for structure and union
types as 1, 2. 4. 8 or 16 bytes. Default is 16.
-arch:SSE
Enables the compiler to use SSE instructions.
-arch:SSE2
Enables the compiler to use SSE2 instructions.
-EHc
Specifies that C functions do not throw exceptions. Default ON.
-G7
Target optimization to Intel Pentium 4 processors. Default ON.
-ML
Compiles and links with the static, single-thread C run time library. Default ON.
-QA
Enables all predefined macros and all assertions. Default ON.
-Qfnsplit
Enables function splitting. Default ON.
-Qms1
Instructs the compiler to enable most Microsoft compatability bugs. Default ON.
-Qmspp
Enables Microsoft C++ 6.0 Processor Pack binary compatability. Default ON.
-Qpc64
Enables floating-point significand precision control. The value is used to round
the significand to the correct number of bits. The value must be either 32, 64,
or 80. Default ON.
-Qpchi
Enables precompiled header files coexistence to reduce build time. Default ON.
-Qsfalign8
May align stack for functions with 8 or 16 byte vars. Default ON.
-Qvc7
Enables compatability with Visual C++ .NET. Default ON.
-Qvec_report1
Indicate vectorized loops in diagnostic information. Default ON.
-vmb
Selects the smallest representation for pointers to members. Use this
option if you define each class before you declare a pointer to a member of the class.
Default ON.
Description of compiler flags for Intel C++ Compiler 9.0
--------------------------------------------------------
Portability flags:
-Dalloca=_alloca so as to use the built-in optimized alloc
/Fn 176.gcc uses alloca and this options tells
the linker to pre-allocate n bytes of stack.
The default amount of stack allocated is not
enough and 176.gcc crashes with a run-time
error
-DNT_i386 Specifies that it is a Windows NT Intel
processor-based system which makes the compiler
use "long long" as the 64-bit variable that
186.crafty needs.
-DSPEC_CPU2000_NTOS This enables the code changes for porting to
Windows get included.
-DPERLDLL On Windows, we need a perl.exe instead of a
perl.exe and perl.dll. This pre-define ensures
that the changes necessary to get a single,
UNIX-style executable without getting the
indirect calls that can cause a 10% performance
degradation. This allows the Windows-based
executable to be as close as possible to
the Unix-based one.
/MT Use the static multi-threaded library else
it will not compile.
-DSYS_HAS_CALLOC_PROTO These two pre-defines tell of the existence
-DSYS_HAS_MALLOC_PROTO of malloc and calloc prototypes.
Optimization Flags:
-O2
Optimizes for speed. The -O2 option includes the following options:
-Og, -Oi-, -Os, -Oy, -Ob1, and -Gs This options defaults to ON.
This option also enables.
* inlining of intrinsics
* Intra-file interprocedural optimizations including:
* inlining
* constant propagation
* forward substitution
* routine attribute propagation
* variable address-taken analysis
* dead static function elimination
* removal of unreferenced variables.
* The following performance optimizations:
* copy propogation.
* dead-code elimination
* global register allocation
* global instruction scheduling and control speculation
* loop unrolliing
* optimized code selection
* partial redundancy elimination
* strength reduction/induction variable simplification
* variable renaming
* exception handling optimizations
* tail recursions
* peephole optimizations
* structure assignment lowering and optimizations
* dead store elimination
-O3
Optimizes for speed. Enables high-level optimization. This level does
not guarantee higher performance. Using this option may increase the
compilation time. Impact on performance is application dependent, some
applications may not see a performance improvement. The optimizations
include:
* All optimizations done with -O2
* loop unrolling, including instruction scheduling
* code replication to eliminate branches
* padding the size of certain power-of-two arrays to allow more efficient
cache use.
* When used with -Qax or -Qx, it causes the compiler to perform more aggressive
data dependency analysis than for -O2.
-Oa[-]
Assume [not assume] no aliasing. Default Disabled.
-Obn
Controls the compiler's inline expansion. The amount of inline
expansion performed varies with the value of n as follows:
0: Disables inlining. Statement functions are always inlined.
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
-Qip.
Default n=2.
-Og
Enables global optimizations. Default ON.
-Ot
Enables all speed optimizations. Overrides -Os
-Oi[-]
Enables/disables inline expansion of intrinsic functions. Default Enabled.
-Ow[-]
Assume[not assume] no cross function aliasing.
-Oy[-]
Enables [disables] the use of the EBP register in optimizations. When
you disable with -Oy-, the EBP register is used as frame pointer. -Oy has
the effect of reducing the number of general-purpose registers by 1, and can
produce slightly less efficient code.
Default Enabled.
-Gf
Enables string-pooling optimization.
-Gs[n]
Disables stack-checking for routines with n or more bytes of local
variables and compiler temporaries. Default: n=4096
-Gy
Packages functions to enable linker optimization. Default ON.
-Qax{K|W|N}
Generates specialized code for processor specific codes
K, W, N while also generating generic IA-32 code.
K = Intel Pentium III and compatible Intel processors
W = Intel Pentium 4 and compatible Intel processors
N = Intel Pentium 4 and compatible Intel processors. These options also enable
advanced data layout and code restructuring optimizations to improve memory
accesses for Intel processors.
-Qx{K|W|N}
Generate specialized code to run exclusively on processors
supporting the extensions indicated by <codes> as
described above.
-Qip
Enables single-file interprocedural optimizations within a file.
-Qipo
Enables multi-file ip optimizations which allows inline function expansion for
calls to functions defined in separate files. The compiler decides whether to create
one or more object files based on an estimate of the size of the application. It
generates one object file for small applications and two for large ones.
-Qprof_gen
Instruments the program for profiling: to get the execution
count of each basic block.
-Qprof_use
Enables the use of profiling dynamic feedback information
during optimization. Turns on -Qfnsplit. Forces function grouping.
-Qrcd
Enables[disables] fast conversions of floating-point to
integer conversions. This option does not guarantee that
any particular rounding mode will be used.
-Qansi_alias[-]
-Qansi_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 -Qansi_alias
flag will help the compiler better optimize the program. However, if your
program does not satisfy one of the above conditions, the -Qansi_alias
flag may lead the compiler to generate incorrect code.
-GR[-]
Enables[disables] C++ Run Time Type Information (RTTI).
-GX[-]
Enables[disables] C++ Exception Handling. Default Disabled.
-fast
Maximize speed across the entire program. Turns on -O3, -Qipo,
-Qprec-div-, and -QxP.
-Qfp_port
round fp results at assignments & casts (some speed impact)
-Qprefetch
Enable prefetch insertion. Default ON.
-Qunroll[n]
Specifies the maximum number of times to unroll a loop. n=0 disables
loop unrolling. Default: the compiler uses default heuristics when
unrolling loops.
-Qoption,tool,optlist
-Qoption passes an option specified by optlist to a tool, where
optlist is a comma-separated list of options.
tool Description
------------------------------------
cpp Specifies the compiler front-end preprocessor
c Specifies the C++ compiler
asm Specifies the assembler
link Specifies the linker
oplist Indicates one or more valid argument strings for the
designated program. If the argument is a command-line
option, you must include the hyphen. If the argument
contains a space or tab character, you must enclose the
entire argument in quotation characters (""). You must
separate multiple arguments with commas
NOTE: If 'tool' is incorrectly specified, the compiler gives an
warning and the option is ignored. For example, if
-Qoption,f,... is used with the Intel C++ compiler, the
option is ignored with an warning.
-Qoption can be used with the -Qipo flag to refine IPO. The valid options
that can be used for this purpose are:
-ip_args_in_regs=0
Disables the passing of arguments in registers.
-ip_ninl_max_stats=n
Sets the valid max number of intermediate
language statements for a function that is
expanded in line. The number n is a positive
integer. The number of intermediate language
statements usually exceeds the actual number of
source language statements. The default value
for n is 230. The compiler uses a larger limit
for user inline functions.
-ip_ninl_min_stats=n
Sets the valid min number of intermediate
language statements for a function that is
expanded in line. The number n is a positive
integer. The default values for
ip_ninl_min_stats are:
IA-32 compiler: ip_ninl_min_stats = 7
-ip_ninl_max_total_stats=n
Sets the maximum increase in size of a function,
measured in intermediate language statements,
due to inlining. n is a positive integer whose
default value is 2000.
shlW32M.lib:
MicroQuill SmartHeap Library available from
http://www.microquill.com/
-Zp{1|2|4|8|16}
Specifies the strictest alignment constraint for structure and union
types as 1, 2. 4. 8 or 16 bytes. Default is 16.
-arch:SSE
Enables the compiler to use SSE instructions.
-arch:SSE2
Enables the compiler to use SSE2 instructions.
-Qprec-div[-]
Enables[disables] improved precision of floating-point divides. Disabling may
slightly improve speed. Default Enabled.
-Qpc64
Enables floating-point significand precision control. The value is used to round
the significand to the correct number of bits. The value must be either 32, 64,
or 80. Default ON.
Description of compiler flags for Intel Fortran Compiler 9.0
------------------------------------------------------------
Portability flags:
-FI Fixed-format F90 source code.
-F32000000 Same as with 176.gcc, pre-allocates a 32MB
stack
Optimization Flags:
-O2
Optimizes for speed. The -O2 option includes the following options:
-Og, Ot, -Oy, -Ob1, and -Gs This options defaults to ON.
This option also enables.
* inlining of intrinsics
* Intra-file interprocedural optimizations including:
* inlining
* constant propagation
* forward substitution
* routine attribute propagation
* variable address-taken analysis
* dead static function elimination
* removal of unreferenced variables.
* The following performance optimizations:
* copy propogation.
* dead-code elimination
* global register allocation
* global instruction scheduling and control speculation
* loop unrolliing
* optimized code selection
* partial redundancy elimination
* strength reduction/induction variable simplification
* variable renaming
* exception handling optimizations
* tail recursions
* peephole optimizations
* structure assignment lowering and optimizations
* dead store elimination
-O3
Optimizes for speed. Enables high-level optimization. This level does
not guarantee higher performance. Using this option may increase the
compilation time. Impact on performance is application dependent, some
applications may not see a performance improvement. The optimizations
include:
* All optimizations done with -O2
* loop unrolling, including instruction scheduling
* code replication to eliminate branches
* padding the size of certain power-of-two arrays to allow more efficient
cache use.
* When used with -Qax or -Qx, it causes the compiler to perform more aggressive
data dependency analysis than for -O2.
-Oa[-]
Assume [not assume] no aliasing
-Ob{0|1|2}
Controls the compiler's inline expansion. The amount of inline
expansion performed varies as follows:
-Ob0: Disable inlining.
-Ob1: Disables (default) inlining unless -Qip or -Ob2 is
specified. Enables inlining of functions.
-Ob2: Enables inlining of any function. However, the
compiler decides which functions to inline. Enables
interprocedural optimizations and has the same effect as
-Qip.
-Og
Enables global optimizations.
-Ot
Enables all speed optimizations.
-Oi[-]
Enables/disables inline expansion of intrinsic functions
-Ow[-]
Assume[not assume] no cross-function aliasing.
-Ox
Same as the -O2 option: enables -Gs, and -Ob1, -Og, -Oy, and -Ot.
-Oy[-]
Enables [disables] the use of the EBP register in optimizations. When
you disable with -Oy-, the EBP register is used as frame pointer.
-auto
Determines whether local variables are put on the run-time stack.
-Gf
Enables string-pooling optimization.
-Gs[n]
Disables stack-checking for routines with n or more bytes of local
variables and compiler temporaries. Default: n=4096
-Gy
Packages functions to enable linker optimization.
-fast
Maximize speed across the entire program. Turns on -O3, -Qprec-div-, -QxP, and -Qipo.
-Qax{K|W|N|P}
Generates specialized code for processor specific codes
K, W, N, P while also generating generic IA-32 code.
K = Intel Pentium III and compatible Intel processors
W = Intel Pentium 4 and compatible Intel processors
N = Intel Pentium 4 and compatible Intel processors. These option also enable
advanced data layout and code restructuring optimizations to improve memory
accesses for Intel processors.
P = Intel Pentium 4 processor with Streaming SIMD 3 (SSE3) support. These option
also enable advanced data layout and code restructuring optimizations to improve memory
accesses for Intel processors.
-Qx{K|W|N|P}
Generate specialized code to run exclusively on processors
supporting the extensions indicated by <codes> as
described above.
-Qip
Enables single-file interprocedural optimizations within a file.
-Qipo
multi-file ip optimizations that includes:
- inline function expansion
- interprocedural constant propagation
- monitoring module-level static variables
- dead code elimination
- propagation of function characteristics
- passing arguments in registers
- loop-invariant code motion
-Qprof_gen
Instruments the program for profiling: to get the execution
count of each basic block.
-Qprof_use
Enables the use of profiling dynamic feedback information
during optimization.
-Qrcd
Enables[disables] fast conversions of floating-point to
integer conversions. This option does not guarantee that
any particular rounding mode will be used.
-Qansi_alias
Enables (default) or disables the compiler to assume that the program
adheres to the ANSI Fortran type aliasablility rules. For example, an object
of type real cannot be accessed as an integer. You should see the ANSI
Standard for the complete set of rules.
-Qscalar_rep[-]
Enables[disables] scalar replacement performed during loop
transformations. (requires /O3).
-Qunroll[n]
Specifies the maximum number of times to unroll a loop. n=0 disables
loop unrolling.
-Qprefetch[-]
Enables[disables] prefetch insertion (requires -O3).
-Qoption,tool,optlist
-Qoption passes an option specified by optlist to a tool, where
optlist is a comma-separated list of options.
tool Description
------------------------------------
fpp Specifies the Fortran preprocessor
f Specifies the Fortran compiler
asm Specifies the assembler
link Specifies the linker
oplist Indicates one or more valid argument strings for the
designated tool. You must separate multiple arguments with commas.
-Qoption can be used with the -Qipo flag to refine IPO. The valid option
list that can be used for this purpose are
-ip_args_in_regs=0
Disables the passing of arguments in registers.
-ip_ninl_max_stats=n
Sets the valid max number of intermediate
language statements for a function that is
expanded in line. The number n is a positive
integer. The number of intermediate language
statements usually exceeds the actual number of
source language statements. The default value
for n is 230. The compiler uses a larger limit
for user inline functions.
-ip_ninl_min_stats=n
Sets the valid min number of intermediate
language statements for a function that is
expanded in line. The number n is a positive
integer. The default values for
ip_ninl_min_stats are:
IA-32 compiler: ip_ninl_min_stats = 7
-ip_ninl_max_total_stats=n Sets
the maximum increase in size of a function,
measured in intermediate language statements,
due to inlining. n is a positive integer whose
default value is 2000.
shlW32M.lib:
MicroQuill SmartHeap Library available from
http://www.microquill.com/
-Zp{1|2|4|8|16}
Specifies the strictest alignment constraint for structure and union
types as 1, 2. 4. 8 or 16 bytes. Default is 16.
-Qprec-div[-]
Enables[disables] improved precision of floating-point divides. Disabling may
slightly improve speed. Default Enabled.
Other Notes:
------------
"/" and "-" are both allowable starting tokens for flags passed to the
compiler i.e. -QxK and /QxK are identical switches.
Compiler options for PGI Fortran compiler 6.0 for Windows XP IA32
-----------------------------------------------------------------
The optimization levels and their meanings are as follows:
-lacml
Link with the AMD Core Math Library 2.5.3, packaged with the
compiler. Also available at www.amd.com
-O0
A basic block is generated for each Fortran statement. No scheduling
is done between statements. No global optimizations are performed.
-O1
Scheduling within extended basic blocks is performed. Some register
allocation is performed. No global optimizations are performed.
-O2
All level 1 optimizations are performed. In addition, scalar
optimizations such as induction recognition and loop invariant motion
are performed by the global optimizer.
-O3
This level performs all level-one and level-two optimizations and
enables more aggressive hoisting and scalar replacement optimizations.
-fast
Equivalent to "-O2 -Munroll=c:1 -Mnoframe -Mlre"
-fastsse
Equivalent to "-fast -Mscalarsse -Mvect=sse -Mcache_align -Mflushz"
-Mpfi
Generate profile feedback instrumentation; this
includes extra code to collect run-time statistics to
be used in a subsequent compile; -Mpfi must also appear
when the program is linked. When the program is run, a
profile feedback file pgfi.out will be generated; see
-Mpfo.
-Mpfo
Enable profile feedback optimizations; there must be a
profile feedback file pgfi.out in the current
directory, which contains the result of an execution of
the program compiled with -Mpfi.
-Mcache_align
Align unconstrained objects of length greater than or equal to 16 bytes on
cache-line boundaries. An unconstrained object is a data object that is not
a member of an aggregate structure or common block. This option does
not affect the alignment of allocatable or automatic arrays.
Note: To effect cache-line alignment of stack-based local variables, the
main program or function must be compiled with -Mcache_align.
-Mfixed
Process source using Fortran90 freeform specifications.
-Mflushz
Set SSE MXCSR register to flush-to-zero mode.
-Mipa=[option]
Enables interprocedural analysis with the specified option. The valid options are:
-Mipa=align
Instructs the IPA to recognize when pointer targets are all cache-line
aligned, allowing better SSE code generation.
-Mipa=arg
Instructs the IPA to remove arguments replaced by -Mipa=ptr,const
-Mipa=const
Enable propagation of constants across procedure calls.
-Mipa=fast
Equivalent to: -Mipa=align,arg,const,globals,f90ptr,shape,localarg,ptr,vestigial
-Mipa=f90ptr
Enable Fortran 90 pointer disambiguation across procdure calls.
-Mipa=globals
Instructs the IPA to optimize references to globals when not used in procedure calls.
-Mipa=inline
Automatically determine which functions to inline
-Mipa=safe
Assume unknown function references are safe
-Mipa=localarg
Externalizes local variables for use with -Mipa=arg
-Mipa=ptr
Instructs the IPA to perform pointer disambiguation across procedure calls.
-Mipa=vestigial
Instructs the IPA to eliminate functions that are not called.
-Mlre
Enables loop-carried redundancy elimination.
-Mnoframe
Eliminate operations that set up a true stack frame pointer for functions.
-Mnovect
Disables the vectorizer.
-Mscalarsse
Utilize the SSE (Streaming SIMD(Single Instruction Multiple Data)
Extensions) and SSE2 instructions to perform the operations coded.
This implies -Mflushz.
-Munix
Use UNIX calling conventions, no trailing underscores.
-Munroll
Invokes the loop unroller. This also sets the optimization level to 2
if the level is set to less than 2.
:m Instructs the compiler to completely unroll loops with a
constant loop count less than or equal to m, a supplied constant.
If this value is not supplied, the m count is set to 4.
n:u Instructs the compiler to unroll u times, a loop which is
not completely unrolled, or has a non-constant loop count.
If u is not supplied, the unroller computes the number of times a
candidate loop is unrolled.
-Mvect=sse
Instructs the vectorizer to search for loops, and where possible,
use the SSE or SSE2 and prefetch instructions
(depending on which processor is targeted).
Compiler options for PGI C compiler 6.0 for Windows XP
------------------------------------------------------
The optimization levels and their meanings are as follows:
-lacml
Link with the AMD Core Math Library 2.5.3. Available from www.amd.com
-O0
A basic block is generated for each C statement. No scheduling
is done between statements. No global optimizations are performed.
-O1
Scheduling within extended basic blocks is performed. Some register
allocation is performed. No global optimizations are performed.
-O2
All level 1 optimizations are performed. In addition, scalar
optimizations such as induction recognition and loop invariant motion
are performed by the global optimizer.
-O3
This level performs all level-one and level-two optimizations and
enables more aggressive hoisting and scalar replacement optimizations.
-fast
Equivalent to "-O2 -Munroll=c:1 -Mnoframe -Mlre"
-fastsse
Equivalent to "-fast -Mscalarsse -Mvect=sse -Mcache_align -Mflushz"
-Mpfi
Generate profile feedback instrumentation; this
includes extra code to collect run-time statistics to
be used in a subsequent compile; -Mpfi must also appear
when the program is linked. When the program is run, a
profile feedback file pgfi.out will be generated; see
-Mpfo.
-Mpfo
Enable profile feedback optimizations; there must be a
profile feedback file pgfi.out in the current
directory, which contains the result of an execution of
the program compiled with -Mpfi.
-Mcache_align
Align unconstrained objects of length greater than or equal to 16 bytes on
cache-line boundaries. An unconstrained object is a data object that is not
a member of an aggregate structure or common block. This option does
not affect the alignment of allocatable or automatic arrays.
Note: To effect cache-line alignment of stack-based local variables, the
main program or function must be compiled with -Mcache_align.
-Mflushz
Set SSE MXCSR register to flush-to-zero mode.
-Mipa=[option]
Enables interprocedural analysis with the specified option. The valid options are:
-Mipa=align
Instructs the IPA to recognize when pointer targets are all cache-line
aligned, allowing better SSE code generation.
-Mipa=arg
Instructs the IPA to remove arguments replaced by -Mipa=ptr,const
-Mipa=const
Enable propagation of constants across procedure calls.
-Mipa=fast
Equivalent to: -Mipa=align,arg,const,globals,f90ptr,shape,localarg,ptr,vestigial
-Mipa=f90ptr
Enable Fortran 90 pointer disambiguation across procdure calls.
-Mipa=globals
Instructs the IPA to optimize references to globals when not used in procedure calls.
-Mipa=inline
Automatically determine which functions to inline
-Mipa=safe
Assume unknown function references are safe
-Mipa=localarg
Externalizes local variables for use with -Mipa=arg
-Mipa=ptr
Instructs the IPA to perform pointer disambiguation across procedure calls.
-Mipa=vestigial
Instructs the IPA to eliminate functions that are not called.
-Mlre
Enables loop-carried redundancy elimination.
-Mnoframe
Eliminate operations that set up a true stack frame pointer for functions.
-Mnovect
Disables the vectorizer.
-Mscalarsse
Utilize the SSE (Streaming SIMD(Single Instruction Multiple Data)
Extensions) and SSE2 instructions to perform the operations coded.
This implies -Mflushz.
-Munix
Use UNIX calling conventions, no trailing underscores.
-Munroll
Invokes the loop unroller. This also sets the optimization level to 2
if the level is set to less than 2.
c:m Instructs the compiler to completely unroll loops with a
constant loop count less than or equal to m, a supplied constant.
If this value is not supplied, the m count is set to 4.
n:u Instructs the compiler to unroll u times, a loop which is
not completely unrolled, or has a non-constant loop count.
If u is not supplied, the unroller computes the number of times a
candidate loop is unrolled.
-Mvect=sse
Instructs the vectorizer to search for loops, and where possible,
use the SSE or SSE2 and prefetch instructions
(depending on which processor is targeted).
Description of compiler flags for PathScale EKOPath(TM) Compiler Suite (Fortran, C and C++ compilers)
-----------------------------------------------------------------------------------------------------
Portability Flags:
-DSPEC_CPU2000_LP64 Compile using LP64 programming model.
-DLINUX_i386 Linux Intel system, use "long long" as
64bit variable.
-DHAS_ERRLIST Prog env provides specification for
"sys_errlist[]".
-DNDEBUG Defining this disables any assert macros used for
debugging.
-DSPEC_CPU2000_NEED_BOOL Use SPEC provided definition of the boolean type.
-DSPEC_CPU2000_LINUX_I386 Compile for an I386 system running Linux.
-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_IOCTL_PROTO Do not explicitly declare ioctl().
-DSYS_HAS_ANSI System is ANSI compliant.
-DSYS_HAS_CALLOC_PROTO Do not explicitly declare calloc().
-fixedform tells f90 compiler to use fixed format
(F77 72 column format), instead of F90 free format.
Optimization Flags:
Some suboptions either enable or disable the feature. To enable a feature,
either specify only the suboption name or specify =1, =ON, or =TRUE. Disabling
a feature, is accomplished by adding =0, =OFF, or =FALSE. These values are
insensitive to case: 'on' & 'ON' mean the same thing. Below, ON & OFF indicate
the enabling or disabling of a feature.
-CG[:...]
Code Generation option group: control the optimizations
and transformations of the instruction-level code generator.
-CG:cflow=(ON|OFF)
A value of OFF disables control flow optimization in the code
generation. Default is ON.
-CG:gcm=(ON|OFF)
Specifying OFF disables the instruction-level global code
motion optimization phase. The default is ON.
-CG:load_exe=n
Specifies the threshold for subsuming a memory load operation into
the operand of an arithmetic instruction. The value of 0 turns
off this subsumption optimization. The default is 1, when this
subsumption is performed only when the result of the load has only
one use. This subsumption is not performed if the number of times
the result of the load is used exceeds the value n, a non-negative
integer.
-CG:local_fwd_sched=(ON|OFF)
Changes the instruction scheduling algorithm to work forward
instead of backward for the instructions in each basic block.
The default is OFF.
-CG:movnti=N
Convert ordinary stores to non-temporal stores when writing memory
blocks of size larger than N KB. When N is set to 0, this
transformation is avoided. The default value is 120 (KB).
-CG:p2align=(ON|OFF)
Align loop heads to 64-byte boundaries. The default is
OFF.
-CG:p2align_freq=n
Aligns branch targets based on execution frequency. This option
is meaningful only under feedback-directed compilation. The
default value n=0 turns off the alignment optimization. Any
other value specifies the frequency threshold at or above which
this alignment will be performed by the compiler.
-CG:prefetch=(ON|OFF)
Turning this OFF suppresses any generation of prefetch instructions
in the code generator. This has the same effect as -LNO:prefetch=0.
The default is ON which implies using default prefetch algorithms.
-CG:prefetchnta=(ON|OFF)
Prefetch when data is non-temporal at all levels of the cache
hierarchy. This is for data streaming situations in which the
data will not need to be re-used soon. The default is OFF.
-fb_create <prefix for feedback data files>
Used to specify that an instrumented executable program
is to be generated. Such an executable is suitable for
producing feedback data files with the specified prefix
for use in feedback-directed compilation (FDO). The commonly
used prefix is "fbdata". This is OFF by default.
-fb_opt <prefix for feedback data files>
Used to specify feedback-directed compilation (FDO) by extracting
feedback data from files with the specified prefix, which were
previously generated using -fb_create. The commonly used prefix
is "fbdata". This optimization is off by default.
-fno-exceptions
Tells the compiler that the program does not use exception
handling, so it can perform more aggressive optimization in
the code. The generation of exception handling constructs
is also suppressed. Under this flag, code that uses exception
handling cannot be guaranteed to work correctly. Note that
the absence of exception handling construct does not mean
that the function can be compiled with this flag. For
exception handling to work preperly, the scopes
crossed between throwing and catching an exception must
all have been compiled with exceptions on.
-fno-math-errno
Do not set ERRNO after calling math functions that are executed
with a single instruction, e.g., sqrt. A program that relies
on IEEE exceptions for math error handling may want to use this
flag for speed while maintaining IEEE arithmetic compatibility.
This is implied by -Ofast. The default is -fmath-errno.
-GRA:optimize_boundary=(ON|OFF)
Allow the Global Register Allocator to allocate the same
register to different variables in the same basic-block.
Default is OFF.
-INLINE:aggressive=(ON|OFF)
Tells the compiler to be more aggressive about inlining. The
default is -INLINE:aggressive=OFF.
-IPA[:...]
IPA option group: control the inter-procedural analyses and
transformations performed. Note that giving just the group name
without any options, i.e., -IPA, will invoke the interprocedural
analyzer. -IPA is off by default unless -Ofast is specified.
-ipa Same as -IPA alone.
-IPA:callee_limit=(n)
Functions whose size exceeds this limit will never be
automatically inlined by the compiler. The default is n=2000.
-IPA:min_hotness=N
Is applicable only under feedback compilation. A call site's
invocation count must be at least N befre it can be inlined by
IPA. The default is 10.
-IPA:ctype=(ON|OFF)
Turns on optimizations that speed up interfaces to the constructs
defined in ctype.h by assuming that the program will not be run
in a multi-threaded environment. The default is OFF.
-IPA:field_reorder=(ON|OFF)
Enables the re-ordering of fields in large structs based
on their reference patterns in feedback compilation to
minimize data cache misses. The default is OFF.
-IPA:linear=(ON|OFF)
Controls conversion of a multi-dimensional array to a single
dimensional (linear) array that covers the same block of memory.
When inlining Fortran subroutines, IPA tries to map formal
array parameters to the shape of the actual parameter. In the
case that it cannot map the parameter, it linearizes the array
reference. By default, IPA will not inline such callsites
because they may cause performance problems. The default is OFF.
-IPA:plimit=(n)
Inline calls to a procedure until the procedure has grown to
size of n. The default is 2500.
-IPA:pu_reorder=(0|1|2)
Controls the phase that optimizes the layout of the program
units (functions) in the program.
0 = Disables procedure reordering (default)
1 = Reorder based on the frequency in which different
procedures are invoked.
2 = Reorder based on caller-callee relationship.
-IPA:small_pu=(n)
A procedure with size smaller than n is not subjected to the
plimit restriction.The default is n=30
-IPA:space=N
Inline until a program expansion of N% is reached. For example,
-IPA:space=20 limits code expansion due to inlining to approx-
imately 20%. Default is no limit.
-IPA:use_intrinsic[=(ON|OFF)]
Enable/disable loading the intrinsic version of standard library
functions. The default is OFF.
-L<path_of_acml> -lacml
The flags above are needed to use the PathScale compiler to link
with the ACML (AMD Core Math Library) library.
ACML is available as a free download
from http://www.developwithamd.com/acml.
-LANG:short_circuit_conditionals=(ON|OFF)
Handles .AND. and .OR. via short-circuiting, in which the
second operand is not evaluated if unnecessary, even if it
contains side effects. Applies only to Fortran. Default is ON.
-LNO:
option group specifies options and transformations performed
on loop nests. The -LNO: option group is enabled only if the -O3
option is also specified on the compiler command line.
-LNO:blocking[=(ON|OFF)]
Enable/disable the cache blocking transformation. The default
is on at -O3 or higher.
-LNO:fission=(0|1|2)
This option controls loop fission. The options can be one of the
following:
0 = Disables loop fission (default)
1 = Performs normal fission as necessary
2 = Specifies that fission be tried before fusion
If -LNO:fission=1:fusion=1 or -LNO:fission=2:fusion=2 are spec-
ified, then fusion is performed.
-LNO:full_unroll,fu=N
Fully unroll innermost loops with trip_count <= N inside LNO.
N can be any integer between 0 and 100. The default value for N
is 5. Setting this flag to 0 disables full unrolling of small
trip count loops inside LNO.
-LNO:full_unroll_size=N
Fully unroll innermost loops with unrolled loop size <= N inside
LNO. N can be any integer between 0 and 10000. The conditions
implied by the full_unroll option must also be satisfied for
the loop to be fully unrolled. The default value for N is 1600.
-LNO:full_unroll_outer=(ON|OFF)
Control the full unrolling of loops with known trip count that
do not contain a loop and are not contained in a loop. The
conditions implied by both the full_unroll and the
full_unroll_size options must be satisfied for the loop to be
fully unrolled. The default is OFF.
-LNO:fusion=n
Perform loop fusion, n: 0 - off, 1 - conservative, 2 - aggressive.
The default is 1.
-LNO:opt=(0|1)
This option controls the LNO optimization level.
The options can be one of the following:
0 = Disable nearly all loop nest optimizations.
1 = Perform full loop nest transformations.
This is the default.
-LNO:prefetch[=(0|1|2|3)]
Specify level of prefetching.
0 = Prefetch disabled.
1 = Prefetch is done only for arrays that are always
referenced in each iteration of a loop, the default.
2 = Prefetch is done without the above restrictions.
3 = Most aggressive.
-LNO:prefetch_ahead=n
Prefetch n cache line(s) ahead. The default is 2.
-LNO:sclrze=(ON|OFF)
Turns on/off the optimization that replaces an array by a scalar
variable. The default is ON.
-LNO:simd=(0|1|2)
This option enables or disables inner loop vectorization.
0 = Turn off the vectorizer.
1 = (Default) Vectorize only if the compiler can determine that
there is no undesirable performance impact due to sub-optimal
alignment. Vectorize only if vectorization does not introduce
accuracy problems with floating-point operations.
2 = Vectorize without any constraints (most aggressive).
-LNO:simd_reduction=(ON|OFF)
This controls whether reduction loops will be vectorized.
Default is ON.
-m32
Generates code according to the 32-bit ABI, also known as x86
or IA32.
-m64
Compile for 64-bit ABI, also known as AMD64, x86_64, or IA32e.
This is the default.
-m3dnow Enable use of 3DNow instructions. The default is OFF.
-mcpu=(opteron|athlon64|athlon64fx|em64t|pentium4|xeon|anyx86|auto)
Compiler will optimize code for selected platform. auto means to
optimize for the platform that the compiler is running on, which
the compiler determines by reading /proc/cpuinfo. anyx86 means a
generic 32-bit x86 processor without SSE2 support. The
default is opteron.
-msse2
Enable use of SSE2 instructions. This is the default under
both -m64 and -m32.
-mno-sse2 This flag is only applicable to -m32. -mno-sse2 is ignored
under -m64 with a warning.
-O or -O2
Turn on extensive optimization. The optimizations at this level are
generally conservative, in the sense that they (1) are virtually
always beneficial, (2) provide improvements commensurate to the
compile time spent to achieve them, and (3) avoid changes which
affect such things as floating point accuracy.
-O3
Turn on aggressive optimization. The optimizations at this level
are distinguished from -O2 by their aggressiveness, generally
seeking highest-quality generated code even if it requires extensive
compile time. They may include optimizations which are generally
beneficial but occasionally hurt performance. This includes but
is not limited to turning on the Loop Nest Optimizer, -LNO:opt=1,
and setting -OPT:ro=1:IEEE_arith=2:Olimit=9000.
-Ofast Equivalent to "-O3 -ipa -OPT:Ofast -fno-math-errno." -OPT:Ofast is
described below.
-OPT:alias=<name>
Specifies the pointer aliasing model to be used. By
specifiying one or more of the following for <name>, the
compiler is able to make assumptions throughout the compilation:
typed Assume that the code adheres to the ANSI/ISO C
standard which states that two pointers of different
types cannot point to the same location in memory.
This is on by default when -Ofast is specified.
restrict Specifies that distinct pointers are assumed
to point to distinct, non-overlapping objects.
This is off by default.
disjoint Specifies that any two pointer expressions are
assumed to point to distinct, non-overlapping objects.
This is off by default.
-OPT:div_split=(ON|OFF)
Enable/disable changing x/y into x*(recip(y)). This is
OFF by default but is enabled by -OPT:Ofast or
-OPT:IEEE_arithmetic=3.
-OPT:early_intrinsics=(ON|OFF)
When ON, this option causes calls to intrinsics to be
expanded to inline code early in the backend compilation.
This may enable more vectorization opportunities if vector
forms of the expanded operations exist. Default is OFF.
-OPT:fast_complex=(ON|OFF)
Setting fast_complex=ON enables fast calculations for values
declared to be of type complex. When this is set to ON,
complex absolute value (norm) and complex division use fast
algorithms that are more likely to overflow or underflow than
the standard algorithms. OFF is the default. fast_complex=ON
is enabled if -OPT:roundoff=3 is in effect.
-OPT:fast_nint=(ON|OFF)
This option uses a hardware feature to implement NINT and ANINT
(both single- and double-precision versions). Default is OFF but
fast_nint=ON is enabled by default if -OPT:ro=3 is in effect.
-OPT:goto=(OFF|ON)
Disable/enable the conversion of GOTOs into higher level
structures like FOR loops. The default is ON for -O2 or higher.
-OPT:IEEE_arithmetic,IEEE_arith,IEEE_a=(n)
specify level of conformance to IEEE 754 floating pointing
roundoff/overflow behavior. n can be one of the following:
1 Adheres to IEEE accuracy. This is the default when
optimization levels -O0, -O1 and -O2 are in effect.
2. May produce inexact result not conforming to IEEE 754.
This is the default when -O3 is in effect.
3. All mathematically valid transformations are allowed.
-OPT:IEEE_NaN_Inf=(ON|OFF)
OFF specifies non-IEEE-754 results in operations that might
have IEEE 754 NaN or infinity operands; this enables many
optimizations which would be invalid for NaN or infinity
operands. The default is ON.
-OPT:Ofast
Use optimizations selected to maximize performance.
Although the optimizations are generally safe,
they may affect floating point accuracy due to rearrangement
of computations. This effectively turns on the following
optimizations: -OPT:ro=2:Olimit=0:div_split=ON:alias=typed.
-OPT:Olimit=(n)
Disable optimization when size of program unit is > n. When n
is 0, program unit size is ignored and optimization process
will not be disabled due to compile time limit. The default is
0 when -Ofast is specified, otherwise the default is 6000
under -O2 and 9000 under -O3.
-OPT:roundoff,ro=(n)
Specifies the level of acceptable departure from source
language floating-point, round-off, and overflow semantics. n
can be one of the following:
0 Inhibits optimizations that might affect the
floating-point behavior. This is the default when
optimization levels -O0, -O1, and -O2 are in effect.
1 Allows simple transformations that might cause limited
round-off or overflow differences. Compounding such
transformations could have more extensive effects.
This is the default level when -O3 is in effect.
2 Allows more extensive transformations, such as the
reordering of reduction loops. This is the default
level when -Ofast is specified.
3 Enables any mathematically valid transformation.
-OPT:transform_to_memlib=(ON|OFF)
When ON, this option enables transformation of loop constructs
to calls to memcpy or memset. Default is ON when target
processor is EM64T, OFF otherwise.
-OPT:treeheight=(ON|OFF)
The value ON turns on re-association in expressions to reduce
the expressions' tree height. The default value is OFF.
-OPT:unroll_analysis=(ON|OFF)
The default value of ON lets the compiler analyze the
content of the loop to determine the best unrolling
parameters, instead of strictly adhering to the
-OPT:unroll_times_max and -OPT:unroll_size parameters.
-OPT:unroll_times_max,unroll_times=(n)
Unroll inner loops by a maximum of n. The default is 4.
-OPT:unroll_size=(n)
Sets the ceiling of maximum number of instructions for an
unrolled inner loop. If n = 0, the ceiling is disregarded.
-static
Suppresses dynamic linking at run-time for shared libraries;
uses static linking instead.
-TENV:X=(0|1|2|3|4)
Specify the level of enabled exceptions that will be assumed
for purposes of performing speculative code motion (default
is 1 at all optimization levels). In general, an instruction
will not be speculated (i.e. moved above a branch by the
optimizer) unless any exceptions it might cause are disabled
by this option. At level 0, no speculative code motion may
be performed. At level 1, safe speculative code motion may
be performed, with IEEE-754 underflow and inexact exceptions
disabled. At level 2, all IEEE-754 exceptions are disabled
except divide by zero. At level 3, all IEEE-754 exceptions
are disabled including divide by zero. At level 4, memory
exceptions may be disabled or ignored.
-TENV:frame_pointer=(ON|OFF)
Default is ON for C++ and OFF otherwise.
Local variables in the function stack frame are addressed via
the frame pointer register. Ordinarily, the compiler will
replace this use of frame pointer by addressing local variables
via the stack pointer when it determines that the stack pointer
is fixed throughout the function invocation. This frees up the
frame pointer for other purposes. Turning this flag on forces
the compiler to use the frame pointer to address local variables.
This flag defaults to on for C++ because the exception handling
mechanism relies on the frame pointer register being used to
address local variables. This flag can be turned off for C++
for programs that do not throw exceptions.
-Wl,-x
Passes the -x option to the linker. With this flag set, the
linker will not preserve local (non-global) symbols in the output
symbol table. The linker enters external and static symbols
only. This option conserves space in the output file. This is
OFF by default.
-WOPT:aggstr=(ON|OFF)
ON instructs the scalar optimizer to perform aggressive strength
reduction, in which all induction expressions within a loop are
replaced by temporaries that are incremented together with
the loop variable. When OFF, strength reduction is only
performed for non-trivial induction expressions. Turning this
off sometimes can improve performance when registers are scarce.
-WOPT:if_conv=(ON|OFF)
Enables the translation of simple IF statements to condi-
tional move instructions in the target CPU. Default is
ON.
-WOPT:mem_opnds=(ON|OFF)
ON makes the scalar optimizer preserve any memory operands of
arithmetic operations so as to help bring about subsumption of
memory loads into the operands of arithmetic operations. Load
subsumption is the combining of an arithmetic instruction and
a memory load into one instruction. The default is OFF.
-WOPT:retype_expr=(ON|OFF)
ON enables the optimization in the compiler that converts 64-bit
address computation to use 32-bit arithmetic as much as
possible. The default is OFF.
-WOPT:unroll=(0|1|2)
Control the unrolling of innermost loops in the scalar optimizer.
Setting to 0 suppresses this unroller. The default is 1, which
makes the scalar optimizer unroll only loops that contain IF
statements. Setting to 2 makes the unrolling to also apply to
loop bodies that are straight line code, which duplicates the
unrolling done in the code generator, and is thus unnecessary.
The default setting of 1 makes this unrolling complementary to
what is done in the code generator. This unrolling is not
affected by the unrolling options under the -OPT group.
-WOPT:val=(0|1|2)
Controls the number of times the value-numbering optimization is
performed in the global optimizer, with the default being 1.
This optimization tries to recognize expressions that will
compute identical run-time values and changes the program to avoid
re-computing them.
Description of the submit command MYMASK=`printf '0x%x' \$((1<<\$SPECUSERNUM))`; /usr/bin/taskset \$MYMASK $command
-------------------------------------------------------------------------------------------------------------------
/usr/bin/taskset [options] [mask] [pid | command [arg] ... ]
taskset is used to set or retreive the CPU affinity of a running process given its
PID or to launch a new COMMAND with a given CPU affinity. The CPU affinity is
represented as a bitmask, with the lowest order bit corresponding to the first logical
CPU and highest order bit corresponding to the last logical CPU.
When the taskset returns, it is gauranteed that the given program has been scheduled to
a legal CPU.
The default behaviour of taskset is to run a new command with a given affinity mask:
taskset [mask] [command] [arguments]
The taskset command is used in the following form in the config file:
submit= MYMASK=`printf '0x%x' \$((1<<\$SPECUSERNUM))`; /usr/bin/taskset \$MYMASK $command
$MYMASK is the bitmask (in hexadecimal) corresponding to a specific SPECUSERNUM. For example, $MYMASK value for the first copy
of a rate run will be 0x00000001, for the second copy of the rate will be 0x00000002
etc. Thus, the first copy of the rate run will have a CPU affinity of CPU0, the second copy will have the
affinity CPU1 etc.
Description of the submit command 'specperl -e "system sprintf qq{start /b /wait /affinity %x %s}, (1<<$SPECUSERNUM), qq{$command}"'
------------------------------------------------------------------------------------------------------------------------------------
This command is used to bind CPUs to processes
specperl -e 'script'
perl command to invoke one line of script
system "command"
specperl starts "command" and waits for its termination.
sprintf "format-string" arg1 arg2
specperl writes a string (to be used later by 'system').
The operation of sprintf is controlled by format-string.
%x is conversion to hexadecimal format.
%s is conversion to string (in effect, it is just appending a string)
The string written by sprintf is something like
/start /b /wait /affinity 4 command_to_be_executed
qq
qq is a double-quoted interpolated string
It is a Perl way to say double quotes (") without using double quotes in a string
the generated string is:
system sprintf "start /b /wait /affinity %x %s",(1<<$SPECUSERNUM),"$command"
where $SPECUSERNUM and $command have been (at this point) replaced by the shell.
1<<$SPECUSERNUM
The number 1 is left-shifted by $SPECUSERNUM positions, yielding a mask where only
bit number $SPECUSERNUM is set. (Bits are counted from right, starting with zero.)
This mask is used for the affinity in the 'start' command.
Description of the 'start' command used for rate runs:
------------------------------------------------------
Starts a separate window to run a specified program or command.
START ["title"] [/D path] [/I] [/MIN] [/MAX] [/SEPARATE | /SHARED]
[/LOW | /NORMAL | /HIGH | /REALTIME | /ABOVENORMAL | /BELOWNORMAL]
[/AFFINITY <hex affinity>] [/WAIT] [/B] [command/program]
[parameters]
"title" Title to display in window title bar.
path Starting directory
B Start application without creating a new window. The
application has ^C handling ignored. Unless the application
enables ^C processing, ^Break is the only way to interrupt
the application
I The new environment will be the original environment passed
to the cmd.exe and not the current environment.
MIN Start window minimized
MAX Start window maximized
SEPARATE Start 16-bit Windows program in separate memory space
SHARED Start 16-bit Windows program in shared memory space
LOW Start application in the IDLE priority class
NORMAL Start application in the NORMAL priority class
HIGH Start application in the HIGH priority class
REALTIME Start application in the REALTIME priority class
ABOVENORMAL Start application in the ABOVENORMAL priority class
BELOWNORMAL Start application in the BELOWNORMAL priority class
AFFINITY The new application will have the specified processor
affinity mask, expressed as a hexadecimal number.
WAIT Start application and wait for it to terminate
command/program
If it is an internal cmd command or a batch file then
the command processor is run with the /K switch to cmd.exe.
This means that the window will remain after the command
has been run.
If it is not an internal cmd command or batch file then
it is a program and will run as either a windowed application
or a console application.
parameters These are the parameters passed to the command/program
Description of Boot options (boot.ini file):
--------------------------------------------
/EXECUTE
This option disables no-execute protection. See the /NOEXECUTE switch for more information.
/NOEXECUTE
This option is only available on 32-bit versions of Windows when running on
processors supporting no-execute protection. It enables no-execute protection
(also known as Data Execution Protection - DEP), which results in the Memory
Manager marking pages containing data as no-execute so that they cannot be
executed as code. This can be useful for preventing malicious code from exploiting
buffer overflow bugs with unexpected program input in order to execute arbitrary
code. No-execute protection is always enabled on 64-bit versions of Windows on
processors that support no-execute protection. There are several options you can
specify with this switch:
/NOEXECUTE=OPTIN Enables DEP for core system images and those specified
in the DEP configuration dialog.
/NOEXECUTE=OPTOUT Enables DEP for all images except those specified in
the DEP configuration dialog.</li>
/NOEXECUTE=ALWAYSON Enables DEP on all images.
/NOEXECUTE=ALWAYSOFF Disables DEP.
/NOPAE
Forces Ntldr to load the non-Physical Address Extension (PAE) version of the Windows kernel,
even if the system is detected as supporting x86 PAEs and has more than 4 GB of physical memory.
/USEPMTIMER
This switch forces the MP HAL to use the frequency-independent PMTimer,
and NOT use the frequency-dependent Time Stamp Counter.
Description of BIOS options:
----------------------------
DRAM Bank Interleave
AUTO Interleave memory blocks across DRAM chip selects. BIOS will AUTO
detect capability on each Node (Default: DISABLED)
Memory Timing
1T Enable fast memory timing (Default: 2T)