-------------------------------------------------------
Hewlett-Packard Company
SPEC CPU2000 FLAG DESCRIPTIONS

- INTEL C++ AND FORTRAN COMPILERS 8.1

- hp-20041115-IC81-Windows.txt
-------------------------------------------------------

Description of compiler flags for Intel C++ Compiler 8.1
--------------------------------------------------------
-arch:SSE2 Enables the compiler to use SSE2 instructions.

-fast The -fast option enhances execution speed across the entire program by
including the following options that can improve run-time performance:

-O3 (maximum speed and high-level optimizations).
-Qipo (enables interprocedural optimizations across files).
-QxP (specific optimization for Intel Pentium 4 processor with Streaming
SIMD Extensions 3). The -fast option does not include -QxP when
compiling on Itanium�-based systems.

To override one of the options set by -fast, specify that option after the /fast
option on the command line. To target -fast optimizations for a specific
processor, use one of the -Qx options. For example:

prompt>icl -fast -QxW source_file.cpp

The options set by -fast may change from release to release.

-GR Enables C++ Runtime Type Information (RTTI).

-Gs[n] Disables stack-checking for routines with n or more bytes of local variables
and compiler temporaries. Default: n=4096

-GX Enables the full C++ Exception Handling unwind semantics.

-Qcxx_features Enables both -GX and -GR as described above so C++ Runtime Type Information and
Exception Handling are both enabled

O1 Optimizes to favor code size and code locality. Disables
loop unrolling. /O1 may improve performance for applications
with very large code size, many branches, and execution time
not dominated by code within loops. In most cases /O2 is
recommended over /O1.

IA-32 systems: Enables options /Og, /Oi-, /Os, /Oy, /Ob1,
and /Gs. Disables intrinsics inlining to reduce code size.

-O2 This is the default level of optimization.
Optimizes for code speed. This is the generally recommended
optimization level.

IA-32 systems: Enables options /Og, /Os, /Oy, /Ob1, and /Gs..

-O3 Enables /O2 optimizations and more aggressive optimizations such
as loop and memory access transformation. The /O3 optimizations
may slow down code in some cases compared to /O2 optimizations.
Recommended for applications that have loops with heavy use of
floating-point calculations and process large data sets.

IA-32 systems: In conjunction with /Qax{K|W|N|B|P} and /Qx{K|W|N|B|P}
options, this option causes the compiler to perform more aggressive data
dependency analysis than for /O2. This may result in longer compilation times.

-Oa[-] Assume [do not assume] no aliasing in program

-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.

-Og Enables global optimizations.

-Oi[-] Enables [disables] inline expansion of intrinsic functions.

-Os Enables most speed optimizations, but disable optimizations that increase
code size for a small speed benefit.

-Oy[-] Enables [disables] the use of the EBP register in optimizations. When you
disable with /Oy-, the EBP register is used as frame pointer.

-Qansi_alias [-] Directs the compiler to assume that the program adheres
to the type-based aliasing rules defined in the ISO C Standard. If your
program adheres to these rules, this option will allow the compiler to
optimize more aggressively. If it doesn't adhere to these rules, it can
cause the compiler to generate incorrect code.

-Qax<codes> Generate code specialized for processor extensions
specified by <codes> while also generating generic IA-32 code.
<codes> includes one or more of the following characters:
i Pentium Pro and Pentium II processor instructions
M MMX(TM) instructions
K streaming SIMD extensions (implies i and M above)
W Pentium 4 processor with Streaming SIMD Extensions 2
(implies i, M and K)
N Pentium 4 processor with Streaming SIMD Extensions 2
P Pentium 4 processor with Streaming SIMD Extensions 3

-Qx<codes> Generate specialized code to run exclusively on processors
supporting the extensions indicated by <codes> as
described above.

----------------------------------------------------------------------------------
Additional Notes on /QxN and /QxP:
----------------------------------------------------------------------------------
-Qx{N|P} The /QxN and /QxP options target your program to run on Intel
Pentium 4 and compatible Intel processors. The resulting code might
contain unconditional use of features that are not supported
on other processors. Programs, where the function main() is
compiled with this option, will detect non compatible processors
and generate an error message during execution. This option
also enables new optimizations in addition to Intel processor
specific optimizations.

These options also enable advanced data layout and code restructuring
optimizations to improve memory accesses for Intel processors.
----------------------------------------------------------------------------------

-Qip Enable single-file IP optimizations (within files, same as -Ob2)

-Qipo [value] Enables interprocedural optimizations across files. The
optional value argument controls the maximum number of link-time
compilations (or number of object files) that are spawned. The default
for value is 1 when value is not specified. This option is not compatible
with the Microsoft /GL option.

Multi-file ip optimizations that includes:
- inline function expansion
- interprocedural constant propogation
- monitoring module-level static variables
- dead code elimination
- propagation of function characteristics
- multifile optimization
- passing arguments in registers
- loop-invariant code motion

-Qoption, tool,optlist Passes an argument list to another program in the
compilation sequence, such as the assembler or linker. The parameter
'tool' can be:

cpp Specifies the compiler front-end preprocessor
c Specifies the C++ compiler
asm Specifies the assembler
link Specifies the linker
optlist 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.

-Qprefetch[-] Enables [disables] the insertion of software prefetching by the
compiler. Default is /Qprefetch.

-Qprof_gen Instrument program for profiling for the first phase of two-phase
profile guided otimization

-Qprof_use Instructs the compiler to produce a profile-optimized executable
and merges available dynamic information (.dyn) files into a pgopti.dpi file.
If you perform multiple executions of the instrumented program, -Qprof_use
merges the dynamic information files again and overwrites the previous
pgopti.dpi file. Without any other options, the current directory is searched for
.dyn files

-Qrcd The Intel compiler uses the -Qrcd option to improve the
performance of code that requires floating-point-to-integer
conversions.

The system default floating point rounding mode is
round-to-nearest. This means that values are rounded during
floating point calculations. However, the C language requires
floating point values to be truncated when a conversion to an
integer is involved. To do this, the compiler must change the
rounding mode to truncation before each floating
point-to-integer conversion and change it back afterwards.

The -Qrcd option disables the change to truncation of the
rounding mode for all floating point calculations, including
floating point-to-integer conversions. Turning on this option
can improve performance, but floating point conversions to
integer will not conform to C semantics.

-Qunroll[n] Specifies the maximum number of times to unroll a loop. Omit n
to let the compiler decide whether to perform unrolling or not.
Use n = 0 to disable unroller.
If n is not specified, the compiler automatically chooses the
maximum number of times to unroll a loop.

-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 (default)
bytes.

Description of compiler flags for Intel FORTRAN Compiler 8.1
-------------------------------------------------------------
-fast The -fast option enhances execution speed across the entire program by
including the following options that can improve run-time performance:

prompt>icl -fast -QxW source_file.cpp

The options set by -fast may change from release to release.

-Gs[n] Disables stack-checking for routines with n or more bytes of local variables
and compiler temporaries. Default: n=4096

-inline:speed Enable speed optimizations (same as -Ob2 -Ot)

-[no]f77rtl Specifies that the FORTRAN-77-specific run-time support should be
used.

-[no]fpp Determines whether the Fortran preprocessor is run on source files
prior to compilation.

-O1 Optimizes to favor code size and code locality. Disables
loop unrolling. /O1 may improve performance for applications
with very large code size, many branches, and execution time
not dominated by code within loops. In most cases /O2 is
recommended over /O1.

IA-32 systems: Enables options /Og, /Oi-, /Os, /Oy, /Ob1,
and /Gs. Disables intrinsics inlining to reduce code size.

-O2 This is the default level of optimization.
Optimizes for code speed. This is the generally recommended
optimization level.

IA-32 systems: Enables options /Og, /Os, /Oy, /Ob1, and /Gs..

-Oa[-] Assume [do not assume] no aliasing in program

-Og Enables global optimizations.

-Oi[-] Enables [disables] inline expansion of intrinsic functions.

-Os Enables most speed optimizations, but disable optimizations that increase
code size for a small speed benefit.

-Ot Enables all speed optimizations.

-Oy[-] Enables [disables] the use of the EBP register in optimizations. When you
disable with /Oy-, the EBP register is used as frame pointer.

-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

-Qauto Causes all variables to be allocated on the stack, rather than in local
static storage. Does not affect variables that have the SAVE attribute or
appear in an EQUIVALENCE statement or common block; same as
-automatic, -auto or -4Ya. Opposite of -Qsave.

If -recursive or -Qopenmp is specified, the default is -Qauto.

-Qx<codes> Generate specialized code to run exclusively on processors
supporting the extensions indicated by <codes> as
described above.

----------------------------------------------------------------------------------
Additional Notes on /QxN and /QxP:
----------------------------------------------------------------------------------
-Qx{N|P} The /QxN and /QxP options target your program to run on Intel Pentium
4 and compatible Intel processors. The resulting code might
contain unconditional use of features that are not supported
on other processors. Programs, where the function main() is
compiled with this option, will detect non compatible processors
and generate an error message during execution. This option
also enables new optimizations in addition to Intel processor
specific optimizations.

-Qip enable single-file IP optimizations (within files, same as -Ob2)

-Qipo[n] Enables multifile interprocedural (IP) optimizations (between files).
When you specify this option, the compiler performs inline function
expansion for calls to functions defined in separate files.

n is an optional integer that specifies the number of object files the compiler
should create. Any integer greater than or equal to 0 is valid.

If n is 0, the compiler decides whether to create one or more object files based
on an estimate of the size of the object file. It generates one object file for small
applications, and two or more object files for large applications.

If n is greater than 0, the compiler generates n object files, unless n exceeds the
number of source files (m), in which case the compiler generates only m object files.

If you do not specify n, the default is 1.

-Qoption, tool,list Passes an argument list to another program in the
compilation sequence, such as the assembler or linker. The
parameter 'tool' can be:

fpp Specifies the Intel Fortran preprocessor
f Specifies the Fortran compiler
asm Specifies the assembler
link Specifies the linker

-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.

-Qparallel Automatically detects loops capable of being executed safely in parallel
and generates multithreaded code for these loops.

-Qprec Improves floating-point precision. Some speed impact.

-Qprefetch[-] Enables [disables] the insertion of software prefetching by the
compiler (requires -O3). Default is /Qprefetch.

-Qprof_gen Instrument program for profiling for the first phase of
two-phase profile guided otimization

-Qprof_use Instructs the compiler to produce a profile-optimized
executable and merges available dynamic information (.dyn)
files into a pgopti.dpi file. If you perform multiple
executions of the instrumented program, -Qprof_use merges
the dynamic information files again and overwrites the
previous pgopti.dpi file.
Without any other options, the current directory is
searched for .dyn files

-Qrcd Enables fast float-to-int conversion.

-Qscalar_rep[-] Enables [disables] scalar replacement performed during loop
transformations (requires -O3).

-Qunroll[n] Specifies the maximum number of times to unroll a loop. Omit n to
let the compiler decide whether to perform unrolling or not. Use
n = 0 to disable unroller.
If n is not specified, the compiler automatically chooses the maximum
number of times to unroll a loop.

Additional Libraries Used
-------------------------

Supplied by MicroQuill:

shlW32M.lib: MicroQuill SmartHeap Library 7.0 available from
http://www.microquill.com/

Other Notes:
------------
"/" and "-" are both allowable starting tokens for flags passed to the
compiler i.e. -QxK and /QxK are identical switches.

Portability options for CPU2000:
-------------------------------
176.gcc:
-Dalloca=_alloca : so as to use the built-in optimized alloca
-F10000000 : 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

178.galgel:
-FI : Fixed-format F90 source code.
-F32000000 : Same as with 176.gcc, pre-allocates a 32MB
stack

186.crafty:
-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.

253.perlbmk:
-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 executible without getting the
indirect calls that can cause a 10% performance
degradation. This allows the Windows-based
executible to be as close as possible to
the Unix-based one.
-MT : Use the static multi-threaded library else
it will not compile.

254.gap:
-DSYS_HAS_CALLOC_PROTO :
-DSYS_HAS_MALLOC_PROTO : These two pre-defines tell of the existence
of malloc and calloc prototypes.