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QLOGIC Corporation
SPEC CPU2000 FLAG DESCRIPTIONS

- Intel C/C++/Visual FORTRAN Compilers Version 9.1
- Windows and Linux
- QLOGIC-20061128-IC91.txt
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General Options (C/C++/FORTRAN)
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-arch:<keyword> Determines the version of the architecture for which the
compiler generates instructions
keyword Is the processor type. Possible values are:
SSE: Optimizes for Intel Pentium 4 processors with
Streaming SIMD Extensions (SSE).
SSE2: Optimizes for Intel Pentium 4 processors with
Streaming SIMD Extensions 2 (SSE2).

-fast This option maximizes speed across the entire program by
including the following options (IA32, EM64T)

-O3 -Qipo -Qprec-div- -QxP (Windows)
-O3 -ipo -no-prec-div -xP -static (Linux)

-O{1|2|3} Optimization-level options:
1: optimize for speed, but disable some optimizations which
increase code size for a small speed benefit. Includes
inline expansion for intrinsic functions, global
optimizations, string pooling optimizations.
2: This is the default level of optimization.
Optimizes for speed. The -O2 option includes O1
optimizations and in addition enables inlining of
intrinsics and more speed optimizations.
3: Builds on -01 and -02 optimizations by enabling high-level
optimization. This level does not guarantee higher performance
unless loop and memory access transformation take place. In
conjunction with -QaxK/-QxK and QaxW/QxW, this switch 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.

-Qansi_alias[-] (Windows)
-ansi-alias[-] (Linux)
Enable/disable use of ANSI aliasing rules in
optimizations; user asserts that the program adheres to
these rules. The default for C++ is -Qansi_alias-
which is that aliasing rules are not assumed. The default for
the Fortran compiler is -Qansi_alias. For C++, the -Qansi_alias
flag will enable optimizations that would otherwise be
prevented by potential aliasing.

-Qauto-ilp32 (Windows)
-auto-ilp32 (Linux)
This option instructs the compiler to analyze the program to
determine if there are 64-bit pointers which can be safely
shrunk into 32-bit pointers. In order for this option to be
effective the compiler must be able to optimize using the
-ipo/-Qipo option, and must be able to analyze all library/
external calls the program makes. This option imposes the
following restriction on the program:

The program cannot malloc any objects greater than 2**31 bytes
in size.

If the program does not satisfy this restriction, unpredictable
behavior may occur.

-Qipo (Windows)
-ipo (Linux)
Multi-file ip optimizations that includes:
- inline function expansion
- interprocedural constant propogation
- dead code elimination
- propagation of function characteristics
- passing arguments in registers
- loop-invariant code motion

-Qoption,<string>,options
Passes options to a specified tool.

<string> Is the name of the tool. string can be any of the following:
c - Indicates the Intel C++ compiler.
cpp (or fpp) - Indicates the Intel C++ preprocessor.
cxxinc - Indicates C++ header files.
cinc - Indicates C header files.
asm - Indicates the assembler.
link - Indicates the linker.
prof - Indicates the profiler.
On Windows systems, the following is also available:
masm - Indicates the Microsoft assembler.
On Linux and Mac OS systems, the following are also available:
as - Indicates the assembler.
gas - Indicates the GNU assembler.
ld - Indicates the loader.
gld - Indicates the GNU loader.
lib - Indicates an additional library.
crt - Indicates the crt%.o files linked into executables
to contain the place to start execution.

<options> Are one or more comma-separated,
valid options for the designated tool.

-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.

-Qprec-div[-] (Windows)
-[no-]prec-div (Linux)
Improves precision of floating point divides.

-Qprof_gen (Windows)
-prof_gen (Linux)
Instrument program for profiling for the first phase of
two-phase profile guided optimization.

-Qprof_use (Windows)
-prof_use (Linux)
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 (Windows)
-rcd (Linux)
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 may not conform to C semantics.

-static (Linux)
This option prevents linking with shared libraries. It causes
the executable to link all libraries statically.

-Qunroll[n] (Windows)
-unroll[n] (Linux)
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.

-Qax<processor> (Windows)
-ax<processor> (Linux)
Directs the compiler to generate processor-specific code if there is a
performance benefit, while also generating generic IA-32 code.

<processor> is the processor for which you want to target your program.
Possible values are:

K: Code is optimized for Intel� Pentium� III and compatible Intel processors.
W: Code is optimized for Intel Pentium 4 and compatible Intel processors.
N: Code is optimized for Intel Pentium 4 and compatible Intel processors
with Streaming SIMD Extensions 2. The resulting code may contain
unconditional use of features that are not supported on other
processors.
This option also enables new optimizations in addition to Intel
processor-specific optimizations including advanced data layout and
code restructuring optimizations to improve memory accesses for Intel
processors.
B: Code is optimized for Intel Pentium M and compatible Intel processors.
This option also enables new optimizations in addition to Intel
processor-specific optimizations.
P: Code is optimized for Intel� Core� Duo processors, Intel� Core� Solo
processors, Intel� Pentium� 4 processors with Streaming SIMD
Extensions 3, and compatible Intel processors with Streaming SIMD
Extensions 3. The resulting code may contain unconditional use of
features that are not supported on other processors.
This option also enables new optimizations in addition to Intel
processor-specific optimizations including advanced data layout and
code restructuring optimizations to improve memory accesses for Intel
processors.

-Qx<processor> (Windows)
-x<processor> (Linux)
Generate specialized code for processor specified by <codes>
while also generating generic code.

<processor> is the processor for which you want to target your program.
Possible values are:

Additional Notes on <codes> N and P:
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The N and P 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. These options also
enable new optimizations in addition to Intel processor-specific
optimizations including advanced data layout and code restructuring
optimizations to improve memory accesses for Intel processors.

-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.
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Flags Specific to C/C++
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-Qcxx_features (Windows)
Enables standard C++ features without disabling Microsoft features and within
the bounds of what is provided in the Microsoft headers and libraries.

This option also enables -GR and -GX.

-GR Enables C++ Runtime Type Information (RTTI).
-GX Enables the full C++ Exception Handling unwind semantics.

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Flags Specific to FORTRAN
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-Qauto (Windows)
-auto (Linux)
Causes all variables to be allocated on the stack, rather than
in local static storage.

-Qscalar_rep[-] (Windows)
-[no-]scalar-rep (Linux)
Enables (DEFAULT) [disables] scalar replacement performed
during loop transformations.

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General Options and Libraries
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The starting tokens "/" and "-" are both equivalent for flags passed to the
compiler. For example, -QxW and /QxW are identical switches.

+FDO PASS1=-Qprof_gen PASS2=-Qprof_use

Using feedback-directed optimization, a profile is generated
on the first pass of compilation and used on the second pass.

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

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Benchmark-Specific Portability Options
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-DSPEC__CPU2000_LP64
Compile using LP64 programming model.

176.gcc:
-Dalloca=_alloca So as to use the built-in optimized alloca.
/F10000000 176.gcc uses alloca and this option tells the
linker to pre-allocate 10MB of stack. The default
amount of stack allocated is not enough and 176.gcc
crashes with a run-time error

178.galgel:
-FI (Linux)
/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 "_int64"
as the 64-bit variable that 186.crafty needs.
-DLINUX_i386 Linux Intel system, use "long long" as 64-bit variable.

252.eon:
-DHAS_ERRLIST Prog env provides specification for
"sys_errlist[]".
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-defines 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.
-DSPEC_CPU2000_LINUX_I386 Compile for an I386 system running Linux.
-DSPEC_CPU2000_NEED_BOOL Use SPEC provided definition of the boolean type.

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

-DSYS_IS_USG Specifies that the operating system is USG compliant.

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BIOS Settings Notes
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Note: The settings described in this section do not apply to every ProLiant server.

Power Regulator for ProLiant support (Default = HP Dynamic Power Savings Mode):
- HP Dynamic Power Savings Mode: Automatically varies processor
speed and power usage based on processor utilization. Allows
reducing overall power consumption with little or no impact to
performance. Does not require OS support.

- HP Static Low Power Mode: Reduces processor speed and power usage.
Guarantees a lower maximum power usage for the system. Performance
impacts will be greater for environments with higher processor
utilization.

- HP Static High Performance Mode: Processors will run in their
maximum power/performance state at all times regardless of the
OS power managment policy.

- OS Control Mode: Processors will run in their maximum power/
performance state at all times unless the OS enables' a power
management policy.

Adjacent Sector Prefetch (Default = Enabled):
This option allows the enabling/disabling of a processor mechanism to
fetch the adjacent cache line within an 128-byte sector that contains
the data needed due to a cache line miss.

In some limited cases, setting this option to Disabled may improve
performance. In the majority of cases, the default value of Enabled
provides better performance. Users should only disable this option
after performing application benchmarking to verify improved
performance in their environment.