Acer-CPU2006-ic91-flags-file-20070215.xml
Acer SPEC CPU2006 Flag Description for the Linux Intel(R) C++ Compiler 9.1
for EM64T-based applications and Intel(R) Fortran Compiler 9.1 for EM64T-based
applications
Platform settings
ulimit -s (Linux)
Sets the stack size to n kbytes, or unlimited to allow the stack size
to grow without limit.
]]>
Invoke the Intel C compiler for EM64T based applications
]]>
Invoke the Intel C++ compiler for EM64T based applications
]]>
Invoke the Intel Fortran compiler for EM64T based applications
For mixed-language benchmarks, tell the compiler to ignore the main routine in Fortran
]]>
optimize for speed, but disable some optimizations which increase
code size for a small speed benefit. Includes inline expansion
except for intrinsic functions, global optimizations, string
pooling optimizations. On Linux platforms, -O1 sets the
following:
-unroll0, -fno-builtin -mno-ieee-fp -fomit-frame-pointer -ffunction-sections
]]>
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.
]]>
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 -axK/-xK and -axW/-xW, this switch causes the
compiler to perform more aggressive data dependency analysis than
for -O2. This may result in longer compilation times. On Linux
platforms, -O3 sets the following:
-fp
]]>
enable single-file IP optimizations
(within files, same as -Ob2)
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
]]>
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)
-ipo (enables interprocedural optimizations across files)
-xP (generate code specialized for Intel Pentium 4 processor
and compatible Intel processors with Streaming SIMD Extensions 3)
-no-prec-div (disable -prec-div)
where -prec-div improves precision of FP divides (some speed impact)
-static (statically link libraries during compilation)
To override one of the options set by /fast, specify that option after the
-fast option on the command line. The options set by /fast may change from
release to release.
]]>
The -xN and -xP 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.
]]>
(disable -prec-div)
Allows the compiler to perform optimizations in FP divides that may
impact precision while improving speed.
]]>
Instrument program for profiling for the first phase of
two-phase profile guided otimization. This instrumentation gathers information
about a program's execution paths and data values but does not gather
information from hardware performance counters. The profile instrumentation
also gathers data for optimizations which are unique to profile-feedback
optimization.
]]>
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, -prof_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
]]>
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 option, and must be able to analyze all library/external
calls the program makes. This option imposes the following
restrictions 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.
]]>
Enables improved floating-point consistency. Floating-point operations
are not reordered and the result of each floating-point operation is
stored in the target variable rather than being kept in the floating-
point processor for use in a subsequent calculation. This is the same
as specifying -fltconsistency or -mp.
The default, -mno-ieee-fp, provides better accuracy and run-time per-
formance at the expense of less consistent floating-point results.
]]>
Enable using EBP as general purpose register.
]]>
Separate functions for the linker (COMDAT). Same as -fdata-sections.
]]>
Tells the compiler the maximum number of times to unroll loops.
Disables inline expansion of all intrinsic functions.
Disable using EBP as general purpose register.
]]>
This option prevents linking with shared libraries. It
causes the executable to link all libraries statically.
]]>