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Hewlett-Packard Company
SPEC CPU2000 FLAG DESCRIPTIONS
- INTEL C++ AND FORTRAN COMPILERS 7.0
- hp-20030630-ICL70-Windows.txt
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Description of compiler flags for Intel C Compiler 7.0
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-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.
-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.
-Oy[-] Enables [disables] the use of the EBP register in optimizations. When
you disable with -Oy-, the EBP register is used as frame pointer.
-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.
-Qax{i|M|K|W} Generates specialized code for processor specific codes
i, M, K, W while also generating generic IA-32 code.
i = Pentium Pro and Pentium II processor instructions
M = MMX(TM) instructions
K = streaming SIMD extensions
W = Pentium 4 processor instructions
-Qx{i|M|K|W} Generate specialized code to run exclusively on processors
supporting the extensions indicated by <codes> as
described above.
-QxK, -QaxK, -QxW, -QaxW ensure consistent floating point arithmetic.
-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.
-GR[-] Enables[disables] C++ Run Time Type Information (RTTI).
Default is -GR-
-GX[-] Enables[disables] C++ Exception Handling. Default is -GX-
/Qfp_port round fp results at assignments & casts (some speed impact)
/Qprefetch is warned and ignored by the Intel C/C++ Compiler
-Qunroll[n] Specifies the maximum number of times to unroll a loop. n=0 disables
loop unrolling.
shlW32M.lib: MicroQuill SmartHeap Library 6.03 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.
Description of compiler flags for Intel Fortran Compiler 7.0
------------------------------------------------------
-O2 Optimizes for maximum speed. The -O2 option has the same effect as
-Ox. This options defaults to ON.
-O3 Enables -O2 option with more aggressive optimization, for example,
loop transformation. Optimizes for maximum speed but may not improve
performance for some programs.
-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, -Ot, -Oi.
-Oy[-] Enables [disables] the use of the EBP register in optimizations. When
you disable with -Oy-, the EBP register is used as frame pointer.
-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.
-Qax{i|M|K|W} Generates specialized code for processor specific codes
i, M, K, W while also generating generic IA-32 code.
i = Pentium Pro and Pentium II processor instructions
M = MMX(TM) instructions
K = streaming SIMD extensions
W = Pentium 4 processor instructions
-Qx{i|M|K|W} Generate specialized code to run exclusively on processors
supporting the extensions indicated by <codes> as
described above.
-QxK, -QaxK, -QxW, -QaxW ensure consistent floating point arithmetic.
-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.
-GR[-] Enables[disables] C++ Run Time Type Information (RTTI).
Default is -GR-
-GX[-] Enables[disables] C++ Exception Handling. Default is -GX-
-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 or disables prefetch insertion (requires -O3).
shlW32M6.lib: MicroQuill SmartHeap Library 6.0 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.
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:
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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 10MB 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 "_int64"
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-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.
254.gap:
-DSYS_HAS_CALLOC_PROTO :
-DSYS_HAS_MALLOC_PROTO : These two pre-defines tell of the existence of
malloc and calloc prototypes.