3.4 Options Reference
which could cause a performance degradation. The mapfile ensures that the segments are aligned on an appropriate boundary.
The n value must be one of the following:
SPARC: The following values are valid: 8K, 64K, 512K, 2M, 4M, 32M, 256M, 1G, and none.
x86: The following values are valid: 4K, 8K, 64K, 512K, 2M, 4M, 32M, 256M, 1G, and none.
The default for both SPARC and x86 is none.
Recommended usage is as follows:
SPARC 32-bit compilation: -xsegment_align=64K
SPARC 64-bit compilation: -xsegment_align=4M
x86 32-bit compilation: -xsegment_align=8K
x86 64-bit compilation: -xsegment_align=4M
The driver will include the appropriate mapfile. For example, if the user specifies - xsegment_align=4M, the driver adds -M install-directory/lib/compilers/mapfiles/ map.4M.align to the link line, where install-directory is the installation directory. The aforementioned segments will then be aligned on a 4M boundary.
3.4.181 –xspace
Do no optimizations that increase the code size.
Example: Do not unroll or parallelize loops if it increases code size.
3.4.182 –xtarget=t
Specifies the target system for the instruction set and optimization.
t must be one of: native, generic, or platform–name.
Each specific value for -xtarget expands into a specific set of values for the -xarch, -xchip, and -xcache options. Use the -xdryrun option to determine the expansion of -xtarget=native on a running system.
For example, -xtarget=T3 is equivalent to -xchip=T3 -xcache=8/16/4:6144/64/24 -xarch=sparcvis3.
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cc-dryrun -xtarget=T3 |& grep ###
###command line files and options (expanded):
###-dryrun -xchip=T3 -xcache=8/16/4:6144/64/24 -xarch=sparcvis3
The data type model, either 32-bit or 64-bit, is indicated by the -m32|-m64 option. To specify the 64-bit data type model, specify the -m64 option as follows:
-xtarget=<value> ... -m64
To specify the 32-bit data type model, use the -m32 option as follows:
-xtarget=<value> ... -m32
See also the -m32|-m64 option for a discussion of the default data type model.
Note - The expansion of -xtarget for a specific host system might not expand to the same - xarch, -xchip, or -xcache settings as -xtarget=native when compiling on that system.
demo% f95 -dryrun -xtarget=T3 |& grep ###
###command line files and options (expanded):
###-dryrun -xchip=T3 -xcache=8/16/4:6144/64/24 -xarch=sparcvis3
Note that the —xtarget expansion for a particular named platform might not be the same as — xtarget=native on that same platform.
TABLE 23 |
-xtarget Values for All Systems |
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|
Value |
|
Meaning |
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|
native |
|
Equivalent to |
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—m32 —xarch=native —xchip=native —xcache=native |
|
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to give best performance on the host 32–bit system. |
|
|
|
generic |
|
Equivalent to |
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—m32 —xarch=generic —xchip=generic —xcache=generic |
|
|
to give best performance on most 32–bit systems. |
|
|
|
system-name |
|
Gets the best performance for the specified platform. |
|
|
Select a system name from the following lists that represents the actual system you are |
|
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targeting. |
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|
|
The performance of some programs may benefit by providing the compiler with an accurate description of the target computer hardware. When program performance is critical, the proper specification of the target hardware could be very important, especially when running on the
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3.4 Options Reference
newer SPARC processors. However, for most programs and older SPARC processors, the performance gain is negligible and a generic specification is sufficient.
3.4.182.1 SPARC Platforms
The following table gives a list of the commonly used system platform names accepted by the compiler.
TABLE 24 |
Expansions of Commonly Used -xtarget System Platforms |
|||
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|
-xtarget= platform-name |
-xarch |
-xchip |
-xcache |
|
|
|
|
|
|
sparc64vi (Obsolete) |
sparcfmaf |
sparc64vi |
128/64/2:5120/64/10 |
|
|
|
|
|
|
sparc64vii (Obsolete) |
sparcima |
sparc64vii |
64/64/2:5120/256/10 |
|
|
|
|
|
|
sparc64viiplus |
|
sparcima |
sparc64viiplus |
64/64/2:11264/256/11 |
|
|
|
|
|
sparc64x |
|
sparcace |
sparc64x |
64/128/4/2:24576/128/24/32 |
|
|
|
|
|
sparc64xplus |
|
sparcaceplus |
sparc64xplus |
64/128/4/2:24576/128/24/32 |
|
|
|
|
|
sparc64xii |
|
sparcace2 |
sparc64xii |
64/128/4/8:512/128/8/96:32768/128/16/96 |
|
|
|
|
|
ultraT1 (Obsolete) |
sparc |
ultraT1 |
8/16/4/4:3072/64/12/32 |
|
|
|
|
|
|
ultraT2 (Obsolete) |
sparcvis2 |
ultraT2 |
8/16/4:4096/64/16 |
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|
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|
ultraT2plus (Obsolete) |
sparcvis2 |
ultraT2plus |
8/16/4:4096/64/16 |
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|
ultraT3 |
|
sparcvis3 |
ultraT3 |
8/16/4:6144/64/24 |
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|
T3 (Obsolete) |
|
sparcvis3 |
T3 |
8/16/4:6144/64/24 |
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|
T4 |
|
sparc4 |
T4 |
16/32/4:128/32/8:4096/64/16 |
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|
T5 |
|
sparc4 |
T5 |
16/32/4/8:128/32/8/8:8192/64/16/128 |
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|
|
|
T7 |
|
sparc5 |
T7 |
16/32/4/8:256/64/8/16:8192/64/8/32 |
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|
|
|
M5 |
|
sparc4 |
M5 |
16/32/4/8:128/32/8/8:49152/64/12/48 |
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|
M6 |
|
sparc4 |
M6 |
16/32/4/8:128/32/8/8:49152/64/12/96 |
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|
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|
M7 |
|
sparc5 |
M7 |
16/32/4/8:256/64/8/16:8192/64/8/32 |
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3.4.182.2 x86 Platforms
The valid -xtarget platform names for x86 systems and their expansions are shown in the following table.
TABLE 25 |
-xtarget Values on x86 Platforms |
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|
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|
-xtarget= |
|
-xarch |
-xchip |
-xcache |
|
|
|
|
|
pentium (Obsolete) |
generic |
generic |
generic |
|
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|
|
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