B.2.74.2 -xarch Flags for x86 (Sun Studio 12 Update 1: C User's Guide)

Sun Studio 12 Update 1: C User's Guide

B.2.74.2 `-xarch` Flags for x86

The following table lists the -xarch flags on the x86 architecture.

Table B–15 The -xarch Flags on x86


Flag	Meaning
`amd64`	Is equivalent to `-m64` `-xarch=sse2` (Solaris only). Legacy makefiles and scripts that use `-xarch=amd64` to obtain the 64-bit memory model need only use `-m64`.
`amd64a`	Is equivalent to `-m64` `-xarch=sse2a` (Solaris only).
`amdsse4a`	Uses the AMD SSE4a Instruction set.
`generic`	Uses the instruction set common to most processors. This is the default, and is equivalent to `pentium_pro` when compiling with `—m32`, and `sse2` with `—m64`.
`generic64`	Compile for good performance on most 64-bit platforms. (Solaris only). This option is equivalent to `-m64` `-xarch=generic` and is provided for compatibility with earlier releases. Use `-m64` to specify 64-bit compilation instead of `-xarch=generic64`.
`native`	Compile for good performance on this system. The compiler chooses the appropriate setting for the current system processor it is running on.
`native64`	Compile for good performance on this system (Solaris only). This option is equivalent to `-m64` `-xarch=native` and is provided for compatibility with earlier releases.
`pentium_pro`	Limits the instruction set to the 32–bit pentium_pro architecture.
`pentium_proa`	Adds the AMD extensions (3DNow!, 3DNow! extensions, and MMX extensions) to the 32-bit pentium_pro architecture.
`sse`	Adds the `SSE` instruction set to the `pentium_pro` architecture.
`ssea`	Adds the AMD extensions (3DNow!, 3DNow! extensions, and MMX extensions) to the 32-bit SSE architecture.
`sse2`	Adds the `SSE2` instruction set to the `pentium_pro` architecture.
`sse2a`	Adds the AMD extensions (3DNow!, 3DNow! extensions, and MMX extensions) to the 32-bit SSE2 architecture.
`sse3`	Adds the SSE3 instruction set to SSE2 instruction set.
`ssse3`	Supplements the pentium_pro, SSE, SSE2, and SSE3 instruction sets with the SSSE3 instruction set.
`sse4_1`	Supplements the pentium_pro, SSE, SSE2, SSE3, and SSSE3 instruction sets with the SSE4.1 instruction set.
`sse4_2`	Supplements the pentium_pro, SSE, SSE2, SSE3,SSSE3, and SSE4.1 instruction sets with the SSE4.2 instruction set.

Special x86 Notes

There are some important issues to be aware of when compiling for x86 Solaris platforms.

The legacy Sun-style parallelization pragmas are not available on x86. Use OpenMP instead. See the Sun Studio OpenMP API User’s Guide for information on converting legacy parallelization directives to OpenMP.

Programs compiled with -xarch set to sse, sse2, sse2a, sse3, and beyond, can be run only on platforms that provide these extensions and features.

OS releases starting with Solaris 9 4/04 are SSE/SSE2-enabled on Pentium 4-compatible platforms. Earlier versions of Solaris OS are not SSE/SSE2-enabled. If an instruction set selected by -xarch is not enabled in the running Solaris OS, the compiler will not be able to generate or link code for that instruction set.

If you compile and link in separate steps, always link using the compiler and using the same -xarch setting to ensure that the correct startup routine is linked.

Numerical results on x86 may differ from results on SPARC due to the x86 80-bit floating-point registers. To minimize these differences, use the -fstore option or compile with -xarch=sse2 if the hardware supports SSE2.

Numerical results can also differ between Solaris and Linux because the intrinsic math libraries (for example, sin(x)) are not the same.

Binary Compatibility Verification

Starting with Sun Studio 11 and the Solaris 10 OS, program binaries compiled and built using these specialized -xarch hardware flags are verified that they are being run on the appropriate platform.

On systems prior to Solaris 10, no verification is done and it is the user's responsibility to ensure objects built using these flags are deployed on suitable hardware.

Running programs compiled with these -xarch options on platforms that are not enabled with the appropriate features or instruction set extensions could result in segmentation faults or incorrect results occurring without any explicit warning messages.

This warning extends also to programs that employ .il inline assembly language functions or __asm() assembler code that utilize SSE, SSE2, SSE2a, and SSE3 instructions and extensions.