SIMD: Difference between revisions

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==x86 XMM==
==x86 XMM==
The Streaming SIMD Extensions operate on the 128-bit XMM registers (XMM0..XMM7 in 32-bit mode, XMM0..XMM15 in 64-bit mode).
The Streaming SIMD Extensions operate on the 128-bit XMM registers (XMM0..XMM7 in 32-bit mode, XMM0..XMM15 in 64-bit mode). In its original incarnation on the PIII, execution units (but not registers) were shared with the x87 floating-point architecture. The execution units were separated in the NetBurst microarchitecture. In the Core microarchitecture, the execution engine has been widened for greater SSE throughput.
===SSE5 (AMD)===
===SSE5 (AMD)===
* Unimplemented extensions competing with SSE4, encoded using a method incompatible with VEX
* Unimplemented extensions competing with SSE4, encoded using a method incompatible with VEX
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===SSE2===
===SSE2===
*Introduced with the P4.
*Extends the [[SIMD#MMX|MMX]] instructions to XMM registers.
*<tt>[http://www.sesp.cse.clrc.ac.uk/html/SoftwareTools/vtune/users_guide/mergedProjects/analyzer_ec/mergedProjects/reference_olh/mergedProjects/instructions/instruct32_hh/vc180.htm movapd]</tt> -- move two packed doubles from a 16-byte-aligned memory location to XMM registers, or vice versa, or between two XMM registers.
*<tt>[http://www.sesp.cse.clrc.ac.uk/html/SoftwareTools/vtune/users_guide/mergedProjects/analyzer_ec/mergedProjects/reference_olh/mergedProjects/instructions/instruct32_hh/vc180.htm movapd]</tt> -- move two packed doubles from a 16-byte-aligned memory location to XMM registers, or vice versa, or between two XMM registers.
**<tt>[http://www.sesp.cse.clrc.ac.uk/html/SoftwareTools/vtune/users_guide/mergedProjects/analyzer_ec/mergedProjects/reference_olh/mergedProjects/instructions/instruct32_hh/vc205.htm movupd]</tt> -- <tt>movapd</tt> safe for unaligned memory references, with far inferior performance.
**<tt>[http://www.sesp.cse.clrc.ac.uk/html/SoftwareTools/vtune/users_guide/mergedProjects/analyzer_ec/mergedProjects/reference_olh/mergedProjects/instructions/instruct32_hh/vc205.htm movupd]</tt> -- <tt>movapd</tt> safe for unaligned memory references, with far inferior performance.