• SIMD

    SSE State Management

    LDMXCSR loads the SSE control and status register from memory, while STMXCSR stores it to memory. FXSAVE saves FP, MMX and SSE state to memory, while FXRSTOR loads it from memory.

  • SIMD

    SSE Shuffle

    SHUFPS is able to shuffle any of the numbers from one source operand to the lower two destination fields; the upper two destination fields are generated from a shuffle of any of the four SP FP numbers from the second source operand. By using the same register for both sources,…

  • SIMD

    SSE Reciprocal

    A basic building block operation in geometry involves computing divisions and square roots. For instance, transformation often involves dividing each x, y, z coordinate by the W perspective coordinate; normalization is another common geometry operation, which requires the computation of 1/square-root. In order to optimize these cases, SSE introduces two…

  • SIMD

    SSE Logical

    ANDPS returns a bitwise AND between the two operands. ANDNPS returns a bitwise AND NOT between the two operands. ORPS returns a bitwise OR between the two operands. XORPS returns a bitwise XOR between the two operands.

  • SIMD

    SSE Data Movement

    MOVAPS transfers 128 bits of packed data from memory to SIMD floating-point registers and vice versa, or between SIMD floating-point registers, while MOVUPS makes no assumption for alignment. MOVHPS transfers 64 bits of packed data from memory to the upper two fields of a SIMD floating-point register and vice versa,…

  • SIMD

    SSE Conversion

    These instructions support packed and scalar conversions between 128-bit SIMD floating-point registers and either 64-bit integer MMX registers or 32-bit integer x86 registers.  CVTPI2PS converts two 32-bit signed integers in an MMX register to the two least significant numbers of the SSE destination register. The upper two significant numbers in…

  • SIMD

    SSE Comparison

    The basic single precision FP comparison instruction is similar to existing MMX instruction variants: it produces a redundant mask per float of all 1?s or all 0?s, depending upon the result of the comparison. This approach allows the mask to be used with subsequent logic operations (AND, ANDN, OR, XOR)…

  • SIMD

    SSE Cacheability Control

    Data referenced by a program can have temporal (data will be used again) or spatial (data will be in adjacent locations, such as the same cache line) locality, but some multimedia data types are referenced once and not reused in the immediate future (called non-temporal data). Thus, non-temporal data should…

  • SIMD

    SSE2 64-bit FP instructions

    In the introduction we have outlined the applications that require 64-bit precision, scientific simulations and CAD/CAM being notable examples. However, the transition from normal scalar code to 64-bit floating-point SSE2 code is complex and it may require some major design changes. A more conservative approach would be moving to scalar…

  • SIMD

    SSE2 preview

    The forthcoming Intel Pentium 4 processor (code-named Willamette)  will feature a new set of SIMD instructions that improve the capabilities of both the MMX and SSE instruction sets. The key benefits of SSE2 are that MMX instructions can work on 128-bit data blocks, and that SSE instructions now support 64-bit…