MIPS SIMD Architecture (MSA) Support (Using the GNU Compiler Collection (GCC))

#### 7.13.18 MIPS SIMD Architecture (MSA) Support ¶

GCC provides intrinsics to access the SIMD instructions provided by the MSA MIPS SIMD Architecture. The interface is made available by including `<msa.h>` and using `-mmsa -mhard-float -mfp64 -mnan=2008`. For each `__builtin_msa_*`, there is a shortened name of the intrinsic, `__msa_*`.

MSA implements 128-bit wide vector registers, operating on 8-, 16-, 32- and 64-bit integer, 16- and 32-bit fixed-point, or 32- and 64-bit floating point data elements. The following vectors typedefs are included in `msa.h`:

- `v16i8`, a vector of sixteen signed 8-bit integers;
- `v16u8`, a vector of sixteen unsigned 8-bit integers;
- `v8i16`, a vector of eight signed 16-bit integers;
- `v8u16`, a vector of eight unsigned 16-bit integers;
- `v4i32`, a vector of four signed 32-bit integers;
- `v4u32`, a vector of four unsigned 32-bit integers;
- `v2i64`, a vector of two signed 64-bit integers;
- `v2u64`, a vector of two unsigned 64-bit integers;
- `v4f32`, a vector of four 32-bit floats;
- `v2f64`, a vector of two 64-bit doubles.

Instructions and corresponding built-ins may have additional restrictions and/or input/output values manipulated:

- `imm0_1`, an integer literal in range 0 to 1;
- `imm0_3`, an integer literal in range 0 to 3;
- `imm0_7`, an integer literal in range 0 to 7;
- `imm0_15`, an integer literal in range 0 to 15;
- `imm0_31`, an integer literal in range 0 to 31;
- `imm0_63`, an integer literal in range 0 to 63;
- `imm0_255`, an integer literal in range 0 to 255;
- `imm_n16_15`, an integer literal in range -16 to 15;
- `imm_n512_511`, an integer literal in range -512 to 511;
- `imm_n1024_1022`, an integer literal in range -512 to 511 left shifted by 1 bit, i.e., -1024, -1022, …, 1020, 1022;
- `imm_n2048_2044`, an integer literal in range -512 to 511 left shifted by 2 bits, i.e., -2048, -2044, …, 2040, 2044;
- `imm_n4096_4088`, an integer literal in range -512 to 511 left shifted by 3 bits, i.e., -4096, -4088, …, 4080, 4088;
- `imm1_4`, an integer literal in range 1 to 4;
- `i32, i64, u32, u64, f32, f64`, defined as follows:

    {
    typedef int i32;
    #if __LONG_MAX__ == __LONG_LONG_MAX__
    typedef long i64;
    #else
    typedef long long i64;
    #endif

    typedef unsigned int u32;
    #if __LONG_MAX__ == __LONG_LONG_MAX__
    typedef unsigned long u64;
    #else
    typedef unsigned long long u64;
    #endif

    typedef double f64;
    typedef float f32;
    }