test_mulhi32_i32_4()

bool autoresearch::simd_check::test_mulhi32_i32_4 ( )

inline

Definition at line 537 of file AutoResearchSimd.h.

                                 {
    // mulhi32_i32_4: ((i64)a * (i64)b) >> 32
    // Test: 0x40000000 * 0x40000000 >> 32 = 0x10000000
    uint32_t a[4] = {0x40000000, as_u32(-0x40000000), 0x7FFFFFFF, 0x00000001};
    uint32_t b[4] = {0x40000000, 0x40000000, 0x00000002, 0x7FFFFFFF};
    uint32_t output[4] = {0};
    store_u32_4(output, mulhi32_i32_4(load_u32_4(a), load_u32_4(b)));
    if (output[0] != 0x10000000) return false;             // 0.5 * 0.5 = 0.25 (Q31)
    if (as_i32(output[1]) != as_i32(0xF0000000)) return false;  // -0.5 * 0.5 = -0.25
    if (output[2] != 0x00000000) return false;             // small * small -> 0
    if (output[3] != 0x00000000) return false;             // 1 * MAX -> 0 (high bits only)
    return true;
}

References as_i32(), and as_u32().

Referenced by getTests().

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