VPEXPANDQ — Load Sparse Packed Quadword Integer Values from Dense Memory / Register

Instruction Operand Encoding ¶

Description ¶

Expand (load) up to 8 quadword integer values from the source operand (the second operand) to sparse elements in the destination operand (the first operand), selected by the writemask k1. The destination operand is a ZMM register, the source operand can be a ZMM register or memory location.

The input vector starts from the lowest element in the source operand. The opmask register k1 selects the destination elements (a partial vector or sparse elements if less than 8 elements) to be replaced by the ascending elements in the input vector. Destination elements not selected by the writemask k1 are either unmodified or zeroed, depending on EVEX.z.

Note: EVEX.vvvv is reserved and must be 1111b otherwise instructions will #UD.

Note that the compressed displacement assumes a pre-scaling (N) corresponding to the size of one single element instead of the size of the full vector.

Operation ¶

VPEXPANDQ (EVEX encoded versions) ¶

(KL, VL) = (2, 128), (4, 256), (8, 512)
k←0
FOR j←0 TO KL-1
    i←j * 64
    IF k1[j] OR *no writemask*
        THEN
            DEST[i+63:i] ← SRC[k+63:k];
            k←k + 64
        ELSE
            IF *merging-masking*
                        ; merging-masking
                THEN *DEST[i+63:i] remains unchanged*
                ELSE ; zeroing-masking
                    THEN DEST[i+63:i]←0
            FI
    FI;
ENDFOR
DEST[MAXVL-1:VL] ← 0

Intel C/C++ Compiler Intrinsic Equivalent ¶

VPEXPANDQ __m512i _mm512_mask_expandloadu_epi64(__m512i s, __mmask8 k, void * a);

VPEXPANDQ __m512i _mm512_maskz_expandloadu_epi64( __mmask8 k, void * a);

VPEXPANDQ __m512i _mm512_mask_expand_epi64(__m512i s, __mmask8 k, __m512i a);

VPEXPANDQ __m512i _mm512_maskz_expand_epi64( __mmask8 k, __m512i a);

VPEXPANDQ __m256i _mm256_mask_expandloadu_epi64(__m256i s, __mmask8 k, void * a);

VPEXPANDQ __m256i _mm256_maskz_expandloadu_epi64( __mmask8 k, void * a);

VPEXPANDQ __m256i _mm256_mask_expand_epi64(__m256i s, __mmask8 k, __m256i a);

VPEXPANDQ __m256i _mm256_maskz_expand_epi64( __mmask8 k, __m256i a);

VPEXPANDQ __m128i _mm_mask_expandloadu_epi64(__m128i s, __mmask8 k, void * a);

VPEXPANDQ __m128i _mm_maskz_expandloadu_epi64( __mmask8 k, void * a);

VPEXPANDQ __m128i _mm_mask_expand_epi64(__m128i s, __mmask8 k, __m128i a);

VPEXPANDQ __m128i _mm_maskz_expand_epi64( __mmask8 k, __m128i a);

SIMD Floating-Point Exceptions ¶

None

Other Exceptions ¶

EVEX-encoded instruction, see Exceptions Type E4.nb.