UNPCKLPD — Unpack and Interleave Low Packed Double Precision Floating-Point Values

Instruction Operand Encoding ¶

Description ¶

Performs an interleaved unpack of the low double precision floating-point values from the first source operand and the second source operand.

128-bit Legacy SSE version: The second source can be an XMM register or an 128-bit memory location. The destination is not distinct from the first source XMM register and the upper bits (MAXVL-1:128) of the corresponding ZMM register destination are unmodified. When unpacking from a memory operand, an implementation may fetch only the appropriate 64 bits; however, alignment to 16-byte boundary and normal segment checking will still be enforced.

VEX.128 encoded version: The first source operand is a XMM register. The second source operand can be a XMM register or a 128-bit memory location. The destination operand is a XMM register. The upper bits (MAXVL-1:128) of the corresponding ZMM register destination are zeroed.

VEX.256 encoded version: The first source operand is a YMM register. The second source operand can be a YMM register or a 256-bit memory location. The destination operand is a YMM register.

EVEX.512 encoded version: The first source operand is a ZMM register. The second source operand is a ZMM register, a 512-bit memory location, or a 512-bit vector broadcasted from a 64-bit memory location. The destination operand is a ZMM register, conditionally updated using writemask k1.

EVEX.256 encoded version: The first source operand is a YMM register. The second source operand is a YMM register, a 256-bit memory location, or a 256-bit vector broadcasted from a 64-bit memory location. The destination operand is a YMM register, conditionally updated using writemask k1.

EVEX.128 encoded version: The first source operand is an XMM register. The second source operand is a XMM register, a 128-bit memory location, or a 128-bit vector broadcasted from a 64-bit memory location. The destination operand is a XMM register, conditionally updated using writemask k1.

Operation ¶

VUNPCKLPD (EVEX Encoded Versions When SRC2 is a Register) ¶

(KL, VL) = (2, 128), (4, 256), (8, 512)
IF VL >= 128
    TMP_DEST[63:0] := SRC1[63:0]
    TMP_DEST[127:64] := SRC2[63:0]
FI;
IF VL >= 256
    TMP_DEST[191:128] := SRC1[191:128]
    TMP_DEST[255:192] := SRC2[191:128]
FI;
IF VL >= 512
    TMP_DEST[319:256] := SRC1[319:256]
    TMP_DEST[383:320] := SRC2[319:256]
    TMP_DEST[447:384] := SRC1[447:384]
    TMP_DEST[511:448] := SRC2[447:384]
FI;
FOR j := 0 TO KL-1
    i := j * 64
    IF k1[j] OR *no writemask*
        THEN DEST[i+63:i] := TMP_DEST[i+63:i]
        ELSE
            IF *merging-masking*
                        ; merging-masking
                THEN *DEST[i+63:i] remains unchanged*
                ELSE *zeroing-masking*
                            ; zeroing-masking
                    DEST[i+63:i] := 0
            FI
    FI;
ENDFOR
DEST[MAXVL-1:VL] := 0

VUNPCKLPD (EVEX Encoded Version When SRC2 is Memory) ¶

(KL, VL) = (2, 128), (4, 256), (8, 512)
FOR j := 0 TO KL-1
    i := j * 64
    IF (EVEX.b = 1)
        THEN TMP_SRC2[i+63:i] := SRC2[63:0]
        ELSE TMP_SRC2[i+63:i] := SRC2[i+63:i]
    FI;
ENDFOR;
IF VL >= 128
    TMP_DEST[63:0] := SRC1[63:0]
    TMP_DEST[127:64] := TMP_SRC2[63:0]
FI;
IF VL >= 256
    TMP_DEST[191:128] := SRC1[191:128]
    TMP_DEST[255:192] := TMP_SRC2[191:128]
FI;
IF VL >= 512
    TMP_DEST[319:256] := SRC1[319:256]
    TMP_DEST[383:320] := TMP_SRC2[319:256]
    TMP_DEST[447:384] := SRC1[447:384]
    TMP_DEST[511:448] := TMP_SRC2[447:384]
FI;
FOR j := 0 TO KL-1
    i := j * 64
    IF k1[j] OR *no writemask*
        THEN DEST[i+63:i] := TMP_DEST[i+63:i]
        ELSE
            IF *merging-masking*
                        ; merging-masking
                THEN *DEST[i+63:i] remains unchanged*
                ELSE *zeroing-masking*
                            ; zeroing-masking
                    DEST[i+63:i] := 0
            FI
    FI;
ENDFOR
DEST[MAXVL-1:VL] := 0

VUNPCKLPD (VEX.256 Encoded Version) ¶

DEST[63:0] := SRC1[63:0]
DEST[127:64] := SRC2[63:0]
DEST[191:128] := SRC1[191:128]
DEST[255:192] := SRC2[191:128]
DEST[MAXVL-1:256] := 0

VUNPCKLPD (VEX.128 Encoded Version) ¶

DEST[63:0] := SRC1[63:0]
DEST[127:64] := SRC2[63:0]
DEST[MAXVL-1:128] := 0

UNPCKLPD (128-bit Legacy SSE Version) ¶

DEST[63:0] := SRC1[63:0]
DEST[127:64] := SRC2[63:0]
DEST[MAXVL-1:128] (Unmodified)

Intel C/C++ Compiler Intrinsic Equivalent ¶

VUNPCKLPD __m512d _mm512_unpacklo_pd( __m512d a, __m512d b);

VUNPCKLPD __m512d _mm512_mask_unpacklo_pd(__m512d s, __mmask8 k, __m512d a, __m512d b);

VUNPCKLPD __m512d _mm512_maskz_unpacklo_pd(__mmask8 k, __m512d a, __m512d b);

VUNPCKLPD __m256d _mm256_unpacklo_pd(__m256d a, __m256d b)

VUNPCKLPD __m256d _mm256_mask_unpacklo_pd(__m256d s, __mmask8 k, __m256d a, __m256d b);

VUNPCKLPD __m256d _mm256_maskz_unpacklo_pd(__mmask8 k, __m256d a, __m256d b);

UNPCKLPD __m128d _mm_unpacklo_pd(__m128d a, __m128d b)

VUNPCKLPD __m128d _mm_mask_unpacklo_pd(__m128d s, __mmask8 k, __m128d a, __m128d b);

VUNPCKLPD __m128d _mm_maskz_unpacklo_pd(__mmask8 k, __m128d a, __m128d b);

SIMD Floating-Point Exceptions ¶

None.

Other Exceptions ¶

Non-EVEX-encoded instructions, see Table 2-21, “Type 4 Class Exception Conditions.”

EVEX-encoded instructions, see Table 2-50, “Type E4NF Class Exception Conditions.”