VBLENDMPD/VBLENDMPS — Blend Float64/Float32 Vectors Using an OpMask Control

Instruction Operand Encoding ¶

Description ¶

Performs an element-by-element blending between float64/float32 elements in the first source operand (the second operand) with the elements in the second source operand (the third operand) using an opmask register as select control. The blended result is written to the destination register.

The destination and first source operands are ZMM/YMM/XMM registers. The second source operand can be a ZMM/YMM/XMM register, a 512/256/128-bit memory location or a 512/256/128-bit vector broadcasted from a 64-bit memory location.

The opmask register is not used as a writemask for this instruction. Instead, the mask is used as an element selector: every element of the destination is conditionally selected between first source or second source using the value of the related mask bit (0 for first source operand, 1 for second source operand).

If EVEX.z is set, the elements with corresponding mask bit value of 0 in the destination operand are zeroed.

Operation ¶

VBLENDMPD (EVEX encoded versions) ¶

(KL, VL) = (2, 128), (4, 256), (8, 512)
FOR j←0 TO KL-1
    i←j * 64
    IF k1[j] OR *no controlmask*
        THEN
            IF (EVEX.b = 1) AND (SRC2 *is memory*)
                THEN
                    DEST[i+63:i] ← SRC2[63:0]
                ELSE
                    DEST[i+63:i] ← SRC2[i+63:i]
            FI;
        ELSE
            IF *merging-masking*
                THEN DEST[i+63:i]←SRC1[i+63:i]
                ELSE ; zeroing-masking
                    DEST[i+63:i] ← 0
            FI;
    FI;
ENDFOR
DEST[MAXVL-1:VL] ← 0

VBLENDMPS (EVEX encoded versions) ¶

(KL, VL) = (4, 128), (8, 256), (16, 512)
FOR j←0 TO KL-1
    i←j * 32
    IF k1[j] OR *no controlmask*
        THEN
            IF (EVEX.b = 1) AND (SRC2 *is memory*)
                THEN
                    DEST[i+31:i] ← SRC2[31:0]
                ELSE
                    DEST[i+31:i] ← SRC2[i+31:i]
            FI;
        ELSE
            IF *merging-masking*
                        ; merging-masking
                THEN DEST[i+31:i]←SRC1[i+31:i]
                ELSE
                        ; zeroing-masking
                    DEST[i+31:i] ← 0
            FI;
    FI;
ENDFOR
DEST[MAXVL-1:VL] ← 0

Intel C/C++ Compiler Intrinsic Equivalent ¶

VBLENDMPD __m512d _mm512_mask_blend_pd(__mmask8 k, __m512d a, __m512d b);

VBLENDMPD __m256d _mm256_mask_blend_pd(__mmask8 k, __m256d a, __m256d b);

VBLENDMPD __m128d _mm_mask_blend_pd(__mmask8 k, __m128d a, __m128d b);

VBLENDMPS __m512 _mm512_mask_blend_ps(__mmask16 k, __m512 a, __m512 b);

VBLENDMPS __m256 _mm256_mask_blend_ps(__mmask8 k, __m256 a, __m256 b);

VBLENDMPS __m128 _mm_mask_blend_ps(__mmask8 k, __m128 a, __m128 b);

SIMD Floating-Point Exceptions ¶

None

Other Exceptions ¶

See Exceptions Type E4.