SQRTPD - Square Root of Double Precision Floating-Point Values

Opcode/ Instruction

Op / En

64/32 bit Mode Support

CPUID Feature Flag

Description

66 0F 51 /r SQRTPD xmm1, xmm2/m128

A

V/V

SSE2

Computes Square Roots of the packed double precision floating-point values in xmm2/m128 and stores the result in xmm1.

VEX.128.66.0F.WIG 51 /r VSQRTPD xmm1, xmm2/m128

A

V/V

AVX

Computes Square Roots of the packed double precision floating-point values in xmm2/m128 and stores the result in xmm1.

VEX.256.66.0F.WIG 51 /r VSQRTPD ymm1, ymm2/m256

A

V/V

AVX

Computes Square Roots of the packed double precision floating-point values in ymm2/m256 and stores the result in ymm1.

EVEX.128.66.0F.W1 51 /r VSQRTPD xmm1 {k1}{z}, xmm2/m128/m64bcst

B

V/V

AVX512VL AVX512F

Computes Square Roots of the packed double precision floating-point values in xmm2/m128/m64bcst and stores the result in xmm1 subject to writemask k1.

EVEX.256.66.0F.W1 51 /r VSQRTPD ymm1 {k1}{z}, ymm2/m256/m64bcst

B

V/V

AVX512VL AVX512F

Computes Square Roots of the packed double precision floating-point values in ymm2/m256/m64bcst and stores the result in ymm1 subject to writemask k1.

EVEX.512.66.0F.W1 51 /r VSQRTPD zmm1 {k1}{z}, zmm2/m512/m64bcst{er}

B

V/V

AVX512F

Computes Square Roots of the packed double precision floating-point values in zmm2/m512/m64bcst and stores the result in zmm1 subject to writemask k1.

Instruction Operand Encoding

Op/En

Tuple Type

Operand 1

Operand 2

Operand 3

Operand 4

A

N/A

ModRM:reg (w)

ModRM:r/m (r)

N/A

N/A

B

Full

ModRM:reg (w)

ModRM:r/m (r)

N/A

N/A

Description

Performs a SIMD computation of the square roots of the two, four or eight packed double precision floating-point values in the source operand (the second operand) stores the packed double precision floating-point results in the destination operand (the first operand).

EVEX encoded versions: The source operand is 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 destination operand is a ZMM/YMM/XMM register updated according to the writemask.

VEX.256 encoded version: The source operand is a YMM register or a 256-bit memory location. The destination operand is a YMM register. The upper bits (MAXVL-1:256) of the corresponding ZMM register destination are zeroed.

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

128-bit Legacy SSE version: The second source can be an XMM register or 128-bit memory location. The destina- tion is not distinct from the first source XMM register and the upper bits (MAXVL-1:128) of the corresponding ZMM register destination are unmodified.

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

Operation

VSQRTPD (EVEX Encoded Versions) 

(KL, VL) = (2, 128), (4, 256), (8, 512)
IF (VL = 512) AND (EVEX.b = 1) AND (SRC *is register*)
   THEN
       SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(EVEX.RC);
   ELSE 
       SET_ROUNDING_MODE_FOR_THIS_INSTRUCTION(MXCSR.RC);
FI;
FOR j := 0 TO KL-1
   i := j * 64
   IF k1[j] OR *no writemask* THEN
            IF (EVEX.b = 1) AND (SRC *is memory*)
                THEN DEST[i+63:i] := SQRT(SRC[63:0])
                ELSE DEST[i+63:i] := SQRT(SRC[i+63:i])
            FI;
       ELSE 
            IF *merging-masking*                ; merging-masking
                THEN *DEST[i+63:i] remains unchanged*
                ELSE                            ; zeroing-masking
                     DEST[i+63:i] := 0
            FI
   FI;
ENDFOR
DEST[MAXVL-1:VL] := 0

VSQRTPD (VEX.256 Encoded Version) 

DEST[63:0] := SQRT(SRC[63:0])
DEST[127:64] := SQRT(SRC[127:64])
DEST[191:128] := SQRT(SRC[191:128])
DEST[255:192] := SQRT(SRC[255:192])
DEST[MAXVL-1:256] := 0
.
 VSQRTPD (VEX.128 Encoded Version)
DEST[63:0] := SQRT(SRC[63:0])
DEST[127:64] := SQRT(SRC[127:64])
DEST[MAXVL-1:128] := 0

SQRTPD (128-bit Legacy SSE Version) 

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

Intel C/C++ Compiler Intrinsic Equivalent 

VSQRTPD __m512d _mm512_sqrt_round_pd(__m512d a, int r);
VSQRTPD __m512d _mm512_mask_sqrt_round_pd(__m512d s, __mmask8 k, __m512d a, int r);
VSQRTPD __m512d _mm512_maskz_sqrt_round_pd( __mmask8 k, __m512d a, int r);
VSQRTPD __m256d _mm256_sqrt_pd (__m256d a);
VSQRTPD __m256d _mm256_mask_sqrt_pd(__m256d s, __mmask8 k, __m256d a, int r);
VSQRTPD __m256d _mm256_maskz_sqrt_pd( __mmask8 k, __m256d a, int r);
SQRTPD __m128d _mm_sqrt_pd (__m128d a);
VSQRTPD __m128d _mm_mask_sqrt_pd(__m128d s, __mmask8 k, __m128d a, int r);
VSQRTPD __m128d _mm_maskz_sqrt_pd( __mmask8 k, __m128d a, int r);

SIMD Floating-Point Exceptions

Invalid, Precision, Denormal.

Other Exceptions

Non-EVEX-encoded instruction, see Table 2-19, "Type 2 Class Exception Conditions," additionally:

#UD

If VEX.vvvv != 1111B.

EVEX-encoded instruction, see Table 2-46, "Type E2 Class Exception Conditions," additionally:

#UD

If EVEX.vvvv != 1111B.