image/svg+xml VEXP2PD—Approximation to the Exponential 2^x of Packed Double-Precision Floating-Point Values with Less Than 2^-23 Relative Error Instruction Operand Encoding Description Computes the approximate base-2 exponential evaluation of the double-precision floating-point values in the source operand (the second operand) and stores the results to the destination operand (the first operand) using the writemask k1. The approximate base-2 exponential is evaluated with less than 2^-23 of relative error. Denormal input values are treated as zeros and do not signal #DE, irrespective of MXCSR.DAZ. Denormal results are flushed to zeros and do not signal #UE, irrespective of MXCSR.FTZ. The 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.vvvv is reserved and must be 1111b otherwise instructions will #UD. A numerically exact implementation of VEXP2xx can be found at https://software.intel.com/en-us/articles/refer- ence-implementations-for-IA-approximation-instructions-vrcp14-vrsqrt14-vrcp28-vrsqrt28-vexp2 . Operation VEXP2PD (KL, VL) = (8, 512) 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] := EXP2_23_DP(SRC[63:0]) ELSE DEST[i+63:i] := EXP2_23_DP(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; Opcode/ Instruction Op / En 64/32 bit Mode Support CPUID Feature Flag Description EVEX.512.66.0F38.W1 C8 /r VEXP2PD zmm1 {k1}{z}, zmm2/m512/m64bcst {sae} AV/VAVX512ERComputes approximations to the exponential 2^x (with less than 2^-23 of maximum relative error) of the packed double- precision floating-point values from zmm2/m512/m64bcst and stores the floating-point result in zmm1with writemask k1. Op/EnTuple TypeOperand 1Operand 2Operand 3Operand 4 AFullModRM:reg (r, w)ModRM:r/m (r)NANA image/svg+xml Intel C/C++ Compiler Intrinsic Equivalent VEXP2PD __m512d _mm512_exp2a23_round_pd (__m512d a, int sae); VEXP2PD __m512d _mm512_mask_exp2a23_round_pd (__m512d a, __mmask8 m, __m512d b, int sae); VEXP2PD __m512d _mm512_maskz_exp2a23_round_pd ( __mmask8 m, __m512d b, int sae); SIMD Floating-Point Exceptions Invalid (if SNaN input), Overflow Other Exceptions See Table2-46, “Type E2 Class Exception Conditions”. Table 6-1. Special Values Behavior Source InputResultComments NaNQNaN(src)If (SRC = SNaN) then #I + ∞ + ∞ +/-01.0f Exact result - ∞ +0.0f Integral value N2^ (N) Exact result This UNOFFICIAL reference was generated from the official Intel® 64 and IA-32 Architectures Software Developer’s Manual by a dumb script. There is no guarantee that some parts aren't mangled or broken and is distributed WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE .