VCVTSH2SD

VCVTSH2SD — Convert Low FP16 Value to an FP64 Value

Opcode/ Instruction	Op/ En	64/32 Bit Mode Support	CPUID Feature Flag	Description
EVEX.LLIG.F3.MAP5.W0 5A /r VCVTSH2SD xmm1{k1}{z}, xmm2, xmm3/m16 {sae}	AV/V		AVX512_FP16 OR AVX10.1	Convert the low FP16 value in xmm3/m16 to an FP64 value and store the result in the low element of xmm1 subject to writemask k1. Bits 127:64 of xmm2 are copied to xmm1[127:64].

Instruction Operand Encoding

Op/En	Tuple	Operand 1	Operand 2	Operand 3	Operand 4
A	Scalar	ModRM:reg (w)	VEX.vvvv (r)	ModRM:r/m (r)	N/A

Description

This instruction converts the low FP16 element in the second source operand to a FP64 element in the low element of the destination operand.

Bits 127:64 of the destination operand are copied from the corresponding bits of the first source operand. Bits

to the writemask.

Operation

VCVTSH2SD dest, src1, src2

IF k1[0] OR *no writemask*:
    DEST.fp64[0] ← Convert_fp16_to_fp64(SRC2.fp16[0])
ELSE IF *zeroing*:
    DEST.fp64[0] ← 0
// else dest.fp64[0] remains unchanged
DEST[127:64] ← SRC1[127:64]

Intel C/C++ Compiler Intrinsic Equivalent

VCVTSH2SD __m128d _mm_cvt_roundsh_sd (__m128d a, __m128h b, const int sae);
VCVTSH2SD __m128d _mm_mask_cvt_roundsh_sd (__m128d src, __mmask8 k, __m128d a, __m128h b, const int sae);
VCVTSH2SD __m128d _mm_maskz_cvt_roundsh_sd (__mmask8 k, __m128d a, __m128h b, const int sae);
VCVTSH2SD __m128d _mm_cvtsh_sd (__m128d a, __m128h b);
VCVTSH2SD __m128d _mm_mask_cvtsh_sd (__m128d src, __mmask8 k, __m128d a, __m128h b);
VCVTSH2SD __m128d _mm_maskz_cvtsh_sd (__mmask8 k, __m128d a, __m128h b);

SIMD Floating-Point Exceptions

Invalid, Denormal.

Other Exceptions

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Source: Intel® 64 and IA-32 Architectures Software Developer's Manual, Combined Volumes (Order Number 325462-091US, March 2026)
Generated: 7-6-2026