# CVTSI2SD (Convert Dword Integer to Scalar Double-Precision FP Value)

## Opcodes

Opcode/Instruction | Op/En | 64/32-bit Mode | CPUID Feature Flag | Description |
---|---|---|---|---|

F2 0F 2A /r
CVTSI2SD xmm, r/m32 |
RM | V/V | SSE2 | Convert one signed doubleword integer from r/m32 to one double-precision floating-point value in xmm. |

F2 REX.W 0F 2A /r
CVTSI2SD xmm, r/m64 |
RM | V/N.E. | SSE2 | Convert one signed quadword integer from r/m64 to one double-precision floating-point value in xmm. |

VEX.NDS.LIG.F2.0F.W0 2A /r VCVTSI2SD xmm1, xmm2, r/m32 | RVM | V/V | AVX | Convert one signed doubleword integer from r/m32 to one double-precision floating-point value in xmm1. |

VEX.NDS.LIG.F2.0F.W1 2A /r VCVTSI2SD xmm1, xmm2, r/m64 | RVM | V/N.E.^{1} |
AVX | Convert one signed quadword integer from r/m64 to one double-precision floating-point value in xmm1. |

**NOTES:**

1. Encoding the VEX prefix with VEX.W=1 in non-64-bit mode is ignored.

## Instruction Operand Encoding

Op/En | Operand 1 | Operand 2 | Operand 3 | Operand 4 |
---|---|---|---|---|

RM | ModRM:reg (w) | ModRM:r/m (r) | NA | NA |

RVM | ModRM:reg (w) | VEX.vvvv (r) | ModRM:r/m (r) | NA |

## Description

Converts a signed doubleword integer (or signed quadword integer if operand size is 64 bits) in the second source operand to a double-precision floating-point value in the destination operand. The result is stored in the low quad-word of the destination operand, and the high quadword left unchanged. When conversion is inexact, the value returned is rounded according to the rounding control bits in the MXCSR register.

Legacy SSE instructions: Use of the REX.W prefix promotes the instruction to 64-bit operands. See the summary chart at the beginning of this section for encoding data and limits.

The second source operand can be a general-purpose register or a 32/64-bit memory location. The first source and destination operands are XMM registers.

128-bit Legacy SSE version: The destination and first source operand are the same. Bits (VLMAX-1:64) of the corresponding YMM destination register remain unchanged.

VEX.128 encoded version: Bits (127:64) of the XMM register destination are copied from corresponding bits in the first source operand. Bits (VLMAX-1:128) of the destination YMM register are zeroed.

## Operation

**CVTSI2SD**

IF 64-Bit Mode And OperandSize = 64 THEN DEST[63:0] ← Convert_Integer_To_Double_Precision_Floating_Point(SRC[63:0]); ELSE DEST[63:0] ← Convert_Integer_To_Double_Precision_Floating_Point(SRC[31:0]); FI; DEST[VLMAX-1:64] (Unmodified)

**VCVTSI2SD**

IF 64-Bit Mode And OperandSize = 64 THEN DEST[63:0] ← Convert_Integer_To_Double_Precision_Floating_Point(SRC2[63:0]); ELSE DEST[63:0] ← Convert_Integer_To_Double_Precision_Floating_Point(SRC2[31:0]); FI; DEST[127:64] ← SRC1[127:64] DEST[VLMAX-1:128] ← 0

## Intel C/C++ Compiler Intrinsic Equivalent

CVTSI2SD:

__m128d _mm_cvtsi32_sd(__m128d a, int b)

CVTSI2SD:

__m128d _mm_cvtsi64_sd(__m128d a, __int64 b)

## SIMD Floating-Point Exceptions

Precision.

## Other Exceptions

See Exceptions Type 3.