# CVTTPD2DQ (Convert with Truncation Packed Double-Precision FP Values to Packed Dword Integers)

## Opcodes

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

66 0F E6 /r
CVTTPD2DQ xmm1, xmm2/m128 |
RM | V/V | SSE2 | Convert two packed double-precision floating-point values from xmm2/m128 to two packed signed doubleword integers in xmm1 using truncation. |

VEX.128.66.0F.WIG E6 /r VCVTTPD2DQ xmm1, xmm2/m128 | RM | V/V | AVX | Convert two packed double-precision floating-point values in xmm2/mem to two signed doubleword integers in xmm1 using truncation. |

VEX.256.66.0F.WIG E6 /r VCVTTPD2DQ xmm1, ymm2/m256 | RM | V/V | AVX | Convert four packed double-precision floating-point values in ymm2/mem to four signed doubleword integers in xmm1 using truncation. |

## Instruction Operand Encoding

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

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

## Description

Converts two or four packed double-precision floating-point values in the source operand (second operand) to two or four packed signed doubleword integers in the destination operand (first operand).

When a conversion is inexact, a truncated (round toward zero) value is returned.If a converted result is larger than the maximum signed doubleword integer, the floating-point invalid exception is raised, and if this exception is masked, the indefinite integer value (80000000H) is returned.

In 64-bit mode, use of the REX.R prefix permits this instruction to access additional registers (XMM8-XMM15).

128-bit Legacy SSE version: The source operand is an XMM register or 128- bit memory location. The destination operation is an XMM register. The upper bits (VLMAX-1:128) of the corresponding YMM register destination are unmodified.

VEX.128 encoded version: The source operand is an XMM register or 128- bit memory location. The destination operation is a YMM register. The upper bits (VLMAX-1:128) of the corresponding YMM register destination are zeroed.

VEX.256 encoded version: The source operand is a YMM register or 256- bit memory location. The destination operation is an XMM register. The upper bits (255:128) of the corresponding YMM register destination are zeroed.

Note: In VEX-encoded versions, VEX.vvvv is reserved and must be 1111b, otherwise instructions will #UD.

SRC

X3

X0

DEST

0

X3

X2

X1

X0

## Figure 3-14. VCVTTPD2DQ (VEX.256 encoded version)

## Operation

**CVTTPD2DQ (128-bit Legacy SSE version)**

DEST[31:0] ← Convert_Double_Precision_Floating_Point_To_Integer_Truncate(SRC[63:0]) DEST[63:32] ← Convert_Double_Precision_Floating_Point_To_Integer_Truncate(SRC[127:64]) DEST[127:64] ← 0 DEST[VLMAX-1:128] (unmodified)

**VCVTTPD2DQ (VEX.128 encoded version)**

DEST[31:0] ← Convert_Double_Precision_Floating_Point_To_Integer_Truncate(SRC[63:0]) DEST[63:32] ← Convert_Double_Precision_Floating_Point_To_Integer_Truncate(SRC[127:64]) DEST[VLMAX-1:64] ← 0

**VCVTTPD2DQ (VEX.256 encoded version)**

DEST[31:0] ← Convert_Double_Precision_Floating_Point_To_Integer_Truncate(SRC[63:0]) DEST[63:32] ← Convert_Double_Precision_Floating_Point_To_Integer_Truncate(SRC[127:64]) DEST[95:64] ← Convert_Double_Precision_Floating_Point_To_Integer_Truncate(SRC[191:128]) DEST[127:96] ← Convert_Double_Precision_Floating_Point_To_Integer_Truncate(SRC[255:192) DEST[255:128]← 0

## Intel C/C++ Compiler Intrinsic Equivalent

CVTTPD2DQ:

__m128i _mm_cvttpd_epi32(__m128d a)

VCVTTPD2DQ:

__m128i _mm256_cvttpd_epi32 (__m256d src)

## SIMD Floating-Point Exceptions

Invalid, Precision.

## Other Exceptions

See Exceptions Type 2; additionally

#UD | If VEX.vvvv ≠ 1111B. |
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