# VCVTTSD2USI — Convert With Truncation Scalar Double Precision Floating-Point Value toUnsigned Integer

Opcode/Instruction | Op/En | 64/32 Bit Mode Support | CPUID Feature Flag | Description
--- | --- | --- | --- | ---
EVEX.LLIG.F2.0F.W0 78 /r VCVTTSD2USI r32, xmm1/m64{sae} | A | V/V | AVX512F | Convert one double precision floating-point value from xmm1/m64 to one unsigned doubleword integer r32 using truncation.
EVEX.LLIG.F2.0F.W1 78 /r VCVTTSD2USI r64, xmm1/m64{sae} | A | V/N.E.1 | AVX512F | Convert one double precision floating-point value from xmm1/m64 to one unsigned quadword integer zero-extended into r64 using truncation.

> 1. For this specific instruction, EVEX.W in non-64 bit is ignored; the instruction behaves as if the W0 version is used.

## Instruction Operand Encoding ¶

Op/En | Tuple Type | Operand 1 | Operand 2 | Operand 3 | Operand 4
--- | --- | --- | --- | --- | ---
A | Tuple1 Fixed | ModRM:reg (w) | ModRM:r/m (r) | N/A | N/A

### Description ¶

Converts with truncation a double precision floating-point value in the source operand (the second operand) to an unsigned doubleword integer (or unsigned quadword integer if operand size is 64 bits) in the destination operand (the first operand). The source operand can be an XMM register or a 64-bit memory location. The destination operand is a general-purpose register. When the source operand is an XMM register, the double precision floating-point value is contained in the low quadword of the register.

When a conversion is inexact, a truncated (round toward zero) value is returned. If a converted result cannot be represented in the destination format, the floating-point invalid exception is raised, and if this exception is masked, the integer value 2w – 1 is returned, where w represents the number of bits in the destination format.

EVEX.W1 version: promotes the instruction to produce 64-bit data in 64-bit mode.

### Operation ¶

#### VCVTTSD2USI (EVEX Encoded Version) ¶

    IF 64-Bit Mode and OperandSize = 64
        THEN DEST[63:0] := Convert_Double_Precision_Floating_Point_To_UInteger_Truncate(SRC[63:0]);
        ELSE DEST[31:0] := Convert_Double_Precision_Floating_Point_To_UInteger_Truncate(SRC[63:0]);
    FI

### Intel C/C++ Compiler Intrinsic Equivalent ¶

    VCVTTSD2USI unsigned int _mm_cvttsd_u32(__m128d);

    VCVTTSD2USI unsigned int _mm_cvtt_roundsd_u32(__m128d, int sae);

    VCVTTSD2USI unsigned __int64 _mm_cvttsd_u64(__m128d);

    VCVTTSD2USI unsigned __int64 _mm_cvtt_roundsd_u64(__m128d, int sae);

### SIMD Floating-Point Exceptions ¶

Invalid, Precision.

### Other Exceptions ¶

EVEX-encoded instructions, see Table 2-48, “Type E3NF Class Exception Conditions.”