VCVTTSS2USI — Convert with Truncation Scalar Single Precision Floating-Point Value to Unsigned Integer

NOTES:

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

Converts with truncation a single 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 memory location. The destination operand is a general-purpose register. When the source operand is an XMM register, the single precision floating-point value is contained in the low doubleword of the register.

When a conversion is inexact, a truncated (round toward zero) value is returned.

If a converted result exceeds the range limits of signed doubleword integer (in non-64-bit modes or 64-bit mode with REX.W/VEX.W/EVEX.W=0), the floating-point invalid exception is raised, and if this exception is masked, the integer value FFFFFFFFH is returned.

If a converted result exceeds the range limits of signed quadword integer (in 64-bit mode and REX.W/VEX.W/EVEX.W = 1), the floating-point invalid exception is raised, and if this exception is masked, the integer value FFFFFFFF_FFFFFFFFH is returned.

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

Note: EVEX.vvvv is reserved and must be 1111b, otherwise instructions will #UD.

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

VCVTTSS2USI unsigned int _mm_cvttss_u32( __m128 a);
VCVTTSS2USI unsigned int _mm_cvtt_roundss_u32( __m128 a, int sae);
VCVTTSS2USI unsigned __int64 _mm_cvttss_u64( __m128 a);
VCVTTSS2USI unsigned __int64 _mm_cvtt_roundss_u64( __m128 a, int sae);

Invalid, Precision.

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