CVTTPS2DQ—Convert with Truncation Packed Single-Precision FP Values to Packed Dword Integers

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

F3 0F 5B /r

CVTTPS2DQ xmm1, xmm2/m128

 RM V/V SSE2 Convert four single-precision floating-point values from xmm2/m128 to four signed doubleword integers in xmm1 using truncation.

VEX.128.F3.0F.WIG 5B /r

VCVTTPS2DQ xmm1, xmm2/m128

 RM V/V AVX Convert four packed single precision floating-point values from xmm2/mem to four packed signed doubleword values in xmm1 using truncation.

VEX.256.F3.0F.WIG 5B /r

VCVTTPS2DQ ymm1, ymm2/m256

 RM V/V AVX Convert eight packed single precision floating-point values from ymm2/mem to eight packed signed doubleword values in ymm1 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 four or eight packed single-precision floating-point values in the source operand to four or eight signed doubleword integers in the destination 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 a YMM register.

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

Operation

CVTTPS2DQ (128-bit Legacy SSE version)

DEST[31:0] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[31:0])
DEST[63:32] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[63:32])
DEST[95:64] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[95:64])
DEST[127:96] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[127:96])
DEST[VLMAX-1:128] (unmodified)

VCVTTPS2DQ (VEX.128 encoded version)

DEST[31:0] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[31:0])
DEST[63:32] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[63:32])
DEST[95:64] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[95:64])
DEST[127:96] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[127:96])
DEST[VLMAX-1:128] ← 0

VCVTTPS2DQ (VEX.256 encoded version)

DEST[31:0] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[31:0])
DEST[63:32] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[63:32])
DEST[95:64] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[95:64])
DEST[127:96] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[127:96)
DEST[159:128] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[159:128])
DEST[191:160] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[191:160])
DEST[223:192] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[223:192])
DEST[255:224] ← Convert_Single_Precision_Floating_Point_To_Integer_Truncate(SRC[255:224])

Intel C/C++ Compiler Intrinsic Equivalent

CVTTPS2DQ:

__m128i _mm_cvttps_epi32(__m128 a)

VCVTTPS2DQ:

__m256i _mm256_cvttps_epi32 (__m256 a)

SIMD Floating-Point Exceptions

Invalid, Precision.

Other Exceptions

See Exceptions Type 2; additionally

#UD If VEX.vvvv ≠ 1111B.