CVTTPD2DQ—Convert with Truncation Packed Double-Precision FP Values to Packed Dword Integers

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.

X2 X1

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.