모두의 코드
CVTPI2PS (Intel x86/64 assembly instruction)

작성일 : 2020-09-01 이 글은 756 번 읽혔습니다.

CVTPI2PS

Convert Packed Dword Integers to Packed Single-Precision FP Values

참고 사항

아래 표를 해석하는 방법은 x86-64 명령어 레퍼런스 읽는 법 글을 참조하시기 바랍니다.

Opcode/
Instruction

Op/
En

64-Bit
Mode

Compat/
Leg Mode

Description

0F 2A /r
CVTPI2PS xmm mm/m64

RM

Valid

Valid

Convert two signed doubleword integers from mm/m64 to two single-precision floating-point values in xmm.

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

The source operand can be an MMX technology register or a 64-bit memory location. The destination operand is an XMM register. The results are stored in the low quadword of the destination operand, and the high quadword remains unchanged. When a conversion is inexact, the value returned is rounded according to the rounding control bits in the MXCSR register.

This instruction causes a transition from x87 FPU to MMX technology operation (that is, the x87 FPU top-of-stack pointer is set to 0 and the x87 FPU tag word is set to all 0s [valid]). If this instruction is executed while an x87 FPU floating-point exception is pending, the exception is handled before the CVTPI2PS instruction is executed.

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

Operation

DEST[31:0] <- Convert_Integer_To_Single_Precision_Floating_Point(SRC[31:0]);
DEST[63:32] <- Convert_Integer_To_Single_Precision_Floating_Point(SRC[63:32]);
(* High quadword of destination unchanged *)

Intel C/C++ Compiler Intrinsic Equivalent

CVTPI2PS : __m128 _mm_cvtpi32_ps(__m128 a, __m64 b)

SIMD Floating-Point Exceptions

Precision

Other Exceptions

See Table 22-5, "Exception Conditions for Legacy SIMD/MMX Instructions with XMM and FP Exception," in the Intel(R) 64 and IA-32 Architectures Software Developer's Manual, Volume 3B.

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