CVTPI2PS

Convert Packed Dword Integers to Packed Single-Precision FP Values

Opcodes

Hex Mnemonic Encoding Long Mode Legacy Mode Description
0F 2A /r CVTPI2PS xmm, mm/m64 A 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 0 Operand 1 Operand 2 Operand 3
A NA NA ModRM:r/m (r) ModRM:reg (w)

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 quad-word 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).

Pseudo Code

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 *)

Exceptions

SIMD Floating-Point Exceptions

Precision.

64-Bit Mode Exceptions

Exception Description
#AC(0) If alignment checking is enabled and an unaligned memory reference is made while the current privilege level is 3.
#UD If an unmasked SIMD floating-point exception and CR4.OSXM MEXCPT[bit 10] = 0. If CR0.EM[bit 2] = 1. If CR4.OSFXSR[bit 9] = 0. If CPUID.01H:EDX.SSE[bit 25] = 0. If the LOCK prefix is used.
#XM If an unmasked SIMD floating-point exception and CR4.OSXM MEXCPT[bit 10] = 1.
#MF If there is a pending x87 FPU exception.
#NM If CR0.TS[bit 3] = 1.
#PF(fault-code) For a page fault.
#GP(0) If the memory address is in a non-canonical form.
#SS(0) If a memory address referencing the SS segment is in a non- canonical form.

Compatibility Mode Exceptions

Same exceptions as in protected mode.

Virtual-8086 Mode Exceptions

Exception Description
#AC(0) If alignment checking is enabled and an unaligned memory reference is made.
#PF(fault-code) For a page fault.
Same exceptions as in real address mode.

Real-Address Mode Exceptions

Exception Description
#UD If an unmasked SIMD floating-point exception and CR4.OSXMMEXCPT[bit 10] = 0. If CR0.EM[bit 2] = 1. If CR4.OSFXSR[bit 9] = 0. If CPUID.01H:EDX.SSE[bit 25] = 0. If the LOCK prefix is used.
#XM If an unmasked SIMD floating-point exception and CR4.OSXMMEXCPT[bit 10] = 1.
#MF If there is a pending x87 FPU exception.
#NM If CR0.TS[bit 3] = 1.
#GP If any part of the operand lies outside the effective address space from 0 to FFFFH.

Protected Mode Exceptions

Exception Description
#AC(0) If alignment checking is enabled and an unaligned memory reference is made while the current privilege level is 3.
#UD If an unmasked SIMD floating-point exception and CR4.OSXM MEXCPT[bit 10] = 0. If CR0.EM[bit 2] = 1. If CR4.OSFXSR[bit 9] = 0. If CPUID.01H:EDX.SSE[bit 25] = 0. If the LOCK prefix is used.
#XM If an unmasked SIMD floating-point exception and CR4.OSXM MEXCPT[bit 10] = 1.
#MF If there is a pending x87 FPU exception.
#NM If CR0.TS[bit 3] = 1.
#PF(fault-code) For a page fault.
#SS(0) For an illegal address in the SS segment.
#GP(0) For an illegal memory operand effective address in the CS, DS, ES, FS or GS segments.