EXTRACTPS - Extract Packed Floating-Point Values

Opcode/ Instruction

Op / En

64/32 bit Mode Support

CPUID Feature Flag

Description

66 0F 3A 17 /r ib EXTRACTPS reg/m32, xmm1, imm8

A

VV

SSE4_1

Extract one single precision floating-point value from xmm1 at the offset specified by imm8 and store the result in reg or m32. Zero extend the results in 64-bit register if applicable.

VEX.128.66.0F3A.WIG 17 /r ib VEXTRACTPS reg/m32, xmm1, imm8

A

V/V

AVX

Extract one single precision floating-point value from xmm1 at the offset specified by imm8 and store the result in reg or m32. Zero extend the results in 64-bit register if applicable.

EVEX.128.66.0F3A.WIG 17 /r ib VEXTRACTPS reg/m32, xmm1, imm8

B

V/V

AVX512F

Extract one single precision floating-point value from xmm1 at the offset specified by imm8 and store the result in reg or m32. Zero extend the results in 64-bit register if applicable.

Instruction Operand Encoding

Op/En

Tuple Type

Operand 1

Operand 2

Operand 3

Operand 4

A

N/A

ModRM:r/m (w)

ModRM:reg (r)

imm8

N/A

B

Tuple1 Scalar

ModRM:r/m (w)

ModRM:reg (r)

imm8

N/A

Description

Extracts a single precision floating-point value from the source operand (second operand) at the 32-bit offset spec- ified from imm8. Immediate bits higher than the most significant offset for the vector length are ignored.

The extracted single precision floating-point value is stored in the low 32-bits of the destination operand

In 64-bit mode, destination register operand has default operand size of 64 bits. The upper 32-bits of the register are filled with zero. REX.W is ignored.

VEX.128 and EVEX encoded version: When VEX.W1 or EVEX.W1 form is used in 64-bit mode with a general purpose register (GPR) as a destination operand, the packed single quantity is zero extended to 64 bits.

VEX.vvvv/EVEX.vvvv is reserved and must be 1111b otherwise instructions will #UD.

128-bit Legacy SSE version: When a REX.W prefix is used in 64-bit mode with a general purpose register (GPR) as a destination operand, the packed single quantity is zero extended to 64 bits.

The source register is an XMM register. Imm8[1:0] determine the starting DWORD offset from which to extract the 32-bit floating-point value.

If VEXTRACTPS is encoded with VEX.L= 1, an attempt to execute the instruction encoded with VEX.L= 1 will cause an #UD exception.

Operation

VEXTRACTPS (EVEX and VEX.128 Encoded Version) 

SRC_OFFSET := IMM8[1:0]
IF (64-Bit Mode and DEST is register)
   DEST[31:0] := (SRC[127:0] >> (SRC_OFFSET*32)) AND 0FFFFFFFFh
   DEST[63:32] := 0
ELSE
   DEST[31:0] := (SRC[127:0] >> (SRC_OFFSET*32)) AND 0FFFFFFFFh
FI

EXTRACTPS (128-bit Legacy SSE Version) 

SRC_OFFSET := IMM8[1:0]
IF (64-Bit Mode and DEST is register)
   DEST[31:0] := (SRC[127:0] >> (SRC_OFFSET*32)) AND 0FFFFFFFFh
   DEST[63:32] := 0
ELSE
   DEST[31:0] := (SRC[127:0] >> (SRC_OFFSET*32)) AND 0FFFFFFFFh
FI

Intel C/C++ Compiler Intrinsic Equivalent 

EXTRACTPS int _mm_extract_ps (__m128 a, const int nidx);

SIMD Floating-Point Exceptions

None.

Other Exceptions

VEX-encoded instructions, see Table 2-22, "Type 5 Class Exception Conditions."

EVEX-encoded instructions, see Table 2-57, "Type E9NF Class Exception Conditions."

Additionally:

#UD

IF VEX.L = 0.

#UD

If VEX.vvvv != 1111B or EVEX.vvvv != 1111B.