PINSRW (Insert Word)

Opcodes

Opcode/Instruction Op/En 64/32 bit Mode Support CPUID Feature Flag Description
0F C4 /r ib1 PINSRW mm, r32/m16, imm8 RMI V/V SSE Insert the low word from r32 or from m16 into mm at the word position specified by imm8.
66 0F C4 /r ib PINSRW xmm, r32/m16, imm8 RMI V/V SSE2 Move the low word of r32 or from m16 into xmm at the word position specified by imm8.
VEX.NDS.128.66.0F.W0 C4 /r ib VPINSRW xmm1, xmm2, r32/m16, imm8 RVMI V2/V AVX Insert a word integer value from r32/m16 and rest from xmm2 into xmm1 at the word offset in imm8.

NOTES:

1. See note in Section 2.4, “Instruction Exception Specification” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 2A and Section 22.25.3, “Exception Conditions of Legacy SIMD Instructions Operating on MMX Registers” in the Intel® 64 and IA-32 Architectures Software Developer’s Manual, Volume 3A.

2. In 64-bit mode, VEX.W1 is ignored for VPINSRW (similar to legacy REX.W=1 prefix in PINSRW).

Instruction Operand Encoding

Op/En Operand 1 Operand 2 Operand 3 Operand 4
RMI ModRM:reg (w) ModRM:r/m (r) imm8 NA
RVMI ModRM:reg (w) VEX.vvvv (r) ModRM:r/m (r) imm8

Description

Copies a word from the source operand (second operand) and inserts it in the destination operand (first operand) at the location specified with the count operand (third operand). (The other words in the destination register are left untouched.) The source operand can be a general-purpose register or a 16-bit memory location. (When the source operand is a general-purpose register, the low word of the register is copied.) The destination operand can be an MMX technology register or an XMM register. The count operand is an 8-bit immediate. When specifying a word location in an MMX technology register, the 2 least-significant bits of the count operand specify the location; for an XMM register, the 3 least-significant bits specify the location.

In 64-bit mode, using a REX prefix in the form of REX.R permits this instruction to access additional registers (XMM8-XMM15, R8-15).

128-bit Legacy SSE version: Bits (VLMAX-1:128) of the corresponding YMM destination register remain unchanged.

VEX.128 encoded version: Bits (VLMAX-1:128) of the destination YMM register are zeroed. VEX.L must be 0, other-wise the instruction will #UD.

Operation

PINSRW (with 64-bit source operand)

    SEL ← COUNT AND 3H;
         CASE (Determine word position) OF
              SEL ← 0:
                              MASK ← 000000000000FFFFH;
              SEL ← 1:
                              MASK ← 00000000FFFF0000H;
              SEL ← 2:
                              MASK ← 0000FFFF00000000H;
              SEL ← 3:
                              MASK ← FFFF000000000000H;
    DEST ← (DEST AND NOT MASK) OR (((SRC 
 (SEL ∗ 16)) AND MASK);

PINSRW (with 128-bit source operand)

    SEL ← COUNT AND 7H;
         CASE (Determine word position) OF
              SEL ← 0:
                              MASK ← 0000000000000000000000000000FFFFH;
              SEL ← 1:
                              MASK ← 000000000000000000000000FFFF0000H;
              SEL ← 2:
                              MASK ← 00000000000000000000FFFF00000000H;
              SEL ← 3:
                              MASK ← 0000000000000000FFFF000000000000H;
              SEL ← 4:
                              MASK ← 000000000000FFFF0000000000000000H;
              SEL ← 5:
                              MASK ← 00000000FFFF00000000000000000000H;
              SEL ← 6:
                              MASK ← 0000FFFF000000000000000000000000H;
              SEL ← 7:
                              MASK ← FFFF0000000000000000000000000000H;
    DEST ← (DEST AND NOT MASK) OR (((SRC 
 (SEL ∗ 16)) AND MASK);

VPINSRW (VEX.128 encoded version)

SEL ← imm8[2:0]
DEST[127:0] ← write_w_element(SEL, SRC2, SRC1)
DEST[VLMAX-1:128] ← 0

Intel C/C++ Compiler Intrinsic Equivalent

PINSRW:

__m64 _mm_insert_pi16 (__m64 a, int d, int n)

PINSRW:

__m128i _mm_insert_epi16 ( __m128i a, int b, int imm)

Flags Affected

None.

Numeric Exceptions

None.

Other Exceptions

See Exceptions Type 5; additionally

#UD If VEX.L = 1. If VPINSRW in non-64-bit mode with VEX.W=1.