PACKUSDW (Pack with Unsigned Saturation)

Opcodes

Opcode/Instruction Op/En 64/32 bit Mode Support CPUID Feature Flag Description
66 0F 38 2B /r PACKUSDW xmm1, xmm2/m128 RM V/V SSE4_1 Convert 4 packed signed doubleword integers from xmm1 and 4 packed signed doubleword integers from xmm2/m128 into 8 packed unsigned word integers in xmm1 using unsigned saturation.
VEX.NDS.128.66.0F38.WIG 2B /r VPACKUSDW xmm1, xmm2, xmm3/m128 RVM V/V AVX Convert 4 packed signed doubleword integers from xmm2 and 4 packed signed doubleword integers from xmm3/m128 into 8 packed unsigned word integers in xmm1 using unsigned saturation.
VEX.NDS.256.66.0F38.WIG 2B /r VPACKUSDW ymm1, ymm2, ymm3/m256 RVM V/V AVX2 Convert 8 packed signed doubleword integers from ymm2 and 8 packed signed doubleword integers from ymm3/m128 into 16 packed unsigned word integers in ymm1 using unsigned saturation.

Instruction Operand Encoding

Op/En Operand 1 Operand 2 Operand 3 Operand 4
RM ModRM:reg (r, w) ModRM:r/m (r) NA NA
RVM ModRM:reg (w) VEX.vvvv (r) ModRM:r/m (r) NA

Description

Converts packed signed doubleword integers into packed unsigned word integers using unsigned saturation to handle overflow conditions. If the signed doubleword value is beyond the range of an unsigned word (that is, greater than FFFFH or less than 0000H), the saturated unsigned word integer value of FFFFH or 0000H, respec-tively, is stored in the destination.

128-bit Legacy SSE version: The first source operand is an XMM register. The second operand can be an XMM register or a 128-bit memory location. The destination is not distinct from the first source XMM register and the upper bits (VLMAX-1:128) of the corresponding YMM register destination are unmodified.

VEX.128 encoded version: The first source operand is an XMM register. The second source operand is an XMM register or 128-bit memory location. The destination operand is an XMM register. The upper bits (VLMAX-1:128) of the corresponding YMM register destination are zeroed.

VEX.256 encoded version: The first source operand is a YMM register. The second source operand is a YMM register or a 256-bit memory location. The destination operand is a YMM register.

Note: VEX.L must be 0, otherwise the instruction will #UD.

Operation

PACKUSDW (Legacy SSE instruction)

TMP[15:0] ← (DEST[31:0] 
 0) ? 0 : DEST[15:0];
DEST[15:0] ← (DEST[31:0] 
 FFFFH) ? FFFFH : TMP[15:0] ;
TMP[31:16] ← (DEST[63:32] 
 0) ? 0 : DEST[47:32];
DEST[31:16] ← (DEST[63:32] 
 FFFFH) ? FFFFH : TMP[31:16] ;
TMP[47:32] ← (DEST[95:64] 
 0) ? 0 : DEST[79:64];
DEST[47:32] ← (DEST[95:64] 
 FFFFH) ? FFFFH : TMP[47:32] ;
TMP[63:48] ← (DEST[127:96] 
 0) ? 0 : DEST[111:96];
DEST[63:48] ← (DEST[127:96] 
 FFFFH) ? FFFFH : TMP[63:48] ;
TMP[79:64] ← (SRC[31:0] 
 0) ? 0 : SRC[15:0];
DEST[63:48] ← (SRC[31:0] 
 FFFFH) ? FFFFH : TMP[79:64] ;
TMP[95:80] ← (SRC[63:32] 
 0) ? 0 : SRC[47:32];
DEST[95:80] ← (SRC[63:32] 
 FFFFH) ? FFFFH : TMP[95:80] ;
TMP[111:96] ← (SRC[95:64] 
 0) ? 0 : SRC[79:64];
DEST[111:96] ← (SRC[95:64] 
 FFFFH) ? FFFFH : TMP[111:96] ;
TMP[127:112] ← (SRC[127:96] 
 0) ? 0 : SRC[111:96];
DEST[127:112] ← (SRC[127:96] 
 FFFFH) ? FFFFH : TMP[127:112] ;

PACKUSDW (VEX.128 encoded version)

TMP[15:0] ← (SRC1[31:0] 
 0) ? 0 : SRC1[15:0];
DEST[15:0] ← (SRC1[31:0] 
 FFFFH) ? FFFFH : TMP[15:0] ;
TMP[31:16] ← (SRC1[63:32] 
 0) ? 0 : SRC1[47:32];
DEST[31:16] ← (SRC1[63:32] 
 FFFFH) ? FFFFH : TMP[31:16] ;
TMP[47:32] ← (SRC1[95:64] 
 0) ? 0 : SRC1[79:64];
DEST[47:32] ← (SRC1[95:64] 
 FFFFH) ? FFFFH : TMP[47:32] ;
TMP[63:48] ← (SRC1[127:96] 
 0) ? 0 : SRC1[111:96];
DEST[63:48] ← (SRC1[127:96] 
 FFFFH) ? FFFFH : TMP[63:48] ;
TMP[79:64] ← (SRC2[31:0] 
 0) ? 0 : SRC2[15:0];
DEST[63:48] ← (SRC2[31:0] 
 FFFFH) ? FFFFH : TMP[79:64] ;
TMP[95:80] ← (SRC2[63:32] 
 0) ? 0 : SRC2[47:32];
DEST[95:80] ← (SRC2[63:32] 
 FFFFH) ? FFFFH : TMP[95:80] ;
TMP[111:96] ← (SRC2[95:64] 
 0) ? 0 : SRC2[79:64];
DEST[111:96] ← (SRC2[95:64] 
 FFFFH) ? FFFFH : TMP[111:96] ;
TMP[127:112] ← (SRC2[127:96] 
 0) ? 0 : SRC2[111:96];
DEST[127:112] ← (SRC2[127:96] 
 FFFFH) ? FFFFH : TMP[127:112];
DEST[VLMAX-1:128] ← 0;

VPACKUSDW (VEX.256 encoded version)

TMP[15:0] ← (SRC1[31:0] 
 0) ? 0 : SRC1[15:0];
DEST[15:0] ← (SRC1[31:0] 
 FFFFH) ? FFFFH : TMP[15:0] ;
TMP[31:16] ← (SRC1[63:32] 
 0) ? 0 : SRC1[47:32];
DEST[31:16] ← (SRC1[63:32] 
 FFFFH) ? FFFFH : TMP[31:16] ;
TMP[47:32] ← (SRC1[95:64] 
 0) ? 0 : SRC1[79:64];
DEST[47:32] ← (SRC1[95:64] 
 FFFFH) ? FFFFH : TMP[47:32] ;
TMP[63:48] ← (SRC1[127:96] 
 0) ? 0 : SRC1[111:96];
DEST[63:48] ← (SRC1[127:96] 
 FFFFH) ? FFFFH : TMP[63:48] ;
TMP[79:64] ← (SRC2[31:0] 
 0) ? 0 : SRC2[15:0];
DEST[63:48] ← (SRC2[31:0] 
 FFFFH) ? FFFFH : TMP[79:64] ;
TMP[95:80] ← (SRC2[63:32] 
 0) ? 0 : SRC2[47:32];
DEST[95:80] ← (SRC2[63:32] 
 FFFFH) ? FFFFH : TMP[95:80] ;
TMP[111:96] ← (SRC2[95:64] 
 0) ? 0 : SRC2[79:64];
DEST[111:96] ← (SRC2[95:64] 
 FFFFH) ? FFFFH : TMP[111:96] ;
TMP[127:112] ← (SRC2[127:96] 
 0) ? 0 : SRC2[111:96];
DEST[128:112] ← (SRC2[127:96] 
 FFFFH) ? FFFFH : TMP[127:112] ;
TMP[143:128] ← (SRC1[159:128] 
 0) ? 0 : SRC1[143:128];
DEST[143:128] ← (SRC1[159:128] 
 FFFFH) ? FFFFH : TMP[143:128] ;
TMP[159:144] ← (SRC1[191:160] 
 0) ? 0 : SRC1[175:160];
DEST[159:144] ← (SRC1[191:160] 
 FFFFH) ? FFFFH : TMP[159:144] ;
TMP[175:160] ← (SRC1[223:192] 
 0) ? 0 : SRC1[207:192];
DEST[175:160] ← (SRC1[223:192] 
 FFFFH) ? FFFFH : TMP[175:160] ;
TMP[191:176] ← (SRC1[255:224] 
 0) ? 0 : SRC1[239:224];
DEST[191:176] ← (SRC1[255:224] 
 FFFFH) ? FFFFH : TMP[191:176] ;
TMP[207:192] ← (SRC2[159:128] 
 0) ? 0 : SRC2[143:128];
DEST[207:192] ← (SRC2[159:128] 
 FFFFH) ? FFFFH : TMP[207:192] ;
TMP[223:208] ← (SRC2[191:160] 
 0) ? 0 : SRC2[175:160];
DEST[223:208] ← (SRC2[191:160] 
 FFFFH) ? FFFFH : TMP[223:208] ;
TMP[239:224] ← (SRC2[223:192] 
 0) ? 0 : SRC2[207:192];
DEST[239:224] ← (SRC2[223:192] 
 FFFFH) ? FFFFH : TMP[239:224] ;
TMP[255:240] ← (SRC2[255:224] 
 0) ? 0 : SRC2[239:224];
DEST[255:240] ← (SRC2[255:224] 
 FFFFH) ? FFFFH : TMP[255:240] ;

Intel C/C++ Compiler Intrinsic Equivalent

(V)PACKUSDW: __m128i _mm_packus_epi32(__m128i m1, __m128i m2);

VPACKUSDW:

__m256i _mm256_packus_epi32(__m256i m1, __m256i m2);

Flags Affected

None.

SIMD Exceptions

None.

Other Exceptions

See Exceptions Type 4; additionally

#UD If VEX.L = 1.