PHMINPOSUW — Packed Horizontal Word Minimum

Opcode/Instruction	Op/En	64/32 bit Mode Support	CPUID Feature Flag	Description
66 0F 38 41 /r PHMINPOSUW xmm1, xmm2/m128	RM	V/V	SSE4_1	Find the minimum unsigned word in xmm2/m128 and place its value in the low word of xmm1 and its index in the second-lowest word of xmm1.
VEX.128.66.0F38.WIG 41 /r VPHMINPOSUW xmm1, xmm2/m128	RM	V/V	AVX	Find the minimum unsigned word in xmm2/m128 and place its value in the low word of xmm1 and its index in the second-lowest word of xmm1.

Instruction Operand Encoding

Op/En	Operand 1	Operand 2	Operand 3	Operand 4
RM	ModRM:reg (w)	ModRM:r/m (r)	NA	NA

Description

Determine the minimum unsigned word value in the source operand (second operand) and place the unsigned word in the low word (bits 0-15) of the destination operand (first operand). The word index of the minimum value is stored in bits 16-18 of the destination operand. The remaining upper bits of the destination are set to zero.

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.vvvv is reserved and must be 1111b, VEX.L must be 0, otherwise the instruction will #UD.

Operation

PHMINPOSUW (128-bit Legacy SSE version)

INDEX ← 0;
MIN ← SRC[15:0]
IF (SRC[31:16] < MIN)
    THEN INDEX ← 1;  MIN ← SRC[31:16]; FI;
IF (SRC[47:32] < MIN)
    THEN INDEX ← 2;  MIN ← SRC[47:32]; FI;
* Repeat operation for words 3 through 6
IF (SRC[127:112] < MIN)
    THEN INDEX ← 7;  MIN ← SRC[127:112]; FI;
DEST[15:0] ← MIN;
DEST[18:16] ← INDEX;
DEST[127:19] ← 0000000000000000000000000000H;

VPHMINPOSUW (VEX.128 encoded version)

INDEX ← 0
MIN ← SRC[15:0]
IF (SRC[31:16] < MIN) THEN INDEX ← 1; MIN ← SRC[31:16]
IF (SRC[47:32] < MIN) THEN INDEX ← 2; MIN ← SRC[47:32]
* Repeat operation for words 3 through 6
IF (SRC[127:112] < MIN) THEN INDEX ← 7; MIN ← SRC[127:112]
DEST[15:0] ← MIN
DEST[18:16] ← INDEX
DEST[127:19] ← 0000000000000000000000000000H
DEST[VLMAX-1:128] ← 0

Intel C/C++ Compiler Intrinsic Equivalent

PHMINPOSUW:

__m128i _mm_minpos_epu16( __m128i packed_words);

Flags Affected

None.

SIMD Floating-Point Exceptions

None.

Other Exceptions

See Exceptions Type 4; additionally

#UD	If VEX.L = 1. If VEX.vvvv ≠ 1111B.