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) | N/A | N/A |
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 (MAXVL-1:128) of the corresponding XMM destination register remain unchanged.
VEX.128 encoded version: Bits (MAXVL-1:128) of the destination XMM 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[MAXVL-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 Table 2-21, “Type 4 Class Exception Conditions,” additionally:
| #UD | If VEX.L = 1. |
|---|---|
| If VEX.vvvv ≠ 1111B. |
This UNOFFICIAL, mechanically-separated, non-verified reference is provided for convenience, but it may be incomplete or broken in various obvious or non-obvious ways. Refer to Intel® 64 and IA-32 Architectures Software Developer’s Manual for anything serious.