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<!---======================= begin_copyright_notice ============================
Copyright (C) 2020-2021 Intel Corporation
SPDX-License-Identifier: MIT
============================= end_copyright_notice ==========================-->
## Opcode
FBL = 0x2e
## Format
| | | | |
| --- | --- | --- | --- |
| 0x2e(FBL) | Exec_size | Pred | Dst | Src0 |
## Semantics
for (i = 0; < exec_size; ++i) {
if (ChEn[i]) {
UD cnt = 0;
UD udScalar = src0[i];
while ( (udScalar & 1 ) == 0 && cnt != 32 ) {
cnt ++;
udScalar = udScalar >> 1;
}
if ( src0[i] == 0x0 ) {
dst[i] = 0xFFFFFFFF;
else {
dst[i] = cnt;
}
}
}
## Description
Performs component-wise counting of the trailing zeros in <src0> and stores the result into <dst>. If src0 has no bit set, the value 0xFFFFFFFF is returned.
- **Exec_size(ub):** Execution size
- Bit[2..0]: size of the region for source and destination operands
- 0b000: 1 element (scalar)
- 0b001: 2 elements
- 0b010: 4 elements
- 0b011: 8 elements
- 0b100: 16 elements
- 0b101: 32 elements
- Bit[7..4]: execution mask (explicit control over the enabled channels)
- 0b0000: M1
- 0b0001: M2
- 0b0010: M3
- 0b0011: M4
- 0b0100: M5
- 0b0101: M6
- 0b0110: M7
- 0b0111: M8
- 0b1000: M1_NM
- 0b1001: M2_NM
- 0b1010: M3_NM
- 0b1011: M4_NM
- 0b1100: M5_NM
- 0b1101: M6_NM
- 0b1110: M7_NM
- 0b1111: M8_NM
- **Pred(uw):** Predication control
- **Dst(vec_operand):** The destination operand. Operand class: general,indirect
- **Src0(vec_operand):** The first source operand. Operand class: general,indirect,immediate
#### Properties
- **Supported Types:** UD
- **Source Modifier:** false
## Text
```
[(<P>)] FBL (<exec_size>) <dst> <src0>
```
## Notes
|
