SFENCE - Port Usage (IACA 2.3)


With blocking instructions for port '4':

Throughput Analysis Report
--------------------------
Block Throughput: 11.00 Cycles       Throughput Bottleneck: Backend. Port4

Port Binding In Cycles Per Iteration:
---------------------------------------------------------------------------------------
|  Port  |  0   -  DV  |  1   |  2   -  D   |  3   -  D   |  4   |  5   |  6   |  7   |
---------------------------------------------------------------------------------------
| Cycles | 0.2    0.0  | 0.2  | 3.7    0.0  | 3.7    0.0  | 11.0 | 0.2  | 0.2  | 3.7  |
---------------------------------------------------------------------------------------


| Num Of |                    Ports pressure in cycles                     |    |
|  Uops  |  0  - DV  |  1  |  2  -  D  |  3  -  D  |  4  |  5  |  6  |  7  |    |
---------------------------------------------------------------------------------
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x40], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x48], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x50], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x58], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x60], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x68], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x70], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x78], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x80], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x88], r8
|   3    | 0.2       | 0.2 | 0.3       | 0.3       | 1.0 | 0.2 | 0.2 | 0.3 | CP | sfence 
Total Num Of Uops: 23
⇨ One μop that can only use port '4'

With blocking instructions for ports {'2', '3', '7'}:

Throughput Analysis Report
--------------------------
Block Throughput: 11.00 Cycles       Throughput Bottleneck: Backend. Port4

Port Binding In Cycles Per Iteration:
---------------------------------------------------------------------------------------
|  Port  |  0   -  DV  |  1   |  2   -  D   |  3   -  D   |  4   |  5   |  6   |  7   |
---------------------------------------------------------------------------------------
| Cycles | 0.2    0.0  | 0.2  | 3.7    0.0  | 3.7    0.0  | 11.0 | 0.2  | 0.2  | 3.7  |
---------------------------------------------------------------------------------------


| Num Of |                    Ports pressure in cycles                     |    |
|  Uops  |  0  - DV  |  1  |  2  -  D  |  3  -  D  |  4  |  5  |  6  |  7  |    |
---------------------------------------------------------------------------------
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x40], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x48], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x50], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x58], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x60], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x68], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x70], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x78], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x80], r8
|   2^   |           |     | 0.3       | 0.3       | 1.0 |     |     | 0.3 | CP | mov qword ptr [r14+0x88], r8
|   3    | 0.2       | 0.2 | 0.3       | 0.3       | 1.0 | 0.2 | 0.2 | 0.3 | CP | sfence 
Total Num Of Uops: 23
⇨ One μop that can only use ports {'2', '3', '7'}

With blocking instructions for ports {'0', '1', '5', '6'}:

Throughput Analysis Report
--------------------------
Block Throughput: 3.71 Cycles       Throughput Bottleneck: FrontEnd

Port Binding In Cycles Per Iteration:
---------------------------------------------------------------------------------------
|  Port  |  0   -  DV  |  1   |  2   -  D   |  3   -  D   |  4   |  5   |  6   |  7   |
---------------------------------------------------------------------------------------
| Cycles | 3.2    0.0  | 3.2  | 0.3    0.0  | 0.3    0.0  | 1.0  | 3.2  | 3.2  | 0.3  |
---------------------------------------------------------------------------------------


| Num Of |                    Ports pressure in cycles                     |    |
|  Uops  |  0  - DV  |  1  |  2  -  D  |  3  -  D  |  4  |  5  |  6  |  7  |    |
---------------------------------------------------------------------------------
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov r8w, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov r9w, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov r10w, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov r11w, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov r12w, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov bx, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov cx, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov dx, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov r8w, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov r9w, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov r10w, 0x100
|   1    | 0.2       | 0.2 |           |           |     | 0.2 | 0.2 |     |    | mov r11w, 0x100
|   3    | 0.2       | 0.2 | 0.3       | 0.3       | 1.0 | 0.2 | 0.2 | 0.3 |    | sfence 
Total Num Of Uops: 15
⇨ One μop that can only use ports {'0', '1', '5', '6'}