XCHG (R64, R64) - Throughput and Uops (IACA 2.1)


With different registers for different operands

With 1 independent instruction

Throughput Analysis Report
--------------------------
Block Throughput: 3.00 Cycles       Throughput Bottleneck: InterIteration

Port Binding In Cycles Per Iteration:
---------------------------------------------------------------------------------------
|  Port  |  0   -  DV  |  1   |  2   -  D   |  3   -  D   |  4   |  5   |  6   |  7   |
---------------------------------------------------------------------------------------
| Cycles | 0.8    0.0  | 0.8  | 0.0    0.0  | 0.0    0.0  | 0.0  | 0.8  | 0.8  | 0.0  |
---------------------------------------------------------------------------------------


| Num Of |                    Ports pressure in cycles                     |    |
|  Uops  |  0  - DV  |  1  |  2  -  D  |  3  -  D  |  4  |  5  |  6  |  7  |    |
---------------------------------------------------------------------------------
|   3    | 0.8       | 0.8 |           |           |     | 0.8 | 0.8 |     | CP | xchg r8, r9
Total Num Of Uops: 3

With 6 independent instructions


Throughput Analysis Report
--------------------------
Block Throughput: 4.70 Cycles       Throughput Bottleneck: FrontEnd, Port5, Port6

Port Binding In Cycles Per Iteration:
---------------------------------------------------------------------------------------
|  Port  |  0   -  DV  |  1   |  2   -  D   |  3   -  D   |  4   |  5   |  6   |  7   |
---------------------------------------------------------------------------------------
| Cycles | 4.4    0.0  | 4.4  | 0.0    0.0  | 0.0    0.0  | 0.0  | 4.5  | 4.6  | 0.0  |
---------------------------------------------------------------------------------------


| Num Of |                    Ports pressure in cycles                     |    |
|  Uops  |  0  - DV  |  1  |  2  -  D  |  3  -  D  |  4  |  5  |  6  |  7  |    |
---------------------------------------------------------------------------------
|   3    | 0.9       | 0.6 |           |           |     | 0.6 | 1.0 |     | CP | xchg r8, r9
|   3    | 0.6       | 0.9 |           |           |     | 0.9 | 0.5 |     | CP | xchg r10, r11
|   3    | 0.9       | 0.6 |           |           |     | 0.6 | 0.8 |     | CP | xchg r12, r13
|   3    | 0.6       | 0.9 |           |           |     | 0.9 | 0.6 |     | CP | xchg r14, rbx
|   3    | 0.9       | 0.4 |           |           |     | 0.6 | 1.0 |     | CP | xchg rcx, rdx
|   3    | 0.5       | 0.9 |           |           |     | 0.9 | 0.6 |     | CP | xchg rdi, rsi
Total Num Of Uops: 18

With the same register for for different operands

With 1 independent instruction

Throughput Analysis Report
--------------------------
Block Throughput: 3.00 Cycles       Throughput Bottleneck: InterIteration

Port Binding In Cycles Per Iteration:
---------------------------------------------------------------------------------------
|  Port  |  0   -  DV  |  1   |  2   -  D   |  3   -  D   |  4   |  5   |  6   |  7   |
---------------------------------------------------------------------------------------
| Cycles | 0.8    0.0  | 0.8  | 0.0    0.0  | 0.0    0.0  | 0.0  | 0.8  | 0.8  | 0.0  |
---------------------------------------------------------------------------------------


| Num Of |                    Ports pressure in cycles                     |    |
|  Uops  |  0  - DV  |  1  |  2  -  D  |  3  -  D  |  4  |  5  |  6  |  7  |    |
---------------------------------------------------------------------------------
|   3    | 0.8       | 0.8 |           |           |     | 0.8 | 0.8 |     | CP | xchg r8, r8
Total Num Of Uops: 3

With 13 independent instructions


Throughput Analysis Report
--------------------------
Block Throughput: 9.90 Cycles       Throughput Bottleneck: FrontEnd, Port0, Port1, Port5, Port6

Port Binding In Cycles Per Iteration:
---------------------------------------------------------------------------------------
|  Port  |  0   -  DV  |  1   |  2   -  D   |  3   -  D   |  4   |  5   |  6   |  7   |
---------------------------------------------------------------------------------------
| Cycles | 9.8    0.0  | 9.8  | 0.0    0.0  | 0.0    0.0  | 0.0  | 9.8  | 9.7  | 0.0  |
---------------------------------------------------------------------------------------


| Num Of |                    Ports pressure in cycles                     |    |
|  Uops  |  0  - DV  |  1  |  2  -  D  |  3  -  D  |  4  |  5  |  6  |  7  |    |
---------------------------------------------------------------------------------
|   3    | 0.8       | 0.8 |           |           |     | 0.8 | 0.7 |     | CP | xchg r8, r8
|   3    | 0.8       | 0.8 |           |           |     | 0.7 | 0.8 |     | CP | xchg r9, r9
|   3    | 0.8       | 0.8 |           |           |     | 0.8 | 0.7 |     | CP | xchg r10, r10
|   3    | 0.8       | 0.7 |           |           |     | 0.8 | 0.8 |     | CP | xchg r11, r11
|   3    | 0.7       | 0.8 |           |           |     | 0.8 | 0.8 |     | CP | xchg r12, r12
|   3    | 0.8       | 0.8 |           |           |     | 0.7 | 0.8 |     | CP | xchg r13, r13
|   3    | 0.8       | 0.8 |           |           |     | 0.8 | 0.7 |     | CP | xchg r14, r14
|   3    | 0.8       | 0.8 |           |           |     | 0.8 | 0.7 |     | CP | xchg rbx, rbx
|   3    | 0.8       | 0.8 |           |           |     | 0.8 | 0.8 |     | CP | xchg rcx, rcx
|   3    | 0.7       | 0.8 |           |           |     | 0.7 | 0.9 |     | CP | xchg rdx, rdx
|   3    | 0.8       | 0.7 |           |           |     | 0.8 | 0.8 |     | CP | xchg rdi, rdi
|   3    | 0.7       | 0.8 |           |           |     | 0.8 | 0.8 |     | CP | xchg rsi, rsi
|   3    | 0.8       | 0.8 |           |           |     | 0.8 | 0.7 |     | CP | xchg rbp, rbp
Total Num Of Uops: 39

With the -no_interiteration flag

Throughput Analysis Report
--------------------------
Block Throughput: 0.75 Cycles       Throughput Bottleneck: FrontEnd, Port0, Port1, Port5, Port6

Port Binding In Cycles Per Iteration:
---------------------------------------------------------------------------------------
|  Port  |  0   -  DV  |  1   |  2   -  D   |  3   -  D   |  4   |  5   |  6   |  7   |
---------------------------------------------------------------------------------------
| Cycles | 0.8    0.0  | 0.8  | 0.0    0.0  | 0.0    0.0  | 0.0  | 0.8  | 0.8  | 0.0  |
---------------------------------------------------------------------------------------


| Num Of |                    Ports pressure in cycles                     |    |
|  Uops  |  0  - DV  |  1  |  2  -  D  |  3  -  D  |  4  |  5  |  6  |  7  |    |
---------------------------------------------------------------------------------
|   3    | 0.8       | 0.8 |           |           |     | 0.8 | 0.8 |     | CP | xchg r8, r9
Total Num Of Uops: 3