XCHG (R64, R64) - Throughput and Uops (IACA 3.0)

With different registers for different operands

With 1 independent instruction

Throughput Analysis Report
--------------------------
Block Throughput: 0.98 Cycles       Throughput Bottleneck: Dependency chains
Loop Count:  52
Port Binding In Cycles Per Iteration:
--------------------------------------------------------------------------------------------------
|  Port  |   0   -  DV   |   1   |   2   -  D    |   3   -  D    |   4   |   5   |   6   |   7   |
--------------------------------------------------------------------------------------------------
| Cycles |  0.3     0.0  |  0.2  |  0.0     0.0  |  0.0     0.0  |  0.0  |  0.2  |  0.2  |  0.0  |
--------------------------------------------------------------------------------------------------

| Num Of   |                    Ports pressure in cycles                         |      |
|  Uops    |  0  - DV    |  1   |  2  -  D    |  3  -  D    |  4   |  5   |  6   |  7   |
-----------------------------------------------------------------------------------------
|   1      | 0.3         | 0.2  |             |             |      | 0.2  | 0.2  |      | xchg r8, r9
Total Num Of Uops: 1

With 6 independent instructions

Throughput Analysis Report
--------------------------
Block Throughput: 1.49 Cycles       Throughput Bottleneck: FrontEnd
Loop Count:  42
Port Binding In Cycles Per Iteration:
--------------------------------------------------------------------------------------------------
|  Port  |   0   -  DV   |   1   |   2   -  D    |   3   -  D    |   4   |   5   |   6   |   7   |
--------------------------------------------------------------------------------------------------
| Cycles |  1.5     0.0  |  1.5  |  0.0     0.0  |  0.0     0.0  |  0.0  |  1.5  |  1.5  |  0.0  |
--------------------------------------------------------------------------------------------------

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

With the same register for for different operands

With 1 independent instruction

Throughput Analysis Report
--------------------------
Block Throughput: 0.98 Cycles       Throughput Bottleneck: Dependency chains
Loop Count:  52
Port Binding In Cycles Per Iteration:
--------------------------------------------------------------------------------------------------
|  Port  |   0   -  DV   |   1   |   2   -  D    |   3   -  D    |   4   |   5   |   6   |   7   |
--------------------------------------------------------------------------------------------------
| Cycles |  0.3     0.0  |  0.2  |  0.0     0.0  |  0.0     0.0  |  0.0  |  0.2  |  0.2  |  0.0  |
--------------------------------------------------------------------------------------------------

| Num Of   |                    Ports pressure in cycles                         |      |
|  Uops    |  0  - DV    |  1   |  2  -  D    |  3  -  D    |  4   |  5   |  6   |  7   |
-----------------------------------------------------------------------------------------
|   1      | 0.3         | 0.2  |             |             |      | 0.2  | 0.2  |      | xchg r8, r8
Total Num Of Uops: 1

With 13 independent instructions

Throughput Analysis Report
--------------------------
Block Throughput: 3.21 Cycles       Throughput Bottleneck: Dependency chains
Loop Count:  22
Port Binding In Cycles Per Iteration:
--------------------------------------------------------------------------------------------------
|  Port  |   0   -  DV   |   1   |   2   -  D    |   3   -  D    |   4   |   5   |   6   |   7   |
--------------------------------------------------------------------------------------------------
| Cycles |  3.3     0.0  |  3.3  |  0.0     0.0  |  0.0     0.0  |  0.0  |  3.3  |  3.2  |  0.0  |
--------------------------------------------------------------------------------------------------

| Num Of   |                    Ports pressure in cycles                         |      |
|  Uops    |  0  - DV    |  1   |  2  -  D    |  3  -  D    |  4   |  5   |  6   |  7   |
-----------------------------------------------------------------------------------------
|   1      | 0.3         | 0.3  |             |             |      | 0.3  | 0.2  |      | xchg r8, r8
|   1      | 0.2         | 0.3  |             |             |      | 0.3  | 0.3  |      | xchg r9, r9
|   1      | 0.3         | 0.2  |             |             |      | 0.3  | 0.3  |      | xchg r10, r10
|   1      | 0.3         | 0.3  |             |             |      | 0.2  | 0.3  |      | xchg r11, r11
|   1      | 0.3         | 0.3  |             |             |      | 0.3  | 0.2  |      | xchg r12, r12
|   1      | 0.2         | 0.3  |             |             |      | 0.3  | 0.3  |      | xchg r13, r13
|   1      | 0.3         | 0.2  |             |             |      | 0.3  | 0.3  |      | xchg r14, r14
|   1      | 0.3         | 0.3  |             |             |      | 0.2  | 0.3  |      | xchg rbx, rbx
|   1      | 0.3         | 0.3  |             |             |      | 0.3  | 0.2  |      | xchg rcx, rcx
|   1      | 0.2         | 0.3  |             |             |      | 0.3  | 0.3  |      | xchg rdx, rdx
|   1      | 0.3         | 0.2  |             |             |      | 0.3  | 0.3  |      | xchg rdi, rdi
|   1      | 0.3         | 0.3  |             |             |      | 0.2  | 0.3  |      | xchg rsi, rsi
|   1      | 0.3         | 0.3  |             |             |      | 0.3  | 0.2  |      | xchg rbp, rbp
Total Num Of Uops: 13