MOVZX (R32, M8) - Latency

Operands

Operand 1 (w): Register (EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI, R8D, R9D, R10D, R11D, R12D, R13D, R14D, R15D)
Operand 2 (r): Memory

Latency operand 2 → 1 (address, base register): 3

Latency operand 2 → 1 (address, index register): 3

Latency operand 2 → 1 (memory): ≤4

Latency operand 2 → 1 (address, base register): 3

Experiment 1

Instruction: MOVZX R8D, byte ptr [R14]
Chain instructions: MOVSX R8, R8D;XOR R14, R8;XOR R14, R8;XOR R14, R8;XOR R14, R8
Chain latency: 5

Code:

   0:	45 0f b6 06          	movzx  r8d,BYTE PTR [r14]
   4:	4d 63 c0             	movsxd r8,r8d
   7:	4d 31 c6             	xor    r14,r8
   a:	4d 31 c6             	xor    r14,r8
   d:	4d 31 c6             	xor    r14,r8
  10:	4d 31 c6             	xor    r14,r8

Show nanoBench command
Results:
- Instructions retired: 6.0
- Core cycles: 8.34
- Reference cycles: 8.33
- RS_UOPS_DISPATCHED: 6.0

Latency operand 2 → 1 (address, index register): 3

Experiment 1

Instruction: MOVZX R8D, byte ptr [R14+R13]
Chain instructions: MOVSX R8, R8D;XOR R13, R8;XOR R13, R8;XOR R13, R8;XOR R13, R8
Chain latency: 5

Code:

   0:	47 0f b6 04 2e       	movzx  r8d,BYTE PTR [r14+r13*1]
   5:	4d 63 c0             	movsxd r8,r8d
   8:	4d 31 c5             	xor    r13,r8
   b:	4d 31 c5             	xor    r13,r8
   e:	4d 31 c5             	xor    r13,r8
  11:	4d 31 c5             	xor    r13,r8

Init:
```
XOR R13, R13
```
Show nanoBench command
Results:
- Instructions retired: 6.0
- Core cycles: 8.34
- Reference cycles: 8.36
- RS_UOPS_DISPATCHED: 6.0

Latency operand 2 → 1 (memory): ≤4

Experiment 1

Instruction: MOVZX R8D, byte ptr [R14]
Chain instructions: MOVSX R12, R8D;MOVSX R12, R12d;MOVSX R12, R12d;MOVSX R12, R12d;mov [R14], R12B
Chain latency: ≥5

Code:

   0:	45 0f b6 06          	movzx  r8d,BYTE PTR [r14]
   4:	4d 63 e0             	movsxd r12,r8d
   7:	4d 63 e4             	movsxd r12,r12d
   a:	4d 63 e4             	movsxd r12,r12d
   d:	4d 63 e4             	movsxd r12,r12d
  10:	45 88 26             	mov    BYTE PTR [r14],r12b

Show nanoBench command
Results:
- Instructions retired: 6.0
- Core cycles: 9.17
- Reference cycles: 9.15
- RS_UOPS_DISPATCHED: 7.0