RCR (R32, I8) - Latency

Experiment 1

• Instruction: RCR R8D, 2
• Chain instructions: MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D
• Chain latency: 7
• Code:

     0:	41 c1 d8 02          	rcr    r8d,0x2
     4:	4d 63 c0             	movsxd r8,r8d
     7:	4d 63 c0             	movsxd r8,r8d
     a:	4d 63 c0             	movsxd r8,r8d
     d:	4d 63 c0             	movsxd r8,r8d
    10:	4d 63 c0             	movsxd r8,r8d
    13:	4d 63 c0             	movsxd r8,r8d
    16:	4d 63 c0             	movsxd r8,r8d
  

• Show nanoBench command
• Results:
  • MPERF: 7.62
  • APERF: 9.0
  • UOPS: 14.0

Experiment 2

• Instruction: RCR R8D, 2
• Code:

     0:	41 c1 d8 02          	rcr    r8d,0x2
  

• Show nanoBench command
• Results:
  • MPERF: 2.46
  • APERF: 3.01
  • UOPS: 7.0

Experiment 3 (with dependency-breaking instructions)

• Instruction: RCR R8D, 2
• Chain instruction: TEST R15, R15
• Code:

     0:	41 c1 d8 02          	rcr    r8d,0x2
     4:	4d 85 ff             	test   r15,r15
  

• Show nanoBench command
• Results:
  • MPERF: 2.52
  • APERF: 3.0
  • UOPS: 8.0

Experiment 1

• Instruction: RCR R8D, 2
• Chain instructions: CMOVC R15D, R15D;MOVSX R8, R15D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D
• Chain latency: 8
• Code:

     0:	41 c1 d8 02          	rcr    r8d,0x2
     4:	45 0f 42 ff          	cmovb  r15d,r15d
     8:	4d 63 c7             	movsxd r8,r15d
     b:	4d 63 c0             	movsxd r8,r8d
     e:	4d 63 c0             	movsxd r8,r8d
    11:	4d 63 c0             	movsxd r8,r8d
    14:	4d 63 c0             	movsxd r8,r8d
    17:	4d 63 c0             	movsxd r8,r8d
    1a:	4d 63 c0             	movsxd r8,r8d
  

• Show nanoBench command
• Results:
  • MPERF: 8.4
  • APERF: 10.0
  • UOPS: 15.0

Experiment 1

• Instruction: RCR R8D, 2
• Chain instructions: MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;MOVSX R8, R8D;TEST R8D, R8D
• Chain latency: 7
• Code:

     0:	41 c1 d8 02          	rcr    r8d,0x2
     4:	4d 63 c0             	movsxd r8,r8d
     7:	4d 63 c0             	movsxd r8,r8d
     a:	4d 63 c0             	movsxd r8,r8d
     d:	4d 63 c0             	movsxd r8,r8d
    10:	4d 63 c0             	movsxd r8,r8d
    13:	4d 63 c0             	movsxd r8,r8d
    16:	45 85 c0             	test   r8d,r8d
  

• Show nanoBench command
• Results:
  • MPERF: 7.74
  • APERF: 9.0
  • UOPS: 14.0

Experiment 2

• Instruction: RCR R8D, 2
• Chain instruction: TEST R8D, R8D
• Chain latency: 1
• Code:

     0:	41 c1 d8 02          	rcr    r8d,0x2
     4:	45 85 c0             	test   r8d,r8d
  

• Show nanoBench command
• Results:
  • MPERF: 2.58
  • APERF: 3.05
  • UOPS: 8.0

Experiment 3 (with dependency-breaking instructions)

• Instruction: RCR R8D, 2
• Chain instructions: TEST R8D, R8D;;MOV R8D, 0
• Chain latency: 1
• Code:

     0:	41 c1 d8 02          	rcr    r8d,0x2
     4:	45 85 c0             	test   r8d,r8d
     7:	41 b8 00 00 00 00    	mov    r8d,0x0
  

• Show nanoBench command
• Results:
  • MPERF: 2.58
  • APERF: 3.14
  • UOPS: 9.0

Experiment 1

• Instruction: RCR R8D, 2
• Chain instructions: CMC;CMC;CMC;CMC;CMC;CMC
• Chain latency: 6
• Code:

     0:	41 c1 d8 02          	rcr    r8d,0x2
     4:	f5                   	cmc    
     5:	f5                   	cmc    
     6:	f5                   	cmc    
     7:	f5                   	cmc    
     8:	f5                   	cmc    
     9:	f5                   	cmc    
  

• Show nanoBench command
• Results:
  • MPERF: 6.72
  • APERF: 8.02
  • UOPS: 13.0

Experiment 2

• Instruction: RCR R8D, 2
• Code:

     0:	41 c1 d8 02          	rcr    r8d,0x2
  

• Show nanoBench command
• Results:
  • MPERF: 2.52
  • APERF: 3.01
  • UOPS: 7.0

Experiment 3 (with dependency-breaking instructions)

• Instruction: RCR R8D, 2
• Chain instruction: MOV R8D, 0
• Code:

     0:	41 c1 d8 02          	rcr    r8d,0x2
     4:	41 b8 00 00 00 00    	mov    r8d,0x0
  

• Show nanoBench command
• Results:
  • MPERF: 2.58
  • APERF: 3.0
  • UOPS: 8.0