Vol. 3B 19-211

PERFORMANCE-MONITORING EVENTS

C2H

UOPS_RETIRED

00H

Number of μops retired.

D0H

INST_DECODED

00H

Number of instructions decoded.

D8H

EMON_KNI_INST_

RETIRED

00H
01H

Number of Streaming SIMD extensions 

retired:
0: packed & scalar
1: scalar

Counters 0 and 1. Pentium III 

processor only.

D9H

EMON_KNI_

COMP_

INST_RET

00H
01H

Number of Streaming SIMD extensions 

computation instructions retired:
0: packed and scalar
1: scalar

Counters 0 and 1. Pentium III 

processor only.

Interrupts

C8H

HW_INT_RX

00H

Number of hardware interrupts received.

C6H

CYCLES_INT_

MASKED

00H

Number of processor cycles for which 

interrupts are disabled.

C7H

CYCLES_INT_

PENDING_

AND_MASKED

00H

Number of processor cycles for which 

interrupts are disabled and interrupts are 

pending.

Branches

C4H

BR_INST_

RETIRED

00H

Number of branch instructions retired.

C5H

BR_MISS_PRED_

RETIRED

00H

Number of mispredicted branches retired.

C9H

BR_TAKEN_

RETIRED

00H

Number of taken branches retired.

CAH

BR_MISS_PRED_

TAKEN_RET

00H

Number of taken mispredictions branches 

retired.

E0H

BR_INST_

DECODED

00H

Number of branch instructions decoded.

E2H

BTB_MISSES

00H

Number of branches for which the BTB did 

not produce a prediction.

E4H

BR_BOGUS

00H

Number of bogus branches. 

E6H

BACLEARS

00H

Number of times BACLEAR is asserted.
This is the number of times that a static 

branch prediction was made, in which the 

branch decoder decided to make a branch 

prediction because the BTB did not.

Stalls

A2H

RESOURCE_

STALLS

00H

Incremented by 1 during every cycle for 

which there is a resource related stall.
Includes register renaming buffer entries, 

memory buffer entries.

Table 19-37.  Events That Can Be Counted with the P6 Family Performance-Monitoring Counters (Contd.)

Unit

Event 

Num.

Mnemonic Event 

Name

Unit 

Mask Description

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