User’s Manual

IBM PowerPC 750GX and 750GL RISC Microprocessor

Table 11-4. PMC3 Events—MMCR1[0:4] Select Encodings (Page 2 of 2)

Encoding

Description

 

 

 

 

1 0000

Number of branches in the second speculative stream that resolve correctly.

 

 

1 0001

Number of cycles the BPU stalls due to LR or CR unresolved dependencies.

 

 

All others

Reserved. Might be used in a later revision.

 

 

Bits MMCR1[5:9] specify events associated with PMC4, as shown in Table 11-5.

Table 11-5. PMC4 Events—MMCR1[5:9] Select Encodings

Encoding

Comments

 

 

 

 

00000

Register holds current value

 

 

00001

Number of processor cycles

 

 

00010

Number of completed instructions, not including folded branches

 

 

00011

Number of transitions from 0 to 1 of specified bits in the Time Base Lower (TBL) register. Bits are specified through

RTCSELECT, MMCR0[7–8]. 00 = 31, 01 = 23, 10 = 19, 11 = 15

 

 

 

00100

Number of instructions dispatched. 0, 1, or 2 per cycle

 

 

00101

Number of L2 castouts

 

 

00110

Number of cycles spent performing table searches for DTLB accesses.

 

 

00111

Reserved. Might be used in a later revision.

 

 

01000

Number of mispredicted branches. Reserved for future use.

 

 

01001

Reserved. Might be used in a later revision.

 

 

01010

Number of store conditional instructions completed with reservation intact

 

 

01011

Number of completed sync instructions

 

 

01100

Number of snoop request retries

 

 

01101

Number of completed integer operations

 

 

01110

Number of cycles the branch processing unit (BPU) cannot process new branches due to having two unresolved

branches

 

 

 

All others

Reserved. Might be used in a later revision.

 

 

The PMC registers can be accessed with the mtspr and mfspr instructions using the following SPR numbers:

PMC1 is SPR 953.

PMC2 is SPR 954.

PMC3 is SPR 957.

PMC4 is SPR 958.

11.2.1.6 User Performance-Monitor Counter Registers (UPMC1–UPMC4)

The contents of the PMC1–PMC4 are reflected to UPMC1–UPMC4, which can be read by user-level soft- ware. The UPMC registers can be read with the mfspr instructions using the following SPR numbers:

UPMC1 is SPR 937.

UPMC2 is SPR 938.

UPMC3 is SPR 941.

UPMC4 is SPR 942.

Performance Monitor and System Related Features

gx_11.fm.(1.2)

Page 354 of 377

March 27, 2006