16-26 Vol. 3

DEBUGGING, PROFILING BRANCHES AND TIME-STAMP COUNTER

When IA-32e mode is active, the structure of a branch trace record is similar to that

shown in Figure 16-6, but each field is 8 bytes in length. This makes each BTS record

24 bytes (see Figure 16-9). The structure of a PEBS record is similar to that shown in

Figure 16-7, but each field is 8 bytes in length and architectural states include

register R8 through R15. This makes the size of a PEBS record in 64-bit mode 144

bytes (see Figure 16-10).

Figure 16-8. IA-32e Mode DS Save Area
BTS Buffer Base
BTS Index
BTS Absolute
BTS Interrupt
PEBS Absolute
PEBS Interrupt
PEBS
Maximum
Maximum
Threshold
PEBS Index
PEBS Buffer Base
Threshold
Counter Reset
Reserved
0H
8H
10H
18H
20H
28H
30H
38H
40H
48H
50H
Branch Record 0
Branch Record 1
Branch Record n
PEBS Record 0
PEBS Record 1
PEBS Record n
BTS Buffer
PEBS Buffer
DS Buffer Management Area
IA32_DS_AREA MSR