This patch fixes the encoding for INST_RETIRED.PREC_DIST as published by Intel
(download.01.org/perfmon/) for Icelake. The official encoding
is event code 0x00 umask 0x1, a change from Skylake where it was code 0xc0
umask 0x1.
With this patch applied it is possible to run:
$ perf record -a -e cpu/event=0x00,umask=0x1/pp .....
Whereas before this would fail.
To avoid problems with tools which may use the old code, we maintain the old
encoding for Icelake.
Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>