PerfCounters: Add support for AMD Family 15h Model 2 (Piledriver)

Extends existing Family 15h Model 30 (Steamroller) support for
Piledriver. Piledriver supports PMCx0C4 (Retired Taken Branch
Instructions) and PMCx0C6 (Retired Far Control Transfer), just
like Model 30h. [1]

Note that PMCx0C4 counts all control flow changes, including
exceptions and interrupts. Like on 15h model 30-3Fh (Steamroller)
we subtract PMCx0C6 (Retired Far Control Transfers) to count
only regular taken branches.

[1]: https://www.amd.com/system/files/TechDocs/42301_15h_Mod_00h-0Fh_BKDG.pdf

Tested:
1) counters-test:
   vsrinivas@ubuntu:~/tmp/rr/src/counters-test$ sudo ./a.out
   Interrupted after 1000025 ticks, expected 1000000 ticks
   EXIT-SUCCESS

src/PerfCounters.cc

@@ -100,7 +100,7 @@ enum CpuMicroarch {
  IntelMeteorLake,
  LastIntel = IntelMeteorLake,
  FirstAMD,
- AMDF15R30 = FirstAMD,
+ AMDF15 = FirstAMD,
  AMDZen,
  AMDZen2,
  AMDZen3,
@@ -200,7 +200,7 @@ static const PmuConfig pmu_configs[] = {
  { IntelWestmere, "Intel Westmere", 0x5101c4, 0, 0, 100, PMU_TICKS_RCB },
  { IntelPenryn, "Intel Penryn", 0, 0, 0, 100, 0 },
  { IntelMerom, "Intel Merom", 0, 0, 0, 100, 0 },
- { AMDF15R30, "AMD Family 15h Revision 30h", 0xc4, 0xc6, 0, 250, PMU_TICKS_TAKEN_BRANCHES },
+ { AMDF15, "AMD Family 15h", 0xc4, 0xc6, 0, 250, PMU_TICKS_TAKEN_BRANCHES },
  // 0xd1 == RETIRED_CONDITIONAL_BRANCH_INSTRUCTIONS - Number of retired conditional branch instructions
  // 0x2c == INTERRUPT_TAKEN - Counts the number of interrupts taken
  // Both counters are available on all Zen microarchitecures so far.

src/PerfCounters_x86.h

@@ -96,15 +96,16 @@ static CpuMicroarch compute_cpu_microarch() {
  return IntelEmeraldRapid;
  case 0xa06a0:
  return IntelMeteorLake;
- case 0x30f00:
- return AMDF15R30;
+ case 0xf20: // Piledriver
+ case 0x30f00: // Steamroller
+ return AMDF15;
  case 0x00f10: // A8-3530MX, Naples, Whitehaven, Summit Ridge, Snowy Owl (Zen), Milan (Zen 3) (UNTESTED)
  if (ext_family == 8) {
  return AMDZen;
  } else if (ext_family == 0xa) {
  return AMDZen3;
  } else if (ext_family == 3) {
- return AMDF15R30;
+ return AMDF15;
  }
  break;
  case 0x00f80: // Colfax, Pinnacle Ridge (Zen+), Chagall (Zen3) (UNTESTED)

src/counters-test/counters.cc

@@ -67,7 +67,7 @@ enum CpuMicroarch {
  IntelSapphireRapid,
  LastIntel = IntelSapphireRapid,
  FirstAMD,
- AMDF15R30 = FirstAMD,
+ AMDF15 = FirstAMD,
  AMDZen,
  LastAMD = AMDZen,
  FirstARM,
@@ -156,7 +156,7 @@ static const PmuConfig pmu_configs[] = {
  { IntelWestmere, "Intel Westmere", 0x5101c4, 0, 0, 100, PMU_TICKS_RCB },
  { IntelPenryn, "Intel Penryn", 0, 0, 0, 100, 0 },
  { IntelMerom, "Intel Merom", 0, 0, 0, 100, 0 },
- { AMDF15R30, "AMD Family 15h Revision 30h", 0xc4, 0xc6, 0, 250, PMU_TICKS_TAKEN_BRANCHES },
+ { AMDF15, "AMD Family 15h", 0xc4, 0xc6, 0, 250, PMU_TICKS_TAKEN_BRANCHES },
  // 0xd1 == RETIRED_CONDITIONAL_BRANCH_INSTRUCTIONS - Number of retired conditional branch instructions
  // 0x2c == INTERRUPT_TAKEN - Counts the number of interrupts taken
  // Both counters are available on Zen, Zen+ and Zen2.
@@ -335,8 +335,9 @@ static CpuMicroarch compute_cpu_microarch(void) {
  return IntelRaptorlake;
  case 0x806f0:
  return IntelSapphireRapid;
+ case 0xf20:
  case 0x30f00:
- return AMDF15R30;
+ return AMDF15;
  case 0x00f10: // Naples, Whitehaven, Summit Ridge, Snowy Owl (Zen), Milan (Zen 3) (UNTESTED)
  case 0x10f10: // Raven Ridge, Great Horned Owl (Zen) (UNTESTED)
  case 0x10f80: // Banded Kestrel (Zen), Picasso (Zen+) (UNTESTED)
@@ -350,7 +351,7 @@ static CpuMicroarch compute_cpu_microarch(void) {
  if (ext_family == 8 || ext_family == 0xa) {
  return AMDZen;
  } else if (ext_family == 3) {
- return AMDF15R30;
+ return AMDF15;
  }
  break;
  case 0x20f10: // Vermeer (Zen 3)