From 03a68d4c4935dd88dbb47042da85a2e743f555ff Mon Sep 17 00:00:00 2001
From: Ben Vanik <ben.vanik@gmail.com>
Date: Wed, 25 Sep 2013 18:36:34 -0700
Subject: [PATCH] PerformanceCounter.

---
 src/xenia/cpu/x64/x64_emit_control.cc         | 13 +++++++++--
 .../modules/xboxkrnl/xboxkrnl_threading.cc    | 22 +++++++++++++++++++
 .../modules/xboxkrnl/xboxkrnl_threading.h     |  2 ++
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/src/xenia/cpu/x64/x64_emit_control.cc b/src/xenia/cpu/x64/x64_emit_control.cc
index 8f1c1f22e..a997271d1 100644
--- a/src/xenia/cpu/x64/x64_emit_control.cc
+++ b/src/xenia/cpu/x64/x64_emit_control.cc
@@ -635,6 +635,7 @@ XEEMITTER(mfspr,        0x7C0002A6, XFX)(X64Emitter& e, X86Compiler& c, InstrDat
     // CTR
     v = e.ctr_value();
     break;
+  // 268 + 269 = TB + TBU
   default:
     XEINSTRNOTIMPLEMENTED();
     return 1;
@@ -648,8 +649,16 @@ XEEMITTER(mfspr,        0x7C0002A6, XFX)(X64Emitter& e, X86Compiler& c, InstrDat
 }
 
 XEEMITTER(mftb,         0x7C0002E6, XFX)(X64Emitter& e, X86Compiler& c, InstrData& i) {
-  XEINSTRNOTIMPLEMENTED();
-  return 1;
+  LARGE_INTEGER counter;
+  if (QueryPerformanceCounter(&counter)) {
+    e.update_gpr_value(i.XFX.RT, e.get_uint64(counter.QuadPart));
+  } else {
+    e.update_gpr_value(i.XFX.RT, e.get_uint64(0));
+  }
+
+  e.clear_constant_gpr_value(i.XFX.RT);
+
+  return 0;
 }
 
 XEEMITTER(mtcrf,        0x7C000120, XFX)(X64Emitter& e, X86Compiler& c, InstrData& i) {
diff --git a/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_threading.cc b/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_threading.cc
index 2bd2fdbf9..d700623e9 100644
--- a/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_threading.cc
+++ b/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_threading.cc
@@ -155,6 +155,26 @@ SHIM_CALL KeGetCurrentProcessType_shim(
 }
 
 
+uint64_t xeKeQueryPerformanceFrequency() {
+  LARGE_INTEGER frequency;
+  if (QueryPerformanceFrequency(&frequency)) {
+    return frequency.QuadPart;
+  } else {
+    return 0;
+  }
+}
+
+
+SHIM_CALL KeQueryPerformanceFrequency_shim(
+    xe_ppc_state_t* ppc_state, KernelState* state) {
+  XELOGD(
+      "KeQueryPerformanceFrequency()");
+
+  uint64_t result = xeKeQueryPerformanceFrequency();
+  SHIM_SET_RETURN(result);
+}
+
+
 // The TLS system used here is a bit hacky, but seems to work.
 // Both Win32 and pthreads use unsigned longs as TLS indices, so we can map
 // right into the system for these calls. We're just round tripping the IDs and
@@ -414,6 +434,8 @@ void xe::kernel::xboxkrnl::RegisterThreadingExports(
 
   SHIM_SET_MAPPING("xboxkrnl.exe", KeGetCurrentProcessType, state);
 
+  SHIM_SET_MAPPING("xboxkrnl.exe", KeQueryPerformanceFrequency, state);
+
   SHIM_SET_MAPPING("xboxkrnl.exe", KeTlsAlloc, state);
   SHIM_SET_MAPPING("xboxkrnl.exe", KeTlsFree, state);
   SHIM_SET_MAPPING("xboxkrnl.exe", KeTlsGetValue, state);
diff --git a/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_threading.h b/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_threading.h
index 9b18d19c3..10326d6f4 100644
--- a/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_threading.h
+++ b/src/xenia/kernel/modules/xboxkrnl/xboxkrnl_threading.h
@@ -28,6 +28,8 @@ X_STATUS xeExCreateThread(
 
 uint32_t xeKeGetCurrentProcessType();
 
+uint64_t xeKeQueryPerformanceFrequency();
+
 uint32_t xeKeTlsAlloc();
 int KeTlsFree(uint32_t tls_index);
 uint32_t xeKeTlsGetValue(uint32_t tls_index);