[Beignet] [PATCH 03/19] Backend: Add ProfilingInserter and a new function pass.

[junyan.he at inbox.com]

From: Junyan He <junyan.he at linux.intel.com>

When user enables profiling feature, we need to insert
extra instructions to record and store the timestamps.
By now, the function pass will just insert the requred
instructions at the head of first 20 blocks. Later, we
will support to insert timestamps at any point in the code.

Signed-off-by: Junyan He <junyan.he at linux.intel.com>
Signed-off-by: Bai Yannan <yannan.bai at intel.com>
---
 backend/src/CMakeLists.txt          |    1 +
 backend/src/llvm/llvm_profiling.cpp |  210 +++++++++++++++++++++++++++++++++++
 2 files changed, 211 insertions(+)
 create mode 100644 backend/src/llvm/llvm_profiling.cpp

diff --git a/backend/src/CMakeLists.txt b/backend/src/CMakeLists.txt
index daab320..e56df5e 100644
--- a/backend/src/CMakeLists.txt
+++ b/backend/src/CMakeLists.txt
@@ -87,6 +87,7 @@ set (GBE_SRC
     llvm/llvm_intrinsic_lowering.cpp
     llvm/llvm_barrier_nodup.cpp
     llvm/llvm_printf_parser.cpp
+    llvm/llvm_profiling.cpp
     llvm/ExpandConstantExpr.cpp
     llvm/ExpandUtils.cpp
     llvm/PromoteIntegers.cpp
diff --git a/backend/src/llvm/llvm_profiling.cpp b/backend/src/llvm/llvm_profiling.cpp
new file mode 100644
index 0000000..c52e241
--- /dev/null
+++ b/backend/src/llvm/llvm_profiling.cpp
@@ -0,0 +1,210 @@
+/*
+ * Copyright © 2012 Intel Corporation
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * \file llvm_profiling.cpp
+ * This file will insert some instructions for each profiling point.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "llvm/Config/llvm-config.h"
+#if LLVM_VERSION_MINOR <= 2
+#include "llvm/Function.h"
+#include "llvm/InstrTypes.h"
+#include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
+#include "llvm/Module.h"
+#else
+#include "llvm/IR/Function.h"
+#include "llvm/IR/InstrTypes.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#endif  /* LLVM_VERSION_MINOR <= 2 */
+#include "llvm/Pass.h"
+#if LLVM_VERSION_MINOR <= 1
+#include "llvm/Support/IRBuilder.h"
+#elif LLVM_VERSION_MINOR == 2
+#include "llvm/IRBuilder.h"
+#else
+#include "llvm/IR/IRBuilder.h"
+#endif /* LLVM_VERSION_MINOR <= 1 */
+
+#if LLVM_VERSION_MINOR >= 5
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/CFG.h"
+#else
+#include "llvm/Support/CallSite.h"
+#include "llvm/Support/CFG.h"
+#endif
+
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/IR/Attributes.h"
+
+#include "llvm/llvm_gen_backend.hpp"
+#include "sys/map.hpp"
+
+#include <iostream>
+#include <vector>
+
+
+using namespace llvm;
+using std::vector;
+
+
+namespace gbe
+{
+  using namespace ir;
+
+  class ProfilingInserter : public FunctionPass
+  {
+  public:
+    static char ID;
+    Module* module;
+    IRBuilder<>* builder;
+    Type* intTy;
+    Type *ptrTy;
+    int profilingType;
+
+    ProfilingInserter(int profiling) : FunctionPass(ID), profilingType(profiling)
+    {
+      module = NULL;
+      builder = NULL;
+      intTy = NULL;
+      ptrTy = NULL;
+    }
+
+    ~ProfilingInserter(void)
+    {
+    }
+
+    virtual const char *getPassName() const
+    {
+      return "Timestamp Parser";
+    }
+
+    virtual bool runOnFunction(llvm::Function &F);
+  };
+
+  bool ProfilingInserter::runOnFunction(llvm::Function &F)
+  {
+    bool changed = false;
+    int pointNum = 0;
+
+    switch (F.getCallingConv()) {
+#if LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR <= 2
+      case CallingConv::PTX_Device:
+        return false;
+      case CallingConv::PTX_Kernel:
+#else
+      case CallingConv::C:
+      case CallingConv::Fast:
+      case CallingConv::SPIR_KERNEL:
+#endif
+        break;
+      default:
+        GBE_ASSERTM(false, "Unsupported calling convention");
+    }
+
+    // As we inline all function calls, so skip non-kernel functions
+    bool bKernel = isKernelFunction(F);
+    if (!bKernel) return changed;
+
+    module = F.getParent();
+    intTy = IntegerType::get(module->getContext(), 32);
+    ptrTy = Type::getInt32PtrTy(module->getContext(), 1);
+    builder = new IRBuilder<>(module->getContext());
+
+    /* alloc a new buffer ptr to collect the timestamps. */
+    builder->SetInsertPoint(F.begin()->begin());
+    llvm::Constant *profilingBuf = module->getGlobalVariable("__gen_ocl_profiling_buf");
+    if (!profilingBuf) {
+      profilingBuf = new GlobalVariable(*module, intTy, false,
+          GlobalVariable::ExternalLinkage, nullptr, StringRef("__gen_ocl_profiling_buf"),
+          nullptr, GlobalVariable::NotThreadLocal, 1);
+    }
+
+    changed = true;
+
+    for (llvm::Function::iterator B = F.begin(), BE = F.end(); B != BE; B++) {
+      /* Skip the empty blocks. */
+      if (B->empty())
+        continue;
+
+      BasicBlock::iterator instI = B->begin();
+      for ( ; instI != B->end(); instI++) {
+        if (dyn_cast<llvm::PHINode>(instI))
+          continue;
+        if (dyn_cast<llvm::ReturnInst>(instI)) {
+          instI++;
+          GBE_ASSERT(instI == B->end());
+          break;
+        }
+        if (dyn_cast<llvm::BranchInst>(instI)) {
+          instI++;
+          GBE_ASSERT(instI == B->end());
+          break;
+        }
+        break;
+      }
+
+      if (instI == B->end())
+        continue;
+
+      if (pointNum >= 20) // To many timestamp.
+        continue;
+
+      // Insert the first one at beginning of not PHI.
+      builder->SetInsertPoint(instI);
+      /* Add the timestamp store function call. */
+      // __gen_ocl_store_timestamp(int nth, int type);
+      builder->CreateCall2(cast<llvm::Function>(module->getOrInsertFunction(
+              "__gen_ocl_calc_timestamp", Type::getVoidTy(module->getContext()),
+              IntegerType::getInt32Ty(module->getContext()),
+              IntegerType::getInt32Ty(module->getContext()),
+              NULL)),
+          /* the args */ ConstantInt::get(intTy, pointNum++), ConstantInt::get(intTy, profilingType));
+    }
+    /* At the end and before return, we want to store the profiling info. */
+    llvm::Function::iterator BE = F.end();
+    BE--;
+    BasicBlock::iterator retInst = BE->end();
+    retInst--;
+    GBE_ASSERT(dyn_cast<llvm::ReturnInst>(retInst));
+    builder->SetInsertPoint(retInst);
+    builder->CreateCall2(cast<llvm::Function>(module->getOrInsertFunction(
+            "__gen_ocl_store_profiling", Type::getVoidTy(module->getContext()),
+            ptrTy,
+            IntegerType::getInt32Ty(module->getContext()),
+            NULL)),
+        /* the args */profilingBuf, ConstantInt::get(intTy, profilingType));
+
+    delete builder;
+    return changed;
+  }
+
+  FunctionPass* createProfilingInserterPass(int profilingType)
+  {
+    return new ProfilingInserter(profilingType);
+  }
+  char ProfilingInserter::ID = 0;
+
+} // end namespace
-- 
1.7.9.5