Emit line number for alloca - continued.

Change-Id: I29d600effe10794df3d4f1ba5362725129342b1c

Author: PiotrFusik

IGC/Compiler/Optimizer/OpenCLPasses/PrivateMemory/PrivateMemoryResolution.cpp

@@ -34,6 +34,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 #include "common/LLVMWarningsPush.hpp"
 #include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugInfoMetadata.h"
 #include "llvm/IR/Dominators.h"
 #include "common/LLVMWarningsPop.hpp"
 
@@ -77,7 +78,7 @@ namespace IGC {
 
         /// @brief  Resolve collected alloca instructions.
         /// @return true if there were resolved alloca, false otherwise.
-        bool resolveAllocaInstuctions(bool stackCall);
+        bool resolveAllocaInstructions(bool stackCall);
 
         /// Initialize setup like UseScratchSpacePrivateMemory.
         bool safeToUseScratchSpace(llvm::Module& M) const;
@@ -493,7 +494,7 @@ bool PrivateMemoryResolution::runOnModule(llvm::Module& M)
         }
         bool hasStackCall = (FGA && FGA->getGroup(m_currFunction)->hasStackCall());
         // Resolve collected alloca instructions for current function
-        changed |= resolveAllocaInstuctions(hasStackCall);
+        changed |= resolveAllocaInstructions(hasStackCall);
     }
 
     if (changed)
@@ -540,7 +541,7 @@ bool PrivateMemoryResolution::runOnModule(llvm::Module& M)
 static void sinkAllocas(SmallVectorImpl<AllocaInst*>& Allocas) {
     assert(!Allocas.empty());
     DominatorTree DT;
-    bool Calcluated = false;
+    bool Calcuated = false;
 
     // For each alloca, sink it if it has a use that dominates all other uses.
     // This use is called the dominating use.
@@ -567,10 +568,10 @@ static void sinkAllocas(SmallVectorImpl<AllocaInst*>& Allocas) {
             continue;
 
         // Compute dominator tree lazily.
-        if (!Calcluated) {
+        if (!Calcuated) {
             Function* F = AI->getParent()->getParent();
             DT.recalculate(*F);
-            Calcluated = true;
+            Calcuated = true;
         }
 
         // Find the Nearest Common Denominator for all the uses
@@ -683,7 +684,7 @@ class TransposeHelperPrivateMem : public TransposeHelper
 };
 
 
-bool PrivateMemoryResolution::resolveAllocaInstuctions(bool stackCall)
+bool PrivateMemoryResolution::resolveAllocaInstructions(bool stackCall)
 {
     // It is possible that there is no alloca instruction in the caller but there
     // is alloca in the callee. Save the total private memory to the metadata.
@@ -745,9 +746,11 @@ bool PrivateMemoryResolution::resolveAllocaInstuctions(bool stackCall)
     llvm::IRBuilder<> entryBuilder(&*m_currFunction->getEntryBlock().getFirstInsertionPt());
     ImplicitArgs implicitArgs(*m_currFunction, m_pMdUtils);
 
-    // This declaration will invoke constructor of DebugLoc class and result in an empty DebugLoc
-    // instance, ie with line and scope set to 0.
-    IF_DEBUG_INFO(DebugLoc emptyDebugLoc);
+    // Construct an empty DebugLoc.
+    IF_DEBUG_INFO(DebugLoc entryDebugLoc);
+    // Assign with the function location if available.
+    IF_DEBUG_INFO_IF(DISubprogram *subprogram = m_currFunction->getSubprogram(), entryDebugLoc = DebugLoc::get(subprogram->getLine(), 0, subprogram););
+    IF_DEBUG_INFO(entryBuilder.SetCurrentDebugLocation(entryDebugLoc));
 
     if (stackCall)
     {
@@ -760,7 +763,7 @@ bool PrivateMemoryResolution::resolveAllocaInstuctions(bool stackCall)
         {
             bool isUniform = pAI->getMetadata("uniform") != nullptr;
             llvm::IRBuilder<> builder(pAI);
-            IF_DEBUG_INFO(builder.SetCurrentDebugLocation(emptyDebugLoc));
+            IF_DEBUG_INFO(builder.SetCurrentDebugLocation(entryDebugLoc));
 
             // SP will be adjusted to include all the alloca space, therefore offset need to be adjusted back
             int scalarBufferOffset = m_ModAllocaInfo->getBufferOffset(pAI) - totalPrivateMemPerWI;
@@ -808,14 +811,13 @@ bool PrivateMemoryResolution::resolveAllocaInstuctions(bool stackCall)
             llvm::IRBuilder<> builder(pAI);
             // Post upgrade to LLVM 3.5.1, it was found that inliner propagates debug info of callee
             // in to the alloca. Further, those allocas are somehow hoisted to the top of program.
-            // When those allocas are lowered to below sequence, they result in prolog instructions
+            // When those allocas are lowered to below sequence, they result in prologue instructions
             // pointing to a much later line of code. This causes a single src line to now have
             // multiple VISA offset mappings and prevents debugger from setting breakpoints
-            // correctly. So instead, we clear DebugLoc for the instructions generated by lowering
-            // alloca and so the incorrect mapping will not be emitted.
+            // correctly. So instead, we set DebugLoc for the instructions generated by lowering
+            // alloca to mark that they are part of the prologue.
             // Note: As per Amjad, later LLVM version has a fix for this in llvm/lib/Transforms/Utils/InlineFunction.cpp.
-
-            IF_DEBUG_INFO(builder.SetCurrentDebugLocation(emptyDebugLoc));
+            IF_DEBUG_INFO(builder.SetCurrentDebugLocation(entryDebugLoc));
 
             // Get buffer information from the analysis
             unsigned int scalarBufferOffset = m_ModAllocaInfo->getBufferOffset(pAI);
@@ -949,7 +951,7 @@ bool PrivateMemoryResolution::resolveAllocaInstuctions(bool stackCall)
         // %privateBuffer               = bitcast i8* %offsettmp1 to <buffer type>
 
         llvm::IRBuilder<> builder(pAI);
-        IF_DEBUG_INFO(builder.SetCurrentDebugLocation(emptyDebugLoc));
+        IF_DEBUG_INFO(builder.SetCurrentDebugLocation(entryDebugLoc));
         bool isUniform = pAI->getMetadata("uniform") != nullptr;
         // Get buffer information from the analysis
         unsigned int scalarBufferOffset = m_ModAllocaInfo->getBufferOffset(pAI);