XCore handling of thread local lowering

[oota-llvm.git] / lib / Target / XCore / XCoreLowerThreadLocal.cpp

diff --git a/lib/Target/XCore/XCoreLowerThreadLocal.cpp b/lib/Target/XCore/XCoreLowerThreadLocal.cpp
index 2e328b4e3441ab48e4027efa4b9ff84e41df3e68..5a832825148c77eb5dba002df8f1ce2411ad1780 100644 (file)
--- a/lib/Target/XCore/XCoreLowerThreadLocal.cpp
+++ b/lib/Target/XCore/XCoreLowerThreadLocal.cpp
@@ -22,6 +22,8 @@
 #include "llvm/IR/Module.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/NoFolder.h"
+#include "llvm/Support/ValueHandle.h"
 
 #define DEBUG_TYPE "xcore-lower-thread-local"
 
@@ -71,13 +73,94 @@ createLoweredInitializer(ArrayType *NewType, Constant *OriginalInitializer) {
   return ConstantArray::get(NewType, Elements);
 }
 
-static bool hasNonInstructionUse(GlobalVariable *GV) {
-  for (Value::use_iterator UI = GV->use_begin(), E = GV->use_end(); UI != E;
-       ++UI)
-    if (!isa<Instruction>(*UI))
-      return true;
+static Instruction *
+createReplacementInstr(ConstantExpr *CE, Instruction *Instr) {
+  IRBuilder<true,NoFolder> Builder(Instr);
+  unsigned OpCode = CE->getOpcode();
+  switch (OpCode) {
+    case Instruction::GetElementPtr: {
+      SmallVector<Value *,4> CEOpVec(CE->op_begin(), CE->op_end());
+      ArrayRef<Value *> CEOps(CEOpVec);
+      return dyn_cast<Instruction>(Builder.CreateInBoundsGEP(CEOps[0],
+                                                             CEOps.slice(1)));
+    }
+    case Instruction::Add:
+    case Instruction::Sub:
+    case Instruction::Mul:
+    case Instruction::UDiv:
+    case Instruction::SDiv:
+    case Instruction::FDiv:
+    case Instruction::URem:
+    case Instruction::SRem:
+    case Instruction::FRem:
+    case Instruction::Shl:
+    case Instruction::LShr:
+    case Instruction::AShr:
+    case Instruction::And:
+    case Instruction::Or:
+    case Instruction::Xor:
+      return dyn_cast<Instruction>(
+                  Builder.CreateBinOp((Instruction::BinaryOps)OpCode,
+                                      CE->getOperand(0), CE->getOperand(1),
+                                      CE->getName()));
+    case Instruction::Trunc:
+    case Instruction::ZExt:
+    case Instruction::SExt:
+    case Instruction::FPToUI:
+    case Instruction::FPToSI:
+    case Instruction::UIToFP:
+    case Instruction::SIToFP:
+    case Instruction::FPTrunc:
+    case Instruction::FPExt:
+    case Instruction::PtrToInt:
+    case Instruction::IntToPtr:
+    case Instruction::BitCast:
+      return dyn_cast<Instruction>(
+                  Builder.CreateCast((Instruction::CastOps)OpCode,
+                                     CE->getOperand(0), CE->getType(),
+                                     CE->getName()));
+    default:
+      assert(0 && "Unhandled constant expression!\n");
+  }
+}
+
+static bool replaceConstantExprOp(ConstantExpr *CE) {
+  do {
+    SmallVector<WeakVH,8> WUsers;
+    for (Value::use_iterator I = CE->use_begin(), E = CE->use_end();
+         I != E; ++I)
+      WUsers.push_back(WeakVH(*I));
+    while (!WUsers.empty())
+      if (WeakVH WU = WUsers.pop_back_val()) {
+        if (Instruction *Instr = dyn_cast<Instruction>(WU)) {
+          Instruction *NewInst = createReplacementInstr(CE, Instr);
+          assert(NewInst && "Must build an instruction\n");
+          // If NewInst uses a CE being handled in an earlier recursion the
+          // earlier recursion's do-while-hasNUsesOrMore(1) will run again.
+          Instr->replaceUsesOfWith(CE, NewInst);
+        } else {
+          ConstantExpr *CExpr = dyn_cast<ConstantExpr>(WU);
+          if (!CExpr || !replaceConstantExprOp(CExpr))
+            return false;
+        }
+      }
+  } while (CE->hasNUsesOrMore(1)); // Does a recursion's NewInst use CE?
+  CE->destroyConstant();
+  return true;
+}
 
-  return false;
+static bool rewriteNonInstructionUses(GlobalVariable *GV) {
+  SmallVector<WeakVH,8> WUsers;
+  for (Value::use_iterator I = GV->use_begin(), E = GV->use_end(); I != E; ++I)
+    if (!isa<Instruction>(*I))
+      WUsers.push_back(WeakVH(*I));
+  while (!WUsers.empty())
+    if (WeakVH WU = WUsers.pop_back_val()) {
+      ConstantExpr *CE = dyn_cast<ConstantExpr>(WU);
+      if (!CE || !replaceConstantExprOp(CE))
+        return false;
+    }
+  return true;
 }
 
 static bool isZeroLengthArray(Type *Ty) {
@@ -92,14 +175,16 @@ bool XCoreLowerThreadLocal::lowerGlobal(GlobalVariable *GV) {
     return false;
 
   // Skip globals that we can't lower and leave it for the backend to error.
-  if (hasNonInstructionUse(GV) ||
+  if (!rewriteNonInstructionUses(GV) ||
       !GV->getType()->isSized() || isZeroLengthArray(GV->getType()))
     return false;
 
   // Create replacement global.
   ArrayType *NewType = createLoweredType(GV->getType()->getElementType());
-  Constant *NewInitializer = createLoweredInitializer(NewType,
-                                                      GV->getInitializer());
+  Constant *NewInitializer = 0;
+  if (GV->hasInitializer())
+    NewInitializer = createLoweredInitializer(NewType,
+                                              GV->getInitializer());
   GlobalVariable *NewGV =
     new GlobalVariable(*M, NewType, GV->isConstant(), GV->getLinkage(),
                        NewInitializer, "", 0, GlobalVariable::NotThreadLocal,