[llvm-commits] [llvm] r121042 - /llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp

[Chris Lattner]

Author: lattner
Date: Mon Dec  6 15:53:07 2010
New Revision: 121042

URL: http://llvm.org/viewvc/llvm-project?rev=121042&view=rev
Log:
replace a linear scan with a symtab lookup, reduce indentation.
No functionality change.

Modified:
    llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp

Modified: llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp?rev=121042&r1=121041&r2=121042&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/GlobalOpt.cpp Mon Dec  6 15:53:07 2010
@@ -1930,47 +1930,47 @@
 /// FindGlobalCtors - Find the llvm.globalctors list, verifying that all
 /// initializers have an init priority of 65535.
 GlobalVariable *GlobalOpt::FindGlobalCtors(Module &M) {
-  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
-       I != E; ++I)
-    if (I->getName() == "llvm.global_ctors") {
-      // Found it, verify it's an array of { int, void()* }.
-      const ArrayType *ATy =dyn_cast<ArrayType>(I->getType()->getElementType());
-      if (!ATy) return 0;
-      const StructType *STy = dyn_cast<StructType>(ATy->getElementType());
-      if (!STy || STy->getNumElements() != 2 ||
-          !STy->getElementType(0)->isIntegerTy(32)) return 0;
-      const PointerType *PFTy = dyn_cast<PointerType>(STy->getElementType(1));
-      if (!PFTy) return 0;
-      const FunctionType *FTy = dyn_cast<FunctionType>(PFTy->getElementType());
-      if (!FTy || !FTy->getReturnType()->isVoidTy() ||
-          FTy->isVarArg() || FTy->getNumParams() != 0)
-        return 0;
-
-      // Verify that the initializer is simple enough for us to handle. We are
-      // only allowed to optimize the initializer if it is unique.
-      if (!I->hasUniqueInitializer()) return 0;
-      ConstantArray *CA = dyn_cast<ConstantArray>(I->getInitializer());
-      if (!CA) return 0;
-      for (User::op_iterator i = CA->op_begin(), e = CA->op_end(); i != e; ++i)
-        if (ConstantStruct *CS = dyn_cast<ConstantStruct>(*i)) {
-          if (isa<ConstantPointerNull>(CS->getOperand(1)))
-            continue;
-
-          // Must have a function or null ptr.
-          if (!isa<Function>(CS->getOperand(1)))
-            return 0;
-
-          // Init priority must be standard.
-          ConstantInt *CI = dyn_cast<ConstantInt>(CS->getOperand(0));
-          if (!CI || CI->getZExtValue() != 65535)
-            return 0;
-        } else {
-          return 0;
-        }
+  GlobalVariable *GV = M.getGlobalVariable("llvm.global_ctors");
+  if (GV == 0) return 0;
+  
+  // Found it, verify it's an array of { int, void()* }.
+  const ArrayType *ATy =dyn_cast<ArrayType>(GV->getType()->getElementType());
+  if (!ATy) return 0;
+  const StructType *STy = dyn_cast<StructType>(ATy->getElementType());
+  if (!STy || STy->getNumElements() != 2 ||
+      !STy->getElementType(0)->isIntegerTy(32)) return 0;
+  const PointerType *PFTy = dyn_cast<PointerType>(STy->getElementType(1));
+  if (!PFTy) return 0;
+  const FunctionType *FTy = dyn_cast<FunctionType>(PFTy->getElementType());
+  if (!FTy || !FTy->getReturnType()->isVoidTy() ||
+      FTy->isVarArg() || FTy->getNumParams() != 0)
+    return 0;
 
-      return I;
-    }
-  return 0;
+  // Verify that the initializer is simple enough for us to handle. We are
+  // only allowed to optimize the initializer if it is unique.
+  if (!GV->hasUniqueInitializer()) return 0;
+  
+  ConstantArray *CA = dyn_cast<ConstantArray>(GV->getInitializer());
+  if (!CA) return 0;
+  
+  for (User::op_iterator i = CA->op_begin(), e = CA->op_end(); i != e; ++i) {
+    ConstantStruct *CS = dyn_cast<ConstantStruct>(*i);
+    if (CS == 0) return 0;
+    
+    if (isa<ConstantPointerNull>(CS->getOperand(1)))
+      continue;
+
+    // Must have a function or null ptr.
+    if (!isa<Function>(CS->getOperand(1)))
+      return 0;
+
+    // Init priority must be standard.
+    ConstantInt *CI = dyn_cast<ConstantInt>(CS->getOperand(0));
+    if (!CI || CI->getZExtValue() != 65535)
+      return 0;
+  }
+
+  return GV;
 }
 
 /// ParseGlobalCtors - Given a llvm.global_ctors list that we can understand,