Add Global AA pass

Author: CodaFi

Sources/LLVM/PassManager.swift

@@ -141,6 +141,12 @@ public enum Pass {
   case scopedNoAliasAA
   /// LLVM's primary stateless and local alias analysis.
   case basicAliasAnalysis
+  /// Performs alias and mod/ref analysis for internal global values that
+  /// do not have their address taken.
+  ///
+  /// Internal global variables that are only loaded from may be marked as
+  /// constants.
+  case globalsAliasAnalysis
   /// This pass is used to ensure that functions have at most one return
   /// instruction in them.  Additionally, it keeps track of which node is
   /// the new exit node of the CFG.

Sources/LLVM/PassPipeliner.swift

@@ -321,6 +321,8 @@ extension PassPipeliner {
       LLVMAddScopedNoAliasAAPass(passManager)
     case .basicAliasAnalysis:
       LLVMAddBasicAliasAnalysisPass(passManager)
+    case .globalsAliasAnalysis:
+      LLVMAddGlobalsAAWrapperPass(passManager)
     case .unifyFunctionExitNodes:
       LLVMAddUnifyFunctionExitNodesPass(passManager)
     case .alwaysInliner:

Sources/llvmshims/include/shim.h

@@ -98,6 +98,8 @@ void LLVMAppendExistingBasicBlock(LLVMValueRef Fn,
 
 void LLVMAddAddDiscriminatorsPass(LLVMPassManagerRef PM);
 
+void LLVMAddGlobalsAAWrapperPass(LLVMPassManagerRef PM);
+
 void LLVMAddInternalizePassWithMustPreservePredicate(
   LLVMPassManagerRef PM, void *Context,
   LLVMBool (*MustPreserve)(LLVMValueRef, void *));

Sources/llvmshims/src/shim.cpp

@@ -127,6 +127,9 @@ extern "C" {
   // https://reviews.llvm.org/D58624
   void LLVMAddAddDiscriminatorsPass(LLVMPassManagerRef PM);
 
+  // https://reviews.llvm.org/D66237
+  void LLVMAddGlobalsAAWrapperPass(LLVMPassManagerRef PM);
+
   // https://reviews.llvm.org/D62456
   void LLVMAddInternalizePassWithMustPreservePredicate(
    LLVMPassManagerRef PM, void *Context,
@@ -377,3 +380,7 @@ void LLVMAddInternalizePassWithMustPreservePredicate(
     return Pred(wrap(&GV), Context) == 0 ? false : true;
   }));
 }
+
+void LLVMAddGlobalsAAWrapperPass(LLVMPassManagerRef PM) {
+  unwrap(PM)->add(createGlobalsAAWrapperPass());
+}