Fix alignment accessors

Alignment is not a general property of values, only
globals, allocas, stores, and loads.

Author: CodaFi

Sources/LLVM/IRBuilder.swift

@@ -1090,11 +1090,14 @@ public class IRBuilder {
   ///
   /// - parameter type: The sized type used to determine the amount of stack
   ///   memory to allocate.
+  /// - parameter alignment: The alignment of the access.
   /// - parameter name: The name for the newly inserted instruction.
   ///
   /// - returns: A value representing `void`.
-  public func buildAlloca(type: IRType, name: String = "") -> IRValue {
-    return LLVMBuildAlloca(llvm, type.asLLVM(), name)
+  public func buildAlloca(type: IRType, alignment: Int = 0, name: String = "") -> IRValue {
+    let allocaInst = LLVMBuildAlloca(llvm, type.asLLVM(), name)!
+    LLVMSetAlignment(allocaInst, UInt32(alignment))
+    return allocaInst
   }
 
   /// Builds a store instruction that stores the first value into the location
@@ -1105,13 +1108,15 @@ public class IRBuilder {
   /// - parameter ordering: The ordering effect of the fence for this store,
   ///   if any.  Defaults to a nonatomic store.
   /// - parameter volatile: Whether this is a store to a volatile memory location.
+  /// - parameter alignment: The alignment of the access.
   ///
   /// - returns: A value representing `void`.
   @discardableResult
-  public func buildStore(_ val: IRValue, to ptr: IRValue, ordering: AtomicOrdering = .notAtomic, volatile: Bool = false) -> IRValue {
+  public func buildStore(_ val: IRValue, to ptr: IRValue, ordering: AtomicOrdering = .notAtomic, volatile: Bool = false, alignment: Int = 0) -> IRValue {
     let storeInst = LLVMBuildStore(llvm, val.asLLVM(), ptr.asLLVM())!
     LLVMSetOrdering(storeInst, ordering.llvm)
     LLVMSetVolatile(storeInst, volatile.llvm)
+    LLVMSetAlignment(storeInst, UInt32(alignment))
     return storeInst
   }
 
@@ -1122,14 +1127,16 @@ public class IRBuilder {
   /// - parameter ordering: The ordering effect of the fence for this load,
   ///   if any.  Defaults to a nonatomic load.
   /// - parameter volatile: Whether this is a load from a volatile memory location.
+  /// - parameter alignment: The alignment of the access.
   /// - parameter name: The name for the newly inserted instruction.
   ///
   /// - returns: A value representing the result of a load from the given
   ///   pointer value.
-  public func buildLoad(_ ptr: IRValue, ordering: AtomicOrdering = .notAtomic, volatile: Bool = false, name: String = "") -> IRValue {
+  public func buildLoad(_ ptr: IRValue, ordering: AtomicOrdering = .notAtomic, volatile: Bool = false, alignment: Int = 0, name: String = "") -> IRValue {
     let loadInst = LLVMBuildLoad(llvm, ptr.asLLVM(), name)!
     LLVMSetOrdering(loadInst, ordering.llvm)
     LLVMSetVolatile(loadInst, volatile.llvm)
+    LLVMSetAlignment(loadInst, UInt32(alignment))
     return loadInst
   }
 

Sources/LLVM/IRGlobal.swift

@@ -7,6 +7,12 @@ import cllvm
 public protocol IRGlobal: IRValue {}
 
 extension IRGlobal {
+  /// Retrieves the alignment of this value.
+  public var alignment: Int {
+    get { return Int(LLVMGetAlignment(asLLVM())) }
+    set { LLVMSetAlignment(asLLVM(), UInt32(newValue)) }
+  }
+  
   /// Retrieves the linkage information for this global.
   public var linkage: Linkage {
     get { return Linkage(llvm: LLVMGetLinkage(asLLVM())) }

Sources/LLVM/IRValue.swift

@@ -15,12 +15,6 @@ public extension IRValue {
     return convertType(LLVMTypeOf(asLLVM()))
   }
 
-  /// Retrieves the alignment of this value.
-  public var alignment: Int {
-    get { return Int(LLVMGetAlignment(asLLVM())) }
-    set { LLVMSetAlignment(asLLVM(), UInt32(newValue)) }
-  }
-
   /// Returns whether this value is a constant.
   public var isConstant: Bool {
     return LLVMIsConstant(asLLVM()) != 0