IRGen: a small refactoring in GenConstant

Just moving a few functions around and make emitConstantValue the main entry point for creating constants.

NFC

Author: eeckstein

lib/IRGen/GenConstant.cpp

@@ -22,6 +22,7 @@
 #include "GenTuple.h"
 #include "TypeInfo.h"
 #include "StructLayout.h"
+#include "Callee.h"
 #include "swift/Basic/Range.h"
 #include "swift/SIL/SILModule.h"
 
@@ -109,11 +110,67 @@ llvm::Constant *irgen::emitAddrOfConstantString(IRGenModule &IGM,
   llvm_unreachable("bad string encoding");
 }
 
-static llvm::Constant *emitConstantValue(IRGenModule &IGM, SILValue operand) {
+namespace {
+
+/// Fill in the missing values for padding.
+void insertPadding(SmallVectorImpl<llvm::Constant *> &Elements,
+                   llvm::StructType *sTy) {
+  // fill in any gaps, which are the explicit padding that swiftc inserts.
+  for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
+    auto &elt = Elements[i];
+    if (elt == nullptr) {
+      auto *eltTy = sTy->getElementType(i);
+      assert(eltTy->isArrayTy() &&
+             eltTy->getArrayElementType()->isIntegerTy(8) &&
+             "Unexpected non-byte-array type for constant struct padding");
+      elt = llvm::UndefValue::get(eltTy);
+    }
+  }
+}
+
+template <typename InstTy, typename NextIndexFunc>
+llvm::Constant *emitConstantStructOrTuple(IRGenModule &IGM, InstTy inst,
+                                          NextIndexFunc nextIndex) {
+  auto type = inst->getType();
+  auto *sTy = cast<llvm::StructType>(IGM.getTypeInfo(type).getStorageType());
+
+  SmallVector<llvm::Constant *, 32> elts(sTy->getNumElements(), nullptr);
+
+  // run over the Swift initializers, putting them into the struct as
+  // appropriate.
+  for (unsigned i = 0, e = inst->getElements().size(); i != e; ++i) {
+    auto operand = inst->getOperand(i);
+    Optional<unsigned> index = nextIndex(IGM, type, i);
+    if (index.hasValue()) {
+      assert(elts[index.getValue()] == nullptr &&
+             "Unexpected constant struct field overlap");
+
+      elts[index.getValue()] = emitConstantValue(IGM, operand);
+    }
+  }
+  insertPadding(elts, sTy);
+  return llvm::ConstantStruct::get(sTy, elts);
+}
+} // end anonymous namespace
+
+llvm::Constant *irgen::emitConstantValue(IRGenModule &IGM, SILValue operand) {
   if (auto *SI = dyn_cast<StructInst>(operand)) {
-    return emitConstantStruct(IGM, SI);
+    // The only way to get a struct's stored properties (which we need to map to
+    // their physical/LLVM index) is to iterate over the properties
+    // progressively. Fortunately the iteration order matches the order of
+    // operands in a StructInst.
+    auto StoredProperties = SI->getStructDecl()->getStoredProperties();
+    auto Iter = StoredProperties.begin();
+
+    return emitConstantStructOrTuple(
+        IGM, SI, [&Iter](IRGenModule &IGM, SILType Type, unsigned _i) mutable {
+          (void)_i;
+          auto *FD = *Iter++;
+          return irgen::getPhysicalStructFieldIndex(IGM, Type, FD);
+        });
   } else if (auto *TI = dyn_cast<TupleInst>(operand)) {
-    return emitConstantTuple(IGM, TI);
+    return emitConstantStructOrTuple(IGM, TI,
+                                     irgen::getPhysicalTupleElementStructIndex);
   } else if (auto *ILI = dyn_cast<IntegerLiteralInst>(operand)) {
     return emitConstantInt(IGM, ILI);
   } else if (auto *FLI = dyn_cast<FloatLiteralInst>(operand)) {
@@ -164,70 +221,6 @@ static llvm::Constant *emitConstantValue(IRGenModule &IGM, SILValue operand) {
   }
 }
 
-namespace {
-
-/// Fill in the missing values for padding.
-void insertPadding(SmallVectorImpl<llvm::Constant *> &Elements,
-                   llvm::StructType *sTy) {
-  // fill in any gaps, which are the explicit padding that swiftc inserts.
-  for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
-    auto &elt = Elements[i];
-    if (elt == nullptr) {
-      auto *eltTy = sTy->getElementType(i);
-      assert(eltTy->isArrayTy() &&
-             eltTy->getArrayElementType()->isIntegerTy(8) &&
-             "Unexpected non-byte-array type for constant struct padding");
-      elt = llvm::UndefValue::get(eltTy);
-    }
-  }
-}
-
-template <typename InstTy, typename NextIndexFunc>
-llvm::Constant *emitConstantStructOrTuple(IRGenModule &IGM, InstTy inst,
-                                          NextIndexFunc nextIndex) {
-  auto type = inst->getType();
-  auto *sTy = cast<llvm::StructType>(IGM.getTypeInfo(type).getStorageType());
-
-  SmallVector<llvm::Constant *, 32> elts(sTy->getNumElements(), nullptr);
-
-  // run over the Swift initializers, putting them into the struct as
-  // appropriate.
-  for (unsigned i = 0, e = inst->getElements().size(); i != e; ++i) {
-    auto operand = inst->getOperand(i);
-    Optional<unsigned> index = nextIndex(IGM, type, i);
-    if (index.hasValue()) {
-      assert(elts[index.getValue()] == nullptr &&
-             "Unexpected constant struct field overlap");
-
-      elts[index.getValue()] = emitConstantValue(IGM, operand);
-    }
-  }
-  insertPadding(elts, sTy);
-  return llvm::ConstantStruct::get(sTy, elts);
-}
-} // end anonymous namespace
-
-llvm::Constant *irgen::emitConstantStruct(IRGenModule &IGM, StructInst *SI) {
-  // The only way to get a struct's stored properties (which we need to map to
-  // their physical/LLVM index) is to iterate over the properties
-  // progressively. Fortunately the iteration order matches the order of
-  // operands in a StructInst.
-  auto StoredProperties = SI->getStructDecl()->getStoredProperties();
-  auto Iter = StoredProperties.begin();
-
-  return emitConstantStructOrTuple(
-      IGM, SI, [&Iter](IRGenModule &IGM, SILType Type, unsigned _i) mutable {
-        (void)_i;
-        auto *FD = *Iter++;
-        return irgen::getPhysicalStructFieldIndex(IGM, Type, FD);
-      });
-}
-
-llvm::Constant *irgen::emitConstantTuple(IRGenModule &IGM, TupleInst *TI) {
-  return emitConstantStructOrTuple(IGM, TI,
-                                   irgen::getPhysicalTupleElementStructIndex);
-}
-
 llvm::Constant *irgen::emitConstantObject(IRGenModule &IGM, ObjectInst *OI,
                                          StructLayout *ClassLayout) {
   auto *sTy = cast<llvm::StructType>(ClassLayout->getType());

lib/IRGen/GenConstant.h

@@ -37,11 +37,8 @@ llvm::Constant *emitConstantFP(IRGenModule &IGM, FloatLiteralInst *FLI);
 llvm::Constant *emitAddrOfConstantString(IRGenModule &IGM,
                                          StringLiteralInst *SLI);
 
-/// Construct a struct literal from a StructInst containing constant values.
-llvm::Constant *emitConstantStruct(IRGenModule &IGM, StructInst *SI);
-
-/// Construct a struct literal from a TupleInst containing constant values.
-llvm::Constant *emitConstantTuple(IRGenModule &IGM, TupleInst *TI);
+/// Construct a constant from a SILValue containing constant values.
+llvm::Constant *emitConstantValue(IRGenModule &IGM, SILValue value);
 
 /// Construct an object (with a HeapObject header) from an ObjectInst
 /// containing constant values.

lib/IRGen/IRGenSIL.cpp

@@ -6414,17 +6414,8 @@ void IRGenModule::emitSILStaticInitializers() {
       continue;
     }
 
-    // Set the IR global's initializer to the constant for this SIL
-    // struct.
-    if (auto *SI = dyn_cast<StructInst>(InitValue)) {
-      IRGlobal->setInitializer(emitConstantStruct(*this, SI));
-      continue;
-    }
-
-    // Set the IR global's initializer to the constant for this SIL
-    // tuple.
-    auto *TI = cast<TupleInst>(InitValue);
-    IRGlobal->setInitializer(emitConstantTuple(*this, TI));
+    IRGlobal->setInitializer(
+      emitConstantValue(*this, cast<SingleValueInstruction>(InitValue)));
   }
 }