IRGen: alloc the vector instruction to be located anywhere in a global initializer

So far it was only possible that `vector` is the top-level instruction in an initializer.

Author: eeckstein

lib/IRGen/GenConstant.cpp

@@ -433,6 +433,24 @@ Explosion irgen::emitConstantValue(IRGenModule &IGM, SILValue operand,
   } else if (auto *atp = dyn_cast<AddressToPointerInst>(operand)) {
     auto *val = emitConstantValue(IGM, atp->getOperand()).claimNextConstant();
     return val;
+  } else if (auto *vector = dyn_cast<VectorInst>(operand)) {
+    if (flatten) {
+      Explosion out;
+      for (SILValue element : vector->getElements()) {
+        Explosion e = emitConstantValue(IGM, element, flatten);
+        out.add(e.claimAll());
+      }
+      return out;
+    }
+    llvm::SmallVector<llvm::Constant *, 8> elementValues;
+    for (SILValue element : vector->getElements()) {
+      auto &ti = cast<FixedTypeInfo>(IGM.getTypeInfo(element->getType()));
+      Size paddingBytes = ti.getFixedStride() - ti.getFixedSize();
+      Explosion e = emitConstantValue(IGM, element, flatten);
+      elementValues.push_back(IGM.getConstantValue(std::move(e), paddingBytes.getValue()));
+    }
+    auto *arrTy = llvm::ArrayType::get(elementValues[0]->getType(), elementValues.size());
+    return llvm::ConstantArray::get(arrTy, elementValues);
   } else {
     llvm_unreachable("Unsupported SILInstruction in static initializer!");
   }

lib/IRGen/GenDecl.cpp

@@ -2847,18 +2847,6 @@ llvm::Constant *IRGenModule::getGlobalInitValue(SILGlobalVariable *var,
       return llvm::ConstantAggregateZero::get(arrayTy);
     }
 
-    if (auto *vector = dyn_cast<VectorInst>(initInst)) {
-      llvm::SmallVector<llvm::Constant *, 8> elementValues;
-      for (SILValue element : vector->getElements()) {
-        auto &ti = cast<FixedTypeInfo>(getTypeInfo(element->getType()));
-        Size paddingBytes = ti.getFixedStride() - ti.getFixedSize();
-        Explosion e = emitConstantValue(*this, element);
-        elementValues.push_back(getConstantValue(std::move(e), paddingBytes.getValue()));
-      }
-      auto *arrTy = llvm::ArrayType::get(elementValues[0]->getType(), elementValues.size());
-      return llvm::ConstantArray::get(arrTy, elementValues);
-    }
-
     Explosion initExp = emitConstantValue(*this,
                                   cast<SingleValueInstruction>(initInst));
     return getConstantValue(std::move(initExp), /*paddingBytes=*/ 0);

lib/SIL/Verifier/SILVerifier.cpp

@@ -7727,8 +7727,6 @@ void SILGlobalVariable::verify() const {
       assert(!init->use_empty() && "dead instruction in static initializer");
       assert(!isa<ObjectInst>(init) &&
              "object instruction is only allowed for final initial value");
-      assert(!isa<VectorInst>(init) &&
-             "vector instruction is only allowed for final initial value");
     }
     assert(I.getParent() == &StaticInitializerBlock);
   }