Avoid generation of dead code in a few more situations.
- Emit variable declarations as "simple", we want to avoid forcing the creation
of a dummy basic block, but still need to make the variable available for
later use.
- With that, we can now skip IRgen for other unreachable statements (which
don't define a label).
- Anders, I added two fixmes on calls to EmitVLASize, can you check them?
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@76361 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index eab5814..6da8649 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -112,7 +112,6 @@
}
void CodeGenFunction::EmitStaticBlockVarDecl(const VarDecl &D) {
-
llvm::Value *&DMEntry = LocalDeclMap[&D];
assert(DMEntry == 0 && "Decl already exists in localdeclmap!");
@@ -124,6 +123,8 @@
DMEntry = GV;
// Make sure to evaluate VLA bounds now so that we have them for later.
+ //
+ // FIXME: Can this happen?
if (D.getType()->isVariablyModifiedType())
EmitVLASize(D.getType());
@@ -274,9 +275,12 @@
::InternalLinkage);
}
+ // FIXME: Can this happen?
if (Ty->isVariablyModifiedType())
EmitVLASize(Ty);
} else {
+ EnsureInsertPoint();
+
if (!DidCallStackSave) {
// Save the stack.
const llvm::Type *LTy =
@@ -321,6 +325,11 @@
// Emit debug info for local var declaration.
if (CGDebugInfo *DI = getDebugInfo()) {
+ // FIXME: Remove this once debug info isn't modeled as instructions.
+ EnsureInsertPoint();
+
+ EmitStopPoint(S);
+
DI->setLocation(D.getLocation());
if (Target.useGlobalsForAutomaticVariables()) {
DI->EmitGlobalVariable(static_cast<llvm::GlobalVariable *>(DeclPtr), &D);
@@ -338,7 +347,18 @@
}
// If this local has an initializer, emit it now.
- if (const Expr *Init = D.getInit()) {
+ const Expr *Init = D.getInit();
+
+ // If we are at an unreachable point, we don't need to emit the initializer
+ // unless it contains a label.
+ if (!HaveInsertPoint()) {
+ if (!ContainsLabel(Init))
+ Init = 0;
+ else
+ EnsureInsertPoint();
+ }
+
+ if (Init) {
llvm::Value *Loc = DeclPtr;
if (isByRef) {
bool needsCopyDispose = BlockRequiresCopying(Ty);
@@ -357,10 +377,12 @@
EmitAggExpr(Init, Loc, D.getType().isVolatileQualified());
}
}
+
if (isByRef) {
const llvm::PointerType *PtrToInt8Ty
= VMContext.getPointerTypeUnqual(llvm::Type::Int8Ty);
+ EnsureInsertPoint();
llvm::Value *isa_field = Builder.CreateStructGEP(DeclPtr, 0);
llvm::Value *forwarding_field = Builder.CreateStructGEP(DeclPtr, 1);
llvm::Value *flags_field = Builder.CreateStructGEP(DeclPtr, 2);