Check in LLVM r95781.
diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
new file mode 100644
index 0000000..008a480
--- /dev/null
+++ b/lib/CodeGen/CGStmt.cpp
@@ -0,0 +1,1138 @@
+//===--- CGStmt.cpp - Emit LLVM Code from Statements ----------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This contains code to emit Stmt nodes as LLVM code.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CGDebugInfo.h"
+#include "CodeGenModule.h"
+#include "CodeGenFunction.h"
+#include "clang/AST/StmtVisitor.h"
+#include "clang/Basic/PrettyStackTrace.h"
+#include "clang/Basic/TargetInfo.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/InlineAsm.h"
+#include "llvm/Intrinsics.h"
+#include "llvm/Target/TargetData.h"
+using namespace clang;
+using namespace CodeGen;
+
+//===----------------------------------------------------------------------===//
+// Statement Emission
+//===----------------------------------------------------------------------===//
+
+void CodeGenFunction::EmitStopPoint(const Stmt *S) {
+ if (CGDebugInfo *DI = getDebugInfo()) {
+ DI->setLocation(S->getLocStart());
+ DI->EmitStopPoint(CurFn, Builder);
+ }
+}
+
+void CodeGenFunction::EmitStmt(const Stmt *S) {
+ assert(S && "Null statement?");
+
+ // Check if we can handle this without bothering to generate an
+ // insert point or debug info.
+ if (EmitSimpleStmt(S))
+ return;
+
+ // Check if we are generating unreachable code.
+ if (!HaveInsertPoint()) {
+ // If so, and the statement doesn't contain a label, then we do not need to
+ // generate actual code. This is safe because (1) the current point is
+ // unreachable, so we don't need to execute the code, and (2) we've already
+ // handled the statements which update internal data structures (like the
+ // local variable map) which could be used by subsequent statements.
+ if (!ContainsLabel(S)) {
+ // Verify that any decl statements were handled as simple, they may be in
+ // scope of subsequent reachable statements.
+ assert(!isa<DeclStmt>(*S) && "Unexpected DeclStmt!");
+ return;
+ }
+
+ // Otherwise, make a new block to hold the code.
+ EnsureInsertPoint();
+ }
+
+ // Generate a stoppoint if we are emitting debug info.
+ EmitStopPoint(S);
+
+ switch (S->getStmtClass()) {
+ default:
+ // Must be an expression in a stmt context. Emit the value (to get
+ // side-effects) and ignore the result.
+ if (!isa<Expr>(S))
+ ErrorUnsupported(S, "statement");
+
+ EmitAnyExpr(cast<Expr>(S), 0, false, true);
+
+ // Expression emitters don't handle unreachable blocks yet, so look for one
+ // explicitly here. This handles the common case of a call to a noreturn
+ // function.
+ if (llvm::BasicBlock *CurBB = Builder.GetInsertBlock()) {
+ if (CurBB->empty() && CurBB->use_empty()) {
+ CurBB->eraseFromParent();
+ Builder.ClearInsertionPoint();
+ }
+ }
+ break;
+ case Stmt::IndirectGotoStmtClass:
+ EmitIndirectGotoStmt(cast<IndirectGotoStmt>(*S)); break;
+
+ case Stmt::IfStmtClass: EmitIfStmt(cast<IfStmt>(*S)); break;
+ case Stmt::WhileStmtClass: EmitWhileStmt(cast<WhileStmt>(*S)); break;
+ case Stmt::DoStmtClass: EmitDoStmt(cast<DoStmt>(*S)); break;
+ case Stmt::ForStmtClass: EmitForStmt(cast<ForStmt>(*S)); break;
+
+ case Stmt::ReturnStmtClass: EmitReturnStmt(cast<ReturnStmt>(*S)); break;
+
+ case Stmt::SwitchStmtClass: EmitSwitchStmt(cast<SwitchStmt>(*S)); break;
+ case Stmt::AsmStmtClass: EmitAsmStmt(cast<AsmStmt>(*S)); break;
+
+ case Stmt::ObjCAtTryStmtClass:
+ EmitObjCAtTryStmt(cast<ObjCAtTryStmt>(*S));
+ break;
+ case Stmt::ObjCAtCatchStmtClass:
+ assert(0 && "@catch statements should be handled by EmitObjCAtTryStmt");
+ break;
+ case Stmt::ObjCAtFinallyStmtClass:
+ assert(0 && "@finally statements should be handled by EmitObjCAtTryStmt");
+ break;
+ case Stmt::ObjCAtThrowStmtClass:
+ EmitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(*S));
+ break;
+ case Stmt::ObjCAtSynchronizedStmtClass:
+ EmitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(*S));
+ break;
+ case Stmt::ObjCForCollectionStmtClass:
+ EmitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(*S));
+ break;
+
+ case Stmt::CXXTryStmtClass:
+ EmitCXXTryStmt(cast<CXXTryStmt>(*S));
+ break;
+ }
+}
+
+bool CodeGenFunction::EmitSimpleStmt(const Stmt *S) {
+ switch (S->getStmtClass()) {
+ default: return false;
+ case Stmt::NullStmtClass: break;
+ case Stmt::CompoundStmtClass: EmitCompoundStmt(cast<CompoundStmt>(*S)); break;
+ case Stmt::DeclStmtClass: EmitDeclStmt(cast<DeclStmt>(*S)); break;
+ case Stmt::LabelStmtClass: EmitLabelStmt(cast<LabelStmt>(*S)); break;
+ case Stmt::GotoStmtClass: EmitGotoStmt(cast<GotoStmt>(*S)); break;
+ case Stmt::BreakStmtClass: EmitBreakStmt(cast<BreakStmt>(*S)); break;
+ case Stmt::ContinueStmtClass: EmitContinueStmt(cast<ContinueStmt>(*S)); break;
+ case Stmt::DefaultStmtClass: EmitDefaultStmt(cast<DefaultStmt>(*S)); break;
+ case Stmt::CaseStmtClass: EmitCaseStmt(cast<CaseStmt>(*S)); break;
+ }
+
+ return true;
+}
+
+/// EmitCompoundStmt - Emit a compound statement {..} node. If GetLast is true,
+/// this captures the expression result of the last sub-statement and returns it
+/// (for use by the statement expression extension).
+RValue CodeGenFunction::EmitCompoundStmt(const CompoundStmt &S, bool GetLast,
+ llvm::Value *AggLoc, bool isAggVol) {
+ PrettyStackTraceLoc CrashInfo(getContext().getSourceManager(),S.getLBracLoc(),
+ "LLVM IR generation of compound statement ('{}')");
+
+ CGDebugInfo *DI = getDebugInfo();
+ if (DI) {
+ DI->setLocation(S.getLBracLoc());
+ DI->EmitRegionStart(CurFn, Builder);
+ }
+
+ // Keep track of the current cleanup stack depth.
+ CleanupScope Scope(*this);
+
+ for (CompoundStmt::const_body_iterator I = S.body_begin(),
+ E = S.body_end()-GetLast; I != E; ++I)
+ EmitStmt(*I);
+
+ if (DI) {
+ DI->setLocation(S.getLBracLoc());
+ DI->EmitRegionEnd(CurFn, Builder);
+ }
+
+ RValue RV;
+ if (!GetLast)
+ RV = RValue::get(0);
+ else {
+ // We have to special case labels here. They are statements, but when put
+ // at the end of a statement expression, they yield the value of their
+ // subexpression. Handle this by walking through all labels we encounter,
+ // emitting them before we evaluate the subexpr.
+ const Stmt *LastStmt = S.body_back();
+ while (const LabelStmt *LS = dyn_cast<LabelStmt>(LastStmt)) {
+ EmitLabel(*LS);
+ LastStmt = LS->getSubStmt();
+ }
+
+ EnsureInsertPoint();
+
+ RV = EmitAnyExpr(cast<Expr>(LastStmt), AggLoc);
+ }
+
+ return RV;
+}
+
+void CodeGenFunction::SimplifyForwardingBlocks(llvm::BasicBlock *BB) {
+ llvm::BranchInst *BI = dyn_cast<llvm::BranchInst>(BB->getTerminator());
+
+ // If there is a cleanup stack, then we it isn't worth trying to
+ // simplify this block (we would need to remove it from the scope map
+ // and cleanup entry).
+ if (!CleanupEntries.empty())
+ return;
+
+ // Can only simplify direct branches.
+ if (!BI || !BI->isUnconditional())
+ return;
+
+ BB->replaceAllUsesWith(BI->getSuccessor(0));
+ BI->eraseFromParent();
+ BB->eraseFromParent();
+}
+
+void CodeGenFunction::EmitBlock(llvm::BasicBlock *BB, bool IsFinished) {
+ // Fall out of the current block (if necessary).
+ EmitBranch(BB);
+
+ if (IsFinished && BB->use_empty()) {
+ delete BB;
+ return;
+ }
+
+ // If necessary, associate the block with the cleanup stack size.
+ if (!CleanupEntries.empty()) {
+ // Check if the basic block has already been inserted.
+ BlockScopeMap::iterator I = BlockScopes.find(BB);
+ if (I != BlockScopes.end()) {
+ assert(I->second == CleanupEntries.size() - 1);
+ } else {
+ BlockScopes[BB] = CleanupEntries.size() - 1;
+ CleanupEntries.back().Blocks.push_back(BB);
+ }
+ }
+
+ CurFn->getBasicBlockList().push_back(BB);
+ Builder.SetInsertPoint(BB);
+}
+
+void CodeGenFunction::EmitBranch(llvm::BasicBlock *Target) {
+ // Emit a branch from the current block to the target one if this
+ // was a real block. If this was just a fall-through block after a
+ // terminator, don't emit it.
+ llvm::BasicBlock *CurBB = Builder.GetInsertBlock();
+
+ if (!CurBB || CurBB->getTerminator()) {
+ // If there is no insert point or the previous block is already
+ // terminated, don't touch it.
+ } else {
+ // Otherwise, create a fall-through branch.
+ Builder.CreateBr(Target);
+ }
+
+ Builder.ClearInsertionPoint();
+}
+
+void CodeGenFunction::EmitLabel(const LabelStmt &S) {
+ EmitBlock(getBasicBlockForLabel(&S));
+}
+
+
+void CodeGenFunction::EmitLabelStmt(const LabelStmt &S) {
+ EmitLabel(S);
+ EmitStmt(S.getSubStmt());
+}
+
+void CodeGenFunction::EmitGotoStmt(const GotoStmt &S) {
+ // If this code is reachable then emit a stop point (if generating
+ // debug info). We have to do this ourselves because we are on the
+ // "simple" statement path.
+ if (HaveInsertPoint())
+ EmitStopPoint(&S);
+
+ EmitBranchThroughCleanup(getBasicBlockForLabel(S.getLabel()));
+}
+
+
+void CodeGenFunction::EmitIndirectGotoStmt(const IndirectGotoStmt &S) {
+ // Ensure that we have an i8* for our PHI node.
+ llvm::Value *V = Builder.CreateBitCast(EmitScalarExpr(S.getTarget()),
+ llvm::Type::getInt8PtrTy(VMContext),
+ "addr");
+ llvm::BasicBlock *CurBB = Builder.GetInsertBlock();
+
+
+ // Get the basic block for the indirect goto.
+ llvm::BasicBlock *IndGotoBB = GetIndirectGotoBlock();
+
+ // The first instruction in the block has to be the PHI for the switch dest,
+ // add an entry for this branch.
+ cast<llvm::PHINode>(IndGotoBB->begin())->addIncoming(V, CurBB);
+
+ EmitBranch(IndGotoBB);
+}
+
+void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
+ // C99 6.8.4.1: The first substatement is executed if the expression compares
+ // unequal to 0. The condition must be a scalar type.
+ CleanupScope ConditionScope(*this);
+
+ if (S.getConditionVariable())
+ EmitLocalBlockVarDecl(*S.getConditionVariable());
+
+ // If the condition constant folds and can be elided, try to avoid emitting
+ // the condition and the dead arm of the if/else.
+ if (int Cond = ConstantFoldsToSimpleInteger(S.getCond())) {
+ // Figure out which block (then or else) is executed.
+ const Stmt *Executed = S.getThen(), *Skipped = S.getElse();
+ if (Cond == -1) // Condition false?
+ std::swap(Executed, Skipped);
+
+ // If the skipped block has no labels in it, just emit the executed block.
+ // This avoids emitting dead code and simplifies the CFG substantially.
+ if (!ContainsLabel(Skipped)) {
+ if (Executed) {
+ CleanupScope ExecutedScope(*this);
+ EmitStmt(Executed);
+ }
+ return;
+ }
+ }
+
+ // Otherwise, the condition did not fold, or we couldn't elide it. Just emit
+ // the conditional branch.
+ llvm::BasicBlock *ThenBlock = createBasicBlock("if.then");
+ llvm::BasicBlock *ContBlock = createBasicBlock("if.end");
+ llvm::BasicBlock *ElseBlock = ContBlock;
+ if (S.getElse())
+ ElseBlock = createBasicBlock("if.else");
+ EmitBranchOnBoolExpr(S.getCond(), ThenBlock, ElseBlock);
+
+ // Emit the 'then' code.
+ EmitBlock(ThenBlock);
+ {
+ CleanupScope ThenScope(*this);
+ EmitStmt(S.getThen());
+ }
+ EmitBranch(ContBlock);
+
+ // Emit the 'else' code if present.
+ if (const Stmt *Else = S.getElse()) {
+ EmitBlock(ElseBlock);
+ {
+ CleanupScope ElseScope(*this);
+ EmitStmt(Else);
+ }
+ EmitBranch(ContBlock);
+ }
+
+ // Emit the continuation block for code after the if.
+ EmitBlock(ContBlock, true);
+}
+
+void CodeGenFunction::EmitWhileStmt(const WhileStmt &S) {
+ // Emit the header for the loop, insert it, which will create an uncond br to
+ // it.
+ llvm::BasicBlock *LoopHeader = createBasicBlock("while.cond");
+ EmitBlock(LoopHeader);
+
+ // Create an exit block for when the condition fails, create a block for the
+ // body of the loop.
+ llvm::BasicBlock *ExitBlock = createBasicBlock("while.end");
+ llvm::BasicBlock *LoopBody = createBasicBlock("while.body");
+ llvm::BasicBlock *CleanupBlock = 0;
+ llvm::BasicBlock *EffectiveExitBlock = ExitBlock;
+
+ // Store the blocks to use for break and continue.
+ BreakContinueStack.push_back(BreakContinue(ExitBlock, LoopHeader));
+
+ // C++ [stmt.while]p2:
+ // When the condition of a while statement is a declaration, the
+ // scope of the variable that is declared extends from its point
+ // of declaration (3.3.2) to the end of the while statement.
+ // [...]
+ // The object created in a condition is destroyed and created
+ // with each iteration of the loop.
+ CleanupScope ConditionScope(*this);
+
+ if (S.getConditionVariable()) {
+ EmitLocalBlockVarDecl(*S.getConditionVariable());
+
+ // If this condition variable requires cleanups, create a basic
+ // block to handle those cleanups.
+ if (ConditionScope.requiresCleanups()) {
+ CleanupBlock = createBasicBlock("while.cleanup");
+ EffectiveExitBlock = CleanupBlock;
+ }
+ }
+
+ // Evaluate the conditional in the while header. C99 6.8.5.1: The
+ // evaluation of the controlling expression takes place before each
+ // execution of the loop body.
+ llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
+
+ // while(1) is common, avoid extra exit blocks. Be sure
+ // to correctly handle break/continue though.
+ bool EmitBoolCondBranch = true;
+ if (llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal))
+ if (C->isOne())
+ EmitBoolCondBranch = false;
+
+ // As long as the condition is true, go to the loop body.
+ if (EmitBoolCondBranch)
+ Builder.CreateCondBr(BoolCondVal, LoopBody, EffectiveExitBlock);
+
+ // Emit the loop body.
+ {
+ CleanupScope BodyScope(*this);
+ EmitBlock(LoopBody);
+ EmitStmt(S.getBody());
+ }
+
+ BreakContinueStack.pop_back();
+
+ if (CleanupBlock) {
+ // If we have a cleanup block, jump there to perform cleanups
+ // before looping.
+ EmitBranch(CleanupBlock);
+
+ // Emit the cleanup block, performing cleanups for the condition
+ // and then jumping to either the loop header or the exit block.
+ EmitBlock(CleanupBlock);
+ ConditionScope.ForceCleanup();
+ Builder.CreateCondBr(BoolCondVal, LoopHeader, ExitBlock);
+ } else {
+ // Cycle to the condition.
+ EmitBranch(LoopHeader);
+ }
+
+ // Emit the exit block.
+ EmitBlock(ExitBlock, true);
+
+
+ // The LoopHeader typically is just a branch if we skipped emitting
+ // a branch, try to erase it.
+ if (!EmitBoolCondBranch && !CleanupBlock)
+ SimplifyForwardingBlocks(LoopHeader);
+}
+
+void CodeGenFunction::EmitDoStmt(const DoStmt &S) {
+ // Emit the body for the loop, insert it, which will create an uncond br to
+ // it.
+ llvm::BasicBlock *LoopBody = createBasicBlock("do.body");
+ llvm::BasicBlock *AfterDo = createBasicBlock("do.end");
+ EmitBlock(LoopBody);
+
+ llvm::BasicBlock *DoCond = createBasicBlock("do.cond");
+
+ // Store the blocks to use for break and continue.
+ BreakContinueStack.push_back(BreakContinue(AfterDo, DoCond));
+
+ // Emit the body of the loop into the block.
+ EmitStmt(S.getBody());
+
+ BreakContinueStack.pop_back();
+
+ EmitBlock(DoCond);
+
+ // C99 6.8.5.2: "The evaluation of the controlling expression takes place
+ // after each execution of the loop body."
+
+ // Evaluate the conditional in the while header.
+ // C99 6.8.5p2/p4: The first substatement is executed if the expression
+ // compares unequal to 0. The condition must be a scalar type.
+ llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
+
+ // "do {} while (0)" is common in macros, avoid extra blocks. Be sure
+ // to correctly handle break/continue though.
+ bool EmitBoolCondBranch = true;
+ if (llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal))
+ if (C->isZero())
+ EmitBoolCondBranch = false;
+
+ // As long as the condition is true, iterate the loop.
+ if (EmitBoolCondBranch)
+ Builder.CreateCondBr(BoolCondVal, LoopBody, AfterDo);
+
+ // Emit the exit block.
+ EmitBlock(AfterDo);
+
+ // The DoCond block typically is just a branch if we skipped
+ // emitting a branch, try to erase it.
+ if (!EmitBoolCondBranch)
+ SimplifyForwardingBlocks(DoCond);
+}
+
+void CodeGenFunction::EmitForStmt(const ForStmt &S) {
+ // FIXME: What do we do if the increment (f.e.) contains a stmt expression,
+ // which contains a continue/break?
+ CleanupScope ForScope(*this);
+
+ // Evaluate the first part before the loop.
+ if (S.getInit())
+ EmitStmt(S.getInit());
+
+ // Start the loop with a block that tests the condition.
+ llvm::BasicBlock *CondBlock = createBasicBlock("for.cond");
+ llvm::BasicBlock *AfterFor = createBasicBlock("for.end");
+ llvm::BasicBlock *IncBlock = 0;
+ llvm::BasicBlock *CondCleanup = 0;
+ llvm::BasicBlock *EffectiveExitBlock = AfterFor;
+ EmitBlock(CondBlock);
+
+ // Create a cleanup scope for the condition variable cleanups.
+ CleanupScope ConditionScope(*this);
+
+ llvm::Value *BoolCondVal = 0;
+ if (S.getCond()) {
+ // If the for statement has a condition scope, emit the local variable
+ // declaration.
+ if (S.getConditionVariable()) {
+ EmitLocalBlockVarDecl(*S.getConditionVariable());
+
+ if (ConditionScope.requiresCleanups()) {
+ CondCleanup = createBasicBlock("for.cond.cleanup");
+ EffectiveExitBlock = CondCleanup;
+ }
+ }
+
+ // As long as the condition is true, iterate the loop.
+ llvm::BasicBlock *ForBody = createBasicBlock("for.body");
+
+ // C99 6.8.5p2/p4: The first substatement is executed if the expression
+ // compares unequal to 0. The condition must be a scalar type.
+ BoolCondVal = EvaluateExprAsBool(S.getCond());
+ Builder.CreateCondBr(BoolCondVal, ForBody, EffectiveExitBlock);
+
+ EmitBlock(ForBody);
+ } else {
+ // Treat it as a non-zero constant. Don't even create a new block for the
+ // body, just fall into it.
+ }
+
+ // If the for loop doesn't have an increment we can just use the
+ // condition as the continue block.
+ llvm::BasicBlock *ContinueBlock;
+ if (S.getInc())
+ ContinueBlock = IncBlock = createBasicBlock("for.inc");
+ else
+ ContinueBlock = CondBlock;
+
+ // Store the blocks to use for break and continue.
+ BreakContinueStack.push_back(BreakContinue(AfterFor, ContinueBlock));
+
+ // If the condition is true, execute the body of the for stmt.
+ CGDebugInfo *DI = getDebugInfo();
+ if (DI) {
+ DI->setLocation(S.getSourceRange().getBegin());
+ DI->EmitRegionStart(CurFn, Builder);
+ }
+
+ {
+ // Create a separate cleanup scope for the body, in case it is not
+ // a compound statement.
+ CleanupScope BodyScope(*this);
+ EmitStmt(S.getBody());
+ }
+
+ BreakContinueStack.pop_back();
+
+ // If there is an increment, emit it next.
+ if (S.getInc()) {
+ EmitBlock(IncBlock);
+ EmitStmt(S.getInc());
+ }
+
+ // Finally, branch back up to the condition for the next iteration.
+ if (CondCleanup) {
+ // Branch to the cleanup block.
+ EmitBranch(CondCleanup);
+
+ // Emit the cleanup block, which branches back to the loop body or
+ // outside of the for statement once it is done.
+ EmitBlock(CondCleanup);
+ ConditionScope.ForceCleanup();
+ Builder.CreateCondBr(BoolCondVal, CondBlock, AfterFor);
+ } else
+ EmitBranch(CondBlock);
+ if (DI) {
+ DI->setLocation(S.getSourceRange().getEnd());
+ DI->EmitRegionEnd(CurFn, Builder);
+ }
+
+ // Emit the fall-through block.
+ EmitBlock(AfterFor, true);
+}
+
+void CodeGenFunction::EmitReturnOfRValue(RValue RV, QualType Ty) {
+ if (RV.isScalar()) {
+ Builder.CreateStore(RV.getScalarVal(), ReturnValue);
+ } else if (RV.isAggregate()) {
+ EmitAggregateCopy(ReturnValue, RV.getAggregateAddr(), Ty);
+ } else {
+ StoreComplexToAddr(RV.getComplexVal(), ReturnValue, false);
+ }
+ EmitBranchThroughCleanup(ReturnBlock);
+}
+
+/// EmitReturnStmt - Note that due to GCC extensions, this can have an operand
+/// if the function returns void, or may be missing one if the function returns
+/// non-void. Fun stuff :).
+void CodeGenFunction::EmitReturnStmt(const ReturnStmt &S) {
+ // Emit the result value, even if unused, to evalute the side effects.
+ const Expr *RV = S.getRetValue();
+
+ // FIXME: Clean this up by using an LValue for ReturnTemp,
+ // EmitStoreThroughLValue, and EmitAnyExpr.
+ if (!ReturnValue) {
+ // Make sure not to return anything, but evaluate the expression
+ // for side effects.
+ if (RV)
+ EmitAnyExpr(RV);
+ } else if (RV == 0) {
+ // Do nothing (return value is left uninitialized)
+ } else if (FnRetTy->isReferenceType()) {
+ // If this function returns a reference, take the address of the expression
+ // rather than the value.
+ Builder.CreateStore(EmitLValue(RV).getAddress(), ReturnValue);
+ } else if (!hasAggregateLLVMType(RV->getType())) {
+ Builder.CreateStore(EmitScalarExpr(RV), ReturnValue);
+ } else if (RV->getType()->isAnyComplexType()) {
+ EmitComplexExprIntoAddr(RV, ReturnValue, false);
+ } else {
+ EmitAggExpr(RV, ReturnValue, false);
+ }
+
+ EmitBranchThroughCleanup(ReturnBlock);
+}
+
+void CodeGenFunction::EmitDeclStmt(const DeclStmt &S) {
+ // As long as debug info is modeled with instructions, we have to ensure we
+ // have a place to insert here and write the stop point here.
+ if (getDebugInfo()) {
+ EnsureInsertPoint();
+ EmitStopPoint(&S);
+ }
+
+ for (DeclStmt::const_decl_iterator I = S.decl_begin(), E = S.decl_end();
+ I != E; ++I)
+ EmitDecl(**I);
+}
+
+void CodeGenFunction::EmitBreakStmt(const BreakStmt &S) {
+ assert(!BreakContinueStack.empty() && "break stmt not in a loop or switch!");
+
+ // If this code is reachable then emit a stop point (if generating
+ // debug info). We have to do this ourselves because we are on the
+ // "simple" statement path.
+ if (HaveInsertPoint())
+ EmitStopPoint(&S);
+
+ llvm::BasicBlock *Block = BreakContinueStack.back().BreakBlock;
+ EmitBranchThroughCleanup(Block);
+}
+
+void CodeGenFunction::EmitContinueStmt(const ContinueStmt &S) {
+ assert(!BreakContinueStack.empty() && "continue stmt not in a loop!");
+
+ // If this code is reachable then emit a stop point (if generating
+ // debug info). We have to do this ourselves because we are on the
+ // "simple" statement path.
+ if (HaveInsertPoint())
+ EmitStopPoint(&S);
+
+ llvm::BasicBlock *Block = BreakContinueStack.back().ContinueBlock;
+ EmitBranchThroughCleanup(Block);
+}
+
+/// EmitCaseStmtRange - If case statement range is not too big then
+/// add multiple cases to switch instruction, one for each value within
+/// the range. If range is too big then emit "if" condition check.
+void CodeGenFunction::EmitCaseStmtRange(const CaseStmt &S) {
+ assert(S.getRHS() && "Expected RHS value in CaseStmt");
+
+ llvm::APSInt LHS = S.getLHS()->EvaluateAsInt(getContext());
+ llvm::APSInt RHS = S.getRHS()->EvaluateAsInt(getContext());
+
+ // Emit the code for this case. We do this first to make sure it is
+ // properly chained from our predecessor before generating the
+ // switch machinery to enter this block.
+ EmitBlock(createBasicBlock("sw.bb"));
+ llvm::BasicBlock *CaseDest = Builder.GetInsertBlock();
+ EmitStmt(S.getSubStmt());
+
+ // If range is empty, do nothing.
+ if (LHS.isSigned() ? RHS.slt(LHS) : RHS.ult(LHS))
+ return;
+
+ llvm::APInt Range = RHS - LHS;
+ // FIXME: parameters such as this should not be hardcoded.
+ if (Range.ult(llvm::APInt(Range.getBitWidth(), 64))) {
+ // Range is small enough to add multiple switch instruction cases.
+ for (unsigned i = 0, e = Range.getZExtValue() + 1; i != e; ++i) {
+ SwitchInsn->addCase(llvm::ConstantInt::get(VMContext, LHS), CaseDest);
+ LHS++;
+ }
+ return;
+ }
+
+ // The range is too big. Emit "if" condition into a new block,
+ // making sure to save and restore the current insertion point.
+ llvm::BasicBlock *RestoreBB = Builder.GetInsertBlock();
+
+ // Push this test onto the chain of range checks (which terminates
+ // in the default basic block). The switch's default will be changed
+ // to the top of this chain after switch emission is complete.
+ llvm::BasicBlock *FalseDest = CaseRangeBlock;
+ CaseRangeBlock = createBasicBlock("sw.caserange");
+
+ CurFn->getBasicBlockList().push_back(CaseRangeBlock);
+ Builder.SetInsertPoint(CaseRangeBlock);
+
+ // Emit range check.
+ llvm::Value *Diff =
+ Builder.CreateSub(SwitchInsn->getCondition(),
+ llvm::ConstantInt::get(VMContext, LHS), "tmp");
+ llvm::Value *Cond =
+ Builder.CreateICmpULE(Diff,
+ llvm::ConstantInt::get(VMContext, Range), "tmp");
+ Builder.CreateCondBr(Cond, CaseDest, FalseDest);
+
+ // Restore the appropriate insertion point.
+ if (RestoreBB)
+ Builder.SetInsertPoint(RestoreBB);
+ else
+ Builder.ClearInsertionPoint();
+}
+
+void CodeGenFunction::EmitCaseStmt(const CaseStmt &S) {
+ if (S.getRHS()) {
+ EmitCaseStmtRange(S);
+ return;
+ }
+
+ EmitBlock(createBasicBlock("sw.bb"));
+ llvm::BasicBlock *CaseDest = Builder.GetInsertBlock();
+ llvm::APSInt CaseVal = S.getLHS()->EvaluateAsInt(getContext());
+ SwitchInsn->addCase(llvm::ConstantInt::get(VMContext, CaseVal), CaseDest);
+
+ // Recursively emitting the statement is acceptable, but is not wonderful for
+ // code where we have many case statements nested together, i.e.:
+ // case 1:
+ // case 2:
+ // case 3: etc.
+ // Handling this recursively will create a new block for each case statement
+ // that falls through to the next case which is IR intensive. It also causes
+ // deep recursion which can run into stack depth limitations. Handle
+ // sequential non-range case statements specially.
+ const CaseStmt *CurCase = &S;
+ const CaseStmt *NextCase = dyn_cast<CaseStmt>(S.getSubStmt());
+
+ // Otherwise, iteratively add consequtive cases to this switch stmt.
+ while (NextCase && NextCase->getRHS() == 0) {
+ CurCase = NextCase;
+ CaseVal = CurCase->getLHS()->EvaluateAsInt(getContext());
+ SwitchInsn->addCase(llvm::ConstantInt::get(VMContext, CaseVal), CaseDest);
+
+ NextCase = dyn_cast<CaseStmt>(CurCase->getSubStmt());
+ }
+
+ // Normal default recursion for non-cases.
+ EmitStmt(CurCase->getSubStmt());
+}
+
+void CodeGenFunction::EmitDefaultStmt(const DefaultStmt &S) {
+ llvm::BasicBlock *DefaultBlock = SwitchInsn->getDefaultDest();
+ assert(DefaultBlock->empty() &&
+ "EmitDefaultStmt: Default block already defined?");
+ EmitBlock(DefaultBlock);
+ EmitStmt(S.getSubStmt());
+}
+
+void CodeGenFunction::EmitSwitchStmt(const SwitchStmt &S) {
+ CleanupScope ConditionScope(*this);
+
+ if (S.getConditionVariable())
+ EmitLocalBlockVarDecl(*S.getConditionVariable());
+
+ llvm::Value *CondV = EmitScalarExpr(S.getCond());
+
+ // Handle nested switch statements.
+ llvm::SwitchInst *SavedSwitchInsn = SwitchInsn;
+ llvm::BasicBlock *SavedCRBlock = CaseRangeBlock;
+
+ // Create basic block to hold stuff that comes after switch
+ // statement. We also need to create a default block now so that
+ // explicit case ranges tests can have a place to jump to on
+ // failure.
+ llvm::BasicBlock *NextBlock = createBasicBlock("sw.epilog");
+ llvm::BasicBlock *DefaultBlock = createBasicBlock("sw.default");
+ SwitchInsn = Builder.CreateSwitch(CondV, DefaultBlock);
+ CaseRangeBlock = DefaultBlock;
+
+ // Clear the insertion point to indicate we are in unreachable code.
+ Builder.ClearInsertionPoint();
+
+ // All break statements jump to NextBlock. If BreakContinueStack is non empty
+ // then reuse last ContinueBlock.
+ llvm::BasicBlock *ContinueBlock = 0;
+ if (!BreakContinueStack.empty())
+ ContinueBlock = BreakContinueStack.back().ContinueBlock;
+
+ // Ensure any vlas created between there and here, are undone
+ BreakContinueStack.push_back(BreakContinue(NextBlock, ContinueBlock));
+
+ // Emit switch body.
+ EmitStmt(S.getBody());
+
+ BreakContinueStack.pop_back();
+
+ // Update the default block in case explicit case range tests have
+ // been chained on top.
+ SwitchInsn->setSuccessor(0, CaseRangeBlock);
+
+ // If a default was never emitted then reroute any jumps to it and
+ // discard.
+ if (!DefaultBlock->getParent()) {
+ DefaultBlock->replaceAllUsesWith(NextBlock);
+ delete DefaultBlock;
+ }
+
+ // Emit continuation.
+ EmitBlock(NextBlock, true);
+
+ SwitchInsn = SavedSwitchInsn;
+ CaseRangeBlock = SavedCRBlock;
+}
+
+static std::string
+SimplifyConstraint(const char *Constraint, const TargetInfo &Target,
+ llvm::SmallVectorImpl<TargetInfo::ConstraintInfo> *OutCons=0) {
+ std::string Result;
+
+ while (*Constraint) {
+ switch (*Constraint) {
+ default:
+ Result += Target.convertConstraint(*Constraint);
+ break;
+ // Ignore these
+ case '*':
+ case '?':
+ case '!':
+ break;
+ case 'g':
+ Result += "imr";
+ break;
+ case '[': {
+ assert(OutCons &&
+ "Must pass output names to constraints with a symbolic name");
+ unsigned Index;
+ bool result = Target.resolveSymbolicName(Constraint,
+ &(*OutCons)[0],
+ OutCons->size(), Index);
+ assert(result && "Could not resolve symbolic name"); result=result;
+ Result += llvm::utostr(Index);
+ break;
+ }
+ }
+
+ Constraint++;
+ }
+
+ return Result;
+}
+
+llvm::Value* CodeGenFunction::EmitAsmInput(const AsmStmt &S,
+ const TargetInfo::ConstraintInfo &Info,
+ const Expr *InputExpr,
+ std::string &ConstraintStr) {
+ llvm::Value *Arg;
+ if (Info.allowsRegister() || !Info.allowsMemory()) {
+ if (!CodeGenFunction::hasAggregateLLVMType(InputExpr->getType())) {
+ Arg = EmitScalarExpr(InputExpr);
+ } else {
+ InputExpr = InputExpr->IgnoreParenNoopCasts(getContext());
+ LValue Dest = EmitLValue(InputExpr);
+
+ const llvm::Type *Ty = ConvertType(InputExpr->getType());
+ uint64_t Size = CGM.getTargetData().getTypeSizeInBits(Ty);
+ if (Size <= 64 && llvm::isPowerOf2_64(Size)) {
+ Ty = llvm::IntegerType::get(VMContext, Size);
+ Ty = llvm::PointerType::getUnqual(Ty);
+
+ Arg = Builder.CreateLoad(Builder.CreateBitCast(Dest.getAddress(), Ty));
+ } else {
+ Arg = Dest.getAddress();
+ ConstraintStr += '*';
+ }
+ }
+ } else {
+ InputExpr = InputExpr->IgnoreParenNoopCasts(getContext());
+ LValue Dest = EmitLValue(InputExpr);
+ Arg = Dest.getAddress();
+ ConstraintStr += '*';
+ }
+
+ return Arg;
+}
+
+void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
+ // Analyze the asm string to decompose it into its pieces. We know that Sema
+ // has already done this, so it is guaranteed to be successful.
+ llvm::SmallVector<AsmStmt::AsmStringPiece, 4> Pieces;
+ unsigned DiagOffs;
+ S.AnalyzeAsmString(Pieces, getContext(), DiagOffs);
+
+ // Assemble the pieces into the final asm string.
+ std::string AsmString;
+ for (unsigned i = 0, e = Pieces.size(); i != e; ++i) {
+ if (Pieces[i].isString())
+ AsmString += Pieces[i].getString();
+ else if (Pieces[i].getModifier() == '\0')
+ AsmString += '$' + llvm::utostr(Pieces[i].getOperandNo());
+ else
+ AsmString += "${" + llvm::utostr(Pieces[i].getOperandNo()) + ':' +
+ Pieces[i].getModifier() + '}';
+ }
+
+ // Get all the output and input constraints together.
+ llvm::SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos;
+ llvm::SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;
+
+ for (unsigned i = 0, e = S.getNumOutputs(); i != e; i++) {
+ TargetInfo::ConstraintInfo Info(S.getOutputConstraint(i),
+ S.getOutputName(i));
+ assert(Target.validateOutputConstraint(Info) &&
+ "Failed to parse output constraint");
+ OutputConstraintInfos.push_back(Info);
+ }
+
+ for (unsigned i = 0, e = S.getNumInputs(); i != e; i++) {
+ TargetInfo::ConstraintInfo Info(S.getInputConstraint(i),
+ S.getInputName(i));
+ assert(Target.validateInputConstraint(OutputConstraintInfos.data(),
+ S.getNumOutputs(),
+ Info) &&
+ "Failed to parse input constraint");
+ InputConstraintInfos.push_back(Info);
+ }
+
+ std::string Constraints;
+
+ std::vector<LValue> ResultRegDests;
+ std::vector<QualType> ResultRegQualTys;
+ std::vector<const llvm::Type *> ResultRegTypes;
+ std::vector<const llvm::Type *> ResultTruncRegTypes;
+ std::vector<const llvm::Type*> ArgTypes;
+ std::vector<llvm::Value*> Args;
+
+ // Keep track of inout constraints.
+ std::string InOutConstraints;
+ std::vector<llvm::Value*> InOutArgs;
+ std::vector<const llvm::Type*> InOutArgTypes;
+
+ for (unsigned i = 0, e = S.getNumOutputs(); i != e; i++) {
+ TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i];
+
+ // Simplify the output constraint.
+ std::string OutputConstraint(S.getOutputConstraint(i));
+ OutputConstraint = SimplifyConstraint(OutputConstraint.c_str() + 1, Target);
+
+ const Expr *OutExpr = S.getOutputExpr(i);
+ OutExpr = OutExpr->IgnoreParenNoopCasts(getContext());
+
+ LValue Dest = EmitLValue(OutExpr);
+ if (!Constraints.empty())
+ Constraints += ',';
+
+ // If this is a register output, then make the inline asm return it
+ // by-value. If this is a memory result, return the value by-reference.
+ if (!Info.allowsMemory() && !hasAggregateLLVMType(OutExpr->getType())) {
+ Constraints += "=" + OutputConstraint;
+ ResultRegQualTys.push_back(OutExpr->getType());
+ ResultRegDests.push_back(Dest);
+ ResultRegTypes.push_back(ConvertTypeForMem(OutExpr->getType()));
+ ResultTruncRegTypes.push_back(ResultRegTypes.back());
+
+ // If this output is tied to an input, and if the input is larger, then
+ // we need to set the actual result type of the inline asm node to be the
+ // same as the input type.
+ if (Info.hasMatchingInput()) {
+ unsigned InputNo;
+ for (InputNo = 0; InputNo != S.getNumInputs(); ++InputNo) {
+ TargetInfo::ConstraintInfo &Input = InputConstraintInfos[InputNo];
+ if (Input.hasTiedOperand() &&
+ Input.getTiedOperand() == i)
+ break;
+ }
+ assert(InputNo != S.getNumInputs() && "Didn't find matching input!");
+
+ QualType InputTy = S.getInputExpr(InputNo)->getType();
+ QualType OutputTy = OutExpr->getType();
+
+ uint64_t InputSize = getContext().getTypeSize(InputTy);
+ if (getContext().getTypeSize(OutputTy) < InputSize) {
+ // Form the asm to return the value as a larger integer type.
+ ResultRegTypes.back() = llvm::IntegerType::get(VMContext, (unsigned)InputSize);
+ }
+ }
+ } else {
+ ArgTypes.push_back(Dest.getAddress()->getType());
+ Args.push_back(Dest.getAddress());
+ Constraints += "=*";
+ Constraints += OutputConstraint;
+ }
+
+ if (Info.isReadWrite()) {
+ InOutConstraints += ',';
+
+ const Expr *InputExpr = S.getOutputExpr(i);
+ llvm::Value *Arg = EmitAsmInput(S, Info, InputExpr, InOutConstraints);
+
+ if (Info.allowsRegister())
+ InOutConstraints += llvm::utostr(i);
+ else
+ InOutConstraints += OutputConstraint;
+
+ InOutArgTypes.push_back(Arg->getType());
+ InOutArgs.push_back(Arg);
+ }
+ }
+
+ unsigned NumConstraints = S.getNumOutputs() + S.getNumInputs();
+
+ for (unsigned i = 0, e = S.getNumInputs(); i != e; i++) {
+ const Expr *InputExpr = S.getInputExpr(i);
+
+ TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
+
+ if (!Constraints.empty())
+ Constraints += ',';
+
+ // Simplify the input constraint.
+ std::string InputConstraint(S.getInputConstraint(i));
+ InputConstraint = SimplifyConstraint(InputConstraint.c_str(), Target,
+ &OutputConstraintInfos);
+
+ llvm::Value *Arg = EmitAsmInput(S, Info, InputExpr, Constraints);
+
+ // If this input argument is tied to a larger output result, extend the
+ // input to be the same size as the output. The LLVM backend wants to see
+ // the input and output of a matching constraint be the same size. Note
+ // that GCC does not define what the top bits are here. We use zext because
+ // that is usually cheaper, but LLVM IR should really get an anyext someday.
+ if (Info.hasTiedOperand()) {
+ unsigned Output = Info.getTiedOperand();
+ QualType OutputTy = S.getOutputExpr(Output)->getType();
+ QualType InputTy = InputExpr->getType();
+
+ if (getContext().getTypeSize(OutputTy) >
+ getContext().getTypeSize(InputTy)) {
+ // Use ptrtoint as appropriate so that we can do our extension.
+ if (isa<llvm::PointerType>(Arg->getType()))
+ Arg = Builder.CreatePtrToInt(Arg,
+ llvm::IntegerType::get(VMContext, LLVMPointerWidth));
+ unsigned OutputSize = (unsigned)getContext().getTypeSize(OutputTy);
+ Arg = Builder.CreateZExt(Arg, llvm::IntegerType::get(VMContext, OutputSize));
+ }
+ }
+
+
+ ArgTypes.push_back(Arg->getType());
+ Args.push_back(Arg);
+ Constraints += InputConstraint;
+ }
+
+ // Append the "input" part of inout constraints last.
+ for (unsigned i = 0, e = InOutArgs.size(); i != e; i++) {
+ ArgTypes.push_back(InOutArgTypes[i]);
+ Args.push_back(InOutArgs[i]);
+ }
+ Constraints += InOutConstraints;
+
+ // Clobbers
+ for (unsigned i = 0, e = S.getNumClobbers(); i != e; i++) {
+ llvm::StringRef Clobber = S.getClobber(i)->getString();
+
+ Clobber = Target.getNormalizedGCCRegisterName(Clobber);
+
+ if (i != 0 || NumConstraints != 0)
+ Constraints += ',';
+
+ Constraints += "~{";
+ Constraints += Clobber;
+ Constraints += '}';
+ }
+
+ // Add machine specific clobbers
+ std::string MachineClobbers = Target.getClobbers();
+ if (!MachineClobbers.empty()) {
+ if (!Constraints.empty())
+ Constraints += ',';
+ Constraints += MachineClobbers;
+ }
+
+ const llvm::Type *ResultType;
+ if (ResultRegTypes.empty())
+ ResultType = llvm::Type::getVoidTy(VMContext);
+ else if (ResultRegTypes.size() == 1)
+ ResultType = ResultRegTypes[0];
+ else
+ ResultType = llvm::StructType::get(VMContext, ResultRegTypes);
+
+ const llvm::FunctionType *FTy =
+ llvm::FunctionType::get(ResultType, ArgTypes, false);
+
+ llvm::InlineAsm *IA =
+ llvm::InlineAsm::get(FTy, AsmString, Constraints,
+ S.isVolatile() || S.getNumOutputs() == 0);
+ llvm::CallInst *Result = Builder.CreateCall(IA, Args.begin(), Args.end());
+ Result->addAttribute(~0, llvm::Attribute::NoUnwind);
+
+
+ // Extract all of the register value results from the asm.
+ std::vector<llvm::Value*> RegResults;
+ if (ResultRegTypes.size() == 1) {
+ RegResults.push_back(Result);
+ } else {
+ for (unsigned i = 0, e = ResultRegTypes.size(); i != e; ++i) {
+ llvm::Value *Tmp = Builder.CreateExtractValue(Result, i, "asmresult");
+ RegResults.push_back(Tmp);
+ }
+ }
+
+ for (unsigned i = 0, e = RegResults.size(); i != e; ++i) {
+ llvm::Value *Tmp = RegResults[i];
+
+ // If the result type of the LLVM IR asm doesn't match the result type of
+ // the expression, do the conversion.
+ if (ResultRegTypes[i] != ResultTruncRegTypes[i]) {
+ const llvm::Type *TruncTy = ResultTruncRegTypes[i];
+ // Truncate the integer result to the right size, note that
+ // ResultTruncRegTypes can be a pointer.
+ uint64_t ResSize = CGM.getTargetData().getTypeSizeInBits(TruncTy);
+ Tmp = Builder.CreateTrunc(Tmp, llvm::IntegerType::get(VMContext, (unsigned)ResSize));
+
+ if (Tmp->getType() != TruncTy) {
+ assert(isa<llvm::PointerType>(TruncTy));
+ Tmp = Builder.CreateIntToPtr(Tmp, TruncTy);
+ }
+ }
+
+ EmitStoreThroughLValue(RValue::get(Tmp), ResultRegDests[i],
+ ResultRegQualTys[i]);
+ }
+}