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-rw-r--r--lib/CodeGen/CodeGenFunction.cpp35
1 files changed, 22 insertions, 13 deletions
diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index f1b72863ca..ca478707ef 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -408,22 +408,23 @@ bool CodeGenFunction::ContainsLabel(const Stmt *S, bool IgnoreCaseStmts) {
}
-/// ConstantFoldsToSimpleInteger - If the sepcified expression does not fold to
-/// a constant, or if it does but contains a label, return 0. If it constant
-/// folds to 'true' and does not contain a label, return 1, if it constant folds
-/// to 'false' and does not contain a label, return -1.
-int CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond) {
+/// ConstantFoldsToSimpleInteger - If the specified expression does not fold
+/// to a constant, or if it does but contains a label, return false. If it
+/// constant folds return true and set the boolean result in Result.
+bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond,
+ bool &ResultBool) {
// FIXME: Rename and handle conversion of other evaluatable things
// to bool.
Expr::EvalResult Result;
if (!Cond->Evaluate(Result, getContext()) || !Result.Val.isInt() ||
Result.HasSideEffects)
- return 0; // Not foldable, not integer or not fully evaluatable.
+ return false; // Not foldable, not integer or not fully evaluatable.
if (CodeGenFunction::ContainsLabel(Cond))
- return 0; // Contains a label.
+ return false; // Contains a label.
- return Result.Val.getInt().getBoolValue() ? 1 : -1;
+ ResultBool = Result.Val.getInt().getBoolValue();
+ return true;
}
@@ -442,14 +443,17 @@ void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
if (CondBOp->getOpcode() == BO_LAnd) {
// If we have "1 && X", simplify the code. "0 && X" would have constant
// folded if the case was simple enough.
- if (ConstantFoldsToSimpleInteger(CondBOp->getLHS()) == 1) {
+ bool ConstantBool;
+ if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
+ ConstantBool) {
// br(1 && X) -> br(X).
return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
}
// If we have "X && 1", simplify the code to use an uncond branch.
// "X && 0" would have been constant folded to 0.
- if (ConstantFoldsToSimpleInteger(CondBOp->getRHS()) == 1) {
+ if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
+ ConstantBool) {
// br(X && 1) -> br(X).
return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock);
}
@@ -468,17 +472,22 @@ void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond,
eval.end(*this);
return;
- } else if (CondBOp->getOpcode() == BO_LOr) {
+ }
+
+ if (CondBOp->getOpcode() == BO_LOr) {
// If we have "0 || X", simplify the code. "1 || X" would have constant
// folded if the case was simple enough.
- if (ConstantFoldsToSimpleInteger(CondBOp->getLHS()) == -1) {
+ bool ConstantBool;
+ if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) &&
+ !ConstantBool) {
// br(0 || X) -> br(X).
return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock);
}
// If we have "X || 0", simplify the code to use an uncond branch.
// "X || 1" would have been constant folded to 1.
- if (ConstantFoldsToSimpleInteger(CondBOp->getRHS()) == -1) {
+ if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) &&
+ !ConstantBool) {
// br(X || 0) -> br(X).
return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock);
}