optimize scope push/pop to avoid work in the common case.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@41265 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Parse/ParseStmt.cpp b/Parse/ParseStmt.cpp
index 44026f6..e0d527e 100644
--- a/Parse/ParseStmt.cpp
+++ b/Parse/ParseStmt.cpp
@@ -434,8 +434,10 @@
}
// C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
- // there is no compound stmt. C90 does not have this clause.
- if (getLang().C99) EnterScope(0);
+ // there is no compound stmt. C90 does not have this clause. We only do this
+ // if the body isn't a compound statement to avoid push/pop in common cases.
+ bool NeedsInnerScope = getLang().C99 && Tok.getKind() != tok::l_brace;
+ if (NeedsInnerScope) EnterScope(0);
// Read the if condition.
StmtResult CondStmt = ParseStatement();
@@ -445,7 +447,7 @@
CondStmt = Actions.ParseNullStmt(Tok.getLocation());
// Pop the 'if' scope if needed.
- if (getLang().C99) ExitScope();
+ if (NeedsInnerScope) ExitScope();
// If it has an else, parse it.
SourceLocation ElseLoc;
@@ -454,13 +456,16 @@
ElseLoc = ConsumeToken();
// C99 6.8.4p3 - In C99, the body of the if statement is a scope, even if
- // there is no compound stmt. C90 does not have this clause.
- if (getLang().C99) EnterScope(0);
+ // there is no compound stmt. C90 does not have this clause. We only do
+ // this if the body isn't a compound statement to avoid push/pop in common
+ // cases.
+ NeedsInnerScope = getLang().C99 && Tok.getKind() != tok::l_brace;
+ if (NeedsInnerScope) EnterScope(0);
ElseStmt = ParseStatement();
// Pop the 'else' scope if needed.
- if (getLang().C99) ExitScope();
+ if (NeedsInnerScope) ExitScope();
if (ElseStmt.isInvalid)
ElseStmt = Actions.ParseNullStmt(ElseLoc);
@@ -497,14 +502,16 @@
StmtResult Switch = Actions.StartSwitchStmt(Cond.Val);
// C99 6.8.4p3 - In C99, the body of the switch statement is a scope, even if
- // there is no compound stmt. C90 does not have this clause.
- if (getLang().C99) EnterScope(0);
+ // there is no compound stmt. C90 does not have this clause. We only do this
+ // if the body isn't a compound statement to avoid push/pop in common cases.
+ bool NeedsInnerScope = getLang().C99 && Tok.getKind() != tok::l_brace;
+ if (NeedsInnerScope) EnterScope(0);
// Read the body statement.
StmtResult Body = ParseStatement();
// Pop the body scope if needed.
- if (getLang().C99) ExitScope();
+ if (NeedsInnerScope) ExitScope();
if (Body.isInvalid) {
Body = Actions.ParseNullStmt(Tok.getLocation());
@@ -537,14 +544,16 @@
ExprResult Cond = ParseSimpleParenExpression();
// C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if
- // there is no compound stmt. C90 does not have this clause.
- if (getLang().C99) EnterScope(0);
+ // there is no compound stmt. C90 does not have this clause. We only do this
+ // if the body isn't a compound statement to avoid push/pop in common cases.
+ bool NeedsInnerScope = getLang().C99 && Tok.getKind() != tok::l_brace;
+ if (NeedsInnerScope) EnterScope(0);
// Read the body statement.
StmtResult Body = ParseStatement();
// Pop the body scope if needed.
- if (getLang().C99) ExitScope();
+ if (NeedsInnerScope) ExitScope();
ExitScope();
@@ -565,14 +574,16 @@
EnterScope(Scope::BreakScope | Scope::ContinueScope);
// C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if
- // there is no compound stmt. C90 does not have this clause.
- if (getLang().C99) EnterScope(0);
+ // there is no compound stmt. C90 does not have this clause. We only do this
+ // if the body isn't a compound statement to avoid push/pop in common cases.
+ bool NeedsInnerScope = getLang().C99 && Tok.getKind() != tok::l_brace;
+ if (NeedsInnerScope) EnterScope(0);
// Read the body statement.
StmtResult Body = ParseStatement();
// Pop the body scope if needed.
- if (getLang().C99) ExitScope();
+ if (NeedsInnerScope) ExitScope();
if (Tok.getKind() != tok::kw_while) {
ExitScope();
@@ -687,14 +698,16 @@
SourceLocation RParenLoc = MatchRHSPunctuation(tok::r_paren, LParenLoc);
// C99 6.8.5p5 - In C99, the body of the if statement is a scope, even if
- // there is no compound stmt. C90 does not have this clause.
- if (getLang().C99) EnterScope(0);
+ // there is no compound stmt. C90 does not have this clause. We only do this
+ // if the body isn't a compound statement to avoid push/pop in common cases.
+ bool NeedsInnerScope = getLang().C99 && Tok.getKind() != tok::l_brace;
+ if (NeedsInnerScope) EnterScope(0);
// Read the body statement.
StmtResult Body = ParseStatement();
// Pop the body scope if needed.
- if (getLang().C99) ExitScope();
+ if (NeedsInnerScope) ExitScope();
// Leave the for-scope.
ExitScope();