always try to fold a builtin before emitting it. In the future
it is possible that a builtin could sometimes be folded (e.g. __builtin_clz)
if it's operand is a constant.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@57161 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index 99a3463..fc7cc02 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -37,30 +37,17 @@
}
RValue CodeGenFunction::EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E) {
- switch (BuiltinID) {
- default: break; // Handle intrinsics and libm functions below.
-
- case Builtin::BI__builtin_huge_val:
- case Builtin::BI__builtin_huge_valf:
- case Builtin::BI__builtin_huge_vall:
- case Builtin::BI__builtin_inf:
- case Builtin::BI__builtin_inff:
- case Builtin::BI__builtin_infl:
- case Builtin::BI__builtin_nan:
- case Builtin::BI__builtin_nanf:
- case Builtin::BI__builtin_nanl:
- case Builtin::BI__builtin_classify_type:
- case Builtin::BI__builtin_constant_p: {
- APValue Result;
- if (!E->tryEvaluate(Result, CGM.getContext()))
- break; // Not a constant, expand below.
-
+ // See if we can constant fold this builtin. If so, don't emit it at all.
+ APValue Result;
+ if (E->tryEvaluate(Result, CGM.getContext())) {
if (Result.isInt())
return RValue::get(llvm::ConstantInt::get(Result.getInt()));
assert(Result.isFloat() && "Unsupported constant type");
return RValue::get(llvm::ConstantFP::get(Result.getFloat()));
}
+ switch (BuiltinID) {
+ default: break; // Handle intrinsics and libm functions below.
case Builtin::BI__builtin___CFStringMakeConstantString: {
const Expr *Arg = E->getArg(0);