instead of making codegen try to know about all of the builtins to generate

constants for them, just use the constant evaluator to do the job.  This
also fixes crashes on 'unknown constant builtins'.

llvm-svn: 57155

1 files changed, 8 insertions, 23 deletions

diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp
index e0c39c9cbac..50f0d122405 100644
--- a/clang/lib/CodeGen/CGExprConstant.cpp
+++ b/clang/lib/CodeGen/CGExprConstant.cpp
@@ -14,6 +14,7 @@
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
 #include "CGObjCRuntime.h"
+#include "clang/AST/APValue.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/StmtVisitor.h"
 #include "llvm/Constants.h"
@@ -608,14 +609,13 @@ public:
   }
 
   llvm::Constant *VisitCallExpr(const CallExpr *E) {
-    if (const ImplicitCastExpr *IcExpr = 
-        dyn_cast<const ImplicitCastExpr>(E->getCallee()))
-      if (const DeclRefExpr *DRExpr = 
-          dyn_cast<const DeclRefExpr>(IcExpr->getSubExpr()))
-        if (const FunctionDecl *FDecl = 
-            dyn_cast<const FunctionDecl>(DRExpr->getDecl()))
-          if (unsigned builtinID = FDecl->getIdentifier()->getBuiltinID())
-            return EmitBuiltinExpr(builtinID, E);
+    APValue Result;
+    if (E->tryEvaluate(Result, CGM.getContext())) {
+      if (Result.isInt())
+        return llvm::ConstantInt::get(Result.getInt());
+      if (Result.isFloat())
+        return llvm::ConstantFP::get(Result.getFloat());
+    }
 
     CGM.ErrorUnsupported(E, "constant call expression");
     return llvm::Constant::getNullValue(ConvertType(E->getType()));
@@ -818,21 +818,6 @@ public:
     llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
     return llvm::UndefValue::get(Ty);
   }
-
-  llvm::Constant *EmitBuiltinExpr(unsigned BuiltinID, const CallExpr *E)
-  {
-    switch (BuiltinID) {
-    default:
-      CGM.ErrorUnsupported(E, "constant builtin function");
-      return 0;
-    case Builtin::BI__builtin_huge_valf: {
-      const llvm::fltSemantics &Sem =
-      CGM.getContext().getFloatTypeSemantics(E->getType());
-      return llvm::ConstantFP::get(llvm::APFloat::getInf(Sem));
-    }        
-    }
-  }
-    
 };
   
 }  // end anonymous namespace.