[llvm-commits] [124303] Lower calls to "implicit ..." functions more carefully.

[clattner at apple.com]

Revision: 124303
Author:   clattner
Date:     2007-02-25 14:01:13 -0800 (Sun, 25 Feb 2007)

Log Message:
-----------
Lower calls to "implicit ..." functions more carefully.  This implements
test/CFrontend/2007-02-25-C-DotDotDot.c

Modified Paths:
--------------
    apple-local/branches/llvm/gcc/llvm-convert.cpp

Modified: apple-local/branches/llvm/gcc/llvm-convert.cpp
===================================================================
--- apple-local/branches/llvm/gcc/llvm-convert.cpp	2007-02-25 18:44:39 UTC (rev 124302)
+++ apple-local/branches/llvm/gcc/llvm-convert.cpp	2007-02-25 22:01:13 UTC (rev 124303)
@@ -2190,7 +2190,7 @@
 
   // Pass the static chain, if any, as the first parameter.
   if (TREE_OPERAND(exp, 2))
-    CallOperands.push_back (Emit(TREE_OPERAND(exp, 2), 0));
+    CallOperands.push_back(Emit(TREE_OPERAND(exp, 2), 0));
 
   // Loop over the arguments, expanding them and adding them to the op list.
   const PointerType *PFTy = cast<PointerType>(Callee->getType());
@@ -2226,8 +2226,28 @@
     }
   }
   
-  // TODO: Check to see if the arguments and callee types disagree.  If so,
-  // insert a cast of the callee to a type that will work.
+  // Compile stuff like:
+  //   %tmp = call float (...)* bitcast (float ()* @foo to float (...)*)( )
+  // to:
+  //   %tmp = call float @foo( )
+  // This commonly occurs due to C "implicit ..." semantics.
+  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Callee)) {
+    if (CallOperands.empty() && CE->getOpcode() == Instruction::BitCast) {
+      Constant *RealCallee = CE->getOperand(0);
+      assert(isa<PointerType>(RealCallee->getType()) &&
+             "Bitcast to ptr not from ptr?");
+      const PointerType *RealPT = cast<PointerType>(RealCallee->getType());
+      if (const FunctionType *RealFT =
+          dyn_cast<FunctionType>(RealPT->getElementType())) {
+        const PointerType *ActualPT = cast<PointerType>(Callee->getType());
+        const FunctionType *ActualFT =
+          cast<FunctionType>(ActualPT->getElementType());
+        if (RealFT->getReturnType() == ActualFT->getReturnType() &&
+            ActualFT->getNumParams() == 0)
+          Callee = RealCallee;
+      }
+    }
+  }
   
   Value *Call;
   if (!UnwindBlock) {