reapply r101434

with a fix for self-hosting

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101465 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 11 deletions

diff --git a/include/llvm/Support/CallSite.h b/include/llvm/Support/CallSite.h
index 0650b61..7667ba0 100644
--- a/include/llvm/Support/CallSite.h
+++ b/include/llvm/Support/CallSite.h
@@ -255,27 +255,21 @@ public:
 private:
   /// Returns the operand number of the first argument
   unsigned getArgumentOffset() const {
-    if (isCall())
-      return 1; // Skip Function (ATM)
-    else
       return 0; // Args are at the front
   }
 
   unsigned getArgumentEndOffset() const {
     if (isCall())
-      return 0; // Unchanged (ATM)
+      return 1; // Skip Function
     else
       return 3; // Skip BB, BB, Function
   }
 
   IterTy getCallee() const {
-      // FIXME: this is slow, since we do not have the fast versions
-      // of the op_*() functions here. See CallSite::getCallee.
-      //
-    if (isCall())
-      return getInstruction()->op_begin(); // Unchanged (ATM)
-    else
-      return getInstruction()->op_end() - 3; // Skip BB, BB, Function
+    // FIXME: this is slow, since we do not have the fast versions
+		// of the op_*() functions here. See CallSite::getCallee.
+		//
+    return arg_end();
   }
 };