[llvm-commits] [llvm] r56415 - /llvm/trunk/include/llvm/CodeGen/MachineOperand.h

[Chris Lattner]

Author: lattner
Date: Sun Sep 21 18:30:17 2008
New Revision: 56415

URL: http://llvm.org/viewvc/llvm-project?rev=56415&view=rev
Log:
explain what earlyclobber actually is.

Modified:
    llvm/trunk/include/llvm/CodeGen/MachineOperand.h

Modified: llvm/trunk/include/llvm/CodeGen/MachineOperand.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/MachineOperand.h?rev=56415&r1=56414&r2=56415&view=diff

==============================================================================
--- llvm/trunk/include/llvm/CodeGen/MachineOperand.h (original)
+++ llvm/trunk/include/llvm/CodeGen/MachineOperand.h Sun Sep 21 18:30:17 2008
@@ -68,9 +68,9 @@
   /// This is only valid on definitions of registers.
   bool IsDead : 1;
 
-  /// IsEarlyClobber - True if this MO_Register operand is marked earlyclobber
-  /// in an inline asm.  Flag is not valid for any other case.   See gcc doc
-  /// for description of earlyclobber.
+  /// IsEarlyClobber - True if this MO_Register 'def' operand is written to
+  /// by the MachineInstr before all input registers are read.  This is used to
+  /// model the GCC inline asm '&' constraint modifier.
   bool IsEarlyClobber : 1;
 
   /// OverlapsEarlyClobber - True if this MO_Register operand is used as an