Shrink MachineOperand from 40 to 32 bytes on 64-bit hosts.

Pull an unsigned out of the Contents union such that it has the same size as two
pointers and no padding.

Arrange members such that the Contents union and all pointers can be 8-byte
aligned without padding.

This speeds up code generation by 0.8% on a 64-bit host. 32-bit hosts should be
unaffected.

llvm-svn: 116857

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index d30e3c99591..af714d56a08 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -102,13 +102,13 @@ void MachineOperand::setReg(unsigned Reg) {
     if (MachineBasicBlock *MBB = MI->getParent())
       if (MachineFunction *MF = MBB->getParent()) {
         RemoveRegOperandFromRegInfo();
-        Contents.Reg.RegNo = Reg;
+        SmallContents.RegNo = Reg;
         AddRegOperandToRegInfo(&MF->getRegInfo());
         return;
       }
         
   // Otherwise, just change the register, no problem.  :)
-  Contents.Reg.RegNo = Reg;
+  SmallContents.RegNo = Reg;
 }
 
 void MachineOperand::substVirtReg(unsigned Reg, unsigned SubIdx,
@@ -159,7 +159,7 @@ void MachineOperand::ChangeToRegister(unsigned Reg, bool isDef, bool isImp,
   } else {
     // Otherwise, change this to a register and set the reg#.
     OpKind = MO_Register;
-    Contents.Reg.RegNo = Reg;
+    SmallContents.RegNo = Reg;
 
     // If this operand is embedded in a function, add the operand to the
     // register's use/def list.