Changes in directory llvm/lib/CodeGen:
VirtRegMap.cpp updated: 1.49 -> 1.50
---
Log message:
Remove move copies and dead stuff by not clobbering the result reg of a noop
copy.
---
Diffs of the changes: (+21 -12)
VirtRegMap.cpp | 33 +++++++++++++++++++++------------
1 files changed, 21 insertions(+), 12 deletions(-)
Index: llvm/lib/CodeGen/VirtRegMap.cpp
diff -u llvm/lib/CodeGen/VirtRegMap.cpp:1.49
llvm/lib/CodeGen/VirtRegMap.cpp:1.50
--- llvm/lib/CodeGen/VirtRegMap.cpp:1.49 Thu Feb 2 21:06:49 2006
+++ llvm/lib/CodeGen/VirtRegMap.cpp Thu Feb 2 21:16:14 2006
@@ -607,6 +607,15 @@
}
if (!OpTakenCareOf) {
+ // Check to see if this is a noop copy. If so, eliminate the
+ // instruction before considering the dest reg to be changed.
+ unsigned Src, Dst;
+ if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) {
+ ++NumDCE;
+ DEBUG(std::cerr << "Removing now-noop copy: " << MI);
+ MBB.erase(&MI);
+ goto ProcessNextInst;
+ }
ClobberPhysReg(VirtReg, SpillSlotsAvailable, PhysRegsAvailable);
continue;
}
@@ -631,6 +640,18 @@
DEBUG(std::cerr << "Store:\t" << *next(MII));
MI.SetMachineOperandReg(i, PhysReg);
+ // Check to see if this is a noop copy. If so, eliminate the
+ // instruction before considering the dest reg to be changed.
+ {
+ unsigned Src, Dst;
+ if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) {
+ ++NumDCE;
+ DEBUG(std::cerr << "Removing now-noop copy: " << MI);
+ MBB.erase(&MI);
+ goto ProcessNextInst;
+ }
+ }
+
// If there is a dead store to this stack slot, nuke it now.
MachineInstr *&LastStore = MaybeDeadStores[StackSlot];
if (LastStore) {
@@ -654,18 +675,6 @@
++NumStores;
}
}
-
- // Okay, the instruction has been completely processed, input and output
- // registers have been added. As a final sanity check, make sure this is
- // not a noop-copy. If it is, nuke it.
- {
- unsigned Src, Dst;
- if (TII->isMoveInstr(MI, Src, Dst) && Src == Dst) {
- ++NumDCE;
- DEBUG(std::cerr << "Removing now-noop copy: " << MI);
- MBB.erase(&MI);
- }
- }
ProcessNextInst:
MII = NextMII;
}
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