Author: evancheng
Date: Fri Feb 15 20:32:17 2008
New Revision: 47208
URL: http://llvm.org/viewvc/llvm-project?rev=47208&view=rev
Log:
Refactor some code; check if commuteInstruction is able to commute the
instruction.
Modified:
llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h
Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp?rev=47208&r1=47207&r2=47208&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.cpp Fri Feb 15 20:32:17 2008
@@ -192,6 +192,31 @@
return true;
}
+/// HasOtherReachingDefs - Return true if there are definitions of IntB
+/// other than BValNo val# that can reach uses of AValno val# of IntA.
+bool SimpleRegisterCoalescing::HasOtherReachingDefs(LiveInterval &IntA,
+ LiveInterval &IntB,
+ VNInfo *AValNo,
+ VNInfo *BValNo) {
+ for (LiveInterval::iterator AI = IntA.begin(), AE = IntA.end();
+ AI != AE; ++AI) {
+ if (AI->valno != AValNo) continue;
+ LiveInterval::Ranges::iterator BI =
+ std::upper_bound(IntB.ranges.begin(), IntB.ranges.end(), AI->start);
+ if (BI != IntB.ranges.begin())
+ --BI;
+ for (; BI != IntB.ranges.end() && AI->end >= BI->start; ++BI) {
+ if (BI->valno == BValNo)
+ continue;
+ if (BI->start <= AI->start && BI->end > AI->start)
+ return true;
+ if (BI->start > AI->start && BI->start < AI->end)
+ return true;
+ }
+ }
+ return false;
+}
+
/// RemoveCopyByCommutingDef - We found a non-trivially-coalescable copy with
IntA
/// being the source and IntB being the dest, thus this defines a value number
/// in IntB. If the source value number (in IntA) is defined by a commutable
@@ -254,27 +279,15 @@
// Make sure there are no other definitions of IntB that would reach the
// uses which the new definition can reach.
- for (LiveInterval::iterator AI = IntA.begin(), AE = IntA.end();
- AI != AE; ++AI) {
- if (AI->valno != AValNo) continue;
- LiveInterval::Ranges::iterator BI =
- std::upper_bound(IntB.ranges.begin(), IntB.ranges.end(), AI->start);
- if (BI != IntB.ranges.begin())
- --BI;
- for (; BI != IntB.ranges.end() && AI->end >= BI->start; ++BI) {
- if (BI->valno == BLR->valno)
- continue;
- if (BI->start <= AI->start && BI->end > AI->start)
- return false;
- if (BI->start > AI->start && BI->start < AI->end)
- return false;
- }
- }
+ if (HasOtherReachingDefs(IntA, IntB, AValNo, BValNo))
+ return false;
// At this point we have decided that it is legal to do this
// transformation. Start by commuting the instruction.
MachineBasicBlock *MBB = DefMI->getParent();
MachineInstr *NewMI = tii_->commuteInstruction(DefMI);
+ if (!NewMI)
+ return false;
if (NewMI != DefMI) {
li_->ReplaceMachineInstrInMaps(DefMI, NewMI);
MBB->insert(DefMI, NewMI);
@@ -682,7 +695,6 @@
return true;
}
-
// Otherwise, we are unable to join the intervals.
DOUT << "Interference!\n";
Again = true; // May be possible to coalesce later.
Modified: llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h?rev=47208&r1=47207&r2=47208&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h (original)
+++ llvm/trunk/lib/CodeGen/SimpleRegisterCoalescing.h Fri Feb 15 20:32:17 2008
@@ -178,6 +178,11 @@
bool AdjustCopiesBackFrom(LiveInterval &IntA, LiveInterval &IntB,
MachineInstr *CopyMI);
+ /// HasOtherReachingDefs - Return true if there are definitions of IntB
+ /// other than BValNo val# that can reach uses of AValno val# of IntA.
+ bool HasOtherReachingDefs(LiveInterval &IntA, LiveInterval &IntB,
+ VNInfo *AValNo, VNInfo *BValNo);
+
/// RemoveCopyByCommutingDef - We found a non-trivially-coalescable copy.
/// If the source value number is defined by a commutable instruction and
/// its other operand is coalesced to the copy dest register, see if we
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