[llvm-commits] [llvm] r106951 - in /llvm/trunk: lib/CodeGen/IfConversion.cpp test/CodeGen/Thumb2/thumb2-ifcvt3.ll
Bob Wilson
bob.wilson at apple.com
Sat Jun 26 10:47:06 PDT 2010
Author: bwilson
Date: Sat Jun 26 12:47:06 2010
New Revision: 106951
URL: http://llvm.org/viewvc/llvm-project?rev=106951&view=rev
Log:
Revert my if-conversion cleanup since it caused a bunch of nightly test
regressions.
--- Reverse-merging r106939 into '.':
U test/CodeGen/Thumb2/thumb2-ifcvt3.ll
U lib/CodeGen/IfConversion.cpp
Modified:
llvm/trunk/lib/CodeGen/IfConversion.cpp
llvm/trunk/test/CodeGen/Thumb2/thumb2-ifcvt3.ll
Modified: llvm/trunk/lib/CodeGen/IfConversion.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/IfConversion.cpp?rev=106951&r1=106950&r2=106951&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/IfConversion.cpp (original)
+++ llvm/trunk/lib/CodeGen/IfConversion.cpp Sat Jun 26 12:47:06 2010
@@ -186,7 +186,7 @@
SmallVectorImpl<MachineOperand> &Cond,
SmallSet<unsigned, 4> &Redefs,
bool IgnoreBr = false);
- void MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges = true);
+ void MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI);
bool MeetIfcvtSizeLimit(MachineBasicBlock &BB, unsigned Size) const {
return Size > 0 && TII->isProfitableToIfCvt(BB, Size);
@@ -1036,10 +1036,6 @@
IterIfcvt = false;
}
- // RemoveExtraEdges won't work if the block has an unanalyzable branch,
- // which is typically the case for IfConvertSimple, so explicitly remove
- // CvtBBI as a successor.
- BBI.BB->removeSuccessor(CvtBBI->BB);
RemoveExtraEdges(BBI);
// Update block info. BB can be iteratively if-converted.
@@ -1102,7 +1098,8 @@
InitPredRedefs(NextBBI->BB, Redefs, TRI);
bool HasEarlyExit = CvtBBI->FalseBB != NULL;
- if (CvtBBI->BB->pred_size() > 1) {
+ bool DupBB = CvtBBI->BB->pred_size() > 1;
+ if (DupBB) {
BBI.NonPredSize -= TII->RemoveBranch(*BBI.BB);
// Copy instructions in the true block, predicate them, and add them to
// the entry block.
@@ -1114,7 +1111,7 @@
// Now merge the entry of the triangle with the true block.
BBI.NonPredSize -= TII->RemoveBranch(*BBI.BB);
- MergeBlocks(BBI, *CvtBBI, false);
+ MergeBlocks(BBI, *CvtBBI);
}
// If 'true' block has a 'false' successor, add an exit branch to it.
@@ -1187,9 +1184,9 @@
return false;
}
- // Put the predicated instructions from the 'true' block before the
- // instructions from the 'false' block, unless the true block would clobber
- // the predicate, in which case, do the opposite.
+ // Merge the 'true' and 'false' blocks by copying the instructions
+ // from the 'false' block to the 'true' block. That is, unless the true
+ // block would clobber the predicate, in that case, do the opposite.
BBInfo *BBI1 = &TrueBBI;
BBInfo *BBI2 = &FalseBBI;
SmallVector<MachineOperand, 4> RevCond(BBI.BrCond.begin(), BBI.BrCond.end());
@@ -1279,8 +1276,8 @@
PredicateBlock(*BBI2, DI2, *Cond2, Redefs);
// Merge the true block into the entry of the diamond.
- MergeBlocks(BBI, *BBI1, TailBB == 0);
- MergeBlocks(BBI, *BBI2, TailBB == 0);
+ MergeBlocks(BBI, *BBI1);
+ MergeBlocks(BBI, *BBI2);
// If the if-converted block falls through or unconditionally branches into
// the tail block, and the tail block does not have other predecessors, then
@@ -1289,20 +1286,15 @@
if (TailBB) {
BBInfo TailBBI = BBAnalysis[TailBB->getNumber()];
if (TailBB->pred_size() == 1 && !TailBBI.HasFallThrough) {
+ BBI.NonPredSize -= TII->RemoveBranch(*BBI.BB);
MergeBlocks(BBI, TailBBI);
TailBBI.IsDone = true;
} else {
- BBI.BB->addSuccessor(TailBB);
InsertUncondBranch(BBI.BB, TailBB, TII);
BBI.HasFallThrough = false;
}
}
- // RemoveExtraEdges won't work if the block has an unanalyzable branch,
- // which can happen here if TailBB is unanalyzable and is merged, so
- // explicitly remove BBI1 and BBI2 as successors.
- BBI.BB->removeSuccessor(BBI1->BB);
- BBI.BB->removeSuccessor(BBI2->BB);
RemoveExtraEdges(BBI);
// Update block info.
@@ -1375,19 +1367,17 @@
UpdatePredRedefs(MI, Redefs, TRI, true);
}
- if (!IgnoreBr) {
- std::vector<MachineBasicBlock *> Succs(FromBBI.BB->succ_begin(),
- FromBBI.BB->succ_end());
- MachineBasicBlock *NBB = getNextBlock(FromBBI.BB);
- MachineBasicBlock *FallThrough = FromBBI.HasFallThrough ? NBB : NULL;
-
- for (unsigned i = 0, e = Succs.size(); i != e; ++i) {
- MachineBasicBlock *Succ = Succs[i];
- // Fallthrough edge can't be transferred.
- if (Succ == FallThrough)
- continue;
- ToBBI.BB->addSuccessor(Succ);
- }
+ std::vector<MachineBasicBlock *> Succs(FromBBI.BB->succ_begin(),
+ FromBBI.BB->succ_end());
+ MachineBasicBlock *NBB = getNextBlock(FromBBI.BB);
+ MachineBasicBlock *FallThrough = FromBBI.HasFallThrough ? NBB : NULL;
+
+ for (unsigned i = 0, e = Succs.size(); i != e; ++i) {
+ MachineBasicBlock *Succ = Succs[i];
+ // Fallthrough edge can't be transferred.
+ if (Succ == FallThrough)
+ continue;
+ ToBBI.BB->addSuccessor(Succ);
}
std::copy(FromBBI.Predicate.begin(), FromBBI.Predicate.end(),
@@ -1401,14 +1391,21 @@
}
/// MergeBlocks - Move all instructions from FromBB to the end of ToBB.
-/// This will leave FromBB as an empty block, so remove all of its
-/// successor edges except for the fall-through edge. If AddEdges is true,
-/// i.e., when FromBBI's branch is being moved, add those successor edges to
-/// ToBBI.
-void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI, bool AddEdges) {
+///
+void IfConverter::MergeBlocks(BBInfo &ToBBI, BBInfo &FromBBI) {
ToBBI.BB->splice(ToBBI.BB->end(),
FromBBI.BB, FromBBI.BB->begin(), FromBBI.BB->end());
+ // Redirect all branches to FromBB to ToBB.
+ std::vector<MachineBasicBlock *> Preds(FromBBI.BB->pred_begin(),
+ FromBBI.BB->pred_end());
+ for (unsigned i = 0, e = Preds.size(); i != e; ++i) {
+ MachineBasicBlock *Pred = Preds[i];
+ if (Pred == ToBBI.BB)
+ continue;
+ Pred->ReplaceUsesOfBlockWith(FromBBI.BB, ToBBI.BB);
+ }
+
std::vector<MachineBasicBlock *> Succs(FromBBI.BB->succ_begin(),
FromBBI.BB->succ_end());
MachineBasicBlock *NBB = getNextBlock(FromBBI.BB);
@@ -1420,8 +1417,7 @@
if (Succ == FallThrough)
continue;
FromBBI.BB->removeSuccessor(Succ);
- if (AddEdges)
- ToBBI.BB->addSuccessor(Succ);
+ ToBBI.BB->addSuccessor(Succ);
}
// Now FromBBI always falls through to the next block!
Modified: llvm/trunk/test/CodeGen/Thumb2/thumb2-ifcvt3.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Thumb2/thumb2-ifcvt3.ll?rev=106951&r1=106950&r2=106951&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/Thumb2/thumb2-ifcvt3.ll (original)
+++ llvm/trunk/test/CodeGen/Thumb2/thumb2-ifcvt3.ll Sat Jun 26 12:47:06 2010
@@ -23,7 +23,7 @@
; CHECK: movne
; CHECK: moveq
; CHECK: pop
-; CHECK-NEXT: @ BB#1:
+; CHECK-NEXT: LBB0_1:
%0 = load i64* @posed, align 4 ; <i64> [#uses=3]
%1 = sub i64 %0, %.reload78 ; <i64> [#uses=1]
%2 = ashr i64 %1, 1 ; <i64> [#uses=3]
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