Rewrite previous patch to follow Chris' stylistic

preference; no functional change.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78391 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dale Johannesen 2009-08-07 17:41:29 +00:00
parent b7f40c1a2a
commit 1c5a28706d

View File

@ -850,6 +850,27 @@ bool BranchFolder::CanFallThrough(MachineBasicBlock *CurBB) {
return CanFallThrough(CurBB, CurUnAnalyzable, TBB, FBB, Cond); return CanFallThrough(CurBB, CurUnAnalyzable, TBB, FBB, Cond);
} }
/// RemoveDuplicateSuccessor - make sure block Pred has at most one
/// successor edge leading to Succ. This is only called in one place,
/// but Chris prefers that it be a separate function.
static void RemoveDuplicateSuccessor(MachineBasicBlock *Pred,
MachineBasicBlock *Succ) {
MachineBasicBlock::succ_iterator SI = Pred->succ_begin();
bool found = false;
while (SI != Pred->succ_end()) {
if (*SI == Succ) {
if (!found) {
found = true;
++SI;
} else {
SI = Pred->removeSuccessor(SI);
}
} else {
++SI;
}
}
}
/// IsBetterFallthrough - Return true if it would be clearly better to /// IsBetterFallthrough - Return true if it would be clearly better to
/// fall-through to MBB1 than to fall through into MBB2. This has to return /// fall-through to MBB1 than to fall through into MBB2. This has to return
/// a strict ordering, returning true for both (MBB1,MBB2) and (MBB2,MBB1) will /// a strict ordering, returning true for both (MBB1,MBB2) and (MBB2,MBB1) will
@ -896,20 +917,7 @@ void BranchFolder::OptimizeBlock(MachineBasicBlock *MBB) {
// If this resulted in a predecessor with true and false edges // If this resulted in a predecessor with true and false edges
// both going to the fallthrough block, clean up; // both going to the fallthrough block, clean up;
// BranchFolding doesn't like this. // BranchFolding doesn't like this.
MachineBasicBlock::succ_iterator SI = Pred->succ_begin(); RemoveDuplicateSuccessor(Pred, FallThrough);
bool found = false;
while (SI != Pred->succ_end()) {
if (*SI == FallThrough) {
if (!found) {
found = true;
++SI;
} else {
SI = Pred->removeSuccessor(SI);
}
} else {
++SI;
}
}
} }
// If MBB was the target of a jump table, update jump tables to go to the // If MBB was the target of a jump table, update jump tables to go to the
// fallthrough instead. // fallthrough instead.