maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

Revert these. They may have been causing 483_xalancbmk to fail: 

$ svn merge -c -91161 https://llvm.org/svn/llvm-project/llvm/trunk
--- Reverse-merging r91161 into '.':
U    lib/CodeGen/BranchFolding.cpp
U    lib/CodeGen/MachineBasicBlock.cpp
$ svn merge -c -91113 https://llvm.org/svn/llvm-project/llvm/trunk
--- Reverse-merging r91113 into '.':
G    lib/CodeGen/MachineBasicBlock.cpp
$ svn merge -c -91101 https://llvm.org/svn/llvm-project/llvm/trunk
--- Reverse-merging r91101 into '.':
U    include/llvm/CodeGen/MachineBasicBlock.h
G    lib/CodeGen/MachineBasicBlock.cpp
$ svn merge -c -91092 https://llvm.org/svn/llvm-project/llvm/trunk
--- Reverse-merging r91092 into '.':
G    include/llvm/CodeGen/MachineBasicBlock.h
G    lib/CodeGen/MachineBasicBlock.cpp

llvm-svn: 91376
This commit is contained in:
Bill Wendling 2009-12-15 00:39:24 +00:00
parent e8c3b3eca4
commit e8a525a196
3 changed files with 26 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
llvm/include/llvm/CodeGen/MachineBasicBlock.h
View File

@ -327,11 +327,6 @@ public:
/// 'Old', change the code and CFG so that it branches to 'New' instead.
void ReplaceUsesOfBlockWith(MachineBasicBlock *Old, MachineBasicBlock *New);
/// BranchesToLandingPad - The basic block is a landing pad or branches only
/// to a landing pad. No other instructions are present other than the
/// unconditional branch.
bool BranchesToLandingPad(const MachineBasicBlock *MBB) const;
/// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in
/// the CFG to be inserted. If we have proven that MBB can only branch to
/// DestA and DestB, remove any other MBB successors from the CFG. DestA and

42
llvm/lib/CodeGen/BranchFolding.cpp
View File

@ -1205,11 +1205,11 @@ ReoptimizeBlock:
}
}
// If the prior block doesn't fall through into this block and if this block
// doesn't fall through into some other block and it's not branching only to a
// landing pad, then see if we can find a place to move this block where a
// fall-through will happen.
if (!PrevBB.canFallThrough() && !MBB->BranchesToLandingPad(MBB)) {
// If the prior block doesn't fall through into this block, and if this
// block doesn't fall through into some other block, see if we can find a
// place to move this block where a fall-through will happen.
if (!PrevBB.canFallThrough()) {
// Now we know that there was no fall-through into this block, check to
// see if it has a fall-through into its successor.
bool CurFallsThru = MBB->canFallThrough();
@ -1221,32 +1221,28 @@ ReoptimizeBlock:
E = MBB->pred_end(); PI != E; ++PI) {
// Analyze the branch at the end of the pred.
MachineBasicBlock *PredBB = *PI;
MachineFunction::iterator PredNextBB = PredBB; ++PredNextBB;
MachineFunction::iterator PredFallthrough = PredBB; ++PredFallthrough;
MachineBasicBlock *PredTBB, *PredFBB;
SmallVector<MachineOperand, 4> PredCond;
if (PredBB != MBB && !PredBB->canFallThrough()
&& !TII->AnalyzeBranch(*PredBB, PredTBB, PredFBB, PredCond, true)
if (PredBB != MBB && !PredBB->canFallThrough() &&
!TII->AnalyzeBranch(*PredBB, PredTBB, PredFBB, PredCond, true)
&& (!CurFallsThru || !CurTBB || !CurFBB)
&& (!CurFallsThru || MBB->getNumber() >= PredBB->getNumber())) {
// If the current block doesn't fall through, just move it. If the
// current block can fall through and does not end with a conditional
// branch, we need to append an unconditional jump to the (current)
// next block. To avoid a possible compile-time infinite loop, move
// blocks only backward in this case.
//
// Also, if there are already 2 branches here, we cannot add a third.
// I.e. we have the case:
//
// Bcc next
// B elsewhere
// next:
// If the current block doesn't fall through, just move it.
// If the current block can fall through and does not end with a
// conditional branch, we need to append an unconditional jump to
// the (current) next block. To avoid a possible compile-time
// infinite loop, move blocks only backward in this case.
// Also, if there are already 2 branches here, we cannot add a third;
// this means we have the case
// Bcc next
// B elsewhere
// next:
if (CurFallsThru) {
MachineBasicBlock *NextBB =
llvm::next(MachineFunction::iterator(MBB));
MachineBasicBlock *NextBB = llvm::next(MachineFunction::iterator(MBB));
CurCond.clear();
TII->InsertBranch(*MBB, NextBB, 0, CurCond);
}
MBB->moveAfter(PredBB);
MadeChange = true;
goto ReoptimizeBlock;

36
llvm/lib/CodeGen/MachineBasicBlock.cpp
View File

@ -13,16 +13,15 @@
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/BasicBlock.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetInstrDesc.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Support/LeakDetector.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Assembly/Writer.h"
#include <algorithm>
using namespace llvm;
@ -449,28 +448,10 @@ void MachineBasicBlock::ReplaceUsesOfBlockWith(MachineBasicBlock *Old,
addSuccessor(New);
}
/// BranchesToLandingPad - The basic block is a landing pad or branches only to
/// a landing pad. No other instructions are present other than the
/// unconditional branch.
bool
MachineBasicBlock::BranchesToLandingPad(const MachineBasicBlock *MBB) const {
SmallSet<const MachineBasicBlock*, 32> Visited;
const MachineBasicBlock *CurMBB = MBB;
while (!CurMBB->isLandingPad()) {
if (CurMBB->succ_size() != 1) break;
if (!Visited.insert(CurMBB)) break;
CurMBB = *CurMBB->succ_begin();
}
return CurMBB->isLandingPad();
}
/// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in the
/// CFG to be inserted. If we have proven that MBB can only branch to DestA and
/// DestB, remove any other MBB successors from the CFG. DestA and DestB can
/// be null.
///
/// Besides DestA and DestB, retain other edges leading to LandingPads
/// (currently there can be only one; we don't check or require that here).
/// Note it is possible that DestA and/or DestB are LandingPads.
@ -500,17 +481,16 @@ bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA,
}
MachineBasicBlock::succ_iterator SI = succ_begin();
const MachineBasicBlock *OrigDestA = DestA, *OrigDestB = DestB;
MachineBasicBlock *OrigDestA = DestA, *OrigDestB = DestB;
while (SI != succ_end()) {
const MachineBasicBlock *MBB = *SI;
if (MBB == DestA) {
if (*SI == DestA) {
DestA = 0;
++SI;
} else if (MBB == DestB) {
} else if (*SI == DestB) {
DestB = 0;
++SI;
} else if (MBB != OrigDestA && MBB != OrigDestB &&
BranchesToLandingPad(MBB)) {
} else if ((*SI)->isLandingPad() &&
*SI!=OrigDestA && *SI!=OrigDestB) {
++SI;
} else {
// Otherwise, this is a superfluous edge, remove it.
@ -518,14 +498,12 @@ bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA,
MadeChange = true;
}
}
if (!AddedFallThrough) {
assert(DestA == 0 && DestB == 0 &&
"MachineCFG is missing edges!");
} else if (isCond) {
assert(DestA == 0 && "MachineCFG is missing edges!");
}
return MadeChange;
}