//
//===----------------------------------------------------------------------===//
+#ifndef LLVM_CODEGEN_SPLITKIT_H
+#define LLVM_CODEGEN_SPLITKIT_H
+
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
/// 1. | o---x | Internal to block. Variable is only live in this block.
/// 2. |---x | Live-in, kill.
/// 3. | o---| Def, live-out.
- /// 4. |---x o---| Live-in, kill, def, live-out.
+ /// 4. |---x o---| Live-in, kill, def, live-out. Counted by NumGapBlocks.
/// 5. |---o---o---| Live-through with uses or defs.
- /// 6. |-----------| Live-through without uses. Transparent.
+ /// 6. |-----------| Live-through without uses. Counted by NumThroughBlocks.
+ ///
+ /// Two BlockInfo entries are created for template 4. One for the live-in
+ /// segment, and one for the live-out segment. These entries look as if the
+ /// block were split in the middle where the live range isn't live.
+ ///
+ /// Live-through blocks without any uses don't get BlockInfo entries. They
+ /// are simply listed in ThroughBlocks instead.
///
struct BlockInfo {
MachineBasicBlock *MBB;
SlotIndex FirstUse; ///< First instr using current reg.
SlotIndex LastUse; ///< Last instr using current reg.
- SlotIndex Kill; ///< Interval end point inside block.
- SlotIndex Def; ///< Interval start point inside block.
- bool LiveThrough; ///< Live in whole block (Templ 5. or 6. above).
+ bool LiveThrough; ///< Live in whole block (Templ 5. above).
bool LiveIn; ///< Current reg is live in.
bool LiveOut; ///< Current reg is live out.
+
+ /// isOneInstr - Returns true when this BlockInfo describes a single
+ /// instruction.
+ bool isOneInstr() const {
+ return SlotIndex::isSameInstr(FirstUse, LastUse);
+ }
};
private:
/// UseBlocks - Blocks where CurLI has uses.
SmallVector<BlockInfo, 8> UseBlocks;
+ /// NumGapBlocks - Number of duplicate entries in UseBlocks for blocks where
+ /// the live range has a gap.
+ unsigned NumGapBlocks;
+
/// ThroughBlocks - Block numbers where CurLI is live through without uses.
BitVector ThroughBlocks;
/// NumThroughBlocks - Number of live-through blocks.
unsigned NumThroughBlocks;
+ /// DidRepairRange - analyze was forced to shrinkToUses().
+ bool DidRepairRange;
+
SlotIndex computeLastSplitPoint(unsigned Num);
// Sumarize statistics by counting instructions using CurLI.
/// split.
void analyze(const LiveInterval *li);
+ /// didRepairRange() - Returns true if CurLI was invalid and has been repaired
+ /// by analyze(). This really shouldn't happen, but sometimes the coalescer
+ /// can create live ranges that end in mid-air.
+ bool didRepairRange() const { return DidRepairRange; }
+
/// clear - clear all data structures so SplitAnalysis is ready to analyze a
/// new interval.
void clear();
/// getUseBlocks - Return an array of BlockInfo objects for the basic blocks
/// where CurLI has uses.
- ArrayRef<BlockInfo> getUseBlocks() { return UseBlocks; }
+ ArrayRef<BlockInfo> getUseBlocks() const { return UseBlocks; }
/// getNumThroughBlocks - Return the number of through blocks.
unsigned getNumThroughBlocks() const { return NumThroughBlocks; }
/// isThroughBlock - Return true if CurLI is live through MBB without uses.
bool isThroughBlock(unsigned MBB) const { return ThroughBlocks.test(MBB); }
+ /// getThroughBlocks - Return the set of through blocks.
+ const BitVector &getThroughBlocks() const { return ThroughBlocks; }
+
+ /// getNumLiveBlocks - Return the number of blocks where CurLI is live.
+ unsigned getNumLiveBlocks() const {
+ return getUseBlocks().size() - NumGapBlocks + getNumThroughBlocks();
+ }
+
+ /// countLiveBlocks - Return the number of blocks where li is live. This is
+ /// guaranteed to return the same number as getNumLiveBlocks() after calling
+ /// analyze(li).
+ unsigned countLiveBlocks(const LiveInterval *li) const;
+
typedef SmallPtrSet<const MachineBasicBlock*, 16> BlockPtrSet;
/// getMultiUseBlocks - Add basic blocks to Blocks that may benefit from
// entry in LiveOutCache.
BitVector LiveOutSeen;
+ /// LiveInBlock - Info for updateSSA() about a block where a register is
+ /// live-in.
+ /// The updateSSA caller provides DomNode and Kill inside MBB, updateSSA()
+ /// adds the computed live-in value.
+ struct LiveInBlock {
+ // Dominator tree node for the block.
+ // Cleared by updateSSA when the final value has been determined.
+ MachineDomTreeNode *DomNode;
+
+ // Live-in value filled in by updateSSA once it is known.
+ VNInfo *Value;
+
+ // Position in block where the live-in range ends, or SlotIndex() if the
+ // range passes through the block.
+ SlotIndex Kill;
+
+ LiveInBlock(MachineDomTreeNode *node) : DomNode(node), Value(0) {}
+ };
+
+ /// LiveInBlocks - List of live-in blocks used by findReachingDefs() and
+ /// updateSSA(). This list is usually empty, it exists here to avoid frequent
+ /// reallocations.
+ SmallVector<LiveInBlock, 16> LiveInBlocks;
+
/// defValue - define a value in RegIdx from ParentVNI at Idx.
/// Idx does not have to be ParentVNI->def, but it must be contained within
/// ParentVNI's live range in ParentLI. The new value is added to the value
/// Insert PHIDefs as needed to preserve SSA form.
void extendRange(unsigned RegIdx, SlotIndex Idx);
- /// updateSSA - Insert PHIDefs as necessary and update LiveOutCache such that
- /// Edit.get(RegIdx) is live-in to all the blocks in LiveIn.
- /// Return the value that is eventually live-in to IdxMBB.
- VNInfo *updateSSA(unsigned RegIdx,
- SmallVectorImpl<MachineDomTreeNode*> &LiveIn,
- SlotIndex Idx,
- const MachineBasicBlock *IdxMBB);
+ /// findReachingDefs - Starting from MBB, add blocks to LiveInBlocks until all
+ /// reaching defs for LI are found.
+ /// @param LI Live interval whose value is needed.
+ /// @param MBB Block where LI should be live-in.
+ /// @param Kill Kill point in MBB.
+ /// @return Unique value seen, or NULL.
+ VNInfo *findReachingDefs(LiveInterval *LI, MachineBasicBlock *MBB,
+ SlotIndex Kill);
+
+ /// updateSSA - Compute and insert PHIDefs such that all blocks in
+ // LiveInBlocks get a known live-in value. Add live ranges to the blocks.
+ void updateSSA();
- /// transferSimpleValues - Transfer simply defined values to the new ranges.
- /// Return true if any complex ranges were skipped.
- bool transferSimpleValues();
+ /// transferValues - Transfer values to the new ranges.
+ /// Return true if any ranges were skipped.
+ bool transferValues();
/// extendPHIKillRanges - Extend the ranges of all values killed by original
/// parent PHIDefs.
/// Return the beginning of the new live range.
SlotIndex enterIntvBefore(SlotIndex Idx);
+ /// enterIntvAfter - Enter the open interval after the instruction at Idx.
+ /// Return the beginning of the new live range.
+ SlotIndex enterIntvAfter(SlotIndex Idx);
+
/// enterIntvAtEnd - Enter the open interval at the end of MBB.
/// Use the open interval from he inserted copy to the MBB end.
/// Return the beginning of the new live range.
///
void overlapIntv(SlotIndex Start, SlotIndex End);
- /// closeIntv - Indicate that we are done editing the currently open
- /// LiveInterval, and ranges can be trimmed.
- void closeIntv();
-
/// finish - after all the new live ranges have been created, compute the
/// remaining live range, and rewrite instructions to use the new registers.
- void finish();
+ /// @param LRMap When not null, this vector will map each live range in Edit
+ /// back to the indices returned by openIntv.
+ /// There may be extra indices created by dead code elimination.
+ void finish(SmallVectorImpl<unsigned> *LRMap = 0);
/// dump - print the current interval maping to dbgs().
void dump() const;
// ===--- High level methods ---===
+ /// splitSingleBlock - Split CurLI into a separate live interval around the
+ /// uses in a single block. This is intended to be used as part of a larger
+ /// split, and doesn't call finish().
+ void splitSingleBlock(const SplitAnalysis::BlockInfo &BI);
+
/// splitSingleBlocks - Split CurLI into a separate live interval inside each
/// basic block in Blocks.
void splitSingleBlocks(const SplitAnalysis::BlockPtrSet &Blocks);
};
}
+
+#endif
projects / oota-llvm.git / blobdiff