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Sooooo many of these had incorrect or strange main module includes. I have manually inspected all of these, and fixed the main module include to be the nearest plausible thing I could find. If you own or care about any of these source files, I encourage you to take some time and check that these edits were sensible. I can't have broken anything (I strictly added headers, and reordered them, never removed), but they may not be the headers you'd really like to identify as containing the API being implemented. Many forward declarations and missing includes were added to a header files to allow them to parse cleanly when included first. The main module rule does in fact have its merits. =] git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
884 lines
29 KiB
C++
884 lines
29 KiB
C++
//===-- LiveInterval.cpp - Live Interval Representation -------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the LiveRange and LiveInterval classes. Given some
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// numbering of each the machine instructions an interval [i, j) is said to be a
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// live interval for register v if there is no instruction with number j' > j
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// such that v is live at j' and there is no instruction with number i' < i such
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// that v is live at i'. In this implementation intervals can have holes,
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// i.e. an interval might look like [1,20), [50,65), [1000,1001). Each
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// individual range is represented as an instance of LiveRange, and the whole
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// interval is represented as an instance of LiveInterval.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/LiveInterval.h"
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#include "RegisterCoalescer.h"
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#include "llvm/ADT/DenseMap.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/ADT/SmallSet.h"
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#include "llvm/CodeGen/LiveIntervalAnalysis.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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#include "llvm/Support/Debug.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Target/TargetRegisterInfo.h"
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#include <algorithm>
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using namespace llvm;
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LiveInterval::iterator LiveInterval::find(SlotIndex Pos) {
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// This algorithm is basically std::upper_bound.
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// Unfortunately, std::upper_bound cannot be used with mixed types until we
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// adopt C++0x. Many libraries can do it, but not all.
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if (empty() || Pos >= endIndex())
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return end();
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iterator I = begin();
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size_t Len = ranges.size();
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do {
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size_t Mid = Len >> 1;
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if (Pos < I[Mid].end)
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Len = Mid;
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else
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I += Mid + 1, Len -= Mid + 1;
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} while (Len);
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return I;
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}
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VNInfo *LiveInterval::createDeadDef(SlotIndex Def,
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VNInfo::Allocator &VNInfoAllocator) {
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assert(!Def.isDead() && "Cannot define a value at the dead slot");
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iterator I = find(Def);
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if (I == end()) {
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VNInfo *VNI = getNextValue(Def, VNInfoAllocator);
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ranges.push_back(LiveRange(Def, Def.getDeadSlot(), VNI));
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return VNI;
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}
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if (SlotIndex::isSameInstr(Def, I->start)) {
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assert(I->valno->def == I->start && "Inconsistent existing value def");
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// It is possible to have both normal and early-clobber defs of the same
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// register on an instruction. It doesn't make a lot of sense, but it is
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// possible to specify in inline assembly.
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//
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// Just convert everything to early-clobber.
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Def = std::min(Def, I->start);
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if (Def != I->start)
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I->start = I->valno->def = Def;
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return I->valno;
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}
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assert(SlotIndex::isEarlierInstr(Def, I->start) && "Already live at def");
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VNInfo *VNI = getNextValue(Def, VNInfoAllocator);
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ranges.insert(I, LiveRange(Def, Def.getDeadSlot(), VNI));
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return VNI;
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}
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// overlaps - Return true if the intersection of the two live intervals is
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// not empty.
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//
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// An example for overlaps():
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//
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// 0: A = ...
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// 4: B = ...
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// 8: C = A + B ;; last use of A
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//
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// The live intervals should look like:
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//
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// A = [3, 11)
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// B = [7, x)
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// C = [11, y)
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//
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// A->overlaps(C) should return false since we want to be able to join
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// A and C.
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//
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bool LiveInterval::overlapsFrom(const LiveInterval& other,
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const_iterator StartPos) const {
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assert(!empty() && "empty interval");
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const_iterator i = begin();
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const_iterator ie = end();
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const_iterator j = StartPos;
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const_iterator je = other.end();
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assert((StartPos->start <= i->start || StartPos == other.begin()) &&
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StartPos != other.end() && "Bogus start position hint!");
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if (i->start < j->start) {
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i = std::upper_bound(i, ie, j->start);
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if (i != ranges.begin()) --i;
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} else if (j->start < i->start) {
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++StartPos;
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if (StartPos != other.end() && StartPos->start <= i->start) {
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assert(StartPos < other.end() && i < end());
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j = std::upper_bound(j, je, i->start);
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if (j != other.ranges.begin()) --j;
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}
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} else {
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return true;
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}
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if (j == je) return false;
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while (i != ie) {
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if (i->start > j->start) {
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std::swap(i, j);
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std::swap(ie, je);
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}
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if (i->end > j->start)
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return true;
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++i;
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}
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return false;
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}
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bool LiveInterval::overlaps(const LiveInterval &Other,
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const CoalescerPair &CP,
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const SlotIndexes &Indexes) const {
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assert(!empty() && "empty interval");
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if (Other.empty())
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return false;
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// Use binary searches to find initial positions.
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const_iterator I = find(Other.beginIndex());
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const_iterator IE = end();
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if (I == IE)
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return false;
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const_iterator J = Other.find(I->start);
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const_iterator JE = Other.end();
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if (J == JE)
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return false;
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for (;;) {
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// J has just been advanced to satisfy:
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assert(J->end >= I->start);
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// Check for an overlap.
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if (J->start < I->end) {
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// I and J are overlapping. Find the later start.
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SlotIndex Def = std::max(I->start, J->start);
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// Allow the overlap if Def is a coalescable copy.
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if (Def.isBlock() ||
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!CP.isCoalescable(Indexes.getInstructionFromIndex(Def)))
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return true;
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}
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// Advance the iterator that ends first to check for more overlaps.
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if (J->end > I->end) {
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std::swap(I, J);
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std::swap(IE, JE);
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}
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// Advance J until J->end >= I->start.
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do
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if (++J == JE)
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return false;
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while (J->end < I->start);
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}
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}
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/// overlaps - Return true if the live interval overlaps a range specified
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/// by [Start, End).
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bool LiveInterval::overlaps(SlotIndex Start, SlotIndex End) const {
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assert(Start < End && "Invalid range");
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const_iterator I = std::lower_bound(begin(), end(), End);
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return I != begin() && (--I)->end > Start;
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}
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/// ValNo is dead, remove it. If it is the largest value number, just nuke it
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/// (and any other deleted values neighboring it), otherwise mark it as ~1U so
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/// it can be nuked later.
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void LiveInterval::markValNoForDeletion(VNInfo *ValNo) {
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if (ValNo->id == getNumValNums()-1) {
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do {
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valnos.pop_back();
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} while (!valnos.empty() && valnos.back()->isUnused());
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} else {
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ValNo->markUnused();
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}
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}
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/// RenumberValues - Renumber all values in order of appearance and delete the
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/// remaining unused values.
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void LiveInterval::RenumberValues(LiveIntervals &lis) {
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SmallPtrSet<VNInfo*, 8> Seen;
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valnos.clear();
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for (const_iterator I = begin(), E = end(); I != E; ++I) {
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VNInfo *VNI = I->valno;
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if (!Seen.insert(VNI))
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continue;
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assert(!VNI->isUnused() && "Unused valno used by live range");
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VNI->id = (unsigned)valnos.size();
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valnos.push_back(VNI);
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}
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}
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/// extendIntervalEndTo - This method is used when we want to extend the range
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/// specified by I to end at the specified endpoint. To do this, we should
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/// merge and eliminate all ranges that this will overlap with. The iterator is
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/// not invalidated.
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void LiveInterval::extendIntervalEndTo(Ranges::iterator I, SlotIndex NewEnd) {
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assert(I != ranges.end() && "Not a valid interval!");
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VNInfo *ValNo = I->valno;
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// Search for the first interval that we can't merge with.
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Ranges::iterator MergeTo = llvm::next(I);
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for (; MergeTo != ranges.end() && NewEnd >= MergeTo->end; ++MergeTo) {
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assert(MergeTo->valno == ValNo && "Cannot merge with differing values!");
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}
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// If NewEnd was in the middle of an interval, make sure to get its endpoint.
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I->end = std::max(NewEnd, prior(MergeTo)->end);
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// If the newly formed range now touches the range after it and if they have
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// the same value number, merge the two ranges into one range.
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if (MergeTo != ranges.end() && MergeTo->start <= I->end &&
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MergeTo->valno == ValNo) {
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I->end = MergeTo->end;
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++MergeTo;
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}
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// Erase any dead ranges.
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ranges.erase(llvm::next(I), MergeTo);
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}
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/// extendIntervalStartTo - This method is used when we want to extend the range
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/// specified by I to start at the specified endpoint. To do this, we should
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/// merge and eliminate all ranges that this will overlap with.
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LiveInterval::Ranges::iterator
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LiveInterval::extendIntervalStartTo(Ranges::iterator I, SlotIndex NewStart) {
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assert(I != ranges.end() && "Not a valid interval!");
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VNInfo *ValNo = I->valno;
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// Search for the first interval that we can't merge with.
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Ranges::iterator MergeTo = I;
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do {
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if (MergeTo == ranges.begin()) {
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I->start = NewStart;
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ranges.erase(MergeTo, I);
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return I;
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}
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assert(MergeTo->valno == ValNo && "Cannot merge with differing values!");
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--MergeTo;
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} while (NewStart <= MergeTo->start);
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// If we start in the middle of another interval, just delete a range and
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// extend that interval.
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if (MergeTo->end >= NewStart && MergeTo->valno == ValNo) {
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MergeTo->end = I->end;
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} else {
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// Otherwise, extend the interval right after.
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++MergeTo;
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MergeTo->start = NewStart;
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MergeTo->end = I->end;
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}
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ranges.erase(llvm::next(MergeTo), llvm::next(I));
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return MergeTo;
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}
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LiveInterval::iterator
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LiveInterval::addRangeFrom(LiveRange LR, iterator From) {
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SlotIndex Start = LR.start, End = LR.end;
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iterator it = std::upper_bound(From, ranges.end(), Start);
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// If the inserted interval starts in the middle or right at the end of
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// another interval, just extend that interval to contain the range of LR.
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if (it != ranges.begin()) {
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iterator B = prior(it);
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if (LR.valno == B->valno) {
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if (B->start <= Start && B->end >= Start) {
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extendIntervalEndTo(B, End);
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return B;
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}
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} else {
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// Check to make sure that we are not overlapping two live ranges with
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// different valno's.
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assert(B->end <= Start &&
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"Cannot overlap two LiveRanges with differing ValID's"
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" (did you def the same reg twice in a MachineInstr?)");
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}
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}
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// Otherwise, if this range ends in the middle of, or right next to, another
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// interval, merge it into that interval.
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if (it != ranges.end()) {
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if (LR.valno == it->valno) {
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if (it->start <= End) {
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it = extendIntervalStartTo(it, Start);
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// If LR is a complete superset of an interval, we may need to grow its
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// endpoint as well.
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if (End > it->end)
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extendIntervalEndTo(it, End);
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return it;
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}
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} else {
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// Check to make sure that we are not overlapping two live ranges with
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// different valno's.
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assert(it->start >= End &&
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"Cannot overlap two LiveRanges with differing ValID's");
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}
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}
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// Otherwise, this is just a new range that doesn't interact with anything.
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// Insert it.
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return ranges.insert(it, LR);
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}
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/// extendInBlock - If this interval is live before Kill in the basic
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/// block that starts at StartIdx, extend it to be live up to Kill and return
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/// the value. If there is no live range before Kill, return NULL.
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VNInfo *LiveInterval::extendInBlock(SlotIndex StartIdx, SlotIndex Kill) {
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if (empty())
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return 0;
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iterator I = std::upper_bound(begin(), end(), Kill.getPrevSlot());
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if (I == begin())
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return 0;
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--I;
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if (I->end <= StartIdx)
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return 0;
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if (I->end < Kill)
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extendIntervalEndTo(I, Kill);
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return I->valno;
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}
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/// removeRange - Remove the specified range from this interval. Note that
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/// the range must be in a single LiveRange in its entirety.
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void LiveInterval::removeRange(SlotIndex Start, SlotIndex End,
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bool RemoveDeadValNo) {
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// Find the LiveRange containing this span.
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Ranges::iterator I = find(Start);
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assert(I != ranges.end() && "Range is not in interval!");
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assert(I->containsRange(Start, End) && "Range is not entirely in interval!");
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// If the span we are removing is at the start of the LiveRange, adjust it.
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VNInfo *ValNo = I->valno;
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if (I->start == Start) {
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if (I->end == End) {
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if (RemoveDeadValNo) {
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// Check if val# is dead.
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bool isDead = true;
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for (const_iterator II = begin(), EE = end(); II != EE; ++II)
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if (II != I && II->valno == ValNo) {
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isDead = false;
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break;
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}
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if (isDead) {
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// Now that ValNo is dead, remove it.
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markValNoForDeletion(ValNo);
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}
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}
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ranges.erase(I); // Removed the whole LiveRange.
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} else
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I->start = End;
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return;
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}
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// Otherwise if the span we are removing is at the end of the LiveRange,
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// adjust the other way.
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if (I->end == End) {
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I->end = Start;
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return;
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}
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// Otherwise, we are splitting the LiveRange into two pieces.
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SlotIndex OldEnd = I->end;
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I->end = Start; // Trim the old interval.
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// Insert the new one.
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ranges.insert(llvm::next(I), LiveRange(End, OldEnd, ValNo));
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}
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/// removeValNo - Remove all the ranges defined by the specified value#.
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/// Also remove the value# from value# list.
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void LiveInterval::removeValNo(VNInfo *ValNo) {
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if (empty()) return;
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Ranges::iterator I = ranges.end();
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Ranges::iterator E = ranges.begin();
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do {
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--I;
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if (I->valno == ValNo)
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ranges.erase(I);
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} while (I != E);
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// Now that ValNo is dead, remove it.
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markValNoForDeletion(ValNo);
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}
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/// join - Join two live intervals (this, and other) together. This applies
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/// mappings to the value numbers in the LHS/RHS intervals as specified. If
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/// the intervals are not joinable, this aborts.
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void LiveInterval::join(LiveInterval &Other,
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const int *LHSValNoAssignments,
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const int *RHSValNoAssignments,
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SmallVector<VNInfo*, 16> &NewVNInfo,
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MachineRegisterInfo *MRI) {
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verify();
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// Determine if any of our live range values are mapped. This is uncommon, so
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// we want to avoid the interval scan if not.
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bool MustMapCurValNos = false;
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unsigned NumVals = getNumValNums();
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unsigned NumNewVals = NewVNInfo.size();
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for (unsigned i = 0; i != NumVals; ++i) {
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unsigned LHSValID = LHSValNoAssignments[i];
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if (i != LHSValID ||
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(NewVNInfo[LHSValID] && NewVNInfo[LHSValID] != getValNumInfo(i))) {
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MustMapCurValNos = true;
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break;
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}
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}
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// If we have to apply a mapping to our base interval assignment, rewrite it
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// now.
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if (MustMapCurValNos && !empty()) {
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// Map the first live range.
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iterator OutIt = begin();
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OutIt->valno = NewVNInfo[LHSValNoAssignments[OutIt->valno->id]];
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for (iterator I = next(OutIt), E = end(); I != E; ++I) {
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VNInfo* nextValNo = NewVNInfo[LHSValNoAssignments[I->valno->id]];
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assert(nextValNo != 0 && "Huh?");
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// If this live range has the same value # as its immediate predecessor,
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// and if they are neighbors, remove one LiveRange. This happens when we
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// have [0,4:0)[4,7:1) and map 0/1 onto the same value #.
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if (OutIt->valno == nextValNo && OutIt->end == I->start) {
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OutIt->end = I->end;
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} else {
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// Didn't merge. Move OutIt to the next interval,
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++OutIt;
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OutIt->valno = nextValNo;
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if (OutIt != I) {
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OutIt->start = I->start;
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OutIt->end = I->end;
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}
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}
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}
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// If we merge some live ranges, chop off the end.
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++OutIt;
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ranges.erase(OutIt, end());
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}
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// Remember assignements because val# ids are changing.
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SmallVector<unsigned, 16> OtherAssignments;
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for (iterator I = Other.begin(), E = Other.end(); I != E; ++I)
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OtherAssignments.push_back(RHSValNoAssignments[I->valno->id]);
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// Update val# info. Renumber them and make sure they all belong to this
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// LiveInterval now. Also remove dead val#'s.
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unsigned NumValNos = 0;
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for (unsigned i = 0; i < NumNewVals; ++i) {
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VNInfo *VNI = NewVNInfo[i];
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if (VNI) {
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if (NumValNos >= NumVals)
|
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valnos.push_back(VNI);
|
|
else
|
|
valnos[NumValNos] = VNI;
|
|
VNI->id = NumValNos++; // Renumber val#.
|
|
}
|
|
}
|
|
if (NumNewVals < NumVals)
|
|
valnos.resize(NumNewVals); // shrinkify
|
|
|
|
// Okay, now insert the RHS live ranges into the LHS.
|
|
unsigned RangeNo = 0;
|
|
for (iterator I = Other.begin(), E = Other.end(); I != E; ++I, ++RangeNo) {
|
|
// Map the valno in the other live range to the current live range.
|
|
I->valno = NewVNInfo[OtherAssignments[RangeNo]];
|
|
assert(I->valno && "Adding a dead range?");
|
|
}
|
|
mergeIntervalRanges(Other);
|
|
|
|
verify();
|
|
}
|
|
|
|
/// \brief Helper function for merging in another LiveInterval's ranges.
|
|
///
|
|
/// This is a helper routine implementing an efficient merge of another
|
|
/// LiveIntervals ranges into the current interval.
|
|
///
|
|
/// \param LHSValNo If non-NULL, set as the new value number for every range
|
|
/// from RHS which is merged into the LHS.
|
|
/// \param RHSValNo If non-NULL, then only ranges in RHS whose original value
|
|
/// number maches this value number will be merged into LHS.
|
|
void LiveInterval::mergeIntervalRanges(const LiveInterval &RHS,
|
|
VNInfo *LHSValNo,
|
|
const VNInfo *RHSValNo) {
|
|
if (RHS.empty())
|
|
return;
|
|
|
|
// Ensure we're starting with a valid range. Note that we don't verify RHS
|
|
// because it may have had its value numbers adjusted in preparation for
|
|
// merging.
|
|
verify();
|
|
|
|
// The strategy for merging these efficiently is as follows:
|
|
//
|
|
// 1) Find the beginning of the impacted ranges in the LHS.
|
|
// 2) Create a new, merged sub-squence of ranges merging from the position in
|
|
// #1 until either LHS or RHS is exhausted. Any part of LHS between RHS
|
|
// entries being merged will be copied into this new range.
|
|
// 3) Replace the relevant section in LHS with these newly merged ranges.
|
|
// 4) Append any remaning ranges from RHS if LHS is exhausted in #2.
|
|
//
|
|
// We don't follow the typical in-place merge strategy for sorted ranges of
|
|
// appending the new ranges to the back and then using std::inplace_merge
|
|
// because one step of the merge can both mutate the original elements and
|
|
// remove elements from the original. Essentially, because the merge includes
|
|
// collapsing overlapping ranges, a more complex approach is required.
|
|
|
|
// We do an initial binary search to optimize for a common pattern: a large
|
|
// LHS, and a very small RHS.
|
|
const_iterator RI = RHS.begin(), RE = RHS.end();
|
|
iterator LE = end(), LI = std::upper_bound(begin(), LE, *RI);
|
|
|
|
// Merge into NewRanges until one of the ranges is exhausted.
|
|
SmallVector<LiveRange, 4> NewRanges;
|
|
|
|
// Keep track of where to begin the replacement.
|
|
iterator ReplaceI = LI;
|
|
|
|
// If there are preceding ranges in the LHS, put the last one into NewRanges
|
|
// so we can optionally extend it. Adjust the replacement point accordingly.
|
|
if (LI != begin()) {
|
|
ReplaceI = llvm::prior(LI);
|
|
NewRanges.push_back(*ReplaceI);
|
|
}
|
|
|
|
// Now loop over the mergable portions of both LHS and RHS, merging into
|
|
// NewRanges.
|
|
while (LI != LE && RI != RE) {
|
|
// Skip incoming ranges with the wrong value.
|
|
if (RHSValNo && RI->valno != RHSValNo) {
|
|
++RI;
|
|
continue;
|
|
}
|
|
|
|
// Select the first range. We pick the earliest start point, and then the
|
|
// largest range.
|
|
LiveRange R = *LI;
|
|
if (*RI < R) {
|
|
R = *RI;
|
|
++RI;
|
|
if (LHSValNo)
|
|
R.valno = LHSValNo;
|
|
} else {
|
|
++LI;
|
|
}
|
|
|
|
if (NewRanges.empty()) {
|
|
NewRanges.push_back(R);
|
|
continue;
|
|
}
|
|
|
|
LiveRange &LastR = NewRanges.back();
|
|
if (R.valno == LastR.valno) {
|
|
// Try to merge this range into the last one.
|
|
if (R.start <= LastR.end) {
|
|
LastR.end = std::max(LastR.end, R.end);
|
|
continue;
|
|
}
|
|
} else {
|
|
// We can't merge ranges across a value number.
|
|
assert(R.start >= LastR.end &&
|
|
"Cannot overlap two LiveRanges with differing ValID's");
|
|
}
|
|
|
|
// If all else fails, just append the range.
|
|
NewRanges.push_back(R);
|
|
}
|
|
assert(RI == RE || LI == LE);
|
|
|
|
// Check for being able to merge into the trailing sequence of ranges on the LHS.
|
|
if (!NewRanges.empty())
|
|
for (; LI != LE && (LI->valno == NewRanges.back().valno &&
|
|
LI->start <= NewRanges.back().end);
|
|
++LI)
|
|
NewRanges.back().end = std::max(NewRanges.back().end, LI->end);
|
|
|
|
// Replace the ranges in the LHS with the newly merged ones. It would be
|
|
// really nice if there were a move-supporting 'replace' directly in
|
|
// SmallVector, but as there is not, we pay the price of copies to avoid
|
|
// wasted memory allocations.
|
|
SmallVectorImpl<LiveRange>::iterator NRI = NewRanges.begin(),
|
|
NRE = NewRanges.end();
|
|
for (; ReplaceI != LI && NRI != NRE; ++ReplaceI, ++NRI)
|
|
*ReplaceI = *NRI;
|
|
if (NRI == NRE)
|
|
ranges.erase(ReplaceI, LI);
|
|
else
|
|
ranges.insert(LI, NRI, NRE);
|
|
|
|
// And finally insert any trailing end of RHS (if we have one).
|
|
for (; RI != RE; ++RI) {
|
|
LiveRange R = *RI;
|
|
if (LHSValNo)
|
|
R.valno = LHSValNo;
|
|
if (!ranges.empty() &&
|
|
ranges.back().valno == R.valno && R.start <= ranges.back().end)
|
|
ranges.back().end = std::max(ranges.back().end, R.end);
|
|
else
|
|
ranges.push_back(R);
|
|
}
|
|
|
|
// Ensure we finished with a valid new sequence of ranges.
|
|
verify();
|
|
}
|
|
|
|
/// MergeRangesInAsValue - Merge all of the intervals in RHS into this live
|
|
/// interval as the specified value number. The LiveRanges in RHS are
|
|
/// allowed to overlap with LiveRanges in the current interval, but only if
|
|
/// the overlapping LiveRanges have the specified value number.
|
|
void LiveInterval::MergeRangesInAsValue(const LiveInterval &RHS,
|
|
VNInfo *LHSValNo) {
|
|
mergeIntervalRanges(RHS, LHSValNo);
|
|
}
|
|
|
|
/// MergeValueInAsValue - Merge all of the live ranges of a specific val#
|
|
/// in RHS into this live interval as the specified value number.
|
|
/// The LiveRanges in RHS are allowed to overlap with LiveRanges in the
|
|
/// current interval, it will replace the value numbers of the overlaped
|
|
/// live ranges with the specified value number.
|
|
void LiveInterval::MergeValueInAsValue(const LiveInterval &RHS,
|
|
const VNInfo *RHSValNo,
|
|
VNInfo *LHSValNo) {
|
|
mergeIntervalRanges(RHS, LHSValNo, RHSValNo);
|
|
}
|
|
|
|
/// MergeValueNumberInto - This method is called when two value nubmers
|
|
/// are found to be equivalent. This eliminates V1, replacing all
|
|
/// LiveRanges with the V1 value number with the V2 value number. This can
|
|
/// cause merging of V1/V2 values numbers and compaction of the value space.
|
|
VNInfo* LiveInterval::MergeValueNumberInto(VNInfo *V1, VNInfo *V2) {
|
|
assert(V1 != V2 && "Identical value#'s are always equivalent!");
|
|
|
|
// This code actually merges the (numerically) larger value number into the
|
|
// smaller value number, which is likely to allow us to compactify the value
|
|
// space. The only thing we have to be careful of is to preserve the
|
|
// instruction that defines the result value.
|
|
|
|
// Make sure V2 is smaller than V1.
|
|
if (V1->id < V2->id) {
|
|
V1->copyFrom(*V2);
|
|
std::swap(V1, V2);
|
|
}
|
|
|
|
// Merge V1 live ranges into V2.
|
|
for (iterator I = begin(); I != end(); ) {
|
|
iterator LR = I++;
|
|
if (LR->valno != V1) continue; // Not a V1 LiveRange.
|
|
|
|
// Okay, we found a V1 live range. If it had a previous, touching, V2 live
|
|
// range, extend it.
|
|
if (LR != begin()) {
|
|
iterator Prev = LR-1;
|
|
if (Prev->valno == V2 && Prev->end == LR->start) {
|
|
Prev->end = LR->end;
|
|
|
|
// Erase this live-range.
|
|
ranges.erase(LR);
|
|
I = Prev+1;
|
|
LR = Prev;
|
|
}
|
|
}
|
|
|
|
// Okay, now we have a V1 or V2 live range that is maximally merged forward.
|
|
// Ensure that it is a V2 live-range.
|
|
LR->valno = V2;
|
|
|
|
// If we can merge it into later V2 live ranges, do so now. We ignore any
|
|
// following V1 live ranges, as they will be merged in subsequent iterations
|
|
// of the loop.
|
|
if (I != end()) {
|
|
if (I->start == LR->end && I->valno == V2) {
|
|
LR->end = I->end;
|
|
ranges.erase(I);
|
|
I = LR+1;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Now that V1 is dead, remove it.
|
|
markValNoForDeletion(V1);
|
|
|
|
return V2;
|
|
}
|
|
|
|
unsigned LiveInterval::getSize() const {
|
|
unsigned Sum = 0;
|
|
for (const_iterator I = begin(), E = end(); I != E; ++I)
|
|
Sum += I->start.distance(I->end);
|
|
return Sum;
|
|
}
|
|
|
|
raw_ostream& llvm::operator<<(raw_ostream& os, const LiveRange &LR) {
|
|
return os << '[' << LR.start << ',' << LR.end << ':' << LR.valno->id << ")";
|
|
}
|
|
|
|
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
|
|
void LiveRange::dump() const {
|
|
dbgs() << *this << "\n";
|
|
}
|
|
#endif
|
|
|
|
void LiveInterval::print(raw_ostream &OS) const {
|
|
if (empty())
|
|
OS << "EMPTY";
|
|
else {
|
|
for (LiveInterval::Ranges::const_iterator I = ranges.begin(),
|
|
E = ranges.end(); I != E; ++I) {
|
|
OS << *I;
|
|
assert(I->valno == getValNumInfo(I->valno->id) && "Bad VNInfo");
|
|
}
|
|
}
|
|
|
|
// Print value number info.
|
|
if (getNumValNums()) {
|
|
OS << " ";
|
|
unsigned vnum = 0;
|
|
for (const_vni_iterator i = vni_begin(), e = vni_end(); i != e;
|
|
++i, ++vnum) {
|
|
const VNInfo *vni = *i;
|
|
if (vnum) OS << " ";
|
|
OS << vnum << "@";
|
|
if (vni->isUnused()) {
|
|
OS << "x";
|
|
} else {
|
|
OS << vni->def;
|
|
if (vni->isPHIDef())
|
|
OS << "-phi";
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
|
|
void LiveInterval::dump() const {
|
|
dbgs() << *this << "\n";
|
|
}
|
|
#endif
|
|
|
|
#ifndef NDEBUG
|
|
void LiveInterval::verify() const {
|
|
for (const_iterator I = begin(), E = end(); I != E; ++I) {
|
|
assert(I->start.isValid());
|
|
assert(I->end.isValid());
|
|
assert(I->start < I->end);
|
|
assert(I->valno != 0);
|
|
assert(I->valno == valnos[I->valno->id]);
|
|
if (llvm::next(I) != E) {
|
|
assert(I->end <= llvm::next(I)->start);
|
|
if (I->end == llvm::next(I)->start)
|
|
assert(I->valno != llvm::next(I)->valno);
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
|
|
void LiveRange::print(raw_ostream &os) const {
|
|
os << *this;
|
|
}
|
|
|
|
unsigned ConnectedVNInfoEqClasses::Classify(const LiveInterval *LI) {
|
|
// Create initial equivalence classes.
|
|
EqClass.clear();
|
|
EqClass.grow(LI->getNumValNums());
|
|
|
|
const VNInfo *used = 0, *unused = 0;
|
|
|
|
// Determine connections.
|
|
for (LiveInterval::const_vni_iterator I = LI->vni_begin(), E = LI->vni_end();
|
|
I != E; ++I) {
|
|
const VNInfo *VNI = *I;
|
|
// Group all unused values into one class.
|
|
if (VNI->isUnused()) {
|
|
if (unused)
|
|
EqClass.join(unused->id, VNI->id);
|
|
unused = VNI;
|
|
continue;
|
|
}
|
|
used = VNI;
|
|
if (VNI->isPHIDef()) {
|
|
const MachineBasicBlock *MBB = LIS.getMBBFromIndex(VNI->def);
|
|
assert(MBB && "Phi-def has no defining MBB");
|
|
// Connect to values live out of predecessors.
|
|
for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
|
|
PE = MBB->pred_end(); PI != PE; ++PI)
|
|
if (const VNInfo *PVNI = LI->getVNInfoBefore(LIS.getMBBEndIdx(*PI)))
|
|
EqClass.join(VNI->id, PVNI->id);
|
|
} else {
|
|
// Normal value defined by an instruction. Check for two-addr redef.
|
|
// FIXME: This could be coincidental. Should we really check for a tied
|
|
// operand constraint?
|
|
// Note that VNI->def may be a use slot for an early clobber def.
|
|
if (const VNInfo *UVNI = LI->getVNInfoBefore(VNI->def))
|
|
EqClass.join(VNI->id, UVNI->id);
|
|
}
|
|
}
|
|
|
|
// Lump all the unused values in with the last used value.
|
|
if (used && unused)
|
|
EqClass.join(used->id, unused->id);
|
|
|
|
EqClass.compress();
|
|
return EqClass.getNumClasses();
|
|
}
|
|
|
|
void ConnectedVNInfoEqClasses::Distribute(LiveInterval *LIV[],
|
|
MachineRegisterInfo &MRI) {
|
|
assert(LIV[0] && "LIV[0] must be set");
|
|
LiveInterval &LI = *LIV[0];
|
|
|
|
// Rewrite instructions.
|
|
for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LI.reg),
|
|
RE = MRI.reg_end(); RI != RE;) {
|
|
MachineOperand &MO = RI.getOperand();
|
|
MachineInstr *MI = MO.getParent();
|
|
++RI;
|
|
// DBG_VALUE instructions should have been eliminated earlier.
|
|
LiveRangeQuery LRQ(LI, LIS.getInstructionIndex(MI));
|
|
const VNInfo *VNI = MO.readsReg() ? LRQ.valueIn() : LRQ.valueDefined();
|
|
// In the case of an <undef> use that isn't tied to any def, VNI will be
|
|
// NULL. If the use is tied to a def, VNI will be the defined value.
|
|
if (!VNI)
|
|
continue;
|
|
MO.setReg(LIV[getEqClass(VNI)]->reg);
|
|
}
|
|
|
|
// Move runs to new intervals.
|
|
LiveInterval::iterator J = LI.begin(), E = LI.end();
|
|
while (J != E && EqClass[J->valno->id] == 0)
|
|
++J;
|
|
for (LiveInterval::iterator I = J; I != E; ++I) {
|
|
if (unsigned eq = EqClass[I->valno->id]) {
|
|
assert((LIV[eq]->empty() || LIV[eq]->expiredAt(I->start)) &&
|
|
"New intervals should be empty");
|
|
LIV[eq]->ranges.push_back(*I);
|
|
} else
|
|
*J++ = *I;
|
|
}
|
|
LI.ranges.erase(J, E);
|
|
|
|
// Transfer VNInfos to their new owners and renumber them.
|
|
unsigned j = 0, e = LI.getNumValNums();
|
|
while (j != e && EqClass[j] == 0)
|
|
++j;
|
|
for (unsigned i = j; i != e; ++i) {
|
|
VNInfo *VNI = LI.getValNumInfo(i);
|
|
if (unsigned eq = EqClass[i]) {
|
|
VNI->id = LIV[eq]->getNumValNums();
|
|
LIV[eq]->valnos.push_back(VNI);
|
|
} else {
|
|
VNI->id = j;
|
|
LI.valnos[j++] = VNI;
|
|
}
|
|
}
|
|
LI.valnos.resize(j);
|
|
}
|