LLVM  10.0.0svn
LiveRangeUtils.h
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1 //===-- LiveRangeUtils.h - Live Range modification utilities ----*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 /// This file contains helper functions to modify live ranges.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_CODEGEN_LIVERANGEUTILS_H
14 #define LLVM_LIB_CODEGEN_LIVERANGEUTILS_H
15 
17 
18 namespace llvm {
19 
20 /// Helper function that distributes live range value numbers and the
21 /// corresponding segments of a master live range \p LR to a list of newly
22 /// created live ranges \p SplitLRs. \p VNIClasses maps each value number in \p
23 /// LR to 0 meaning it should stay or to 1..N meaning it should go to a specific
24 /// live range in the \p SplitLRs array.
25 template<typename LiveRangeT, typename EqClassesT>
26 static void DistributeRange(LiveRangeT &LR, LiveRangeT *SplitLRs[],
27  EqClassesT VNIClasses) {
28  // Move segments to new intervals.
29  typename LiveRangeT::iterator J = LR.begin(), E = LR.end();
30  while (J != E && VNIClasses[J->valno->id] == 0)
31  ++J;
32  for (typename LiveRangeT::iterator I = J; I != E; ++I) {
33  if (unsigned eq = VNIClasses[I->valno->id]) {
34  assert((SplitLRs[eq-1]->empty() || SplitLRs[eq-1]->expiredAt(I->start)) &&
35  "New intervals should be empty");
36  SplitLRs[eq-1]->segments.push_back(*I);
37  } else
38  *J++ = *I;
39  }
40  LR.segments.erase(J, E);
41 
42  // Transfer VNInfos to their new owners and renumber them.
43  unsigned j = 0, e = LR.getNumValNums();
44  while (j != e && VNIClasses[j] == 0)
45  ++j;
46  for (unsigned i = j; i != e; ++i) {
47  VNInfo *VNI = LR.getValNumInfo(i);
48  if (unsigned eq = VNIClasses[i]) {
49  VNI->id = SplitLRs[eq-1]->getNumValNums();
50  SplitLRs[eq-1]->valnos.push_back(VNI);
51  } else {
52  VNI->id = j;
53  LR.valnos[j++] = VNI;
54  }
55  }
56  LR.valnos.resize(j);
57 }
58 
59 } // End llvm namespace
60 
61 #endif
This class represents lattice values for constants.
Definition: AllocatorList.h:23
VNInfo - Value Number Information.
Definition: LiveInterval.h:52
static void DistributeRange(LiveRangeT &LR, LiveRangeT *SplitLRs[], EqClassesT VNIClasses)
Helper function that distributes live range value numbers and the corresponding segments of a master ...
static GCRegistry::Add< CoreCLRGC > E("coreclr", "CoreCLR-compatible GC")
constexpr bool empty(const T &RangeOrContainer)
Test whether RangeOrContainer is empty. Similar to C++17 std::empty.
Definition: STLExtras.h:209
unsigned id
The ID number of this value.
Definition: LiveInterval.h:57
#define I(x, y, z)
Definition: MD5.cpp:58
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())