MIParser/MIRPrinter: Compute block successors if not explicitely specified

- MIParser: If the successor list is not specified successors will be
  added based on basic block operands in the block and possible
  fallthrough.

- MIRPrinter: Adds a new `simplify-mir` option, with that option set:
  Skip printing of block successor lists in cases where the
  parser is guaranteed to reconstruct it. This means we still print the
  list if some successor cannot be determined (happens for example for
  jump tables), if the successor order changes or branch probabilities
  being unequal.

Differential Revision: https://reviews.llvm.org/D31262

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302289 91177308-0d34-0410-b5e6-96231b3b80d8

docs/MIRLangRef.rst

@@ -78,6 +78,8 @@ Simplifying MIR files
 The MIR code coming out of ``-stop-after``/``-stop-before`` is very verbose;
 Tests are more accessible and future proof when simplified:
 
+- Use the ``-simplify-mir`` option with llc.
+
 - Machine function attributes often have default values or the test works just
   as well with default values. Typical candidates for this are: `alignment:`,
   `exposesReturnsTwice`, `legalized`, `regBankSelected`, `selected`.

lib/CodeGen/MIRPrinter.h → include/llvm/CodeGen/MIRPrinter.h

@@ -17,9 +17,11 @@
 
 namespace llvm {
 
+class MachineBasicBlock;
 class MachineFunction;
 class Module;
 class raw_ostream;
+template <typename T> class SmallVectorImpl;
 
 /// Print LLVM IR using the MIR serialization format to the given output stream.
 void printMIR(raw_ostream &OS, const Module &M);
@@ -28,6 +30,17 @@ void printMIR(raw_ostream &OS, const Module &M);
 /// output stream.
 void printMIR(raw_ostream &OS, const MachineFunction &MF);
 
+/// Determine a possible list of successors of a basic block based on the
+/// basic block machine operand being used inside the block. This should give
+/// you the correct list of successor blocks in most cases except for things
+/// like jump tables where the basic block references can't easily be found.
+/// The MIRPRinter will skip printing successors if they match the result of
+/// this funciton and the parser will use this function to construct a list if
+/// it is missing.
+void guessSuccessors(const MachineBasicBlock &MBB,
+                     SmallVectorImpl<MachineBasicBlock*> &Successors,
+                     bool &IsFallthrough);
+
 } // end namespace llvm
 
 #endif

lib/CodeGen/MIRParser/MIParser.cpp

@@ -12,11 +12,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "MIParser.h"
+
 #include "MILexer.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/AsmParser/Parser.h"
 #include "llvm/AsmParser/SlotMapping.h"
+#include "llvm/CodeGen/MIRPrinter.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
@@ -134,7 +136,8 @@ public:
 
   bool
   parseBasicBlockDefinition(DenseMap<unsigned, MachineBasicBlock *> &MBBSlots);
-  bool parseBasicBlock(MachineBasicBlock &MBB);
+  bool parseBasicBlock(MachineBasicBlock &MBB,
+                       MachineBasicBlock *&AddFalthroughFrom);
   bool parseBasicBlockLiveins(MachineBasicBlock &MBB);
   bool parseBasicBlockSuccessors(MachineBasicBlock &MBB);
 
@@ -518,7 +521,8 @@ bool MIParser::parseBasicBlockSuccessors(MachineBasicBlock &MBB) {
   return false;
 }
 
-bool MIParser::parseBasicBlock(MachineBasicBlock &MBB) {
+bool MIParser::parseBasicBlock(MachineBasicBlock &MBB,
+                               MachineBasicBlock *&AddFalthroughFrom) {
   // Skip the definition.
   assert(Token.is(MIToken::MachineBasicBlockLabel));
   lex();
@@ -538,10 +542,12 @@ bool MIParser::parseBasicBlock(MachineBasicBlock &MBB) {
   //
   // is equivalent to
   //   liveins: %edi, %esi
+  bool ExplicitSuccesors = false;
   while (true) {
     if (Token.is(MIToken::kw_successors)) {
       if (parseBasicBlockSuccessors(MBB))
         return true;
+      ExplicitSuccesors = true;
     } else if (Token.is(MIToken::kw_liveins)) {
       if (parseBasicBlockLiveins(MBB))
         return true;
@@ -557,10 +563,9 @@ bool MIParser::parseBasicBlock(MachineBasicBlock &MBB) {
   // Parse the instructions.
   bool IsInBundle = false;
   MachineInstr *PrevMI = nullptr;
-  while (true) {
-    if (Token.is(MIToken::MachineBasicBlockLabel) || Token.is(MIToken::Eof))
-      return false;
-    else if (consumeIfPresent(MIToken::Newline))
+  while (!Token.is(MIToken::MachineBasicBlockLabel) &&
+         !Token.is(MIToken::Eof)) {
+    if (consumeIfPresent(MIToken::Newline))
       continue;
     if (consumeIfPresent(MIToken::rbrace)) {
       // The first parsing pass should verify that all closing '}' have an
@@ -592,6 +597,22 @@ bool MIParser::parseBasicBlock(MachineBasicBlock &MBB) {
     assert(Token.isNewlineOrEOF() && "MI is not fully parsed");
     lex();
   }
+
+  // Construct successor list by searching for basic block machine operands.
+  if (!ExplicitSuccesors) {
+    SmallVector<MachineBasicBlock*,4> Successors;
+    bool IsFallthrough;
+    guessSuccessors(MBB, Successors, IsFallthrough);
+    for (MachineBasicBlock *Succ : Successors)
+      MBB.addSuccessor(Succ);
+
+    if (IsFallthrough) {
+      AddFalthroughFrom = &MBB;
+    } else {
+      MBB.normalizeSuccProbs();
+    }
+  }
+
   return false;
 }
 
@@ -605,11 +626,18 @@ bool MIParser::parseBasicBlocks() {
   // The first parsing pass should have verified that this token is a MBB label
   // in the 'parseBasicBlockDefinitions' method.
   assert(Token.is(MIToken::MachineBasicBlockLabel));
+  MachineBasicBlock *AddFalthroughFrom = nullptr;
   do {
     MachineBasicBlock *MBB = nullptr;
     if (parseMBBReference(MBB))
       return true;
-    if (parseBasicBlock(*MBB))
+    if (AddFalthroughFrom) {
+      if (!AddFalthroughFrom->isSuccessor(MBB))
+        AddFalthroughFrom->addSuccessor(MBB);
+      AddFalthroughFrom->normalizeSuccProbs();
+      AddFalthroughFrom = nullptr;
+    }
+    if (parseBasicBlock(*MBB, AddFalthroughFrom))
       return true;
     // The method 'parseBasicBlock' should parse the whole block until the next
     // block or the end of file.

lib/CodeGen/MIRPrinter.cpp

@@ -12,7 +12,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "MIRPrinter.h"
+#include "llvm/CodeGen/MIRPrinter.h"
+
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallBitVector.h"
 #include "llvm/CodeGen/GlobalISel/RegisterBank.h"
@@ -34,6 +35,7 @@
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Options.h"
 #include "llvm/Support/YAMLTraits.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Target/TargetInstrInfo.h"
@@ -42,6 +44,9 @@
 
 using namespace llvm;
 
+static cl::opt<bool> SimplifyMIR("simplify-mir",
+    cl::desc("Leave out unnecessary information when printing MIR"));
+
 namespace {
 
 /// This structure describes how to print out stack object references.
@@ -105,6 +110,9 @@ class MIPrinter {
   const DenseMap<const uint32_t *, unsigned> &RegisterMaskIds;
   const DenseMap<int, FrameIndexOperand> &StackObjectOperandMapping;
 
+  bool canPredictBranchProbabilities(const MachineBasicBlock &MBB) const;
+  bool canPredictSuccessors(const MachineBasicBlock &MBB) const;
+
 public:
   MIPrinter(raw_ostream &OS, ModuleSlotTracker &MST,
             const DenseMap<const uint32_t *, unsigned> &RegisterMaskIds,
@@ -454,6 +462,63 @@ void MIRPrinter::initRegisterMaskIds(const MachineFunction &MF) {
     RegisterMaskIds.insert(std::make_pair(Mask, I++));
 }
 
+void llvm::guessSuccessors(const MachineBasicBlock &MBB,
+                           SmallVectorImpl<MachineBasicBlock*> &Result,
+                           bool &IsFallthrough) {
+  SmallPtrSet<MachineBasicBlock*,8> Seen;
+
+  for (const MachineInstr &MI : MBB) {
+    if (MI.isPHI())
+      continue;
+    for (const MachineOperand &MO : MI.operands()) {
+      if (!MO.isMBB())
+        continue;
+      MachineBasicBlock *Succ = MO.getMBB();
+      auto RP = Seen.insert(Succ);
+      if (RP.second)
+        Result.push_back(Succ);
+    }
+  }
+  MachineBasicBlock::const_iterator I = MBB.getLastNonDebugInstr();
+  IsFallthrough = I == MBB.end() || !I->isBarrier();
+}
+
+bool
+MIPrinter::canPredictBranchProbabilities(const MachineBasicBlock &MBB) const {
+  if (MBB.succ_size() <= 1)
+    return true;
+  if (!MBB.hasSuccessorProbabilities())
+    return true;
+
+  SmallVector<BranchProbability,8> Normalized(MBB.Probs.begin(),
+                                              MBB.Probs.end());
+  BranchProbability::normalizeProbabilities(Normalized.begin(),
+                                            Normalized.end());
+  SmallVector<BranchProbability,8> Equal(Normalized.size());
+  BranchProbability::normalizeProbabilities(Equal.begin(), Equal.end());
+
+  return std::equal(Normalized.begin(), Normalized.end(), Equal.begin());
+}
+
+bool MIPrinter::canPredictSuccessors(const MachineBasicBlock &MBB) const {
+  SmallVector<MachineBasicBlock*,8> GuessedSuccs;
+  bool GuessedFallthrough;
+  guessSuccessors(MBB, GuessedSuccs, GuessedFallthrough);
+  if (GuessedFallthrough) {
+    const MachineFunction &MF = *MBB.getParent();
+    MachineFunction::const_iterator NextI = std::next(MBB.getIterator());
+    if (NextI != MF.end()) {
+      MachineBasicBlock *Next = const_cast<MachineBasicBlock*>(&*NextI);
+      if (!is_contained(GuessedSuccs, Next))
+        GuessedSuccs.push_back(Next);
+    }
+  }
+  if (GuessedSuccs.size() != MBB.succ_size())
+    return false;
+  return std::equal(MBB.succ_begin(), MBB.succ_end(), GuessedSuccs.begin());
+}
+
+
 void MIPrinter::print(const MachineBasicBlock &MBB) {
   assert(MBB.getNumber() >= 0 && "Invalid MBB number");
   OS << "bb." << MBB.getNumber();
@@ -492,13 +557,15 @@ void MIPrinter::print(const MachineBasicBlock &MBB) {
 
   bool HasLineAttributes = false;
   // Print the successors
-  if (!MBB.succ_empty()) {
+  bool canPredictProbs = canPredictBranchProbabilities(MBB);
+  if (!MBB.succ_empty() && (!SimplifyMIR || !canPredictProbs ||
+                            !canPredictSuccessors(MBB))) {
     OS.indent(2) << "successors: ";
     for (auto I = MBB.succ_begin(), E = MBB.succ_end(); I != E; ++I) {
       if (I != MBB.succ_begin())
         OS << ", ";
       printMBBReference(**I);
-      if (MBB.hasSuccessorProbabilities())
+      if (!SimplifyMIR || !canPredictProbs)
         OS << '('
            << format("0x%08" PRIx32, MBB.getSuccProbability(I).getNumerator())
            << ')';

lib/CodeGen/MIRPrintingPass.cpp

@@ -12,7 +12,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "MIRPrinter.h"
+#include "llvm/CodeGen/MIRPrinter.h"
+
 #include "llvm/CodeGen/Passes.h"
 #include "llvm/CodeGen/MachineFunctionPass.h"
 #include "llvm/CodeGen/MIRYamlMapping.h"

test/CodeGen/AArch64/loh.mir

@@ -180,7 +180,6 @@ body: |
     %x9 = ADRP target-flags(aarch64-page, aarch64-got) @g5
 
   bb.13:
-    successors: %bb.14
     ; Cannot produce a LOH for multiple users
     ; CHECK-NOT: MCLOH_AdrpAdd
     %x10 = ADRP target-flags(aarch64-page) @g0

test/CodeGen/AArch64/machine-copy-remove.mir

@@ -7,20 +7,16 @@ name:            test1
 tracksRegLiveness: true
 body:             |
   bb.0:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1
 
     %x0 = COPY %x1
     CBNZX %x1, %bb.2
 
   bb.1:
-    successors: %bb.3
-
     %x0 = COPY %xzr
     B %bb.3
 
   bb.2:
-    successors: %bb.3
     liveins: %x1
 
     %x0 = LDRXui %x1, 0
@@ -38,20 +34,16 @@ name:            test2
 tracksRegLiveness: true
 body:             |
   bb.0:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1
 
     %x1 = COPY %x0
     CBNZX %x1, %bb.2
 
   bb.1:
-    successors: %bb.3
-
     %x0 = COPY %xzr
     B %bb.3
 
   bb.2:
-    successors: %bb.3
     liveins: %x1
 
     %x0 = LDRXui %x1, 0
@@ -69,7 +61,6 @@ name:            test3
 tracksRegLiveness: true
 body:             |
   bb.0:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1, %x2
 
     %x0 = COPY %x1
@@ -77,13 +68,10 @@ body:             |
     CBNZX %x1, %bb.2
 
   bb.1:
-    successors: %bb.3
-
     %x0 = COPY %xzr
     B %bb.3
 
   bb.2:
-    successors: %bb.3
     liveins: %x1
 
     %x0 = LDRXui %x1, 0
@@ -101,7 +89,6 @@ name:            test4
 tracksRegLiveness: true
 body:             |
   bb.0:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1, %x2
 
     %x1 = COPY %x0
@@ -109,13 +96,10 @@ body:             |
     CBNZX %x1, %bb.2
 
   bb.1:
-    successors: %bb.3
-
     %x0 = COPY %xzr
     B %bb.3
 
   bb.2:
-    successors: %bb.3
     liveins: %x1
 
     %x0 = LDRXui %x1, 0
@@ -133,7 +117,6 @@ name:            test5
 tracksRegLiveness: true
 body:             |
   bb.0:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1, %x2
 
     %x1 = COPY %x0
@@ -141,13 +124,10 @@ body:             |
     CBNZX %x1, %bb.2
 
   bb.1:
-    successors: %bb.3
-
     %x0 = COPY %xzr
     B %bb.3
 
   bb.2:
-    successors: %bb.3
     liveins: %x1
 
     %x0 = LDRXui %x1, 0
@@ -165,7 +145,6 @@ name:            test6
 tracksRegLiveness: true
 body:             |
   bb.0:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1, %x2
 
     %x2 = COPY %x0
@@ -173,13 +152,10 @@ body:             |
     CBNZX %x1, %bb.2
 
   bb.1:
-    successors: %bb.3
-
     %x0 = COPY %xzr
     B %bb.3
 
   bb.2:
-    successors: %bb.3
     liveins: %x1
 
     %x0 = LDRXui %x1, 0
@@ -197,7 +173,6 @@ name:            test7
 tracksRegLiveness: true
 body:             |
   bb.0:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1, %x2
 
     %x2 = COPY %x0
@@ -206,13 +181,10 @@ body:             |
     CBNZX %x1, %bb.2
 
   bb.1:
-    successors: %bb.3
-
     %x0 = COPY %xzr
     B %bb.3
 
   bb.2:
-    successors: %bb.3
     liveins: %x1
 
     %x0 = LDRXui %x1, 0
@@ -232,14 +204,12 @@ name:            test8
 tracksRegLiveness: true
 body:             |
   bb.0:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1
 
     %x1 = COPY %x0
     CBNZX %x1, %bb.2
 
   bb.1:
-    successors: %bb.3
     liveins: %x0, %x2
 
     %x0, %x1 = LDPXi %x2, 0
@@ -248,7 +218,6 @@ body:             |
     B %bb.3
 
   bb.2:
-    successors: %bb.3
     liveins: %x1
 
     %x0 = LDRXui %x1, 0
@@ -267,20 +236,17 @@ name:            test9
 tracksRegLiveness: true
 body:             |
   bb.0:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1
 
     CBNZX %x0, %bb.2
 
   bb.1:
-    successors: %bb.3
     liveins: %x0, %x2
 
     %x0 = COPY %xzr
     B %bb.3
 
   bb.2:
-    successors: %bb.1, %bb.3
     liveins: %x1
 
     %x0 = LDRXui %x1, 0
@@ -304,7 +270,6 @@ name:            test10
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %w0, %x1
 
     dead %wzr = SUBSWri killed %w0, 7, 0, implicit-def %nzcv
@@ -312,7 +277,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %w0 = MOVi32imm 7
@@ -332,7 +296,6 @@ name:            test11
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1
 
     dead %xzr = SUBSXri killed %x0, 7, 0, implicit-def %nzcv
@@ -340,7 +303,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %w0 = MOVi32imm 7, implicit-def %x0
@@ -360,7 +322,6 @@ name:            test12
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1
 
     dead %xzr = SUBSXri killed %x0, 7, 0, implicit-def %nzcv
@@ -368,7 +329,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %w0 = MOVi32imm 7
@@ -388,7 +348,6 @@ name:            test13
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %w0, %x1
 
     dead %wzr = SUBSWri killed %w0, 7, 0, implicit-def %nzcv
@@ -396,7 +355,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %w0 = MOVi32imm 7, implicit-def %x0
@@ -413,7 +371,6 @@ name:            test14
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %w0, %x1, %x2
 
     dead %wzr = SUBSWri killed %w0, 7, 0, implicit-def %nzcv
@@ -423,7 +380,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %w0 = MOVi32imm 7
@@ -440,7 +396,6 @@ name:            test15
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %w0, %x1, %x2
 
     dead %wzr = SUBSWri killed %w0, 7, 0, implicit-def %nzcv
@@ -448,7 +403,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1, %x2
 
     %w0 = LDRWui %x1, 0
@@ -467,7 +421,6 @@ name:            test16
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %w0, %x1
 
     dead %wzr = SUBSWri %w0, 7, 0, implicit-def %nzcv
@@ -476,7 +429,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %w2 = MOVi32imm 7
@@ -493,7 +445,6 @@ name:            test17
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %w0, %x1
 
     dead %w0 = SUBSWri killed %w0, 7, 0, implicit-def %nzcv
@@ -501,7 +452,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %w0 = MOVi32imm 7
@@ -520,14 +470,12 @@ name:            test18
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1
 
     CBNZX killed %x0, %bb.2
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %x0 = MOVi64imm 4252017623040
@@ -547,7 +495,6 @@ name:            test19
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %w0, %x1
 
     dead %wzr = ADDSWri killed %w0, 1, 0, implicit-def %nzcv
@@ -555,7 +502,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %w0 = MOVi32imm -1
@@ -575,7 +521,6 @@ name:            test20
 tracksRegLiveness: true
 body:             |
   bb.0:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1
 
     dead %xzr = ADDSXri killed %x0, 1, 0, implicit-def %nzcv
@@ -583,7 +528,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %x0 = MOVi64imm -1
@@ -603,7 +547,6 @@ name:            test21
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %x0, %x1
 
     dead %xzr = ADDSXri killed %x0, 1, 0, implicit-def %nzcv
@@ -611,7 +554,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %w0 = MOVi32imm -1
@@ -629,7 +571,6 @@ name:            test22
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %w0, %x1
 
     dead %wzr = ADDSWri killed %w0, 1, 0, implicit-def %nzcv
@@ -637,7 +578,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %x0 = MOVi64imm -1
@@ -654,7 +594,6 @@ name:            test23
 tracksRegLiveness: true
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2
     liveins: %w0, %x1
 
     dead %wzr = SUBSWri killed %w0, 1, 12, implicit-def %nzcv
@@ -662,7 +601,6 @@ body:             |
     B %bb.1
 
   bb.1:
-    successors: %bb.2
     liveins: %x1
 
     %w0 = MOVi32imm 4096

test/CodeGen/AArch64/machine-sink-zr.mir

@@ -17,7 +17,6 @@ body:             |
   ; CHECK-LABEL: bb.0:
   ; CHECK-NOT: COPY %wzr
   bb.0:
-    successors: %bb.3, %bb.1
     liveins: %w0
 
     %0 = COPY %w0
@@ -28,13 +27,9 @@ body:             |
   ; CHECK: COPY %wzr
 
   bb.1:
-    successors: %bb.2
-
     B %bb.2
 
   bb.2:
-    successors: %bb.3, %bb.2
-
     %2 = PHI %0, %bb.1, %4, %bb.2
     %w0 = COPY %1
     %3 = SUBSWri %2, 1, 0, implicit-def dead %nzcv

test/CodeGen/AArch64/regcoal-physreg.mir

@@ -93,7 +93,6 @@ body: |
 name: func1
 body: |
   bb.0:
-    successors: %bb.1, %bb.2
     ; Cannot coalesce physreg because we have reads on other CFG paths (we
     ; currently abort for any control flow)
     ; CHECK-NOT: %fp = SUBXri
@@ -117,7 +116,6 @@ body: |
 name: func2
 body: |
   bb.0:
-    successors: %bb.1, %bb.2
     ; We can coalesce copies from physreg to vreg across multiple blocks.
     ; CHECK-NOT: COPY
     ; CHECK: CBZX undef %x0, %bb.1

test/CodeGen/AMDGPU/detect-dead-lanes.mir

@@ -294,7 +294,6 @@ registers:
   - { id: 5, class: sreg_128 }
 body: |
   bb.0:
-    successors: %bb.1
     S_NOP 0, implicit-def %0
     S_NOP 0, implicit-def %1
     S_NOP 0, implicit-def %2
@@ -302,7 +301,6 @@ body: |
     S_BRANCH %bb.1
 
   bb.1:
-    successors: %bb.1, %bb.2
     %4 = PHI %3, %bb.0, %5, %bb.1
 
     ; let's swiffle some lanes around for fun...
@@ -348,7 +346,6 @@ registers:
   - { id: 6, class: sreg_128 }
 body: |
   bb.0:
-    successors: %bb.1
     S_NOP 0, implicit-def %0
     S_NOP 0, implicit-def %1
     S_NOP 0, implicit-def dead %2
@@ -357,7 +354,6 @@ body: |
     S_BRANCH %bb.1
 
   bb.1:
-    successors: %bb.1, %bb.2
     %5 = PHI %4, %bb.0, %6, %bb.1
 
     ; rotate lanes, but skip sub2 lane...
@@ -396,13 +392,11 @@ registers:
   - { id: 3, class: sreg_128 }
 body: |
   bb.0:
-    successors: %bb.1
     S_NOP 0, implicit-def %0
     %1 = REG_SEQUENCE %0, %subreg.sub0
     S_BRANCH %bb.1
 
   bb.1:
-    successors: %bb.1, %bb.2
     %2 = PHI %1, %bb.0, %3, %bb.1
 
     ; rotate subreg lanes, skipping sub1

test/CodeGen/AMDGPU/inserted-wait-states.mir

@@ -77,19 +77,16 @@ name: div_fmas
 
 body: |
   bb.0:
-    successors: %bb.1
     %vcc = S_MOV_B64 0
     %vgpr0 = V_DIV_FMAS_F32 0, %vgpr1, 0, %vgpr2, 0, %vgpr3, 0, 0, implicit %vcc, implicit %exec
     S_BRANCH %bb.1
 
   bb.1:
-    successors: %bb.2
     implicit %vcc = V_CMP_EQ_I32_e32 %vgpr1, %vgpr2, implicit %exec
     %vgpr0 = V_DIV_FMAS_F32 0, %vgpr1, 0, %vgpr2, 0, %vgpr3, 0, 0, implicit %vcc, implicit %exec
     S_BRANCH %bb.2
 
   bb.2:
-    successors: %bb.3
     %vcc = V_CMP_EQ_I32_e64 %vgpr1, %vgpr2, implicit %exec
     %vgpr0 = V_DIV_FMAS_F32 0, %vgpr1, 0, %vgpr2, 0, %vgpr3, 0, 0, implicit %vcc, implicit %exec
     S_BRANCH %bb.3
@@ -130,19 +127,16 @@ name: s_getreg
 
 body: |
   bb.0:
-    successors: %bb.1
     S_SETREG_B32 %sgpr0, 1
     %sgpr1 = S_GETREG_B32 1
     S_BRANCH %bb.1
 
   bb.1:
-    successors: %bb.2
     S_SETREG_IMM32_B32 0, 1
     %sgpr1 = S_GETREG_B32 1
     S_BRANCH %bb.2
 
   bb.2:
-    successors: %bb.3
     S_SETREG_B32 %sgpr0, 1
     %sgpr1 = S_MOV_B32 0
     %sgpr2 = S_GETREG_B32 1
@@ -178,13 +172,11 @@ name: s_setreg
 
 body: |
   bb.0:
-    successors: %bb.1
     S_SETREG_B32 %sgpr0, 1
     S_SETREG_B32 %sgpr1, 1
     S_BRANCH %bb.1
 
   bb.1:
-    successors: %bb.2
     S_SETREG_B32 %sgpr0, 64
     S_SETREG_B32 %sgpr1, 128
     S_BRANCH %bb.2
@@ -237,7 +229,6 @@ name: vmem_gt_8dw_store
 
 body: |
   bb.0:
-    successors: %bb.1
     BUFFER_STORE_DWORD_OFFSET %vgpr3, %sgpr0_sgpr1_sgpr2_sgpr3, %sgpr4, 0, 0, 0, 0, implicit %exec
     %vgpr3 = V_MOV_B32_e32 0, implicit %exec
     BUFFER_STORE_DWORDX3_OFFSET %vgpr2_vgpr3_vgpr4, %sgpr0_sgpr1_sgpr2_sgpr3, 0, 0, 0, 0, 0, implicit %exec
@@ -310,19 +301,16 @@ name: readwrite_lane
 
 body: |
   bb.0:
-    successors: %bb.1
     %vgpr0,%sgpr0_sgpr1 = V_ADD_I32_e64 %vgpr1, %vgpr2, implicit %vcc, implicit %exec
     %sgpr4 = V_READLANE_B32 %vgpr4, %sgpr0
     S_BRANCH %bb.1
 
   bb.1:
-    successors: %bb.2
     %vgpr0,%sgpr0_sgpr1 = V_ADD_I32_e64 %vgpr1, %vgpr2, implicit %vcc, implicit %exec
     %vgpr4 = V_WRITELANE_B32 %sgpr0, %sgpr0
     S_BRANCH %bb.2
 
   bb.2:
-    successors: %bb.3
     %vgpr0,implicit %vcc = V_ADD_I32_e32 %vgpr1, %vgpr2, implicit %vcc, implicit %exec
     %sgpr4 = V_READLANE_B32 %vgpr4, %vcc_lo
     S_BRANCH %bb.3
@@ -352,7 +340,6 @@ name: rfe
 
 body: |
   bb.0:
-    successors: %bb.1
     S_SETREG_B32 %sgpr0, 3
     S_RFE_B64 %sgpr2_sgpr3
     S_BRANCH %bb.1
@@ -382,7 +369,6 @@ name: s_mov_fed_b32
 
 body: |
   bb.0:
-    successors: %bb.1
     %sgpr0 = S_MOV_FED_B32 %sgpr0
     %sgpr0 = S_MOV_B32 %sgpr0
     S_BRANCH %bb.1
@@ -423,19 +409,16 @@ name: s_movrel
 
 body: |
   bb.0:
-    successors: %bb.1
     %m0 = S_MOV_B32 0
     %sgpr0 = S_MOVRELS_B32 %sgpr0, implicit %m0
     S_BRANCH %bb.1
 
   bb.1:
-    successors: %bb.2
     %m0 = S_MOV_B32 0
     %sgpr0_sgpr1 = S_MOVRELS_B64 %sgpr0_sgpr1, implicit %m0
     S_BRANCH %bb.2
 
   bb.2:
-    successors: %bb.3
     %m0 = S_MOV_B32 0
     %sgpr0 = S_MOVRELD_B32 %sgpr0, implicit %m0
     S_BRANCH %bb.3
@@ -475,19 +458,16 @@ name: v_interp
 
 body: |
   bb.0:
-    successors: %bb.1
     %m0 = S_MOV_B32 0
     %vgpr0 = V_INTERP_P1_F32 %vgpr0, 0, 0, implicit %m0, implicit %exec
     S_BRANCH %bb.1
 
   bb.1:
-    successors: %bb.2
     %m0 = S_MOV_B32 0
     %vgpr0 = V_INTERP_P2_F32 %vgpr0, %vgpr1, 0, 0, implicit %m0, implicit %exec
     S_BRANCH %bb.2
 
   bb.2:
-    successors: %bb.3
     %m0 = S_MOV_B32 0
     %vgpr0 = V_INTERP_P1_F32_16bank %vgpr0, 0, 0, implicit %m0, implicit %exec
     S_BRANCH %bb.3

test/CodeGen/AMDGPU/invert-br-undef-vcc.mir

@@ -53,7 +53,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.entry:
-    successors: %bb.2.if, %bb.1.else
     liveins: %sgpr0_sgpr1
 
     %sgpr0_sgpr1 = S_LOAD_DWORDX2_IMM killed %sgpr0_sgpr1, 11, 0 :: (non-temporal dereferenceable invariant load 8 from `i64 addrspace(2)* undef`)
@@ -62,7 +61,6 @@ body:             |
     S_CBRANCH_VCCNZ %bb.2.if, implicit undef %vcc
 
   bb.1.else:
-    successors: %bb.3.done
     liveins: %sgpr6, %sgpr7, %sgpr0_sgpr1_sgpr2_sgpr3:0x00000003
 
     %vgpr0 = V_MOV_B32_e32 100, implicit %exec
@@ -71,7 +69,6 @@ body:             |
     S_BRANCH %bb.3.done
 
   bb.2.if:
-    successors: %bb.3.done
     liveins: %sgpr6, %sgpr7, %sgpr0_sgpr1_sgpr2_sgpr3:0x00000003
 
     %vgpr0 = V_MOV_B32_e32 9, implicit %exec

test/CodeGen/AMDGPU/liveness.mir

@@ -16,13 +16,11 @@ registers:
   - { id: 0, class: sreg_64 }
 body: |
   bb.0:
-    successors: %bb.1, %bb.2
     S_NOP 0, implicit-def undef %0.sub0
     S_CBRANCH_VCCNZ %bb.1, implicit undef %vcc
     S_BRANCH %bb.2
 
   bb.1:
-    successors: %bb.2
     S_NOP 0, implicit-def %0.sub1
     S_NOP 0, implicit %0.sub1
     S_BRANCH %bb.2

test/CodeGen/AMDGPU/optimize-if-exec-masking.mir

@@ -176,7 +176,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.main_body:
-    successors: %bb.1.if, %bb.2.end
     liveins: %vgpr0
 
     %sgpr0_sgpr1 = COPY %exec
@@ -189,7 +188,6 @@ body:             |
     S_BRANCH %bb.1.if
 
   bb.1.if:
-    successors: %bb.2.end
     liveins: %sgpr0_sgpr1
 
     %sgpr7 = S_MOV_B32 61440
@@ -236,7 +234,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.main_body:
-    successors: %bb.1.if, %bb.2.end
     liveins: %vgpr0
 
     %sgpr0_sgpr1 = COPY %exec
@@ -248,7 +245,6 @@ body:             |
     S_BRANCH %bb.1.if
 
   bb.1.if:
-    successors: %bb.2.end
     liveins: %sgpr0_sgpr1
 
     %sgpr7 = S_MOV_B32 61440
@@ -295,7 +291,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.main_body:
-    successors: %bb.1.if, %bb.2.end
     liveins: %vgpr0
 
     %sgpr0_sgpr1 = COPY %exec
@@ -307,7 +302,6 @@ body:             |
     S_BRANCH %bb.1.if
 
   bb.1.if:
-    successors: %bb.2.end
     liveins: %sgpr0_sgpr1
 
     %sgpr7 = S_MOV_B32 61440
@@ -356,7 +350,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.main_body:
-    successors: %bb.1.if, %bb.2.end
     liveins: %vgpr0
 
     %sgpr0_sgpr1 = COPY %exec
@@ -370,7 +363,6 @@ body:             |
     S_BRANCH %bb.1.if
 
   bb.1.if:
-    successors: %bb.2.end
     liveins: %sgpr0_sgpr1
 
     %sgpr7 = S_MOV_B32 61440
@@ -418,7 +410,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.main_body:
-    successors: %bb.1.if, %bb.2.end
     liveins: %vgpr0
 
     %sgpr6 = S_MOV_B32 -1
@@ -433,7 +424,6 @@ body:             |
     S_BRANCH %bb.1.if
 
   bb.1.if:
-    successors: %bb.2.end
     liveins: %sgpr0_sgpr1 , %sgpr4_sgpr5_sgpr6_sgpr7
     %vgpr0 = BUFFER_LOAD_DWORD_OFFSET %sgpr4_sgpr5_sgpr6_sgpr7, 0, 0, 0, 0, 0, implicit %exec :: (volatile load 4 from `i32 addrspace(1)* undef`)
 
@@ -480,7 +470,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.main_body:
-    successors: %bb.1.if, %bb.2.end
     liveins: %vgpr0
 
     %sgpr0_sgpr1 = COPY %exec
@@ -494,7 +483,6 @@ body:             |
     S_BRANCH %bb.1.if
 
   bb.1.if:
-    successors: %bb.2.end
     liveins: %sgpr0_sgpr1
 
     %sgpr7 = S_MOV_B32 61440
@@ -544,7 +532,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.main_body:
-    successors: %bb.1.if, %bb.2.end
     liveins: %vgpr0
 
     %sgpr0_sgpr1 = COPY %exec
@@ -557,7 +544,6 @@ body:             |
     S_BRANCH %bb.1.if
 
   bb.1.if:
-    successors: %bb.2.end
     liveins: %sgpr0_sgpr1, %sgpr2_sgpr3
     S_SLEEP 0, implicit %sgpr2_sgpr3
     %sgpr7 = S_MOV_B32 61440
@@ -606,7 +592,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.main_body:
-    successors: %bb.1.if, %bb.2.end
     liveins: %vgpr0
 
     %sgpr0_sgpr1 = COPY %exec
@@ -618,7 +603,6 @@ body:             |
     S_BRANCH %bb.1.if
 
   bb.1.if:
-    successors: %bb.2.end
     liveins: %sgpr0_sgpr1
 
     %sgpr7 = S_MOV_B32 61440
@@ -665,7 +649,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.main_body:
-    successors: %bb.1.if, %bb.2.end
     liveins: %vgpr0
 
     %sgpr0_sgpr1 = COPY %exec
@@ -677,7 +660,6 @@ body:             |
     S_BRANCH %bb.1.if
 
   bb.1.if:
-    successors: %bb.2.end
     liveins: %sgpr0_sgpr1
 
     %sgpr7 = S_MOV_B32 61440
@@ -724,7 +706,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.main_body:
-    successors: %bb.1.if, %bb.2.end
     liveins: %vgpr0
 
     %sgpr0_sgpr1 = COPY %exec
@@ -736,7 +717,6 @@ body:             |
     S_BRANCH %bb.1.if
 
   bb.1.if:
-    successors: %bb.2.end
     liveins: %sgpr0_sgpr1
 
     %sgpr7 = S_MOV_B32 61440

test/CodeGen/AMDGPU/rename-independent-subregs.mir

@@ -49,7 +49,6 @@ registers:
   - { id: 1, class: sreg_128 }
 body: |
   bb.0:
-    successors: %bb.1, %bb.2
     S_NOP 0, implicit-def undef %0.sub2
     S_CBRANCH_VCCNZ %bb.1, implicit undef %vcc
     S_BRANCH %bb.2

test/CodeGen/AMDGPU/si-fix-sgpr-copies.mir

@@ -20,12 +20,10 @@ body: |
   ; GCN: V_ADD_I32
   bb.0:
     liveins: %vgpr0
-    successors: %bb.1
     %7 = COPY %vgpr0
     %8 = S_MOV_B32 0
 
   bb.1:
-    successors: %bb.1, %bb.2
     %0 = PHI %8, %bb.0, %0, %bb.1, %2, %bb.2
     %9 = V_MOV_B32_e32 9, implicit %exec
     %10 = V_CMP_EQ_U32_e64 %7, %9, implicit %exec
@@ -33,7 +31,6 @@ body: |
     S_BRANCH %bb.1
 
   bb.2:
-    successors: %bb.1
     SI_END_CF %1, implicit-def %exec, implicit-def %scc, implicit %exec
     %11 = S_MOV_B32 1
     %2 = S_ADD_I32 %0, %11, implicit-def %scc

test/CodeGen/AMDGPU/subreg-intervals.mir

@@ -31,17 +31,14 @@ registers:
   - { id: 0, class: sreg_64 }
 body: |
   bb.0:
-    successors: %bb.1, %bb.2
     S_CBRANCH_VCCNZ %bb.1, implicit undef %vcc
     S_BRANCH %bb.2
 
   bb.1:
-    successors: %bb.3
     S_NOP 0, implicit-def undef %0.sub0
     S_BRANCH %bb.3
 
   bb.2:
-    successors: %bb.3
     S_NOP 0, implicit-def %0
     S_BRANCH %bb.3
 

test/CodeGen/AMDGPU/vccz-corrupt-bug-workaround.mir

@@ -75,7 +75,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.entry:
-    successors: %bb.2.if, %bb.1.else
     liveins: %sgpr0_sgpr1
 
     %sgpr2 = S_LOAD_DWORD_IMM %sgpr0_sgpr1, 9, 0 :: (non-temporal dereferenceable invariant load 4 from `float addrspace(2)* undef`)
@@ -86,7 +85,6 @@ body:             |
     S_CBRANCH_VCCZ %bb.1.else, implicit killed %vcc
 
   bb.2.if:
-    successors: %bb.3.done
     liveins: %sgpr6, %sgpr7, %sgpr0_sgpr1_sgpr2_sgpr3:0x00000003
 
     %vgpr0 = V_MOV_B32_e32 9, implicit %exec
@@ -95,7 +93,6 @@ body:             |
     S_BRANCH %bb.3.done
 
   bb.1.else:
-    successors: %bb.3.done
     liveins: %sgpr6, %sgpr7, %sgpr0_sgpr1_sgpr2_sgpr3:0x00000003
 
     %vgpr0 = V_MOV_B32_e32 100, implicit %exec
@@ -141,7 +138,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.entry:
-    successors: %bb.2.if, %bb.1.else
     liveins: %sgpr0_sgpr1
 
     %sgpr0_sgpr1 = S_LOAD_DWORDX2_IMM killed %sgpr0_sgpr1, 11, 0 :: (non-temporal dereferenceable invariant load 8 from `i64 addrspace(2)* undef`)
@@ -150,7 +146,6 @@ body:             |
     S_CBRANCH_VCCZ %bb.1.else, implicit undef %vcc
 
   bb.2.if:
-    successors: %bb.3.done
     liveins: %sgpr6, %sgpr7, %sgpr0_sgpr1_sgpr2_sgpr3:0x00000003
 
     %vgpr0 = V_MOV_B32_e32 9, implicit %exec
@@ -159,7 +154,6 @@ body:             |
     S_BRANCH %bb.3.done
 
   bb.1.else:
-    successors: %bb.3.done
     liveins: %sgpr6, %sgpr7, %sgpr0_sgpr1_sgpr2_sgpr3:0x00000003
 
     %vgpr0 = V_MOV_B32_e32 100, implicit %exec

test/CodeGen/ARM/ARMLoadStoreDBG.mir

@@ -118,7 +118,6 @@ stack:
   - { id: 1, type: spill-slot, offset: -8, size: 4, alignment: 4, callee-saved-register: '%r7' }
 body:             |
   bb.0.entry:
-    successors: %bb.1, %bb.2.if.end
     liveins: %r0, %r1, %r2, %r3, %lr, %r7
 
     DBG_VALUE debug-use %r0, debug-use _, !18, !27, debug-location !28

test/CodeGen/ARM/cmp1-peephole-thumb.mir

@@ -55,7 +55,6 @@ frameInfo:
 # CHECK-NOT: tCMPi8
 body:             |
   bb.0.entry:
-    successors: %bb.1.entry(0x40000000), %bb.2.entry(0x40000000)
     liveins: %r0, %r1
 
     %1 = COPY %r1
@@ -67,8 +66,6 @@ body:             |
     tBcc %bb.2.entry, 0, %cpsr
 
   bb.1.entry:
-    successors: %bb.2.entry(0x80000000)
-
 
   bb.2.entry:
     %5 = PHI %4, %bb.1.entry, %3, %bb.0.entry

test/CodeGen/ARM/cmp2-peephole-thumb.mir

@@ -76,7 +76,6 @@ stack:
 # CHECK-NEXT: tCMPi8
 body:             |
   bb.0.entry:
-    successors: %bb.1.if.then(0x40000000), %bb.2.if.end(0x40000000)
     liveins: %r0, %r1
 
     %1 = COPY %r1
@@ -88,15 +87,11 @@ body:             |
     tB %bb.1.if.then, 14, _
 
   bb.1.if.then:
-    successors: %bb.3.return(0x80000000)
-
     %4, %cpsr = tMOVi8 42, 14, _
     tSTRspi killed %4, %stack.0.retval, 0, 14, _ :: (store 4 into %ir.retval)
     tB %bb.3.return, 14, _
 
   bb.2.if.end:
-    successors: %bb.3.return(0x80000000)
-
     %3, %cpsr = tMOVi8 1, 14, _
     tSTRspi killed %3, %stack.0.retval, 0, 14, _ :: (store 4 into %ir.retval)
 

test/CodeGen/ARM/dbg-range-extension.mir

@@ -209,7 +209,6 @@ stack:
   - { id: 5, type: spill-slot, offset: -24, size: 4, alignment: 4, callee-saved-register: '%r4' }
 body:             |
   bb.0.entry:
-    successors: %bb.5.if.end, %bb.1.if.then
     liveins: %r0, %r4, %r5, %r6, %r7, %r11, %lr
   
     %sp = frame-setup STMDB_UPD %sp, 14, _, killed %r4, killed %r5, killed %r6, killed %r7, killed %r11, killed %lr
@@ -232,7 +231,6 @@ body:             |
     Bcc %bb.5.if.end, 0, killed %cpsr
   
   bb.1.if.then:
-    successors: %bb.3.for.cond
     liveins: %r4, %r5
   
     %r0 = MOVi 12, 14, _, _, debug-location !26
@@ -245,7 +243,6 @@ body:             |
     B %bb.3.for.cond
   
   bb.2.for.body:
-    successors: %bb.3.for.cond
     liveins: %r4, %r5, %r6, %r7
   
     %r1 = ADDrr %r5, %r7, 14, _, _, debug-location !36
@@ -255,7 +252,6 @@ body:             |
     DBG_VALUE debug-use %r7, debug-use _, !18, !20, debug-location !28
   
   bb.3.for.cond:
-    successors: %bb.2.for.body, %bb.4.for.cond.cleanup
     liveins: %r4, %r5, %r6, %r7
   
     DBG_VALUE debug-use %r7, debug-use _, !18, !20, debug-location !28
@@ -263,7 +259,6 @@ body:             |
     Bcc %bb.2.for.body, 11, killed %cpsr, debug-location !33
   
   bb.4.for.cond.cleanup:
-    successors: %bb.5.if.end
     liveins: %r4, %r5, %r6
   
     %r0 = MOVr %r5, 14, _, _, debug-location !34

test/CodeGen/MIR/Generic/branch-probabilities.ll

@@ -1,28 +0,0 @@
-; RUN: llc -stop-after machine-sink %s -o %t.mir
-; RUN: FileCheck %s < %t.mir
-; RUN: llc %t.mir -run-pass machine-sink
-; Check that branch probabilities are printed in a format that can then be parsed.
-; This test fails on powerpc because of an undefined physical register use in the MIR.  See PR31062.
-; XFAIL: powerpc
-
-declare void @foo()
-declare void @bar()
-
-define void @test(i1 %c) {
-; CHECK-LABEL: name: test
-entry:
-        br i1 %c, label %then, label %else
-
-then:
-        call void @foo()
-        br label %end
-; CHECK: successors: %{{[a-z0-9\-\.]+}}({{0x[0-9a-f]+}}), %{{[a-z0-9\-\.]+}}({{0x[0-9a-f]+}})
-
-else:
-        call void @bar()
-        br label %end
-; CHECK: successors: %{{[a-z0-9\-\.]+}}({{0x[0-9a-f]+}})
-
-end:
-        ret void
-}

test/CodeGen/MIR/X86/auto-successor.mir

@@ -0,0 +1,61 @@
+# RUN: llc -o - %s -run-pass=none -verify-machineinstrs -simplify-mir | FileCheck %s
+---
+# We shouldn't need any explicit successor lists in these examples
+# CHECK-LABEL: name: func0
+# CHECK: bb.0:
+# CHECK-NOT: successors
+# CHECK: JE_1 %bb.1, implicit undef %eflags
+# CHECK: JMP_1 %bb.3
+# CHECK: bb.1:
+# CHECK-NOT: successors
+# CHECK: bb.2:
+# CHECK-NOT: successors
+# CHECK: JE_1 %bb.1, implicit undef %eflags
+# CHECK: bb.3:
+# CHECK: RETQ undef %eax
+name: func0
+body: |
+  bb.0:
+    JE_1 %bb.1, implicit undef %eflags
+    JMP_1 %bb.3
+
+  bb.1:
+
+  bb.2:
+    JE_1 %bb.1, implicit undef %eflags
+
+  bb.3:
+    JE_1 %bb.4, implicit undef %eflags   ; condjump+fallthrough to same block
+
+  bb.4:
+    RETQ undef %eax
+...
+---
+# Some cases that need explicit successors:
+# CHECK-LABEL: name: func1
+name: func1
+body: |
+  bb.0:
+    ; CHECK: bb.0:
+    ; CHECK: successors: %bb.3, %bb.1
+    successors: %bb.3, %bb.1   ; different order than operands
+    JE_1 %bb.1, implicit undef %eflags
+    JMP_1 %bb.3
+
+  bb.1:
+    ; CHECK: bb.1:
+    ; CHECK: successors: %bb.2, %bb.1
+    successors: %bb.2, %bb.1   ; different order (fallthrough variant)
+    JE_1 %bb.1, implicit undef %eflags
+
+  bb.2:
+    ; CHECK: bb.2:
+    ; CHECK: successors: %bb.1(0x60000000), %bb.3(0x20000000)
+    successors: %bb.1(3), %bb.3(1)  ; branch probabilities not normalized
+    JE_1 %bb.1, implicit undef %eflags
+
+  bb.3:
+    ; CHECK: bb.3:
+    ; CHECK: RETQ undef %eax
+    RETQ undef %eax
+...

test/CodeGen/MIR/X86/branch-probabilities.mir

@@ -0,0 +1,18 @@
+# RUN: llc -o - %s -mtriple=x86_64-- -run-pass=none | FileCheck %s
+---
+# Check that branch probabilities are printed correctly as hex numbers.
+# CHECK-LABEL: name: test
+# CHECK: bb.0:
+# CHECK-NEXT: successors: %bb.1(0x66666666), %bb.2(0x1999999a)
+name: test
+body: |
+  bb.0:
+    successors: %bb.1(4), %bb.2(1)
+    JE_1 %bb.2, implicit undef %eflags
+
+  bb.1:
+    NOOP
+
+  bb.2:
+    RETQ undef %eax
+...

test/CodeGen/MIR/X86/successor-basic-blocks.mir

@@ -32,7 +32,6 @@
 name:            foo
 body: |
   ; CHECK-LABEL: bb.0.entry:
-  ; CHECK:         successors: %bb.1.less(0x40000000), %bb.2.exit(0x40000000)
   ; CHECK-LABEL: bb.1.less:
   bb.0.entry:
     successors: %bb.1.less, %bb.2.exit

test/CodeGen/X86/branchfolding-undef.mir

@@ -16,7 +16,6 @@ name: func
 tracksRegLiveness: true
 body: |
   bb.0:
-    successors: %bb.1, %bb.2
     JE_1 %bb.1, implicit undef %eflags
     JMP_1 %bb.2
 

test/CodeGen/X86/eflags-copy-expansion.mir

@@ -25,7 +25,6 @@ liveins:
 body:             |
   bb.0.entry:
     liveins: %edi
-    successors: %bb.1.false
     NOOP implicit-def %al
 
     ; The bug was triggered only when LivePhysReg is used, which

test/CodeGen/X86/implicit-null-checks.mir

@@ -384,14 +384,12 @@ liveins:
 
 body:             |
   bb.0.entry:
-    successors: %bb.3.is_null, %bb.1.not_null
     liveins: %esi, %rdi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
     JE_1 %bb.3.is_null, implicit %eflags
 
   bb.1.not_null:
-    successors: %bb.4.ret_100, %bb.2.ret_200
     liveins: %esi, %rdi
 
     %eax = MOV32ri 2200000
@@ -427,7 +425,6 @@ liveins:
 
 body:             |
   bb.0.entry:
-    successors: %bb.3.is_null, %bb.1.not_null
     liveins: %esi, %rdi, %rdx
 
     %eax = MOV32rm killed %rdx, 1, _, 0, _ :: (volatile load 4 from %ir.ptr)
@@ -435,7 +432,6 @@ body:             |
     JE_1 %bb.3.is_null, implicit %eflags
 
   bb.1.not_null:
-    successors: %bb.4.ret_100, %bb.2.ret_200
     liveins: %esi, %rdi
 
     %eax = MOV32ri 2200000
@@ -444,7 +440,6 @@ body:             |
     JE_1 %bb.4.ret_100, implicit %eflags
 
   bb.2.ret_200:
-    successors: %bb.3.is_null
 
     %eax = MOV32ri 200
 
@@ -472,14 +467,12 @@ liveins:
 
 body:             |
   bb.0.entry:
-    successors: %bb.3.is_null, %bb.1.not_null
     liveins: %esi, %rdi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
     JE_1 %bb.3.is_null, implicit %eflags
 
   bb.1.not_null:
-    successors: %bb.4.ret_100, %bb.2.ret_200
     liveins: %esi, %rdi
 
     %eax = MOV32ri 2200000
@@ -515,14 +508,12 @@ liveins:
 
 body:             |
   bb.0.entry:
-    successors: %bb.3.is_null, %bb.1.not_null
     liveins: %rsi, %rdi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
     JE_1 %bb.3.is_null, implicit %eflags
 
   bb.1.not_null:
-    successors: %bb.4.ret_100, %bb.2.ret_200
     liveins: %rsi, %rdi
 
     %rdi  = MOV64ri 5000
@@ -557,14 +548,12 @@ liveins:
 
 body:             |
   bb.0.entry:
-    successors: %bb.3.is_null, %bb.1.not_null
     liveins: %rsi, %rdi, %rdx
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
     JE_1 %bb.3.is_null, implicit %eflags
 
   bb.1.not_null:
-    successors: %bb.4.ret_100, %bb.2.ret_200
     liveins: %rsi, %rdi, %rdx
 
     %rbx  = MOV64rr %rdx
@@ -603,7 +592,6 @@ calleeSavedRegisters: [ '%bh', '%bl', '%bp', '%bpl', '%bx', '%ebp', '%ebx',
 # CHECK: CALL64pcrel32
 body:             |
   bb.0.entry:
-    successors: %bb.2.leave, %bb.1.stay
     liveins: %rdi, %rbx
 
     frame-setup PUSH64r killed %rbx, implicit-def %rsp, implicit %rsp
@@ -645,7 +633,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -680,7 +667,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -712,7 +698,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.1.is_null(0x30000000), %bb.2.not_null(0x50000000)
     liveins: %rsi, %rdi
   
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -745,7 +730,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.1.is_null(0x30000000), %bb.2.not_null(0x50000000)
     liveins: %rsi, %rdi
   
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -779,7 +763,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -810,7 +793,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -842,7 +824,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -874,7 +855,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -910,7 +890,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -941,7 +920,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -974,7 +952,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -1006,7 +983,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -1042,7 +1018,6 @@ calleeSavedRegisters: [ '%bh', '%bl', '%bp', '%bpl', '%bx', '%ebp', '%ebx',
                         '%r14d', '%r15d', '%r12w', '%r13w', '%r14w', '%r15w' ]
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rbx
 
     frame-setup PUSH64r killed %rbx, implicit-def %rsp, implicit %rsp
@@ -1082,7 +1057,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -1116,7 +1090,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -1149,7 +1122,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -1182,7 +1154,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -1214,7 +1185,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -1246,7 +1216,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags
@@ -1279,7 +1248,6 @@ liveins:
   - { reg: '%rsi' }
 body:             |
   bb.0.entry:
-    successors: %bb.2.is_null, %bb.1.not_null
     liveins: %rdi, %rsi
 
     TEST64rr %rdi, %rdi, implicit-def %eflags

test/CodeGen/X86/invalid-liveness.mir

@@ -16,12 +16,10 @@ registers:
   - { id: 0, class: gr32 }
 body: |
   bb.0:
-    successors: %bb.2, %bb.3
     JG_1 %bb.2, implicit %eflags
     JMP_1 %bb.3
 
   bb.2:
-    successors: %bb.3
     %0 = IMPLICIT_DEF
     JMP_1 %bb.3
 

test/CodeGen/X86/machine-region-info.mir

@@ -4,67 +4,48 @@
 name:            fun
 body:             |
   bb.0:
-    successors: %bb.1, %bb.7
-
     CMP32ri8 %edi, 40, implicit-def %eflags
     JNE_1 %bb.7, implicit killed %eflags
     JMP_1 %bb.1
 
   bb.1:
-    successors: %bb.2, %bb.11
-
     CMP32ri8 %edi, 1, implicit-def %eflags
     JNE_1 %bb.11, implicit killed %eflags
     JMP_1 %bb.2
 
   bb.2:
-    successors: %bb.3, %bb.5
-
     CMP32ri8 %edi, 2, implicit-def %eflags
     JNE_1 %bb.5, implicit killed %eflags
     JMP_1 %bb.3
 
   bb.3:
-    successors: %bb.4, %bb.5
-
     CMP32ri8 %edi, 90, implicit-def %eflags
     JNE_1 %bb.5, implicit killed %eflags
     JMP_1 %bb.4
 
   bb.4:
-    successors: %bb.5
 
   bb.5:
-    successors: %bb.6, %bb.11
-
     CMP32ri8 %edi, 4, implicit-def %eflags
     JNE_1 %bb.11, implicit killed %eflags
     JMP_1 %bb.6
 
   bb.6:
-    successors: %bb.11
-
     JMP_1 %bb.11
 
   bb.7:
-    successors: %bb.9, %bb.8
-
     CMP32ri8 %edi, 5, implicit-def %eflags
     JE_1 %bb.9, implicit killed %eflags
     JMP_1 %bb.8
 
   bb.8:
-    successors: %bb.9
 
   bb.9:
-    successors: %bb.11, %bb.10
-
     CMP32ri8 %edi, 6, implicit-def %eflags
     JE_1 %bb.11, implicit killed %eflags
     JMP_1 %bb.10
 
   bb.10:
-    successors: %bb.11
 
   bb.11:
     RET 0
@@ -74,10 +55,10 @@ body:             |
 # CHECK: Region tree:
 # CHECK-NEXT: [0] BB#0 => <Function Return>
 # CHECK-NEXT:   [1] BB#0 => BB#11
+# CHECK-NEXT:     [2] BB#7 => BB#9
+# CHECK-NEXT:     [2] BB#9 => BB#11
 # CHECK-NEXT:     [2] BB#1 => BB#11
 # CHECK-NEXT:       [3] BB#2 => BB#5
 # CHECK-NEXT:         [4] BB#3 => BB#5
 # CHECK-NEXT:       [3] BB#5 => BB#11
-# CHECK-NEXT:     [2] BB#7 => BB#9
-# CHECK-NEXT:     [2] BB#9 => BB#11
 # CHECK-NEXT: End region tree

test/CodeGen/X86/pr27681.mir

@@ -25,7 +25,6 @@ stack:
   - { id: 2, type: spill-slot, offset: -32, size: 4, alignment: 4 }
 body:             |
   bb.0:
-    successors: %bb.1
     liveins: %ebp, %ebx, %edi, %esi
 
     frame-setup PUSH32r killed %ebp, implicit-def %esp, implicit %esp
@@ -41,7 +40,6 @@ body:             |
     %edx = MOV32ri 6
 
   bb.1:
-    successors: %bb.3, %bb.2
     liveins: %eax, %ebp, %ebx, %ecx, %edi, %edx
 
     %ebp = SHR32rCL killed %ebp, implicit-def dead %eflags, implicit %cl
@@ -66,7 +64,6 @@ body:             |
     JE_1 %bb.3, implicit %eflags
 
   bb.2:
-    successors: %bb.3
     liveins: %cl, %eax, %ebp, %esi
 
     OR32mr %esp, 1, _, 8, _, killed %eax, implicit-def %eflags ; :: (store 4 into %stack.1)

test/CodeGen/X86/pre-coalesce.mir

@@ -83,8 +83,6 @@ frameInfo:
   hasMustTailInVarArgFunc: false
 body:             |
   bb.0.entry:
-    successors: %bb.4(0x30000000), %bb.1.while.body.preheader(0x50000000)
-  
     %0 = MOV64rm %rip, 1, _, @b, _ :: (dereferenceable load 8 from @b)
     %12 = MOV8rm %0, 1, _, 0, _ :: (load 1 from %ir.t0)
     TEST8rr %12, %12, implicit-def %eflags
@@ -92,17 +90,12 @@ body:             |
     JNE_1 %bb.1.while.body.preheader, implicit killed %eflags
   
   bb.4:
-    successors: %bb.3.while.end(0x80000000)
-  
     %10 = COPY %11
     JMP_1 %bb.3.while.end
   
   bb.1.while.body.preheader:
-    successors: %bb.2.while.body(0x80000000)
 
   bb.2.while.body:
-    successors: %bb.3.while.end(0x04000000), %bb.2.while.body(0x7c000000)
-  
     %8 = MOVSX32rr8 %12
     %10 = COPY %11
     %10 = SHL32ri %10, 5, implicit-def dead %eflags