IR: Support parsing numeric block ids, and emit them in textual output.

Just as as llvm IR supports explicitly specifying numeric value ids
for instructions, and emits them by default in textual output, now do
the same for blocks.

This is a slightly incompatible change in the textual IR format.

Previously, llvm would parse numeric labels as string names. E.g.
  define void @f() {
    br label %"55"
  55:
    ret void
  }
defined a label *named* "55", even without needing to be quoted, while
the reference required quoting. Now, if you intend a block label which
looks like a value number to be a name, you must quote it in the
definition too (e.g. `"55":`).

Previously, llvm would print nameless blocks only as a comment, and
would omit it if there was no predecessor. This could cause confusion
for readers of the IR, just as unnamed instructions did prior to the
addition of "%5 = " syntax, back in 2008 (PR2480).

Now, it will always print a label for an unnamed block, with the
exception of the entry block. (IMO it may be better to print it for
the entry-block as well. However, that requires updating many more
tests.)

Thus, the following is supported, and is the canonical printing:
  define i32 @f(i32, i32) {
    %3 = add i32 %0, %1
    br label %4

  4:
    ret i32 %3
  }

New test cases covering this behavior are added, and other tests
updated as required.

Differential Revision: https://reviews.llvm.org/D58548

llvm-svn: 356789

38 files changed, 368 insertions, 282 deletions

diff --git a/clang/test/CodeGenCXX/discard-name-values.cpp b/clang/test/CodeGenCXX/discard-name-values.cpp
index d4d7527c285..aa30dae7501 100644
--- a/clang/test/CodeGenCXX/discard-name-values.cpp
+++ b/clang/test/CodeGenCXX/discard-name-values.cpp
@@ -10,7 +10,7 @@ bool test(bool pred) {
   // CHECK: br i1 %pred, label %if.then, label %if.end
 
   if (pred) {
-    // DISCARDVALUE: ; <label>:2:
+    // DISCARDVALUE: 2:
     // DISCARDVALUE-NEXT: tail call void @branch()
     // DISCARDVALUE-NEXT: br label %3
 
@@ -20,7 +20,7 @@ bool test(bool pred) {
     branch();
   }
 
-  // DISCARDVALUE: ; <label>:3:
+  // DISCARDVALUE: 3:
   // DISCARDVALUE-NEXT: ret i1 %0
 
   // CHECK: if.end:
diff --git a/llgo/test/irgen/imports.go b/llgo/test/irgen/imports.go
index ae6498a8cbe..c0f9f56a325 100644
--- a/llgo/test/irgen/imports.go
+++ b/llgo/test/irgen/imports.go
@@ -13,7 +13,7 @@ var X interface{}
 // CHECK-NEXT: %[[N:.*]] = load i1, i1* @"init$guard"
 // CHECK-NEXT: br i1 %[[N]], label %{{.*}}, label %[[L:.*]]
 
-// CHECK: ; <label>:[[L]]
+// CHECK: [[L]]:
 // CHECK-NEXT: call void @__go_register_gc_roots
 // CHECK-NEXT: store i1 true, i1* @"init$guard"
 // CHECK-NEXT: call void @fmt..import(i8* undef)
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index a43b0ee3c45..66490b85834 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -741,11 +741,13 @@ A function definition contains a list of basic blocks, forming the CFG (Control
 Flow Graph) for the function. Each basic block may optionally start with a label
 (giving the basic block a symbol table entry), contains a list of instructions,
 and ends with a :ref:`terminator <terminators>` instruction (such as a branch or
-function return). If an explicit label is not provided, a block is assigned an
-implicit numbered label, using the next value from the same counter as used for
-unnamed temporaries (:ref:`see above<identifiers>`). For example, if a function
-entry block does not have an explicit label, it will be assigned label "%0",
-then the first unnamed temporary in that block will be "%1", etc.
+function return). If an explicit label name is not provided, a block is assigned
+an implicit numbered label, using the next value from the same counter as used
+for unnamed temporaries (:ref:`see above<identifiers>`). For example, if a
+function entry block does not have an explicit label, it will be assigned label
+"%0", then the first unnamed temporary in that block will be "%1", etc. If a
+numeric label is explicitly specified, it must match the numeric label that
+would be used implicitly.
 
 The first basic block in a function is special in two ways: it is
 immediately executed on entrance to the function, and it is not allowed
diff --git a/llvm/lib/AsmParser/LLLexer.cpp b/llvm/lib/AsmParser/LLLexer.cpp
index 9e5bfb1f72b..bc3776da966 100644
--- a/llvm/lib/AsmParser/LLLexer.cpp
+++ b/llvm/lib/AsmParser/LLLexer.cpp
@@ -1048,7 +1048,17 @@ lltok::Kind LLLexer::LexDigitOrNegative() {
   for (; isdigit(static_cast<unsigned char>(CurPtr[0])); ++CurPtr)
     /*empty*/;
 
-  // Check to see if this really is a label afterall, e.g. "-1:".
+  // Check if this is a fully-numeric label:
+  if (isdigit(TokStart[0]) && CurPtr[0] == ':') {
+    uint64_t Val = atoull(TokStart, CurPtr);
+    ++CurPtr; // Skip the colon.
+    if ((unsigned)Val != Val)
+      Error("invalid value number (too large)!");
+    UIntVal = unsigned(Val);
+    return lltok::LabelID;
+  }
+
+  // Check to see if this really is a string label, e.g. "-1:".
   if (isLabelChar(CurPtr[0]) || CurPtr[0] == ':') {
     if (const char *End = isLabelTail(CurPtr)) {
       StrVal.assign(TokStart, End-1);
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index 71315f3c0fb..1ab2702941d 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -2926,13 +2926,27 @@ BasicBlock *LLParser::PerFunctionState::GetBB(unsigned ID, LocTy Loc) {
 /// unnamed.  If there is an error, this returns null otherwise it returns
 /// the block being defined.
 BasicBlock *LLParser::PerFunctionState::DefineBB(const std::string &Name,
-                                                 LocTy Loc) {
+                                                 int NameID, LocTy Loc) {
   BasicBlock *BB;
-  if (Name.empty())
+  if (Name.empty()) {
+    if (NameID != -1 && unsigned(NameID) != NumberedVals.size()) {
+      P.Error(Loc, "label expected to be numbered '" +
+                       Twine(NumberedVals.size()) + "'");
+      return nullptr;
+    }
     BB = GetBB(NumberedVals.size(), Loc);
-  else
+    if (!BB) {
+      P.Error(Loc, "unable to create block numbered '" +
+                       Twine(NumberedVals.size()) + "'");
+      return nullptr;
+    }
+  } else {
     BB = GetBB(Name, Loc);
-  if (!BB) return nullptr; // Already diagnosed error.
+    if (!BB) {
+      P.Error(Loc, "unable to create block named '" + Name + "'");
+      return nullptr;
+    }
+  }
 
   // Move the block to the end of the function.  Forward ref'd blocks are
   // inserted wherever they happen to be referenced.
@@ -5489,20 +5503,23 @@ bool LLParser::ParseFunctionBody(Function &Fn) {
 }
 
 /// ParseBasicBlock
-///   ::= LabelStr? Instruction*
+///   ::= (LabelStr|LabelID)? Instruction*
 bool LLParser::ParseBasicBlock(PerFunctionState &PFS) {
   // If this basic block starts out with a name, remember it.
   std::string Name;
+  int NameID = -1;
   LocTy NameLoc = Lex.getLoc();
   if (Lex.getKind() == lltok::LabelStr) {
     Name = Lex.getStrVal();
     Lex.Lex();
+  } else if (Lex.getKind() == lltok::LabelID) {
+    NameID = Lex.getUIntVal();
+    Lex.Lex();
   }
 
-  BasicBlock *BB = PFS.DefineBB(Name, NameLoc);
+  BasicBlock *BB = PFS.DefineBB(Name, NameID, NameLoc);
   if (!BB)
-    return Error(NameLoc,
-                 "unable to create block named '" + Name + "'");
+    return true;
 
   std::string NameStr;
 
diff --git a/llvm/lib/AsmParser/LLParser.h b/llvm/lib/AsmParser/LLParser.h
index 95aea0c775a..452492b862a 100644
--- a/llvm/lib/AsmParser/LLParser.h
+++ b/llvm/lib/AsmParser/LLParser.h
@@ -445,7 +445,7 @@ namespace llvm {
       /// DefineBB - Define the specified basic block, which is either named or
       /// unnamed.  If there is an error, this returns null otherwise it returns
       /// the block being defined.
-      BasicBlock *DefineBB(const std::string &Name, LocTy Loc);
+      BasicBlock *DefineBB(const std::string &Name, int NameID, LocTy Loc);
 
       bool resolveForwardRefBlockAddresses();
     };
diff --git a/llvm/lib/AsmParser/LLToken.h b/llvm/lib/AsmParser/LLToken.h
index 50bdf05092a..80a1eb99e35 100644
--- a/llvm/lib/AsmParser/LLToken.h
+++ b/llvm/lib/AsmParser/LLToken.h
@@ -422,6 +422,7 @@ enum Kind {
   kw_varFlags,
 
   // Unsigned Valued tokens (UIntVal).
+  LabelID,    // 42:
   GlobalID,   // @42
   LocalVarID, // %42
   AttrGrpID,  // #42
diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index 07dea403d56..ad6c2c8e883 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -3482,23 +3482,24 @@ void AssemblyWriter::printArgument(const Argument *Arg, AttributeSet Attrs) {
 
 /// printBasicBlock - This member is called for each basic block in a method.
 void AssemblyWriter::printBasicBlock(const BasicBlock *BB) {
+  bool IsEntryBlock = BB == &BB->getParent()->getEntryBlock();
   if (BB->hasName()) {              // Print out the label if it exists...
     Out << "\n";
     PrintLLVMName(Out, BB->getName(), LabelPrefix);
     Out << ':';
-  } else if (!BB->use_empty()) {      // Don't print block # of no uses...
-    Out << "\n; <label>:";
+  } else if (!IsEntryBlock) {
+    Out << "\n";
     int Slot = Machine.getLocalSlot(BB);
     if (Slot != -1)
       Out << Slot << ":";
     else
-      Out << "<badref>";
+      Out << "<badref>:";
   }
 
   if (!BB->getParent()) {
     Out.PadToColumn(50);
     Out << "; Error: Block without parent!";
-  } else if (BB != &BB->getParent()->getEntryBlock()) {  // Not the entry block?
+  } else if (!IsEntryBlock) {
     // Output predecessors for the block.
     Out.PadToColumn(50);
     Out << ";";
diff --git a/llvm/test/Analysis/DominanceFrontier/new_pm_test.ll b/llvm/test/Analysis/DominanceFrontier/new_pm_test.ll
index 7ab1fca8053..c14239c726c 100644
--- a/llvm/test/Analysis/DominanceFrontier/new_pm_test.ll
+++ b/llvm/test/Analysis/DominanceFrontier/new_pm_test.ll
@@ -3,48 +3,48 @@
 
 define void @a_linear_impl_fig_1() nounwind {
 0:
-  br label %"1"
+  br label %1
 1:
-  br label %"2"
+  br label %2
 2:
-  br label %"3"
+  br label %3
 3:
-  br i1 1, label %"13", label %"4"
+  br i1 1, label %12, label %4
 4:
-  br i1 1, label %"5", label %"1"
+  br i1 1, label %5, label %1
 5:
-  br i1 1, label %"8", label %"6"
+  br i1 1, label %8, label %6
 6:
-  br i1 1, label %"7", label %"4"
+  br i1 1, label %7, label %4
 7:
   ret void
 8:
-  br i1 1, label %"9", label %"1"
+  br i1 1, label %9, label %1
 9:
-  br label %"10"
+  br label %10
 10:
-  br i1 1, label %"12", label %"11"
+  br i1 1, label %13, label %11
 11:
-  br i1 1, label %"9", label %"8"
-13:
-  br i1 1, label %"2", label %"1"
+  br i1 1, label %9, label %8
 12:
-   switch i32 0, label %"1" [ i32 0, label %"9"
-                              i32 1, label %"8"]
+  br i1 1, label %2, label %1
+13:
+   switch i32 0, label %1 [ i32 0, label %9
+                              i32 1, label %8]
 }
 
 ; CHECK: DominanceFrontier for function: a_linear_impl_fig_1
-; CHECK-DAG:  DomFrontier for BB %"0" is:
-; CHECK-DAG:  DomFrontier for BB %"11" is:   %"{{[8|9]}}" %"{{[8|9]}}"
-; CHECK-DAG:  DomFrontier for BB %"1" is:    %"1"
-; CHECK-DAG:  DomFrontier for BB %"2" is:    %"{{[1|2]}}" %"{{[1|2]}}"
-; CHECK-DAG:  DomFrontier for BB %"3" is:    %"{{[1|2]}}" %"{{[1|2]}}"
-; CHECK-DAG:  DomFrontier for BB %"13" is:   %"{{[1|2]}}" %"{{[1|2]}}"
-; CHECK-DAG:  DomFrontier for BB %"4" is:    %"{{[1|4]}}" %"{{[1|4]}}"
-; CHECK-DAG:  DomFrontier for BB %"5" is:    %"{{[1|4]}}" %"{{[1|4]}}"
-; CHECK-DAG:  DomFrontier for BB %"8" is:    %"{{[1|8]}}" %"{{[1|8]}}"
-; CHECK-DAG:  DomFrontier for BB %"6" is:    %"4"
-; CHECK-DAG:  DomFrontier for BB %"7" is:
-; CHECK-DAG:  DomFrontier for BB %"9" is:    %"{{[1|8|9]}}" %"{{[1|8|9]}}" %"{{[1|8|9]}}"
-; CHECK-DAG:  DomFrontier for BB %"10" is:   %"{{[1|8|9]}}" %"{{[1|8|9]}}" %"{{[1|8|9]}}"
-; CHECK-DAG:  DomFrontier for BB %"12" is:   %"{{[1|8|9]}}" %"{{[1|8|9]}}" %"{{[1|8|9]}}"
+; CHECK-DAG:  DomFrontier for BB %0 is:
+; CHECK-DAG:  DomFrontier for BB %11 is:   %{{[8|9]}} %{{[8|9]}}
+; CHECK-DAG:  DomFrontier for BB %1 is:    %1
+; CHECK-DAG:  DomFrontier for BB %2 is:    %{{[1|2]}} %{{[1|2]}}
+; CHECK-DAG:  DomFrontier for BB %3 is:    %{{[1|2]}} %{{[1|2]}}
+; CHECK-DAG:  DomFrontier for BB %12 is:   %{{[1|2]}} %{{[1|2]}}
+; CHECK-DAG:  DomFrontier for BB %4 is:    %{{[1|4]}} %{{[1|4]}}
+; CHECK-DAG:  DomFrontier for BB %5 is:    %{{[1|4]}} %{{[1|4]}}
+; CHECK-DAG:  DomFrontier for BB %8 is:    %{{[1|8]}} %{{[1|8]}}
+; CHECK-DAG:  DomFrontier for BB %6 is:    %4
+; CHECK-DAG:  DomFrontier for BB %7 is:
+; CHECK-DAG:  DomFrontier for BB %9 is:    %{{[1|8|9]}} %{{[1|8|9]}} %{{[1|8|9]}}
+; CHECK-DAG:  DomFrontier for BB %10 is:   %{{[1|8|9]}} %{{[1|8|9]}} %{{[1|8|9]}}
+; CHECK-DAG:  DomFrontier for BB %13 is:   %{{[1|8|9]}} %{{[1|8|9]}} %{{[1|8|9]}}
diff --git a/llvm/test/Analysis/RegionInfo/cond_loop.ll b/llvm/test/Analysis/RegionInfo/cond_loop.ll
index 2d0c7348eba..7dc311a299c 100644
--- a/llvm/test/Analysis/RegionInfo/cond_loop.ll
+++ b/llvm/test/Analysis/RegionInfo/cond_loop.ll
@@ -7,18 +7,18 @@
 ; RUN: opt < %s -passes='print<regions>' 2>&1 | FileCheck %s
 
 define void @normal_condition() nounwind {
-5:
+"5":
         br label %"0"
 
-0:
+"0":
 	br label %"1"
-1:
+"1":
 	br i1 1, label %"2", label %"3"
-2:
+"2":
 	ret void
-3:
+"3":
 	br i1 1, label %"1", label %"4"
-4:
+"4":
         br label %"0"
 }
 
diff --git a/llvm/test/Analysis/RegionInfo/condition_forward_edge.ll b/llvm/test/Analysis/RegionInfo/condition_forward_edge.ll
index 427b71de113..cc9a3294e14 100644
--- a/llvm/test/Analysis/RegionInfo/condition_forward_edge.ll
+++ b/llvm/test/Analysis/RegionInfo/condition_forward_edge.ll
@@ -7,13 +7,13 @@
 ; RUN: opt < %s -passes='print<regions>' 2>&1 | FileCheck %s
 
 define void @normal_condition() nounwind {
-0:
+"0":
 	br label %"1"
-1:
+"1":
 	br i1 1, label %"2", label %"3"
-2:
+"2":
 	br label %"3"
-3:
+"3":
 	ret void
 }
 ; CHECK-NOT: =>
diff --git a/llvm/test/Analysis/RegionInfo/condition_same_exit.ll b/llvm/test/Analysis/RegionInfo/condition_same_exit.ll
index 0499082813b..f3f443b2ba6 100644
--- a/llvm/test/Analysis/RegionInfo/condition_same_exit.ll
+++ b/llvm/test/Analysis/RegionInfo/condition_same_exit.ll
@@ -7,16 +7,16 @@
 ; RUN: opt < %s -passes='print<regions>' 2>&1 | FileCheck %s
 
 define void @normal_condition() nounwind {
-0:
+"0":
 	br i1 1, label %"1", label %"4"
 
-1:
+"1":
 	br i1 1, label %"2", label %"3"
-2:
+"2":
 	br label %"4"
-3:
+"3":
 	br label %"4"
-4:
+"4":
 	ret void
 }
 ; CHECK-NOT: =>
diff --git a/llvm/test/Analysis/RegionInfo/condition_simple.ll b/llvm/test/Analysis/RegionInfo/condition_simple.ll
index 3b4d527db8c..67bdb506702 100644
--- a/llvm/test/Analysis/RegionInfo/condition_simple.ll
+++ b/llvm/test/Analysis/RegionInfo/condition_simple.ll
@@ -7,15 +7,15 @@
 ; RUN: opt < %s -passes='print<regions>' 2>&1 | FileCheck %s
 
 define void @normal_condition() nounwind {
-0:
+"0":
 	br label %"1"
-1:
+"1":
 	br i1 1, label %"2", label %"3"
-2:
+"2":
 	br label %"4"
-3:
+"3":
 	br label %"4"
-4:
+"4":
 	ret void
 }
 
diff --git a/llvm/test/Analysis/RegionInfo/infinite_loop.ll b/llvm/test/Analysis/RegionInfo/infinite_loop.ll
index 4d9057e0406..35c82ce8e04 100644
--- a/llvm/test/Analysis/RegionInfo/infinite_loop.ll
+++ b/llvm/test/Analysis/RegionInfo/infinite_loop.ll
@@ -4,16 +4,16 @@
 
 define void @normal_condition() nounwind {
 0:
-	br label %"1"
+	br label %1
 1:
-	br i1 1, label %"2", label %"3"
+	br i1 1, label %2, label %3
 2:
-	br label %"2"
+	br label %2
 3:
-	br label %"4"
+	br label %4
 4:
 	ret void
 }
 ; CHECK-NOT: =>
 ; CHECK: [0] 0 => <Function Return>
-; STAT: 1 region - The # of regions
\ No newline at end of file
+; STAT: 1 region - The # of regions
diff --git a/llvm/test/Analysis/RegionInfo/infinite_loop_2.ll b/llvm/test/Analysis/RegionInfo/infinite_loop_2.ll
index 09feecd96f5..76ecdd833c4 100644
--- a/llvm/test/Analysis/RegionInfo/infinite_loop_2.ll
+++ b/llvm/test/Analysis/RegionInfo/infinite_loop_2.ll
@@ -5,23 +5,23 @@
 ; RUN: opt -regions -print-region-style=rn  -analyze < %s 2>&1 | FileCheck -check-prefix=RNIT %s
 
 define void @normal_condition() nounwind {
-0:
+"0":
 	br label %"1"
-1:
+"1":
 	br i1 1, label %"2", label %"3"
-2:
+"2":
 	br label %"5"
-5:
+"5":
 	br i1 1, label %"11", label %"12"
-11:
+"11":
         br label %"6"
-12:
+"12":
         br label %"6"
-6:
+"6":
         br label %"2"
-3:
+"3":
 	br label %"4"
-4:
+"4":
 	ret void
 }
 ; CHECK-NOT: =>
diff --git a/llvm/test/Analysis/RegionInfo/infinite_loop_3.ll b/llvm/test/Analysis/RegionInfo/infinite_loop_3.ll
index 00d555177af..2b1b643005c 100644
--- a/llvm/test/Analysis/RegionInfo/infinite_loop_3.ll
+++ b/llvm/test/Analysis/RegionInfo/infinite_loop_3.ll
@@ -6,35 +6,35 @@
 ; RUN: opt -regions -print-region-style=rn  -analyze < %s 2>&1 | FileCheck -check-prefix=RNIT %s
 
 define void @normal_condition() nounwind {
-0:
+"0":
 	br label %"7"
-7:
+"7":
 	br i1 1, label %"1", label %"8"
-1:
+"1":
 	br i1 1, label %"2", label %"3"
-2:
+"2":
 	br label %"5"
-5:
+"5":
 	br i1 1, label %"11", label %"12"
-11:
+"11":
         br label %"6"
-12:
+"12":
         br label %"6"
-6:
+"6":
         br label %"2"
-8:
+"8":
 	br label %"9"
-9:
+"9":
 	br i1 1, label %"13", label %"14"
-13:
+"13":
         br label %"10"
-14:
+"14":
         br label %"10"
-10:
+"10":
         br label %"8"
-3:
+"3":
 	br label %"4"
-4:
+"4":
 	ret void
 }
 ; CHECK-NOT: =>
diff --git a/llvm/test/Analysis/RegionInfo/infinite_loop_4.ll b/llvm/test/Analysis/RegionInfo/infinite_loop_4.ll
index 51d8ffe0d5b..c3ad028b0e5 100644
--- a/llvm/test/Analysis/RegionInfo/infinite_loop_4.ll
+++ b/llvm/test/Analysis/RegionInfo/infinite_loop_4.ll
@@ -5,35 +5,35 @@
 ; RUN: opt -regions -print-region-style=rn  -analyze < %s 2>&1 | FileCheck -check-prefix=RNIT %s
 
 define void @normal_condition() nounwind {
-0:
+"0":
 	br label %"7"
-7:
+"7":
 	br i1 1, label %"1", label %"8"
-1:
+"1":
 	br i1 1, label %"2", label %"3"
-2:
+"2":
 	br label %"5"
-5:
+"5":
 	br i1 1, label %"11", label %"12"
-11:
+"11":
         br label %"6"
-12:
+"12":
         br label %"6"
-6:
+"6":
 	br i1 1, label %"2", label %"10"
-8:
+"8":
 	br label %"9"
-9:
+"9":
 	br i1 1, label %"13", label %"14"
-13:
+"13":
         br label %"10"
-14:
+"14":
         br label %"10"
-10:
+"10":
         br label %"8"
-3:
+"3":
 	br label %"4"
-4:
+"4":
 	ret void
 }
 ; CHECK-NOT: =>
@@ -48,4 +48,4 @@ define void @normal_condition() nounwind {
 ; BBIT: 5, 11, 12,
 ; RNIT: 0, 7, 1, 2 => 10, 10, 8, 9, 13, 14, 3, 4,
 ; RNIT: 2, 5 => 6, 6,
-; RNIT: 5, 11, 12,
\ No newline at end of file
+; RNIT: 5, 11, 12,
diff --git a/llvm/test/Analysis/RegionInfo/infinite_loop_5_a.ll b/llvm/test/Analysis/RegionInfo/infinite_loop_5_a.ll
index 12796417351..bf56add87ac 100644
--- a/llvm/test/Analysis/RegionInfo/infinite_loop_5_a.ll
+++ b/llvm/test/Analysis/RegionInfo/infinite_loop_5_a.ll
@@ -1,19 +1,19 @@
 ; RUN: opt -regions -analyze < %s | FileCheck %s
 
 define void @normal_condition() nounwind {
-0:
+"0":
     br label %"7"
-7:
+"7":
     br i1 1, label %"1", label %"8"
-1:
+"1":
     br i1 1, label %"6", label %"3"
-6:
+"6":
     br label %"8"
-8:
+"8":
     br label %"8"
-3:
+"3":
     br label %"4"
-4:
+"4":
     ret void
 }
 
diff --git a/llvm/test/Analysis/RegionInfo/infinite_loop_5_b.ll b/llvm/test/Analysis/RegionInfo/infinite_loop_5_b.ll
index 9759ea873c5..d8602054cd0 100644
--- a/llvm/test/Analysis/RegionInfo/infinite_loop_5_b.ll
+++ b/llvm/test/Analysis/RegionInfo/infinite_loop_5_b.ll
@@ -1,21 +1,21 @@
 ; RUN: opt -regions -analyze < %s | FileCheck %s
 
 define void @normal_condition() nounwind {
-0:
+"0":
     br label %"7"
-7:
+"7":
     br i1 1, label %"1", label %"9"
-9:
+"9":
     br label %"8"
-1:
+"1":
     br i1 1, label %"6", label %"3"
-6:
+"6":
     br label %"9"
-8:
+"8":
     br label %"8"
-3:
+"3":
     br label %"4"
-4:
+"4":
     ret void
 }
 
diff --git a/llvm/test/Analysis/RegionInfo/infinite_loop_5_c.ll b/llvm/test/Analysis/RegionInfo/infinite_loop_5_c.ll
index 51b48c90b4a..0508d0a45bd 100644
--- a/llvm/test/Analysis/RegionInfo/infinite_loop_5_c.ll
+++ b/llvm/test/Analysis/RegionInfo/infinite_loop_5_c.ll
@@ -1,19 +1,19 @@
 ; RUN: opt -regions -analyze < %s | FileCheck %s
 
 define void @normal_condition() nounwind {
-0:
+"0":
     br label %"7"
-7:
+"7":
     br i1 1, label %"1", label %"8"
-1:
+"1":
     br i1 1, label %"6", label %"3"
-6:
+"6":
     br label %"8"
-8:
+"8":
     br i1 1, label %"8", label %"7"
-3:
+"3":
     br label %"4"
-4:
+"4":
     ret void
 }
 
diff --git a/llvm/test/Analysis/RegionInfo/loop_with_condition.ll b/llvm/test/Analysis/RegionInfo/loop_with_condition.ll
index 527f1fc065f..244f253d25d 100644
--- a/llvm/test/Analysis/RegionInfo/loop_with_condition.ll
+++ b/llvm/test/Analysis/RegionInfo/loop_with_condition.ll
@@ -8,25 +8,25 @@
 ; RUN: opt < %s -passes='print<regions>' 2>&1 | FileCheck %s
 
 define void @normal_condition() nounwind {
-0:
+"0":
         br label %"1"
-1:
+"1":
 	br i1 1, label %"6", label %"2"
-2:
+"2":
 	br i1 1, label %"3", label %"4"
-3:
+"3":
 	br label %"5"
-4:
+"4":
 	br label %"5"
-5:
+"5":
         br label %"8"
-8:
+"8":
         br i1 1, label %"7", label %"9"
-9:
+"9":
         br label %"2"
-7:
+"7":
         br label %"6"
-6:
+"6":
 	ret void
 }
 
diff --git a/llvm/test/Analysis/RegionInfo/mix_1.ll b/llvm/test/Analysis/RegionInfo/mix_1.ll
index 17b4263a7fb..a462119575a 100644
--- a/llvm/test/Analysis/RegionInfo/mix_1.ll
+++ b/llvm/test/Analysis/RegionInfo/mix_1.ll
@@ -8,45 +8,45 @@
 ; RUN: opt < %s -passes='print<regions>' 2>&1 | FileCheck %s
 
 define void @a_linear_impl_fig_1() nounwind {
-0:
+"0":
 
 	br i1 1, label %"1", label %"15"
-1:
+"1":
  	switch i32 0, label %"2" [ i32 0, label %"3"
                                   i32 1, label %"7"]
-2:
+"2":
 	br label %"4"
-3:
+"3":
 	br label %"5"
-4:
+"4":
 	br label %"6"
-5:
+"5":
 	br label %"6"
-6:
+"6":
 	br label %"7"
-7:
+"7":
 	br label %"15"
-15:
+"15":
 	br label %"8"
-8:
+"8":
 	br label %"16"
-16:
+"16":
         br label %"9"
-9:
+"9":
 	br i1 1, label %"10", label %"11"
-11:
+"11":
 	br i1 1, label %"13", label %"12"
-13:
+"13":
 	br label %"14"
-12:
+"12":
 	br label %"14"
-14:
+"14":
 	br label %"8"
-10:
+"10":
         br label %"17"
-17:
+"17":
         br label %"18"
-18:
+"18":
         ret void
 }
 
diff --git a/llvm/test/Analysis/RegionInfo/paper.ll b/llvm/test/Analysis/RegionInfo/paper.ll
index e5c3da7d3f1..bc0fb18a0e2 100644
--- a/llvm/test/Analysis/RegionInfo/paper.ll
+++ b/llvm/test/Analysis/RegionInfo/paper.ll
@@ -7,33 +7,33 @@
 ; RUN: opt < %s -passes='print<regions>' 2>&1 | FileCheck %s
 
 define void @a_linear_impl_fig_1() nounwind {
-0:
+"0":
         br label %"1"
-1:
+"1":
 	br label %"2"
-2:
+"2":
 	br label %"3"
-3:
+"3":
 	br i1 1, label %"13", label %"4"
-4:
+"4":
 	br i1 1, label %"5", label %"1"
-5:
+"5":
 	br i1 1, label %"8", label %"6"
-6:
+"6":
 	br i1 1, label %"7", label %"4"
-7:
+"7":
 	ret void
-8:
+"8":
 	br i1 1, label %"9", label %"1"
-9:
+"9":
 	br label %"10"
-10:
+"10":
 	br i1 1, label %"12", label %"11"
-11:
+"11":
 	br i1 1, label %"9", label %"8"
-13:
+"13":
 	br i1 1, label %"2", label %"1"
-12:
+"12":
  	switch i32 0, label %"1" [ i32 0, label %"9"
                                   i32 1, label %"8"]
 }
diff --git a/llvm/test/Assembler/block-labels.ll b/llvm/test/Assembler/block-labels.ll
new file mode 100644
index 00000000000..1dcf496ad49
--- /dev/null
+++ b/llvm/test/Assembler/block-labels.ll
@@ -0,0 +1,48 @@
+; RUN: llvm-as < %s | llvm-dis | llvm-as | llvm-dis | FileCheck %s --match-full-lines
+; RUN: verify-uselistorder %s
+
+define i32 @test1(i32 %X) {
+; Implicit entry label. Not printed on output.
+  %1 = alloca i32
+  br label %2
+; Implicit label ids still allowed.
+  br label %3
+3: ; Explicit numeric label
+  br label %"2"
+"2": ; string label, quoted number
+  br label %-3
+-3: ; numeric-looking, but actually string, label
+  br label %-N-
+-N-:
+  br label %$N
+$N:
+  %4 = add i32 1, 1
+  ret i32 %4
+}
+
+; CHECK-LABEL: define i32 @test1(i32 %X) {
+; CHECK-NEXT:   %1 = alloca i32
+; CHECK-NEXT:   br label %2
+; CHECK:      2:       ; preds = %0
+; CHECK-NEXT:   br label %3
+; CHECK:      3:       ; preds = %2
+; CHECK-NEXT:   br label %"2"
+; CHECK:      "2":     ; preds = %3
+; CHECK-NEXT:   br label %-3
+; CHECK:      -3:      ; preds = %"2"
+; CHECK-NEXT:   br label %-N-
+; CHECK:      -N-:     ; preds = %-3
+; CHECK-NEXT:   br label %"$N"
+; CHECK:      "$N":    ; preds = %-N-
+; CHECK-NEXT:   %4 = add i32 1, 1
+; CHECK-NEXT:   ret i32 %4
+; CHECK-NEXT: }
+
+define void @test2(i32, i32) {
+; entry label id still not printed on output
+2:
+  ret void
+}
+
+; CHECK-LABEL: define void @test2(i32, i32) {
+; CHECK-NEXT:    ret void
diff --git a/llvm/test/Assembler/invalid-block-label-num.ll b/llvm/test/Assembler/invalid-block-label-num.ll
new file mode 100644
index 00000000000..4f02300849e
--- /dev/null
+++ b/llvm/test/Assembler/invalid-block-label-num.ll
@@ -0,0 +1,7 @@
+; RUN: not llvm-as < %s 2>&1 | FileCheck %s
+
+define void @f () {
+1:
+; CHECK: error: label expected to be numbered '0'
+  ret void
+}
diff --git a/llvm/test/CodeGen/X86/atomic-pointer.ll b/llvm/test/CodeGen/X86/atomic-pointer.ll
index 66e021742fc..54739e269b6 100644
--- a/llvm/test/CodeGen/X86/atomic-pointer.ll
+++ b/llvm/test/CodeGen/X86/atomic-pointer.ll
@@ -5,7 +5,7 @@ define i32* @test_atomic_ptr_load(i32** %a0) {
 ; CHECK: movl
 ; CHECK: movl
 ; CHECK: ret
-0:
+entry:
   %0 = load atomic i32*, i32** %a0 seq_cst, align 4
   ret i32* %0
 }
@@ -16,7 +16,7 @@ define void @test_atomic_ptr_store(i32* %a0, i32** %a1) {
 ; CHECK: movl
 ; CHECK: xchgl
 ; CHECK: ret
-0:
-  store atomic i32* %a0, i32** %a1 seq_cst, align 4
+entry:
+store atomic i32* %a0, i32** %a1 seq_cst, align 4
   ret void
 }
diff --git a/llvm/test/Instrumentation/AddressSanitizer/asan-masked-load-store.ll b/llvm/test/Instrumentation/AddressSanitizer/asan-masked-load-store.ll
index ddfd7ca7c36..1b069255880 100644
--- a/llvm/test/Instrumentation/AddressSanitizer/asan-masked-load-store.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/asan-masked-load-store.ll
@@ -75,39 +75,39 @@ define void @store.v4f32.variable(<4 x float> %arg, <4 x i1> %mask) sanitize_add
   %p = load <4 x float>*, <4 x float>** @v4f32, align 8
 ; STORE: [[MASK0:%[0-9A-Za-z]+]] = extractelement <4 x i1> %mask, i64 0
 ; STORE: br i1 [[MASK0]], label %[[THEN0:[0-9A-Za-z]+]], label %[[AFTER0:[0-9A-Za-z]+]]
-; STORE: <label>:[[THEN0]]:
+; STORE: [[THEN0]]:
 ; STORE: [[GEP0:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 0
 ; STORE: [[PGEP0:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP0]] to i64
 ; STORE: call void @__asan_store4(i64 [[PGEP0]])
 ; STORE: br label %[[AFTER0]]
-; STORE: <label>:[[AFTER0]]
+; STORE: [[AFTER0]]:
 
 ; STORE: [[MASK1:%[0-9A-Za-z]+]] = extractelement <4 x i1> %mask, i64 1
 ; STORE: br i1 [[MASK1]], label %[[THEN1:[0-9A-Za-z]+]], label %[[AFTER1:[0-9A-Za-z]+]]
-; STORE: <label>:[[THEN1]]:
+; STORE: [[THEN1]]:
 ; STORE: [[GEP1:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 1
 ; STORE: [[PGEP1:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP1]] to i64
 ; STORE: call void @__asan_store4(i64 [[PGEP1]])
 ; STORE: br label %[[AFTER1]]
-; STORE: <label>:[[AFTER1]]
+; STORE: [[AFTER1]]:
 
 ; STORE: [[MASK2:%[0-9A-Za-z]+]] = extractelement <4 x i1> %mask, i64 2
 ; STORE: br i1 [[MASK2]], label %[[THEN2:[0-9A-Za-z]+]], label %[[AFTER2:[0-9A-Za-z]+]]
-; STORE: <label>:[[THEN2]]:
+; STORE: [[THEN2]]:
 ; STORE: [[GEP2:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 2
 ; STORE: [[PGEP2:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP2]] to i64
 ; STORE: call void @__asan_store4(i64 [[PGEP2]])
 ; STORE: br label %[[AFTER2]]
-; STORE: <label>:[[AFTER2]]
+; STORE: [[AFTER2]]:
 
 ; STORE: [[MASK3:%[0-9A-Za-z]+]] = extractelement <4 x i1> %mask, i64 3
 ; STORE: br i1 [[MASK3]], label %[[THEN3:[0-9A-Za-z]+]], label %[[AFTER3:[0-9A-Za-z]+]]
-; STORE: <label>:[[THEN3]]:
+; STORE: [[THEN3]]:
 ; STORE: [[GEP3:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 3
 ; STORE: [[PGEP3:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP3]] to i64
 ; STORE: call void @__asan_store4(i64 [[PGEP3]])
 ; STORE: br label %[[AFTER3]]
-; STORE: <label>:[[AFTER3]]
+; STORE: [[AFTER3]]:
 
 ; STORE: tail call void @llvm.masked.store.v4f32.p0v4f32(<4 x float> %arg, <4 x float>* %p, i32 4, <4 x i1> %mask)
   tail call void @llvm.masked.store.v4f32.p0v4f32(<4 x float> %arg, <4 x float>* %p, i32 4, <4 x i1> %mask)
@@ -203,39 +203,39 @@ define <4 x float> @load.v4f32.variable(<4 x float> %arg, <4 x i1> %mask) saniti
   %p = load <4 x float>*, <4 x float>** @v4f32, align 8
 ; LOAD: [[MASK0:%[0-9A-Za-z]+]] = extractelement <4 x i1> %mask, i64 0
 ; LOAD: br i1 [[MASK0]], label %[[THEN0:[0-9A-Za-z]+]], label %[[AFTER0:[0-9A-Za-z]+]]
-; LOAD: <label>:[[THEN0]]:
+; LOAD: [[THEN0]]:
 ; LOAD: [[GEP0:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 0
 ; LOAD: [[PGEP0:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP0]] to i64
 ; LOAD: call void @__asan_load4(i64 [[PGEP0]])
 ; LOAD: br label %[[AFTER0]]
-; LOAD: <label>:[[AFTER0]]
+; LOAD: [[AFTER0]]:
 
 ; LOAD: [[MASK1:%[0-9A-Za-z]+]] = extractelement <4 x i1> %mask, i64 1
 ; LOAD: br i1 [[MASK1]], label %[[THEN1:[0-9A-Za-z]+]], label %[[AFTER1:[0-9A-Za-z]+]]
-; LOAD: <label>:[[THEN1]]:
+; LOAD: [[THEN1]]:
 ; LOAD: [[GEP1:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 1
 ; LOAD: [[PGEP1:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP1]] to i64
 ; LOAD: call void @__asan_load4(i64 [[PGEP1]])
 ; LOAD: br label %[[AFTER1]]
-; LOAD: <label>:[[AFTER1]]
+; LOAD: [[AFTER1]]:
 
 ; LOAD: [[MASK2:%[0-9A-Za-z]+]] = extractelement <4 x i1> %mask, i64 2
 ; LOAD: br i1 [[MASK2]], label %[[THEN2:[0-9A-Za-z]+]], label %[[AFTER2:[0-9A-Za-z]+]]
-; LOAD: <label>:[[THEN2]]:
+; LOAD: [[THEN2]]:
 ; LOAD: [[GEP2:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 2
 ; LOAD: [[PGEP2:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP2]] to i64
 ; LOAD: call void @__asan_load4(i64 [[PGEP2]])
 ; LOAD: br label %[[AFTER2]]
-; LOAD: <label>:[[AFTER2]]
+; LOAD: [[AFTER2]]:
 
 ; LOAD: [[MASK3:%[0-9A-Za-z]+]] = extractelement <4 x i1> %mask, i64 3
 ; LOAD: br i1 [[MASK3]], label %[[THEN3:[0-9A-Za-z]+]], label %[[AFTER3:[0-9A-Za-z]+]]
-; LOAD: <label>:[[THEN3]]:
+; LOAD: [[THEN3]]:
 ; LOAD: [[GEP3:%[0-9A-Za-z]+]] = getelementptr <4 x float>, <4 x float>* %p, i64 0, i64 3
 ; LOAD: [[PGEP3:%[0-9A-Za-z]+]] = ptrtoint float* [[GEP3]] to i64
 ; LOAD: call void @__asan_load4(i64 [[PGEP3]])
 ; LOAD: br label %[[AFTER3]]
-; LOAD: <label>:[[AFTER3]]
+; LOAD: [[AFTER3]]:
 
 ; LOAD: tail call <4 x float> @llvm.masked.load.v4f32.p0v4f32(<4 x float>* %p, i32 4, <4 x i1> %mask, <4 x float> %arg)
   %res = tail call <4 x float> @llvm.masked.load.v4f32.p0v4f32(<4 x float>* %p, i32 4, <4 x i1> %mask, <4 x float> %arg)
diff --git a/llvm/test/Instrumentation/AddressSanitizer/stack-poisoning-and-lifetime-be.ll b/llvm/test/Instrumentation/AddressSanitizer/stack-poisoning-and-lifetime-be.ll
index 3bdf2639ca1..22610942751 100644
--- a/llvm/test/Instrumentation/AddressSanitizer/stack-poisoning-and-lifetime-be.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/stack-poisoning-and-lifetime-be.ll
@@ -159,14 +159,14 @@ entry:
 
   ; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 40, i8* %zz)
 
-  ; CHECK-LABEL: <label>
+  ; CHECK: {{^[0-9]+}}:
 
   ; CHECK-NEXT: [[OFFSET:%[0-9]+]] = add i64 [[SHADOW_BASE]], 0
   ; CHECK-NEXT: call void @__asan_set_shadow_f5(i64 [[OFFSET]], i64 128)
 
   ; CHECK-NOT: add i64 [[SHADOW_BASE]]
 
-  ; CHECK-LABEL: <label>
+  ; CHECK: {{^[0-9]+}}:
 
   ; 00000000
   ; EXIT-NEXT: [[OFFSET:%[0-9]+]] = add i64 [[SHADOW_BASE]], 0
@@ -205,7 +205,7 @@ entry:
   ; CHECK-NOT: add i64 [[SHADOW_BASE]]
 
   ret void
-  ; CHECK-LABEL: <label>
+  ; CHECK: {{^[0-9]+}}:
   ; CHECK: ret void
 }
 
diff --git a/llvm/test/Instrumentation/AddressSanitizer/stack-poisoning-and-lifetime.ll b/llvm/test/Instrumentation/AddressSanitizer/stack-poisoning-and-lifetime.ll
index 0799b03e455..56a63110a84 100644
--- a/llvm/test/Instrumentation/AddressSanitizer/stack-poisoning-and-lifetime.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/stack-poisoning-and-lifetime.ll
@@ -159,14 +159,14 @@ entry:
 
   ; CHECK-NEXT: call void @llvm.lifetime.end.p0i8(i64 40, i8* %zz)
 
-  ; CHECK-LABEL: <label>
+  ; CHECK: {{^[0-9]+}}:
 
   ; CHECK-NEXT: [[OFFSET:%[0-9]+]] = add i64 [[SHADOW_BASE]], 0
   ; CHECK-NEXT: call void @__asan_set_shadow_f5(i64 [[OFFSET]], i64 128)
 
   ; CHECK-NOT: add i64 [[SHADOW_BASE]]
 
-  ; CHECK-LABEL: <label>
+  ; CHECK: {{^[0-9]+}}:
 
   ; 00000000
   ; EXIT-NEXT: [[OFFSET:%[0-9]+]] = add i64 [[SHADOW_BASE]], 0
@@ -205,7 +205,7 @@ entry:
   ; CHECK-NOT: add i64 [[SHADOW_BASE]]
 
   ret void
-  ; CHECK-LABEL: <label>
+  ; CHECK: {{^[0-9]+}}:
   ; CHECK: ret void
 }
 
diff --git a/llvm/test/Instrumentation/AddressSanitizer/stack_dynamic_alloca.ll b/llvm/test/Instrumentation/AddressSanitizer/stack_dynamic_alloca.ll
index 2d3a241b4e4..90ddd7786b9 100644
--- a/llvm/test/Instrumentation/AddressSanitizer/stack_dynamic_alloca.ll
+++ b/llvm/test/Instrumentation/AddressSanitizer/stack_dynamic_alloca.ll
@@ -12,14 +12,14 @@ entry:
 ; CHECK: entry:
 ; CHECK: load i32, i32* @__asan_option_detect_stack_use_after_return
 
-; CHECK: <label>:[[UAR_ENABLED_BB:[0-9]+]]
+; CHECK: [[UAR_ENABLED_BB:^[0-9]+]]:
 ; CHECK: [[FAKE_STACK_RT:%[0-9]+]] = call i64 @__asan_stack_malloc_
 
-; CHECK: <label>:[[FAKE_STACK_BB:[0-9]+]]
+; CHECK: [[FAKE_STACK_BB:^[0-9]+]]:
 ; CHECK: [[FAKE_STACK:%[0-9]+]] = phi i64 [ 0, %entry ], [ [[FAKE_STACK_RT]], %[[UAR_ENABLED_BB]] ]
 ; CHECK: icmp eq i64 [[FAKE_STACK]], 0
 
-; CHECK: <label>:[[NO_FAKE_STACK_BB:[0-9]+]]
+; CHECK: [[NO_FAKE_STACK_BB:^[0-9]+]]:
 ; CHECK: %MyAlloca = alloca i8, i64
 ; CHECK: [[ALLOCA:%[0-9]+]] = ptrtoint i8* %MyAlloca
 
diff --git a/llvm/test/Instrumentation/MemorySanitizer/check_access_address.ll b/llvm/test/Instrumentation/MemorySanitizer/check_access_address.ll
index 8c245fed50c..7ac6dabd9cb 100644
--- a/llvm/test/Instrumentation/MemorySanitizer/check_access_address.ll
+++ b/llvm/test/Instrumentation/MemorySanitizer/check_access_address.ll
@@ -44,9 +44,9 @@ entry:
 ; CHECK-NOT: xor
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: call void @__msan_warning_noreturn
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: xor
 ; CHECK: store
 ; CHECK: store i32 %x
diff --git a/llvm/test/Instrumentation/MemorySanitizer/msan_basic.ll b/llvm/test/Instrumentation/MemorySanitizer/msan_basic.ll
index 569c2320c5c..a42730de012 100644
--- a/llvm/test/Instrumentation/MemorySanitizer/msan_basic.ll
+++ b/llvm/test/Instrumentation/MemorySanitizer/msan_basic.ll
@@ -39,10 +39,10 @@ entry:
 ; CHECK: store
 ; CHECK-ORIGINS: icmp
 ; CHECK-ORIGINS: br i1
-; CHECK-ORIGINS: <label>
+; CHECK-ORIGINS: {{^[0-9]+}}:
 ; CHECK-ORIGINS: store
 ; CHECK-ORIGINS: br label
-; CHECK-ORIGINS: <label>
+; CHECK-ORIGINS: {{^[0-9]+}}:
 ; CHECK: store
 ; CHECK: ret void
 
@@ -63,10 +63,10 @@ entry:
 ; CHECK: store {{.*}} align 32
 ; CHECK-ORIGINS: icmp
 ; CHECK-ORIGINS: br i1
-; CHECK-ORIGINS: <label>
+; CHECK-ORIGINS: {{^[0-9]+}}:
 ; CHECK-ORIGINS: store {{.*}} align 32
 ; CHECK-ORIGINS: br label
-; CHECK-ORIGINS: <label>
+; CHECK-ORIGINS: {{^[0-9]+}}:
 ; CHECK: store {{.*}} align 32
 ; CHECK: ret void
 
diff --git a/llvm/test/Instrumentation/MemorySanitizer/msan_kernel_basic.ll b/llvm/test/Instrumentation/MemorySanitizer/msan_kernel_basic.ll
index 680a672d12a..870e7768cc6 100644
--- a/llvm/test/Instrumentation/MemorySanitizer/msan_kernel_basic.ll
+++ b/llvm/test/Instrumentation/MemorySanitizer/msan_kernel_basic.ll
@@ -40,10 +40,10 @@ entry:
 }
 
 ; CHECK-LABEL: @Store1
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: [[BASE2:%[0-9]+]] = ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; CHECK: [[BASE:%[0-9]+]] = ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; CHECK: [[SHADOW:%[a-z0-9_]+]] = inttoptr {{.*}} [[BASE]]
@@ -51,18 +51,18 @@ entry:
 ; CHECK: load i64, i64* [[SHADOW]]
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK-LABEL: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: @__msan_metadata_ptr_for_store_1(i8* %p)
 ; CHECK: store i8
 ; If the new shadow is non-zero, jump to __msan_chain_origin()
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: @__msan_chain_origin
 ; Storing origin here:
 ; CHECK: store i32
 ; CHECK: br label
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: store i8
 ; CHECK: ret void
 
@@ -73,28 +73,28 @@ entry:
 }
 
 ; CHECK-LABEL: @Store2
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; Load the shadow of %p and check it
 ; CHECK: load i64
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK-LABEL: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: [[REG:%[0-9]+]] = bitcast i16* %p to i8*
 ; CHECK: @__msan_metadata_ptr_for_store_2(i8* [[REG]])
 ; CHECK: store i16
 ; If the new shadow is non-zero, jump to __msan_chain_origin()
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: @__msan_chain_origin
 ; Storing origin here:
 ; CHECK: store i32
 ; CHECK: br label
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: store i16
 ; CHECK: ret void
 
@@ -106,28 +106,28 @@ entry:
 }
 
 ; CHECK-LABEL: @Store4
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; Load the shadow of %p and check it
 ; CHECK: load i32
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK-LABEL: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: [[REG:%[0-9]+]] = bitcast i32* %p to i8*
 ; CHECK: @__msan_metadata_ptr_for_store_4(i8* [[REG]])
 ; CHECK: store i32
 ; If the new shadow is non-zero, jump to __msan_chain_origin()
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: @__msan_chain_origin
 ; Storing origin here:
 ; CHECK: store i32
 ; CHECK: br label
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: store i32
 ; CHECK: ret void
 
@@ -138,28 +138,28 @@ entry:
 }
 
 ; CHECK-LABEL: @Store8
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; Load the shadow of %p and check it
 ; CHECK: load i64
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK-LABEL: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: [[REG:%[0-9]+]] = bitcast i64* %p to i8*
 ; CHECK: @__msan_metadata_ptr_for_store_8(i8* [[REG]])
 ; CHECK: store i64
 ; If the new shadow is non-zero, jump to __msan_chain_origin()
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: @__msan_chain_origin
 ; Storing origin here:
 ; CHECK: store i32
 ; CHECK: br label
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: store i64
 ; CHECK: ret void
 
@@ -170,28 +170,28 @@ entry:
 }
 
 ; CHECK-LABEL: @Store16
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; Load the shadow of %p and check it
 ; CHECK: load i64
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK-LABEL: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: [[REG:%[0-9]+]] = bitcast i128* %p to i8*
 ; CHECK: @__msan_metadata_ptr_for_store_n(i8* [[REG]], i64 16)
 ; CHECK: store i128
 ; If the new shadow is non-zero, jump to __msan_chain_origin()
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: @__msan_chain_origin
 ; Storing origin here:
 ; CHECK: store i32
 ; CHECK: br label
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: store i128
 ; CHECK: ret void
 
@@ -205,16 +205,16 @@ entry:
 }
 
 ; CHECK-LABEL: @Load1
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; Load the shadow of %p and check it
 ; CHECK: load i64
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK-LABEL: <label>
+; CHECK: {{^[0-9]+}}:
 ; Load the value from %p. This is done before accessing the shadow
 ; to ease atomic handling.
 ; CHECK: load i8
@@ -231,16 +231,16 @@ entry:
 }
 
 ; CHECK-LABEL: @Load2
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; Load the shadow of %p and check it
 ; CHECK: load i64
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK-LABEL: <label>
+; CHECK: {{^[0-9]+}}:
 ; Load the value from %p. This is done before accessing the shadow
 ; to ease atomic handling.
 ; CHECK: load i16
@@ -258,16 +258,16 @@ entry:
 }
 
 ; CHECK-LABEL: @Load4
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; Load the shadow of %p and check it
 ; CHECK: load i64
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK-LABEL: <label>
+; CHECK: {{^[0-9]+}}:
 ; Load the value from %p. This is done before accessing the shadow
 ; to ease atomic handling.
 ; CHECK: load i32
@@ -284,16 +284,16 @@ entry:
 }
 
 ; CHECK-LABEL: @Load8
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; Load the shadow of %p and check it
 ; CHECK: load i64
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK-LABEL: <label>
+; CHECK: {{^[0-9]+}}:
 ; Load the value from %p. This is done before accessing the shadow
 ; to ease atomic handling.
 ; CHECK: load i64
@@ -310,16 +310,16 @@ entry:
 }
 
 ; CHECK-LABEL: @Load16
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; Load the shadow of %p and check it
 ; CHECK: load i64
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK-LABEL: <label>
+; CHECK: {{^[0-9]+}}:
 ; Load the value from %p. This is done before accessing the shadow
 ; to ease atomic handling.
 ; CHECK: load i128
@@ -359,7 +359,7 @@ attributes #0 = { "target-features"="+fxsr,+x87,-sse" }
 ; CHECK: [[VA_ARG_ORIGIN:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 3
 ; CHECK: [[VA_ARG_OVERFLOW_SIZE:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 4
 
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: [[OSIZE:%[0-9]+]] = load i64, i64* [[VA_ARG_OVERFLOW_SIZE]]
 ; Register save area is 48 bytes for non-SSE builds.
 ; CHECK: [[SIZE:%[0-9]+]] = add i64 48, [[OSIZE]]
@@ -380,13 +380,13 @@ entry:
 
 ; CHECK-LABEL: @VarArgCaller
 
-; CHECK-LABEL: entry:
+; CHECK: entry:
 ; CHECK: @__msan_get_context_state()
 ; CHECK: [[PARAM_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 0
 ; CHECK: [[VA_ARG_SHADOW:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 2
 ; CHECK: [[VA_ARG_OVERFLOW_SIZE:%[a-z0-9_]+]] = getelementptr {{.*}} i32 0, i32 4
 
-; CHECK-LABEL: entry.split:
+; CHECK: entry.split:
 ; CHECK: [[PARAM_SI:%[_a-z0-9]+]] = ptrtoint {{.*}} [[PARAM_SHADOW]]
 ; CHECK: [[ARG1_S:%[_a-z0-9]+]] = inttoptr i64 [[PARAM_SI]] to i64*
 ; First argument is initialized
diff --git a/llvm/test/Instrumentation/MemorySanitizer/msan_x86_bts_asm.ll b/llvm/test/Instrumentation/MemorySanitizer/msan_x86_bts_asm.ll
index 1c0072f5cea..f46917d32d2 100644
--- a/llvm/test/Instrumentation/MemorySanitizer/msan_x86_bts_asm.ll
+++ b/llvm/test/Instrumentation/MemorySanitizer/msan_x86_bts_asm.ll
@@ -96,6 +96,6 @@ if.else:                                          ; preds = %entry
 ; CHECK: br i1 [[MSCMP]], label %[[IFTRUE:.*]], label {{.*}}
 
 ; If yes, raise a warning.
-; CHECK: <label>:[[IFTRUE]]
+; CHECK: [[IFTRUE]]:
 ; CHECK: call void @__msan_warning
 
diff --git a/llvm/test/Instrumentation/MemorySanitizer/store-origin.ll b/llvm/test/Instrumentation/MemorySanitizer/store-origin.ll
index 9a0c01936e7..ed8d5362e58 100644
--- a/llvm/test/Instrumentation/MemorySanitizer/store-origin.ll
+++ b/llvm/test/Instrumentation/MemorySanitizer/store-origin.ll
@@ -74,7 +74,7 @@ attributes #1 = { nounwind readnone }
 ; CHECK: store {{.*}}!dbg ![[DBG:[0-9]+]]
 ; CHECK: icmp
 ; CHECK: br i1
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 
 ; Origin tracking level 1: simply store the origin value
 ; CHECK-ORIGINS1: store i32 {{.*}}[[ORIGIN]],{{.*}}!dbg !{{.*}}[[DBG]]
@@ -84,6 +84,6 @@ attributes #1 = { nounwind readnone }
 ; CHECK-ORIGINS2: store i32 {{.*}}[[ORIGIN2]],{{.*}}!dbg !{{.*}}[[DBG]]
 
 ; CHECK: br label{{.*}}!dbg !{{.*}}[[DBG]]
-; CHECK: <label>
+; CHECK: {{^[0-9]+}}:
 ; CHECK: store{{.*}}!dbg !{{.*}}[[DBG]]
 ; CHECK: ret void
diff --git a/llvm/test/Instrumentation/SanitizerCoverage/stack-depth.ll b/llvm/test/Instrumentation/SanitizerCoverage/stack-depth.ll
index 878295cd653..0c6db1a922a 100644
--- a/llvm/test/Instrumentation/SanitizerCoverage/stack-depth.ll
+++ b/llvm/test/Instrumentation/SanitizerCoverage/stack-depth.ll
@@ -29,7 +29,7 @@ entry:
 ; CHECK: [[lowest:%[^ \t]+]] = load [[intType]], [[intType]]* @__sancov_lowest_stack
 ; CHECK: [[cmp:%[^ \t]+]] = icmp ult [[intType]] [[frameInt]], [[lowest]]
 ; CHECK: br i1 [[cmp]], label %[[ifLabel:[^ \t]+]], label
-; CHECK: <label>:[[ifLabel]]:
+; CHECK: [[ifLabel]]:
 ; CHECK: store [[intType]] [[frameInt]], [[intType]]* @__sancov_lowest_stack
 ; CHECK: %call = call i32 @foo()
 ; CHECK: ret i32 %call
diff --git a/llvm/test/Transforms/GVNHoist/pr36787.ll b/llvm/test/Transforms/GVNHoist/pr36787.ll
index 487e2bd335c..387b3e74cf0 100644
--- a/llvm/test/Transforms/GVNHoist/pr36787.ll
+++ b/llvm/test/Transforms/GVNHoist/pr36787.ll
@@ -16,58 +16,58 @@ define void @func() personality i8* bitcast (i32 (...)* @gxx_personality to i8*)
   invoke void @f0()
           to label %3 unwind label %1
 
-; <label>:1:
+1:
   %2 = landingpad { i8*, i32 }
           catch i8* bitcast (i8** @g to i8*)
           catch i8* null
   br label %16
 
-; <label>:3:
+3:
   br i1 undef, label %4, label %10
 
-;CHECK:       <label>:4
+;CHECK:       4:
 ;CHECK-NEXT:    %5 = load i32*, i32** undef, align 8
 ;CHECK-NEXT:    invoke void @f1()
 
-; <label>:4:
+4:
   %5 = load i32*, i32** undef, align 8
   invoke void @f1()
           to label %6 unwind label %1
 
-;CHECK:       <label>:6
+;CHECK:       6:
 ;CHECK-NEXT:    %7 = load i32*, i32** undef, align 8
 ;CHECK-NEXT:    %8 = load i32*, i32** undef, align 8
 
-; <label>:6:
+6:
   %7 = load i32*, i32** undef, align 8
   %8 = load i32*, i32** undef, align 8
   br i1 true, label %9, label %17
 
-; <label>:9:
+9:
   invoke void @f0()
           to label %10 unwind label %1
 
-; <label>:10:
+10:
   invoke void @f2()
           to label %11 unwind label %1
 
-; <label>:11:
+11:
   %12 = invoke signext i32 undef(i32* null, i32 signext undef, i1 zeroext undef)
           to label %13 unwind label %14
 
-; <label>:13:
+13:
   unreachable
 
-; <label>:14:
+14:
   %15 = landingpad { i8*, i32 }
           catch i8* bitcast (i8** @g to i8*)
           catch i8* null
   br label %16
 
-; <label>:16:
+16:
   unreachable
 
-; <label>:17:
+17:
   ret void
 
 ; uselistorder directives
diff --git a/llvm/test/Transforms/LowerSwitch/2014-06-23-PHIlowering.ll b/llvm/test/Transforms/LowerSwitch/2014-06-23-PHIlowering.ll
index c6cddf636a8..24f1d3abeb8 100644
--- a/llvm/test/Transforms/LowerSwitch/2014-06-23-PHIlowering.ll
+++ b/llvm/test/Transforms/LowerSwitch/2014-06-23-PHIlowering.ll
@@ -2,10 +2,10 @@
 
 define i32 @test(i32 %arg) #0 {
 ; CHECK-LABEL: @test
-; CHECK: ; <label>:2
+; CHECK: 2:
 ; CHECK-NEXT:  %res.0 = phi i32 [ 1, %NodeBlock ], [ 2, %1 ]
 ; CHECK-NEXT:  br label %3
-; CHECK: ; <label>:5
+; CHECK: 5:
 ; CHECK-NEXT:   %res.3 = phi i32 [ 0, %NewDefault ], [ %res.2, %4 ]
 ; CHECK-NEXT:   %6 = add nsw i32 %res.3, 1
 ; CHECK-NEXT:   ret i32 %6
@@ -17,23 +17,23 @@ define i32 @test(i32 %arg) #0 {
     i32 4, label %4
   ]
 
-; <label>:1
+1:
   br label %2
 
-; <label>:2
+2:
   %res.0 = phi i32 [ 1, %0 ], [ 2, %1 ]
   br label %3
 
-; <label>:3
+3:
   %res.1 = phi i32 [ 0, %0 ], [ %res.0, %2 ]
   %phitmp = add nsw i32 %res.1, 2
   br label %4
 
-; <label>:4
+4:
   %res.2 = phi i32 [ 1, %0 ], [ %phitmp, %3 ]
   br label %5
 
-; <label>:5
+5:
   %res.3 = phi i32 [ 0, %0 ], [ %res.2, %4 ]
   %6 = add nsw i32 %res.3, 1
   ret i32 %6