MIR Serialization: Change MIR syntax - use custom syntax for MBBs.

This commit modifies the way the machine basic blocks are serialized - now the
machine basic blocks are serialized using a custom syntax instead of relying on
YAML primitives. Instead of using YAML mappings to represent the individual
machine basic blocks in a machine function's body, the new syntax uses a single
YAML block scalar which contains all of the machine basic blocks and
instructions for that function.

This is an example of a function's body that uses the old syntax:

    body:
      - id: 0
        name: entry
        instructions:
          - '%eax = MOV32r0 implicit-def %eflags'
          - 'RETQ %eax'
    ...

The same body is now written like this:

    body: |
      bb.0.entry:
        %eax = MOV32r0 implicit-def %eflags
        RETQ %eax
    ...

This syntax change is motivated by the fact that the bundled machine
instructions didn't map that well to the old syntax which was using a single
YAML sequence to store all of the machine instructions in a block. The bundled
machine instructions internally use flags like BundledPred and BundledSucc to
determine the bundles, and serializing them as MI flags using the old syntax
would have had a negative impact on the readability and the ease of editing
for MIR files. The new syntax allows me to serialize the bundled machine
instructions using a block construct without relying on the internal flags,
for example:

   BUNDLE implicit-def dead %itstate, implicit-def %s1 ... {
      t2IT 1, 24, implicit-def %itstate
      %s1 = VMOVS killed %s0, 1, killed %cpsr, implicit killed %itstate
   }

This commit also converts the MIR testcases to the new syntax. I developed
a script that can convert from the old syntax to the new one. I will post the
script on the llvm-commits mailing list in the thread for this commit.

llvm-svn: 244982

1 files changed, 14 insertions, 4 deletions

diff --git a/llvm/lib/CodeGen/MIRParser/MILexer.h b/llvm/lib/CodeGen/MIRParser/MILexer.h
index d0ae379097c..07bdc3e4549 100644
--- a/llvm/lib/CodeGen/MIRParser/MILexer.h
+++ b/llvm/lib/CodeGen/MIRParser/MILexer.h
@@ -30,6 +30,7 @@ struct MIToken {
     // Markers
     Eof,
     Error,
+    Newline,
 
     // Tokens with no info.
     comma,
@@ -75,11 +76,16 @@ struct MIToken {
     kw_jump_table,
     kw_constant_pool,
     kw_liveout,
+    kw_address_taken,
+    kw_landing_pad,
+    kw_liveins,
+    kw_successors,
 
     // Identifier tokens
     Identifier,
     IntegerType,
     NamedRegister,
+    MachineBasicBlockLabel,
     MachineBasicBlock,
     StackObject,
     FixedStackObject,
@@ -118,6 +124,10 @@ public:
 
   bool isError() const { return Kind == Error; }
 
+  bool isNewlineOrEOF() const { return Kind == Newline || Kind == Eof; }
+
+  bool isErrorOrEOF() const { return Kind == Error || Kind == Eof; }
+
   bool isRegister() const {
     return Kind == NamedRegister || Kind == underscore ||
            Kind == VirtualRegister;
@@ -149,10 +159,10 @@ public:
 
   bool hasIntegerValue() const {
     return Kind == IntegerLiteral || Kind == MachineBasicBlock ||
-           Kind == StackObject || Kind == FixedStackObject ||
-           Kind == GlobalValue || Kind == VirtualRegister ||
-           Kind == ConstantPoolItem || Kind == JumpTableIndex ||
-           Kind == IRBlock;
+           Kind == MachineBasicBlockLabel || Kind == StackObject ||
+           Kind == FixedStackObject || Kind == GlobalValue ||
+           Kind == VirtualRegister || Kind == ConstantPoolItem ||
+           Kind == JumpTableIndex || Kind == IRBlock;
   }
 };