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2 Machine IR (MIR) Format Reference Manual
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9 This is a work in progress.
14 This document is a reference manual for the Machine IR (MIR) serialization
15 format. MIR is a human readable serialization format that is used to represent
16 LLVM's :ref:`machine specific intermediate representation
17 <machine code representation>`.
19 The MIR serialization format is designed to be used for testing the code
20 generation passes in LLVM.
25 The MIR serialization format uses a YAML container. YAML is a standard
26 data serialization language, and the full YAML language spec can be read at
28 <http://www.yaml.org/spec/1.2/spec.html#Introduction>`_.
30 A MIR file is split up into a series of `YAML documents`_. The first document
31 can contain an optional embedded LLVM IR module, and the rest of the documents
32 contain the serialized machine functions.
34 .. _YAML documents: http://www.yaml.org/spec/1.2/spec.html#id2800132
42 When the first YAML document contains a `YAML block literal string`_, the MIR
43 parser will treat this string as an LLVM assembly language string that
44 represents an embedded LLVM IR module.
45 Here is an example of a YAML document that contains an LLVM module:
50 define i32 @inc(i32* %x) {
52 %0 = load i32, i32* %x
59 .. _YAML block literal string: http://www.yaml.org/spec/1.2/spec.html#id2795688
64 The remaining YAML documents contain the machine functions. This is an example
65 of such YAML document:
71 tracksRegLiveness: true
78 %eax = MOV32rm %rdi, 1, _, 0, _
79 %eax = INC32r killed %eax, implicit-def dead %eflags
80 MOV32mr killed %rdi, 1, _, 0, _, %eax
84 The document above consists of attributes that represent the various
85 properties and data structures in a machine function.
87 The attribute ``name`` is required, and its value should be identical to the
88 name of a function that this machine function is based on.
90 The attribute ``body`` is a `YAML block literal string`_. Its value represents
91 the function's machine basic blocks and their machine instructions.
93 .. TODO: Describe the parsers default behaviour when optional YAML attributes
95 .. TODO: Describe the syntax of the machine instructions.
96 .. TODO: Describe the syntax of the immediate machine operands.
97 .. TODO: Describe the syntax of the register machine operands.
98 .. TODO: Describe the syntax of the virtual register operands and their YAML
100 .. TODO: Describe the syntax of the register operand flags and the subregisters.
101 .. TODO: Describe the machine function's YAML flag attributes.
102 .. TODO: Describe the machine basic block's YAML flag, successors and livein
103 attributes. Describe the syntax for the machine basic block operands.
104 .. TODO: Describe the syntax for the global value, external symbol and register
105 mask machine operands.
106 .. TODO: Describe the frame information YAML mapping.
107 .. TODO: Describe the syntax of the stack object machine operands and their
109 .. TODO: Describe the syntax of the constant pool machine operands and their
111 .. TODO: Describe the syntax of the jump table machine operands and their
113 .. TODO: Describe the syntax of the block address machine operands.
114 .. TODO: Describe the syntax of the CFI index machine operands.
115 .. TODO: Describe the syntax of the metadata machine operands, and the
116 instructions debug location attribute.
117 .. TODO: Describe the syntax of the target index machine operands.
118 .. TODO: Describe the syntax of the register live out machine operands.
119 .. TODO: Describe the syntax of the machine memory operands.