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
diff --git a/llvm/test/CodeGen/MIR/X86/undefined-stack-object.mir b/llvm/test/CodeGen/MIR/X86/undefined-stack-object.mir
index bec703a..416e678 100644
--- a/llvm/test/CodeGen/MIR/X86/undefined-stack-object.mir
+++ b/llvm/test/CodeGen/MIR/X86/undefined-stack-object.mir
@@ -20,13 +20,11 @@
maxAlignment: 4
stack:
- { id: 0, name: b, size: 4, alignment: 4 }
-body:
- - id: 0
- name: entry
- instructions:
- - '%0 = COPY %edi'
- # CHECK: [[@LINE+1]]:18: use of undefined stack object '%stack.2'
- - 'MOV32mr %stack.2, 1, _, 0, _, %0'
- - '%eax = COPY %0'
- - 'RETQ %eax'
+body: |
+ bb.0.entry:
+ %0 = COPY %edi
+ ; CHECK: [[@LINE+1]]:13: use of undefined stack object '%stack.2'
+ MOV32mr %stack.2, 1, _, 0, _, %0
+ %eax = COPY %0
+ RETQ %eax
...