[CodeGen] Print external symbols as $symbol in both MIR and debug output

Work towards the unification of MIR and debug output by printing
`$symbol` instead of `<es:symbol>`.

Only debug syntax is affected.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320681 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 15 insertions, 2 deletions

diff --git a/docs/MIRLangRef.rst b/docs/MIRLangRef.rst
index ebc9d456703..14ac63bbd9d 100644
--- a/docs/MIRLangRef.rst
+++ b/docs/MIRLangRef.rst
@@ -665,13 +665,26 @@ Example:
         - id:             1
           blocks:         [ '%bb.7', '%bb.7', '%bb.4.d3', '%bb.5' ]
 
+External Symbol Operands
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+An external symbol operand is represented using an identifier with the ``$``
+prefix. The identifier is surrounded with ""'s and escaped if it has any
+special non-printable characters in it.
+
+Example:
+
+.. code-block:: text
+
+    CALL64pcrel32 $__stack_chk_fail, csr_64, implicit %rsp, implicit-def %rsp
+
+
 .. TODO: Describe the parsers default behaviour when optional YAML attributes
    are missing.
 .. TODO: Describe the syntax for the bundled instructions.
 .. TODO: Describe the syntax for virtual register YAML definitions.
 .. TODO: Describe the machine function's YAML flag attributes.
-.. TODO: Describe the syntax for the external symbol and register
-   mask machine operands.
+.. TODO: Describe the syntax for the register mask machine operands.
 .. TODO: Describe the frame information YAML mapping.
 .. TODO: Describe the syntax of the stack object machine operands and their
    YAML definitions.