This is an archive of the discontinued LLVM Phabricator instance.

Add note to documentation about machine node chains.
ClosedPublic

Authored by arsenm on Jul 28 2014, 1:22 PM.

Download Raw Diff

Details

Reviewers

Summary

I've been assuming chain operands were always the first operand,
since the documentation says this. I was confused about why they
were missing after instruction selection. Apparently the convention
changes to using the last operand for MachineSDNodes and I've never
noticed before.

Diff Detail

Event Timeline

arsenm updated this revision to Diff 11954.Jul 28 2014, 1:22 PM

arsenm retitled this revision from to Add note to documentation about machine node chains. .

arsenm updated this object.

arsenm edited the test plan for this revision. (Show Details)

arsenm added a subscriber: Unknown Object (MLST).

Note that the chain isn't necessarily the last operand for a machine node, and can still be followed by glue

Ping

LGTM.

docs/CodeGenerator.rst
774	by be -> maybe

This revision is now accepted and ready to land.Sep 2 2014, 9:36 AM

r216934

Revision Contents

Path

Size

docs/

CodeGenerator.rst

4 lines

Diff 12041

docs/CodeGenerator.rst

Context not available.
	calls, returns, etc). All nodes that have side effects should take a token	calls, returns, etc). All nodes that have side effects should take a token
	chain as input and produce a new one as output. By convention, token chain	chain as input and produce a new one as output. By convention, token chain
	inputs are always operand #0, and chain results are always the last value	inputs are always operand #0, and chain results are always the last value
	produced by an operation.	produced by an operation. However, after instruction selection, the
		machine nodes have their chain after the instruction's operands, and
		by be followed by glue nodes.
		hfinkelUnsubmitted Not Done Reply Inline Actions by be -> maybe hfinkel: by be -> maybe

	A SelectionDAG has designated "Entry" and "Root" nodes. The Entry node is	A SelectionDAG has designated "Entry" and "Root" nodes. The Entry node is
	always a marker node with an Opcode of ``ISD::EntryToken``. The Root node is	always a marker node with an Opcode of ``ISD::EntryToken``. The Root node is
Context not available.