cpu: Consider instructions waiting for FU completion in draining

Information
Submitter:	Andreas Hansson
Repository:	gem5
Branch:	default
Bugs:
Depends On:
Reviewers
Groups:	Default
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Description

Changeset 9745:f74b7b7af31d
---------------------------
cpu: Consider instructions waiting for FU completion in draining

This patch changes the IEW drain check to include the FU pool as there
can be instructions that are "stored" in FU completion events and thus
not covered by the existing checks. With this patch, we simply include
a check to see if all the FUs are considered non-busy in the next
tick.

Without this patch, the pc-switcheroo-full regression fails after
minor changes to the cache timing (aligning to clock edge).

Testing Done

All regressions pass

Description:

~		Changeset 9744:3039e4f975a8
	~	Changeset 9744:03ce870a5145

		cpu: Consider instructions waiting for FU completion in draining

		This patch changes the IEW drain check to include the FU pool as there
		can be instructions that are "stored" in FU completion events and thus
		not covered by the existing checks. With this patch, we simply include
		a check to see if all the FUs are considered non-busy in the next
		tick.

		Without this patch, the pc-switcheroo-full regression fails after
		minor changes to the cache timing (aligning to clock edge).

Diff:

Revision 2 (+19 -10)

Show changes

	src/cpu/o3/fu_pool.hh
	src/cpu/o3/fu_pool.cc
	src/cpu/o3/iew_impl.hh

LGTM.

src/cpu/o3/fu_pool.cc (Diff revision 2)

Is the bitwise and intended? It shouldn't matter though.

Andreas Hansson June 4, 2013, 5:23 p.m. (June 4, 2013, 5:23 p.m.)

Could re-write it as is_drained = is_drained && unitBusy[i], but as they are both bool it does not matter. Is there such a thing as &&= ?

Description:

~		Changeset 9744:03ce870a5145
	~	Changeset 9745:f74b7b7af31d

		cpu: Consider instructions waiting for FU completion in draining

		This patch changes the IEW drain check to include the FU pool as there
		can be instructions that are "stored" in FU completion events and thus
		not covered by the existing checks. With this patch, we simply include
		a check to see if all the FUs are considered non-busy in the next
		tick.

		Without this patch, the pc-switcheroo-full regression fails after
		minor changes to the cache timing (aligning to clock edge).

Diff:

Revision 3 (+19 -10)

Show changes

	src/cpu/o3/fu_pool.hh
	src/cpu/o3/fu_pool.cc
	src/cpu/o3/iew_impl.hh

Ship It!

You have a pending review.

Review Board 2.0.15

This change has been marked as submitted.

Screenshots

Files

Description:

Changeset 9744:3039e4f975a8

Changeset 9744:03ce870a5145

Diff:

Description:

Changeset 9744:03ce870a5145

Changeset 9745:f74b7b7af31d

Diff:

Status: Closed (submitted)