This CL adds a "deadlocals" pass, which runs after inlining and before
escape analysis, to prune any unneeded local variables and
assignments. In particular, this helps avoid unnecessary Addrtaken
markings from unreachable closures.
Deadlocals is sensitive to "_ = ..." as a signal of explicit
use for testing. This signal occurs only if the entire
left-hand-side is "_" targets; if it is
`_, ok := someInlinedFunc(args)`
then the first return value is eligible for dead code elimination.
Use this (`_ = x`) to fix tests broken by deadlocals elimination.
Includes a test, based on one of the tests that required modification.
Matthew Dempsky wrote this, changing ownership to allow rebases, commits, tweaks.
Fixes#65158.
Old-Change-Id: I723fb69ccd7baadaae04d415702ce6c8901eaf4e
Change-Id: I1f25f4293b19527f305c18c3680b214237a7714c
Reviewed-on: https://go-review.googlesource.com/c/go/+/600498
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: David Chase <drchase@google.com>
Commit-Queue: David Chase <drchase@google.com>
This patch reworks how inlheur.AnalyzeFunc is called by the top level
inliner. Up until this point the strategy was to analyze a function at
the point where CanInline is invoked on it, however it simplifies
things to instead make the call outside of CanInline (for example, so
that directly recursive functions can be analyzed).
Also as part of this patch, change things so that we no longer run
some of the more compile-time intensive analysis on functions that
haven't been marked inlinable (so as to safe compile time), and add a
teardown/cleanup hook in the inlheur package to be invoked by the
inliner when we're done inlining.
Change-Id: Id0772a285d891b0bed66dd86adaffa69d973c26a
Reviewed-on: https://go-review.googlesource.com/c/go/+/539318
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Most of the test cases in the test directory use the new go:build syntax
already. Convert the rest. In general, try to place the build constraint
line below the test directive comment in more places.
For #41184.
For #60268.
Change-Id: I11c41a0642a8a26dc2eda1406da908645bbc005b
Cq-Include-Trybots: luci.golang.try:gotip-linux-386-longtest,gotip-linux-amd64-longtest,gotip-windows-amd64-longtest
Reviewed-on: https://go-review.googlesource.com/c/go/+/536236
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This patch changes the inliner to use callsite scores when deciding to
inline as opposed to looking only at callee cost/hairyness.
For this to work, we have to relax the inline budget cutoff as part of
CanInline to allow for the possibility that a given function might
start off with a cost of N where N > 80, but then be called from a
callsites whose score is less than 80. Once a given function F in
package P has been approved by CanInline (based on the relaxed budget)
it will then be emitted as part of the export data, meaning that other
packages importing P will need to also need to compute callsite scores
appropriately.
For a function F that calls function G, if G is marked as potentially
inlinable then the hairyness computation for F will use G's cost for
the call to G as opposed to the default call cost; for this to work
with the new scheme (given relaxed cost change described above) we
use G's cost only if it falls below inlineExtraCallCost, otherwise
just use inlineExtraCallCost.
Included in this patch are a bunch of skips and workarounds to
selected 'errorcheck' tests in the <GOROOT>/test directory to deal
with the additional "can inline" messages emitted when the new inliner
is turned on.
Change-Id: I9be5f8cd0cd8676beb4296faf80d2f6be7246335
Reviewed-on: https://go-review.googlesource.com/c/go/+/519197
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
