Have nil checks return a pointer that is known non-nil. Users of
that pointer can use the result, ensuring that they are ordered
after the nil check itself.
The order dependence goes away after scheduling, when we've fixed
an order. At that point we move uses back to the original pointer
so it doesn't change regalloc any.
This prevents pointer arithmetic on nil from being spilled to the
stack and then observed by a stack scan.
Fixes#63657
Change-Id: I1a5fa4f2e6d9000d672792b4f90dfc1b7b67f6ea
Reviewed-on: https://go-review.googlesource.com/c/go/+/537775
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
sparse conditional constant propagation can discover optimization
opportunities that cannot be found by just combining constant folding
and constant propagation and dead code elimination separately.
This is a re-submit of PR#59575, which fix a broken dominance relationship caught by ssacheck
Updates https://github.com/golang/go/issues/59399
Change-Id: I57482dee38f8e80a610aed4f64295e60c38b7a47
GitHub-Last-Rev: 830016f24e
GitHub-Pull-Request: golang/go#60469
Reviewed-on: https://go-review.googlesource.com/c/go/+/498795
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
sparse conditional constant propagation can discover optimization opportunities that cannot be found by just combining constant folding and constant propagation and dead code elimination separately.
Updates #59399
Change-Id: Ia954e906480654a6f0cc065d75b5912f96f36b2e
GitHub-Last-Rev: 90fc02db99
GitHub-Pull-Request: golang/go#59575
Reviewed-on: https://go-review.googlesource.com/c/go/+/483875
Reviewed-by: Keith Randall <khr@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Have the write barrier call return a pointer to a buffer into which
the generated code records pointers that need write barrier treatment.
Change-Id: I7871764298e0aa1513de417010c8d46b296b199e
Reviewed-on: https://go-review.googlesource.com/c/go/+/447781
Reviewed-by: Keith Randall <khr@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Bypass: Keith Randall <khr@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Instead of keeping track of in which blocks write barriers complete,
introduce a new op that marks the exact memory state where the
write barrier completes.
For future use. This allows us to move some of the write barrier code
to between the start of the merging block and the WBend marker.
Change-Id: If3809b260292667d91bf0ee18d7b4d0eb1e929f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/447777
Reviewed-by: Keith Randall <khr@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
This change intrinsifies ReverseBytes{16|32|64} by generating the
corresponding new instructions in Power10: brh, brd and brw and
adds a verification test for the same.
On Power 9 and 8, the .go code performs optimally as it is.
Performance improvement seen on Power10:
ReverseBytes32 1.38ns ± 0% 1.18ns ± 0% -14.2
ReverseBytes64 1.52ns ± 0% 1.11ns ± 0% -26.87
ReverseBytes16 1.41ns ± 1% 1.18ns ± 0% -16.47
Change-Id: I88f127f3ab9ba24a772becc21ad90acfba324b37
Reviewed-on: https://go-review.googlesource.com/c/go/+/446675
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Lynn Boger <laboger@linux.vnet.ibm.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
We need to make sure that when we get the stack pointer, we get it
at the right time.
V = GetCallerSP
Call()
W = GetCallerSP
If Call causes a stack growth, then we will be in a situation
where V != W. So it matters when GetCallerSP operations get scheduled.
Add a memory argument to GetCallerSP so it can't be reordered with
things like calls.
Change-Id: I6cc801134c38e358c5a1ec0c09d38379a16a4184
Reviewed-on: https://go-review.googlesource.com/c/go/+/453515
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Martin Möhrmann <martin@golang.org>
Reviewed-by: Robert Griesemer <gri@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
The SPanchored opcode is identical to SP, except that it takes a memory
argument so that it (and more importantly, anything that uses it)
must be scheduled at or after that memory argument.
This opcode ensures that a LEAQ of a variable gets scheduled after the
corresponding VARDEF for that variable.
This may lead to less CSE of LEAQ operations. The effect is very small.
The go binary is only 80 bytes bigger after this CL. Usually LEAQs get
folded into load/store operations, so the effect is only for pointerful
types, large enough to need a duffzero, and have their address passed
somewhere. Even then, usually the CSEd LEAQs will be un-CSEd because
the two uses are on different sides of a function call and the LEAQ
ends up being rematerialized at the second use anyway.
Change-Id: Ib893562cd05369b91dd563b48fb83f5250950293
Reviewed-on: https://go-review.googlesource.com/c/go/+/452916
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Keith Randall <khr@golang.org>
Reviewed-by: Martin Möhrmann <moehrmann@google.com>
Reviewed-by: Martin Möhrmann <martin@golang.org>
Reviewed-by: Keith Randall <khr@google.com>
These two directories are full of //go:build ignore files.
We can ignore them more easily by putting an underscore
at the start of the name. That also works around a bug
in Go 1.17 that was not fixed until Go 1.17.3.
Change-Id: Ia5389b65c79b1e6d08e4fef374d335d776d44ead
Reviewed-on: https://go-review.googlesource.com/c/go/+/435472
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>
2022-10-04 19:35:46 +00:00
Renamed from src/cmd/compile/internal/ssa/gen/genericOps.go (Browse further)
