This is a reland of bcf1172992
The test was timing out in no snapshot builds, as each CodeAssemblerTester
creates a new Context. Reduced the random iterations significantly.
Original change's description:
> [arm64] Preparation for padding of arguments
>
> As part of JSSP removal, we need to align the arguments passed to functions
> on the stack, by adding a padding slot when the total number of arguments
> is odd.
>
> This patch introduces the kPadArguments flag (which is currently set to
> false for all architectures), which will control padding of arguments in
> architecture-independent parts of the code (deoptimizer, instruction
> selector).
>
> It also adds some executable tests for tail calls with various stack
> parameter counts on the caller and callee sides.
>
> This will be turned on for arm64 together with arm64-specific changes to
> the code generator, the MacroAsembler and the builtins, in a later patch.
>
> Bug: v8:6644
> Change-Id: I79a5c149123fe8130cedd1ccffec3d9b50361e08
> Reviewed-on: https://chromium-review.googlesource.com/806554
> Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#50134}
TBR=jarin@chromium.org
Bug: v8:6644
Change-Id: I795877ed9791e126ffac6841dbbb65189e95d207
Reviewed-on: https://chromium-review.googlesource.com/833046
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50238}
This reverts commit bcf1172992.
Reason for revert:
https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20nosnap%20-%20debug/builds/16791
The test cctest/test-run-tail-calls/FuzzStackParamCount hangs on
the nosnap debug bot and times out.
Original change's description:
> [arm64] Preparation for padding of arguments
>
> As part of JSSP removal, we need to align the arguments passed to functions
> on the stack, by adding a padding slot when the total number of arguments
> is odd.
>
> This patch introduces the kPadArguments flag (which is currently set to
> false for all architectures), which will control padding of arguments in
> architecture-independent parts of the code (deoptimizer, instruction
> selector).
>
> It also adds some executable tests for tail calls with various stack
> parameter counts on the caller and callee sides.
>
> This will be turned on for arm64 together with arm64-specific changes to
> the code generator, the MacroAsembler and the builtins, in a later patch.
>
> Bug: v8:6644
> Change-Id: I79a5c149123fe8130cedd1ccffec3d9b50361e08
> Reviewed-on: https://chromium-review.googlesource.com/806554
> Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#50134}
TBR=rmcilroy@chromium.org,jarin@chromium.org,georgia.kouveli@arm.com
Change-Id: Iff4d7da418204834822842b160eacb8980058172
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6644
Reviewed-on: https://chromium-review.googlesource.com/830847
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50144}
As part of JSSP removal, we need to align the arguments passed to functions
on the stack, by adding a padding slot when the total number of arguments
is odd.
This patch introduces the kPadArguments flag (which is currently set to
false for all architectures), which will control padding of arguments in
architecture-independent parts of the code (deoptimizer, instruction
selector).
It also adds some executable tests for tail calls with various stack
parameter counts on the caller and callee sides.
This will be turned on for arm64 together with arm64-specific changes to
the code generator, the MacroAsembler and the builtins, in a later patch.
Bug: v8:6644
Change-Id: I79a5c149123fe8130cedd1ccffec3d9b50361e08
Reviewed-on: https://chromium-review.googlesource.com/806554
Commit-Queue: Georgia Kouveli <georgia.kouveli@arm.com>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50134}
This CL separates the check whether something is tail-callable from
the computation of the size of the stack parameters that a function
takes.
In order to track this precisely, the stack parameter size calculation
uses the recently landed MachineType information that's embedded
in return and parameter value LinkageLocations.
Review-Url: https://codereview.chromium.org/2121753002
Cr-Commit-Position: refs/heads/master@{#37668}
By adding MachineType to LinkageLocation, it is possible not only to reason
about the location of a LinkageLocation on the stack, but also about it's
size. This will be useful in follow-on CLs that attempt to merge some of the
parameter passing logic of tail calls and normal (non-tail) calls.
As a nice side-effect, it is no longer necessary to separately keep a
MachineSignature in a CallDescriptor, because the MachineTypes contianed in
LinkageLocation for all of the Descriptor's parameters and return types are
sufficient. This CL therefore removes the MachineSignature from the
CallDescriptor and adjusts all the calling code accordingly, simplifying and
de-duplicating code in a bunch of places.
R=titzer@chromium.org, bmeurer@chromium.org
LOG=N
Review-Url: https://codereview.chromium.org/2124023003
Cr-Commit-Position: refs/heads/master@{#37633}
This optimizes the passing of stack parameters in function calls.
For some architectures (ia32/x64), using pushes when possible instead
of bumping the stack and then storing parameters generates much
smaller code, and in some cases is faster (e.g. when a push of a memory
location can implement a memory-to-memory copy and thus elide an
intermediate load. On others (e.g. ARM), the benefit is smaller, where
it's only possible to elide direct stack pointer adjustment in certain cases
or combine multiple register stores into a single instruction in other limited
situations. On yet other platforms (ARM64, MIPS), there are no push instructions,
and this optimization isn't used at all.
Ideally, this mechanism would be used for both tail calls and normal calls,
but "normal" calls are currently pretty efficient, and tail calls are very
inefficient, so this CL sets the bar low for building a new mechanism to
handle parameter pushing that only needs to raise the bar on tail calls for now.
The key aspect of this change is that adjustment to the stack pointer
for tail calls (and perhaps later real calls) is an explicit step separate from
instruction selection and gap resolution, but aware of both, making it possible
to safely recognize gap moves that are actually pushes.
Review-Url: https://codereview.chromium.org/2082263002
Cr-Commit-Position: refs/heads/master@{#37477}
MachineType is now a class with two enum fields:
- MachineRepresentation
- MachineSemantic
Both enums are usable on their own, and this change switches some places from using MachineType to use just MachineRepresentation. Most notably:
- register allocator now uses just the representation.
- Phi and Select nodes only refer to representations.
Review URL: https://codereview.chromium.org/1513543003
Cr-Commit-Position: refs/heads/master@{#32738}
* Adds a PrepareForTailCall instruction that bumps the stack in the case that
the number of parameters passed to the callee causes the stack to exceed the
calleer's frame size.
* Uses the gap resolver to move the saved caller return address and frame
pointer to the approprate location in the tail-called frame.
BUG=v8:4076
LOG=n
Review URL: https://codereview.chromium.org/1455833004
Cr-Commit-Position: refs/heads/master@{#32151}
* Limit triggering of tail calls to explicit use of a new inline runtime
function %_TailCall. %_TailCall works just like %_Call except for using
tail-calling mechanics (currently only in TF).
* Remove hack that recognized some specific usages of %_Call and converted them
into tail calls.
* Support tail calls for all calls where the number of callee stack parameters
is less than or equal to the number of caller stack parameters.
* Use the gap resolver to swizzle parameters and registers to tail calls.
BUG=v8:4076
LOG=n
Review URL: https://codereview.chromium.org/1439613003
Cr-Commit-Position: refs/heads/master@{#31987}
Add factory methods for different types of LinkageLocations, and ensure that
accesses to the underlying data in the location are classified by type and
funneled through explicit accessors.
Also change the representation of LinkageLocation to use a BitField rather
than using a reserved section of the integer range.
Review URL: https://codereview.chromium.org/1262343002
Cr-Commit-Position: refs/heads/master@{#29938}
