The control edges in a TurboFan graph can form a cycle. To break this cycle in the int64-lowering we add special handling for loop nodes. Similar handling already exists for phi nodes and effectphi nodes, which breaks cycles formed by value edges and effect edges, respectively.
Review-Url: https://codereview.chromium.org/2511503002
Cr-Commit-Position: refs/heads/master@{#41071}
This is preparation for using TF to create builtins that handle variable number of
arguments and have to remove these arguments dynamically from the stack upon
return.
The gist of the changes:
- Added a second argument to the Return node which specifies the number of stack
slots to pop upon return in addition to those specified by the Linkage of the
compiled function.
- Removed Tail -> Non-Tail fallback in the instruction selector. Since TF now should
handles all tail-call cases except where the return value type differs, this fallback
was not really useful and in fact caused unexpected behavior with variable
sized argument popping, since it wasn't possible to materialize a Return node
with the right pop count from the TailCall without additional context.
- Modified existing Return generation to pass a constant zero as the additional
pop argument since the variable pop functionality
LOG=N
Review-Url: https://codereview.chromium.org/2446543002
Cr-Commit-Position: refs/heads/master@{#40699}
Reason for revert:
Seems to break arm64 sim debug and blocks roll:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm64%20-%20sim%20-%20debug/builds/3294
Original issue's description:
> [turbofan] Support variable size argument removal in TF-generated functions
>
> This is preparation for using TF to create builtins that handle variable number of
> arguments and have to remove these arguments dynamically from the stack upon
> return.
>
> The gist of the changes:
> - Added a second argument to the Return node which specifies the number of stack
> slots to pop upon return in addition to those specified by the Linkage of the
> compiled function.
> - Removed Tail -> Non-Tail fallback in the instruction selector. Since TF now should
> handles all tail-call cases except where the return value type differs, this fallback
> was not really useful and in fact caused unexpected behavior with variable
> sized argument popping, since it wasn't possible to materialize a Return node
> with the right pop count from the TailCall without additional context.
> - Modified existing Return generation to pass a constant zero as the additional
> pop argument since the variable pop functionality
>
> LOG=N
TBR=bmeurer@chromium.org,mstarzinger@chromium.org,epertoso@chromium.org,danno@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
NOPRESUBMIT=true
Review-Url: https://codereview.chromium.org/2473643002
Cr-Commit-Position: refs/heads/master@{#40691}
This is preparation for using TF to create builtins that handle variable number of
arguments and have to remove these arguments dynamically from the stack upon
return.
The gist of the changes:
- Added a second argument to the Return node which specifies the number of stack
slots to pop upon return in addition to those specified by the Linkage of the
compiled function.
- Removed Tail -> Non-Tail fallback in the instruction selector. Since TF now should
handles all tail-call cases except where the return value type differs, this fallback
was not really useful and in fact caused unexpected behavior with variable
sized argument popping, since it wasn't possible to materialize a Return node
with the right pop count from the TailCall without additional context.
- Modified existing Return generation to pass a constant zero as the additional
pop argument since the variable pop functionality
LOG=N
Review-Url: https://codereview.chromium.org/2446543002
Cr-Commit-Position: refs/heads/master@{#40678}
EffectPhis can cause a cycle in a TurboFan graph. We delay the
processing of EffectPhis in the Int64Lowering to break these cycles. We
do the same already for Phis.
R=titzer@chromium.org
BUG=v8:5518
TEST=unittests/Int64LoweringTest.EffectPhiLoop
Review-Url: https://codereview.chromium.org/2428583002
Cr-Commit-Position: refs/heads/master@{#40378}
Implement UnalignedLoad and UnalignedStore optional
turbofan operators and use them in WasmCompiler for unaligned
memory access.
BUG=
Review-Url: https://codereview.chromium.org/2122853002
Cr-Commit-Position: refs/heads/master@{#37988}
Lowering of Int64Load, Int64Store, BitcastInt64ToFloat64 and
BitcastFloat64ToInt64 was using LE word ordering in memory,
causing failures on some tests.
BUG=mjsunit/regress/regress-599719,mjsunit/regress/regress-599717
Review-Url: https://codereview.chromium.org/2080213004
Cr-Commit-Position: refs/heads/master@{#37213}
Int64Mul is lowered to a new turbofan operator, Int32MulPair. The new
operator takes 4 inputs an generates 2 outputs. The inputs are the low
word of the left input, high word of the left input, the low word of the
right input, and high word of the right input. The ouputs are the low
and high word of the result of the multiplication.
R=titzer@chromium.org, v8-arm-ports@googlegroups.com
Review URL: https://codereview.chromium.org/1807273002
Cr-Commit-Position: refs/heads/master@{#35131}
The new implementation deals with cycles in the TF graph in two steps:
1) The lowering of phis is delayed to avoid cyclic dependencies.
2) The replacement nodes of phis are created already when the phi is
pushed onto the stack so that other nodes can use these replacements
for their lowering.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1844553002
Cr-Commit-Position: refs/heads/master@{#35126}
Int64Sub is lowered to a new turbofan operator, Int32SubPair. The new
operator takes 4 inputs an generates 2 outputs. The inputs are the low
word of the left input, high word of the left input, the low word of the
right input, and high word of the right input. The ouputs are the low
and high word of the result of the subtraction.
The implementation is very similar to the implementation of Int64Add.
@v8-arm-ports: please take a careful look at the implementation of sbc
in the simulator.
R=titzer@chromium.org, v8-arm-ports@googlegroups.com
Review URL: https://codereview.chromium.org/1778893005
Cr-Commit-Position: refs/heads/master@{#34808}
Word64Popcnt is lowered to Word32Popcnt(low-word) + Word32Popcnt(high_word).
Since the optional Word64Popcnt operator does not exist on 32 bit platforms,
I introduced a new operator "Word64PopcntPlaceholder" which is generated
in the WasmCompiler and then lowered in the Int64Lowering.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1803453003
Cr-Commit-Position: refs/heads/master@{#34777}
Int64Add is lowered to a new turbofan operator, Int32AddPair. The new
operator takes 4 inputs an generates 2 outputs. The inputs are the low
word of the left input, high word of the left input, the low word of the
right input, and high word of the right input. The ouputs are the low
and high word of the result of the addition.
R=titzer@chromium.org, v8-arm-ports@googlegroups.com
Review URL: https://codereview.chromium.org/1778493004
Cr-Commit-Position: refs/heads/master@{#34747}
I64Shl is lowered to a new turbofan operator, WasmWord64Shl. The new
operator takes 3 inputs, the low-word input, the high-word input, and
the shift, and produces 2 output, the low-word output and the high-word
output.
At the moment I implemented the lowering only for ia32, but I think the
CL is already big enough. I will add the other platforms in separate
CLs.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1756863002
Cr-Commit-Position: refs/heads/master@{#34546}
