For deferred commands (such as in try-finally), some deferred commands
save and restore the accumulator using a result register (e.g. return,
throw, rethrow), while others don't (e.g. break, continue,
fall-through).
However, conditionally reading this result register that may not ever be
written caused it to be considered live from the start of the function,
as far as the liveness analysis could statically tell.
Now, we write the result register for all deferred commands, including
the fall-through. As a micro-optimization, we re-use the Smi command
tokeen to clobber the result, rather than emitting an LdaUndefined.
Bug: chromium:758472
Change-Id: I2ea65e2249b40ee6403216e654a8bb88d50bec3b
Reviewed-on: https://chromium-review.googlesource.com/635592
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47612}
Rather than trying to pre-calculate the number of contexts required during
scope analysis, instead just allocate context registers in the register
allocator. This reduces frame size a bit due to reusing of registers when
the context isn't pushed.
BUG=v8:6322, chromium:716265
Change-Id: I145e38fcb3797a3b86c91e90ea9326a6e55b9b89
Reviewed-on: https://chromium-review.googlesource.com/514087
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45522}
For a single deferred commands, using a jump table is overkill, so
instead simply test the token against the single entry.
Bug: v8:4280
Bug: v8:6218
Change-Id: I0300f640080705fb10f46ad4ed5791703fa4dd77
Reviewed-on: https://chromium-review.googlesource.com/506153
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45393}
Some of the StrictEquality comparisons do not require feedback (for ex: in
try-finally, generators). This cl introduces StrictEqualityNoFeedback bytecode
to be used in such cases. With this change, we no longer have to check if the
type feedback slot is valid in compare bytecode handlers.
This is the first step in reworking the compare bytecode handler to avoid
duplicate checks when collecting feedback and when performing the operation.
BUG=v8:4280
Change-Id: Ia650fd43c0466b8625d3ce98c39ed1073ba42a6b
Reviewed-on: https://chromium-review.googlesource.com/455778
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44020}
Adds a bytecode to set and retrieve the pending message. This avoids a
runtime call in finally blocks, and also ensures that TurboFan builds a
graph using the SetMessage / LoadMessage nodes instead of inserting a
runtime call.
BUG=chromium:662334
Review-Url: https://codereview.chromium.org/2501503005
Cr-Commit-Position: refs/heads/master@{#41023}
For historical reasons, the interpreter's bytecode expectations tests
required a type for the constant pool. This had two disadvantages:
1. Strings and numbers were not visible in mixed pools, and
2. Mismatches of pool types (e.g. when rebaselining) would cause parser
errors
This removes the pool types, making everything 'mixed', but appending
the values to string and number valued constants. Specifying a pool type
in the *.golden header now prints a warning (for backwards compatibility).
BUG=v8:5350
Review-Url: https://codereview.chromium.org/2310103002
Cr-Commit-Position: refs/heads/master@{#39216}
Since the extension field is already used for the catch name, store a
ContextExtension there instead.
In the future, this will allow for chaining ScopeInfos together, so we
no longer need a context chain for lazy parsing / compilation.
BUG=v8:5215
R=bmeurer@chromium.org,neis@chromium.org,marja@chromium.org
Review-Url: https://codereview.chromium.org/2302013002
Cr-Commit-Position: refs/heads/master@{#39164}
One more bytecode to pass info through to TurboFan.
BUG=v8:4280
LOG=n
Review-Url: https://codereview.chromium.org/2260473003
Cr-Commit-Position: refs/heads/master@{#38726}
With this change the bytecode array builder only emits expression
positions for bytecodes that can throw. This allows more peephole
optimization opportunities and results in smaller code.
BUG=v8:4280,chromium:615979
LOG=N
Review-Url: https://codereview.chromium.org/2038323002
Cr-Commit-Position: refs/heads/master@{#36863}
Prints source position information alongside bytecode.
BUG=v8:4280
LOG=N
Review-Url: https://codereview.chromium.org/1963663002
Cr-Commit-Position: refs/heads/master@{#36171}
This change introduces wide prefix bytecodes to support wide (16-bit)
and extra-wide (32-bit) operands. It retires the previous
wide-bytecodes and reduces the number of operand types.
Operands are now either scalable or fixed size. Scalable operands
increase in width when a bytecode is prefixed with wide or extra-wide.
The bytecode handler table is extended to 256*3 entries. The
first 256 entries are used for bytecodes with 8-bit operands,
the second 256 entries are used for bytecodes with operands that
scale to 16-bits, and the third group of 256 entries are used for
bytecodes with operands that scale to 32-bits.
LOG=N
BUG=v8:4747,v8:4280
Review URL: https://codereview.chromium.org/1783483002
Cr-Commit-Position: refs/heads/master@{#34955}
Bytecode expectations have been moved to external (.golden) files,
one per test. Each test in the suite builds a representation of the
the compiled bytecode using BytecodeExpectationsPrinter. The output is
then compared to the golden file. If the comparision fails, a textual
diff can be used to identify the discrepancies.
Only the test snippets are left in the cc file, which also allows to
make it more compact and meaningful. Leaving the snippets in the cc
file was a deliberate choice to allow keeping the "truth" about the
tests in the cc file, which will rarely change, as opposed to golden
files.
Golden files can be generated and kept up to date using
generate-bytecode-expectations, which also means that the test suite
can be batch updated whenever the bytecode or golden format changes.
The golden format has been slightly amended (no more comments about
`void*`, add size of the bytecode array) following the consideration
made while converting the tests.
There is also a fix: BytecodeExpectationsPrinter::top_level_ was left
uninitialized, leading to undefined behaviour.
BUG=v8:4280
LOG=N
Review URL: https://codereview.chromium.org/1717293002
Cr-Commit-Position: refs/heads/master@{#34285}
