7be64db45f
This is a reland of cf93071c91
Original change's description:
> [interpreter] Short Star bytecode
>
> Design doc:
> https://docs.google.com/document/d/1g_NExMT78II_KnIYNa9MvyPYIj23qAiFUEsyemY5KRk/edit
>
> This change adds 16 new interpreter opcodes, kStar0 through kStar15, so
> that we can use a single byte to represent the common operation of
> storing to a low-numbered register. This generally reduces the quantity
> of bytecode generated on web sites by 8-9%.
>
> In order to not degrade speed, a couple of other changes are required:
>
> The existing lookahead logic to check for Star after certain other
> bytecode handlers is updated to check for these new short Star codes
> instead. Furthermore, that lookahead logic is updated to contain its own
> copy of the dispatch jump rather than merging control flow with the
> lookahead-failed case, to improve branch prediction.
>
> A bunch of constants use bytecode size in bytes as a proxy for the size
> or complexity of a function, and are adjusted downward proportionally to
> the decrease in generated bytecode size.
>
> Other small drive-by fix: update generate-bytecode-expectations to emit
> \n instead of \r\n on Windows.
>
> Change-Id: I6307c2b0f5794a3a1088bb0fb94f6e1615441ed5
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2641180
> Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
> Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#72773}
Change-Id: I1afb670c25694498b3989de615858f984a8c7f6f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2698057
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72821}
63 lines
964 B
Plaintext
63 lines
964 B
Plaintext
#
|
|
# Autogenerated by generate-bytecode-expectations.
|
|
#
|
|
|
|
---
|
|
wrap: yes
|
|
|
|
---
|
|
snippet: "
|
|
throw 1;
|
|
"
|
|
frame size: 0
|
|
parameter count: 1
|
|
bytecode array length: 3
|
|
bytecodes: [
|
|
/* 34 S> */ B(LdaSmi), I8(1),
|
|
/* 34 E> */ B(Throw),
|
|
]
|
|
constant pool: [
|
|
]
|
|
handlers: [
|
|
]
|
|
|
|
---
|
|
snippet: "
|
|
throw 'Error';
|
|
"
|
|
frame size: 0
|
|
parameter count: 1
|
|
bytecode array length: 3
|
|
bytecodes: [
|
|
/* 34 S> */ B(LdaConstant), U8(0),
|
|
/* 34 E> */ B(Throw),
|
|
]
|
|
constant pool: [
|
|
ONE_BYTE_INTERNALIZED_STRING_TYPE ["Error"],
|
|
]
|
|
handlers: [
|
|
]
|
|
|
|
---
|
|
snippet: "
|
|
var a = 1; if (a) { throw 'Error'; };
|
|
"
|
|
frame size: 1
|
|
parameter count: 1
|
|
bytecode array length: 10
|
|
bytecodes: [
|
|
/* 42 S> */ B(LdaSmi), I8(1),
|
|
B(Star0),
|
|
/* 45 S> */ B(JumpIfToBooleanFalse), U8(5),
|
|
/* 54 S> */ B(LdaConstant), U8(0),
|
|
/* 54 E> */ B(Throw),
|
|
B(LdaUndefined),
|
|
/* 72 S> */ B(Return),
|
|
]
|
|
constant pool: [
|
|
ONE_BYTE_INTERNALIZED_STRING_TYPE ["Error"],
|
|
]
|
|
handlers: [
|
|
]
|
|
|