We know that `undefined` in the global scope is always the proper
undefined value. This commit takes advantage of that by simply emitting
a constant undefined value instead.
Unfortunately we can't be so sure in other scopes.
This helps some of the Cloudflare Turnstile stuff run faster, since they
are deliberately screwing with JS engines by asking us to do a bunch of
bitwise operations on e.g 65535.56
By rounding such values in bytecode generation, the interpreter can stay
on the happy path while executing, and finish quite a bit faster.
We now fuse sequences like [LessThan, JumpIf] to JumpLessThan.
This is only allowed for temporaries (i.e VM registers) with no other
references to them.
Specify the time in seconds to wait for a reply for each packet sent.
Replies received out of order will not be printed as replied but they
will be considered as replied when calculating statistics. Setting it
to 0 means infinite timeout.
In flood ping mode, the time interval between each request is set
to zero to provide a rapid display of how many packets are being
dropped. For each request a period '.' is printed, while for every
reply a backspace is printed.
Before this change, switch codegen would interleave bytecode like this:
(test for case 1)
(code for case 1)
(test for case 2)
(code for case 2)
This meant that we often had to make many large jumps while looking for
the matching case, since code for each case can be huge.
It now looks like this instead:
(test for case 1)
(test for case 2)
(code for case 1)
(code for case 2)
This way, we can just fall through the tests until we hit one that fits,
without having to make any large jumps.
This removes a layer of indirection in the bytecode where we had to make
sure all the initializer elements were laid out in sequential registers.
Array expressions no longer clobber registers permanently, and they can
be reused immediately afterwards.
This patch adds a register freelist to Bytecode::Generator and switches
all operands inside the generator to a new ScopedOperand type that is
ref-counted and automatically frees the register when nothing uses it.
This dramatically reduces the size of bytecode executable register
windows, which were often in the several thousands of registers for
large functions. Most functions now use less than 100 registers.
The first block in every executable will always execute first, so if it
ends up doing a ResolveThisBinding, it's fine for all other blocks
within the same executable to use the same `this` value.
In the common case, parseInt() is being called with strings that don't
have leading whitespace. By checking for that first, we can avoid the
cost of trimming and multiple malloc/GC allocations.
Once executed, this instruction will always produce the same result
in subsequent executions, so it's okay to cache it.
Unfortunately it may throw, so we can't just hoist it to the top of
every executable, since that would break observable execution order.
Two bugs:
1. Correctly set bits in VP8X header.
Turns out these were set in the wrong order.
2. Correctly set the `has_alpha` flag.
Also add a test for writing webp files with icc data. With the
additional checks in other commits in this PR, this test catches
the bug in WebPWriter.
Rearrange some existing functions to make it easier to write this test:
* Extract encode_bitmap() from get_roundtrip_bitmap().
encode_bitmap() allows passing extra_args that the test uses to pass
in ICC data.
* Extract expect_bitmaps_equal() from test_roundtrip()
If this turns out to be too strict in practice, we can replace it with
a `dbgln("VP8X and VP8L headers disagree about alpha; ignoring VP8X");`
instead.
ALso update catdog-alert-13-alpha-used-false.webp to not trigger this.
I had manually changed the VP8L alpha flag at offset 0x2a in
da48238fbd to clear it, but I hadn't changed the VP8X flag.
This changes the byte at offset 0x14 from 0x10 (has_alpha) to 0x00
(no alpha) as well, to match.
If this turns out to be too strict in practice, we can replace it with
a dbgln() with the same message, but with with ", ignoring header."
tacked on at the end.
The stream passed to LineProgram::create is a temporary, so rather than
keeping an (unused) dangling reference, pass this stream explicitly to
all functions used by LineProgram::create.
