Our first implementation passed the source position as argument to the
runtime function, which would then generate an Error object, patch the
contained stack trace to point to the position given as argument, and
then throw the Error.
Since all our paths are now changed to call a builtin with proper
source position information, we do not need to patch anything any more.

R=ahaas@chromium.org

Bug: v8:5007
Change-Id: I70dce1b9fcf9966a13865c1c373f3e354908b009
Reviewed-on: https://chromium-review.googlesource.com/732117Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48876}

Especially in wasm, many builtins don't actually need a context
parameter. We currently pass Smi::kZero instead. This CL allows to
generate a CallDescriptor for calling stubs without passing a context,
resulting in reduced compile time and code size, and increased
performance when executing these builtins.

We were calling the ThrowWasm* functions without passing a context
anyway (directly from code-generator-<arch>.h). With this change, we
will also call the StackCheck builtin without passing a (null) context.
This saves two bytes of code in each function plus each loop, and also
slightly reduces compile time (very noisy, but statistically
significant).

Drive-by: Use NoContextConstant instead of SmiConstant(Smi::kZero).

R=mstarzinger@chromium.org, ahaas@chromium.org

Change-Id: If794cc4c262a9cca8d29a68010803c01a2eef4a3
Reviewed-on: https://chromium-review.googlesource.com/541423Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46044}

This is in preparation for linking the former only into mksnapshot.
Just shuffling code around, no changes in functionality.

BUG=v8:6055

Review-Url: https://codereview.chromium.org/2752143004
Cr-Commit-Position: refs/heads/master@{#43858}

BUG=v8:5294

Change-Id: If45f25aae8de526027b7851cb4efe0ccf4a7c4b1
Reviewed-on: https://chromium-review.googlesource.com/444226
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43388}

With this CL the out-of-line code of TrapIf will call a builtin instead
of doing a direct runtime call, which is cheaper. In the best case, the
out-of-line code now consists of a single call instruction. The builtin
will load the trapID and then call the runtime to throw a trap.

R=titzer@chromium.org, clemensh@chromium.org

Change-Id: I8a75ba09f40236a3d5cbdc17c1317baf0a3c915a
Reviewed-on: https://chromium-review.googlesource.com/445937
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43366}

Instead of placing a runtime call to StackGuard in the compiled wasm
code, we just call the builtin, which is cheaper. By passing Smi::kZero
as context, we save even more code space and avoid embedding the
context in the code.
The WasmStackGuard builtin then calls the new WasmStackGuard runtime
function, which gets the context from the instance attached to the
calling wasm code, and then does the usual StackGuard logic.

For the unity benchmark in asm-wasm mode, generated code size reduces
from 63.0 to 61.6 MB (-2.1%).

R=titzer@chromium.org, ahaas@chromium.org, mstarzinger@chromium.org

Review-Url: https://codereview.chromium.org/2691993004
Cr-Commit-Position: refs/heads/master@{#43277}