The call sequence is very similar to a classic IC call, except the guarded class and the target are loaded indirectly from the constant pool instead of as immediates. In the monomorphic case, we call directly to the expected target with a class check in the callee. In the unlinked, polymorphic and megamorphic cases, we call a stub; these case are now call-through instead of call-and-return.
Every code, except stubs involved in switchable calls, includes the class check sequence at the beginning. So we now distinguish between a checked and an unchecked entry point. Generated code except the switchable call continues to use the unchecked entry point.
PC offsets are calculated relative to the beginning of the instruction stream, rather than either entry point.
BUG=
R=fschneider@google.com
Review URL: https://codereview.chromium.org/2226893002 .
When setting a breakpoint at a fast Smi op, replace the fast Smi op instruction with a Nop so we don't skip the following DebugBreak in the Smi case and don't attempt to increment an ICData counter through pool slot 0.
R=zra@google.com
Review URL: https://codereview.chromium.org/2194493002 .
Zachary Anderson