RFR: 8279057: Consolidate InstructionPrinter::do_BlockBegin and remove extra lines in logs of blocks with phi functions

[Yi Yang]

On Thu, 23 Dec 2021 01:11:08 GMT, Hamlin Li <mli at openjdk.org> wrote:

> This pr does following things:
>  - First, the code related to printing phi in InstructionPrinter::do_BlockBegin is bit redudant, it could be consolidated;
>  - Second, only locals and stack values related to phi functions are printed out now.
>  - Third, there are extra blank lines in printed log of blocks with phi functions, these blank lines are better to be removed.

src/hotspot/share/c1/c1_InstructionPrinter.cpp line 639:

> 637:       if (v && is_phi_of_block(v, x)) {
> 638:         if (!printed_phis_in_locals_header) {
> 639:           output()->cr(); output()->print("Values in locals related to phi functions:");

Can we keep this old style? i.e. "Locals:" and "Stacks:".

-------------

PR: https://git.openjdk.java.net/jdk/pull/6921