synthesis: allow blackboxing macros

[oharboe]

If a macro is specified in ADDITIONAL_LEFS/LIBS and it is also present in the Verilog files, use MACROS to list those macros so as to have the module be marked as blackbox.

A Verilog file can contain more than one module, so it isn't always convenient to exclude a .v/sv file to have a module marked as black box.

[oharboe]

@maliberty unrelated errors

[maliberty]

If a Liberty and a Verilog for a module are both present, which wins? It seems like the Liberty should which would render this unneeded.

[oharboe]

If a Liberty and a Verilog for a module are both present, which wins? It seems like the Liberty should which would render this unneeded.

Makes sense.

However, that doesn't cover the case where SYNTH_ARGS=-flatten (default).

[maliberty]

However, that doesn't cover the case where SYNTH_ARGS=-flatten (default).

If the Liberty wins then it should appear in the flat netlist not the contents of the .v (certainly both shouldn't appear).

[oharboe]

However, that doesn't cover the case where SYNTH_ARGS=-flatten (default).

If the Liberty wins then it should appear in the flat netlist not the contents of the .v (certainly both shouldn't appear).

Synthesis doesn't load ADDITIONAL_LIBS, nor LEFS, so how can it "win" without having loaded the .lib file?

[maliberty]

Synthesis doesn't load ADDITIONAL_LIBS, nor LEFS, so how can it "win" without having loaded the .lib file?

Why do you think ADDITIONAL_LIBS isn't used? LEFs are not relevant to synthesis.

asap7 config.mk:

export LIB_FILES             += $(ADDITIONAL_LIBS)

Makefile:

export DONT_USE_LIBS   = $(patsubst %.lib.gz, %.lib, $(addprefix $(OBJECTS_DIR)/lib/, $(notdir $(LIB_FILES))))

synth_preamble.tcl:

read_liberty -lib {*}$::env(DONT_USE_LIBS)

[oharboe]

@maliberty I tried introducing a syntax error to track down where ADDITIONAL_LIBS were loaded and I couldn't find them.

Perhaps that is just a false negative too?

https://github.com/The-OpenROAD-Project/OpenROAD/issues/5217

[maliberty]

https://github.com/The-OpenROAD-Project/OpenROAD/issues/5217 relates to LEF not Liberty

[oharboe]

The-OpenROAD-Project/OpenROAD#5217 relates to LEF not Liberty

Yes, but similarly, I created a syntax error in .lib and had no error in synthesis. I will see about creating a standalone testcase.

[oharboe]

@maliberty unrelated error in CI