Improve verilator compilation speed

by asking verilator to split the C++ model into multiple files.

diff --git a/litex/build/sim/core/Makefile b/litex/build/sim/core/Makefile
index 5615fe3d3a603078e8483e42498cfb29603f0351..f14398248a6ec8bdd18db1bc839e81aab74decc9 100644 (file)
--- a/litex/build/sim/core/Makefile
+++ b/litex/build/sim/core/Makefile
@@ -45,6 +45,9 @@ sim: $(OBJS_SIM) | mkdir
                $(if $(TRACE_FST), --trace-fst,) \
                $(if $(COVERAGE), --coverage,) \
                --unroll-count 256 \
+               --output-split 5000 \
+               --output-split-cfuncs 500 \
+               --output-split-ctrace 500 \
                $(INC_DIR) \
                -Wno-BLKANDNBLK \
                -Wno-WIDTH