sv_lab/2_vcs_comp/ReadMe.md

VCS编译加速：三步编译和分块编译

验证问题：有不同穿层信号时，模块的partition库能否reuse?

结论：当穿层信号变化时，受影响的模块不能reuse。

快速开始

第一次编译

make all GENLIB=1

第二次编译

make all GENLIB=0

运行结果

Top Level Modules:
       testbench
TimeScale is 1 ns / 1 ps

Note-[PC_SHARED] Reusing shared partition
  Reusing partition '_vcs_pc_package_' from shared library './partitionlib'.



Note-[PC_SHARED] Reusing shared partition
  Reusing partition 'uvm_pkg' from shared library './partitionlib'.



Note-[PC_SHARED] Reusing shared partition
  Reusing partition 'counter_a' from shared library './partitionlib'.



Warning-[PC_NOT_SHARED] Cannot reuse shared partition
  Cannot reuse partition 'counter_b' from shared library './partitionlib'

  There are additional signals that are now targets of hierarchical
  references.



Note-[PC_GEN_PARTITION] Generating partition
  Generating new partition 'counter_b' at
  './partitionlib_test2/counter_b_ipFRWc'.


Warning-[PC_NOT_SHARED] Cannot reuse shared partition
  Cannot reuse partition 'counter_c' from shared library './partitionlib'

  There are additional signals that are now targets of hierarchical
  references.



Note-[PC_GEN_PARTITION] Generating partition
  Generating new partition 'counter_c' at
  './partitionlib_test2/counter_c_chn5zb'.


Note-[PC_SHARED] Reusing shared partition
  Reusing partition 'top' from shared library './partitionlib'.



Warning-[PC_NOT_SHARED] Cannot reuse shared partition
  Cannot reuse partition 'TB.testbench' from shared library './partitionlib'

  Modified Design Units :
        TB.testbench : "./rtl/testbench.sv", 20
  Type of targets of hierarchical references in this partition have changed.



Note-[PC_RECOMPILE] Recompiling partition
  Recompiling partition 'TB.testbench' because of following changes.

  Modified Design Units :
        TB.testbench : "./rtl/testbench.sv", 20

检查log可以发现，穿层信号变化涉及到的模块counter_b、counter_c都无法reuse。

结论

序号	条件	现象	结论	备注
1	第一次：引用a.name； 第二次引用a.name/b.name/c.name；	b/c重编	不同的模块，增加的引用会重编
2	第一次：引用a.name；第二次引用a.age；	a重编	同一个模块，不同引用也会重编
3	第一次：引用a.name/a.age；第二次引用a.name；	a重编	同一个模块，减少引用也会重编
4	第一次：引用a.name；第二次引用a.name/a.age；	a重编	同一个模块，增加引用也会重编

⚠：只要模块的穿层引用发生变化，就会导致该模块重编。

✍官方文档VCSLCAFeatures.pdf第408页，也有类似表述：Any change in XMRs, trigger recompilation of the referee partition.