submodule(utility), transforms: collect XSLogs to SimTop.LogPerfEndpoint

[klin02]

XSLog depends on LogPerfCtrl declared at Top Module. Previous we annotate such signal as dontTouch, and accessed through Hierarchical name like SimTop.xx by dummy LogPerfHelper.

However, as XSLog is called in many spaces in DUT, which are not visible to each other, especailly some in WhenContext. XS will generate thousands of LogPerfHelper to get same LogPerfCtrl. Too many module instantiations greately slow down compilation speed, especailly in Palladium (more than 5 times slower than same DUT without Log).

This change collect all XSLog to SimTop.LogPerfEndpoint, with LogPerfCtrl directly passed by IO. Some tips as follows:

1. Not call XSLog inside whenContext. To collect XSLogs, we should access Cond and Data from other module, but data in WhenContext is not accessible even through tap. Use XSLog(cond, pable) instead of when(cond) {XSLog(pable)}. We also add chisel Internal API currentWhen to check that.

2. Generate Hierarchical Module path through FIRRTL transforms. Sometimes we want to append module path for better debugging. XSCompatibility add a hacky way to use Chisel internal API to get tag of current Module. Then we will replace these tag with path during ChiselStage. Note path can only be acessed after circuit elaboration.

3. Register and invoke caller of XSPerf and related object. As XSPerf depends on LogPerfCtrl such as dump. We should deferred apply() until collect. So we regirster collect() method when firstly apply XSLog, then XSLog will automatically call XSPerf.collect() method during collection. Note deferred apply is called in another module, so original module tag should be recorded for path generation.

4. Concat XSLogs with same condition. Too many fwrites in same module will cause UPOPTTHREADS warning with 16-threads Verilator. Consider many XSLogs have same condition (especailly XSPerfs), we reuse same condition and concat their printables to reduce fwrites. Note we also limit size of concatation to 1000 to avoid segmentation fault caused by too long printf.

[klin02]

Related Utility PR OpenXiangShan/Utility#89

[XiangShanRobot]

[Generated by IPC robot]
commit: 616f937

commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
616f937	1.821	0.441	2.636	1.224	2.154	2.143	2.363	0.945	1.405	1.985	3.109	2.561	2.274	3.307

master branch:

commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
0ed0e48
74fd4f5	1.821	0.441	2.636	1.224	2.154	2.143	2.363	0.945	1.394	1.985	3.109	2.561	2.274	3.307
22b25a0	1.821	0.441	2.636	1.224	2.154	2.143	2.363	0.945	1.405	1.985	3.109	2.561	2.274	3.307
99f369f	1.821			1.224	2.154	2.143		0.945		1.985	3.109		2.274	3.307
452b584	1.821			1.224	2.154	2.143		0.945		1.985	3.109		2.274	3.307