As Verilator continuously allocates and releases small objects (e.g.:
AstNode, V3GraphVertex, V3GraphEdge), it spends a significant amount of
time in malloc/free and friends. This patch adds the --enable-tcmalloc
configure option to link Verilator against the high performance malloc
implementation library libtcmalloc. The default is to use libtcmalloc if
available on the system. Note that there are no source code change, we
are simply replacing the standard library memory allocation functions.
Measured major compilation speed improvement of 27% when running
Verilator with -O3 on a large design.
dynamic_cast can have large run-time cost, so here we implement type
tests for AstNode instances by checking the unique type() property, which
in turn is a constant generated by astgen. For leaf types in the AstNode
type hierarchy, this is a simple equality check. To handle intermediate
types, we generate the type ids of leaf types in a pre-order traversal of
the type hierarchy. This yields contiguous ranges of ids for sub-type
trees, which means we can check membership of a non-leaf type via 2
comparisons against a low and high id. This single patch makes Verilator
itself 6-13% faster (depending on which optimizations are enabled) on a
large design of over 250k lines of Verilog.
The intention was that all subclasses of AstNode which are
intermediate must be abstract as well and called AstNode*. This was
violated recently by 28b9db1903. This
patch restores that property by:
- Renaming AstFile to AstNodeFile
- Introducing AstNodeSimpleText as the common base of AstText and
AstTextBlock, rather than AstTextBlock deriving from AstText.
* Add VL_OVERRIDE macro so that compiler can tell my typo when trying to override a function.
* Mark visit() with VL_OVERRIDE. No functional change intended.
* Add detailed location to XML output
* Fixing build failures
* less cryptic regulary expressions
* correcting typo in test
* Adding file letter to the location attribute, and cleaning up the regular expression in the tests.
* Add remaining test expected output files for XML changes
* spacing fix, adding documentation on changes
When running make with the "bear" command, the generated
compile_commands.json file shouldn't be considered new source. This file
allows clangd-based code completion tools (e.g. YouCompleteMe) to know
the flags that each file was compiled with.
* Add more directives to configuration files
Allow to set the same directives in configuration files that can also
be set by comment attributes (such as /* verilator public */ etc).
* Add support for lint messsage waivers
Add configuration file switch '-match' for lint_off. It takes a string
with wildcards allowed and warnings will be matched against it (if
rule and file also match). If it matches, the warning is waived.
Fixes#1649 and #1514Closes#2072
