This patch introduces a new version for the basic block sections profile
as was requested in D158442, while keeping backward compatibility for
the old version.
The new encoding is as follows:
```
m <module_name>
f <function_name_1> <function_name_2>...
c <bb_id_1> <bb_id_2> <bb_id_3>
c <bb_id_4> <bb_id_5>
...
```
Module name specifier (starting with 'm') is optional and allows
distinguishing profiles for internal-linkage functions with the same
name. If not specified, profile will be applied to any function with the
same name.
Function name specifier (starting with 'f') can specify multiple
function name aliases.
Finally, basic block clusters are specified by 'c' and specify the
cluster of basic blocks, and the internal order in which they must be
placed in the same section.
Test updates were performed using:
https://gist.github.com/nikic/98357b71fd67756b0f064c9517b62a34
These are only the test updates where the test passed without
further modification (which is almost all of them, as the backend
is largely pointer-type agnostic).
Every basic block section symbol created by -fbasic-block-sections will contain
".__part." to know that this symbol corresponds to a basic block fragment of
the function.
This patch solves two problems:
a) Like D89617, we want function symbols with suffixes to be properly qualified
so that external tools like profile aggregators know exactly what this
symbol corresponds to.
b) The current basic block naming just adds a ".N" to the symbol name where N is
some integer. This collides with how clang creates __cxx_global_var_init.N.
clang creates these symbol names to call constructor functions and basic
block symbol naming should not use the same style.
Fixed all the test cases and added an extra test for __cxx_global_var_init
breakage.
Differential Revision: https://reviews.llvm.org/D93082
After using this for a while, we find that it is generally useful to
have it set to .text.split. by default, removing the need for an
additional -mllvm option.
Differential Revision: https://reviews.llvm.org/D88997
This patch changes the functionality of AsmPrinter to name the basic block end labels as LBB_END${i}_${j}, with ${i} being the identifier for the function and ${j} being the identifier for the basic block. The new naming scheme is consistent with how basic block labels are named (.LBB${i}_{j}), and how function end symbol are named (.Lfunc_end${i}) and helps to write stronger tests for the upcoming patch for BB-Info section (as proposed in https://lists.llvm.org/pipermail/llvm-dev/2020-July/143512.html). The end label is used with basicblock-labels (BB-Info section in future) and basicblock-sections to compute the size of basic blocks and basic block sections, respectively. For BB sections, the section containing the entry basic block will not have a BB end label since it already gets the function end-label.
This label is cached for every basic block (CachedEndMCSymbol) like the label for the basic block (CachedMCSymbol).
Differential Revision: https://reviews.llvm.org/D83885
D68049 created options for basic block sections: -fbasic-block-sections=,
-funique-basic-block-section-names. Rename options in llc and lld (--lto-)
to be consistent. Specifically,
+ Rename basicblock-sections to basic-block-sections
+ Rename unique-bb-section-names to unique-basic-block-section-names
Differential Revision: https://reviews.llvm.org/D84462
