Commit Graph

6 Commits

Author SHA1 Message Date
Arthur Eubanks 6144fc2da1 [NewPM] Print pre-transformation IR name in --print-after-all
Sometimes a transformation can change the name of some IR (e.g. an SCC
with functions added/removed). This can be confusing when debug logging
doesn't match the post-transformation name. The specific example I came
across was that --print-after-all said the inliner was working on an SCC
that only contained one function, but calls in multiple functions were
getting inlined. After all inlining, the current SCC only contained one
function.

Piggyback off of the existing logic to handle invalidated IR +
--print-module-scope. Simply always store the IR description and use
that.

Reviewed By: jamieschmeiser

Differential Revision: https://reviews.llvm.org/D106290
2021-07-20 10:20:10 -07:00
Arthur Eubanks c8f0a7c215 [NewPM] Cleanup IR printing instrumentation
Being lazy with printing the banner seems hard to reason with, we should print it
unconditionally first (it could also lead to duplicate banners if we
have multiple functions in -filter-print-funcs).

The printIR() functions were doing too many things. I separated out the
call from PrintPassInstrumentation since we were essentially doing two
completely separate things in printIR() from different callers.

There were multiple ways to generate the name of some IR. That's all
been moved to getIRName(). The printing of the IR name was also
inconsistent, now it's always "IR Dump on $foo" where "$foo" is the
name. For a function, it's the function name. For a loop, it's what's
printed by Loop::print(), which is more detailed. For an SCC, it's the
list of functions in parentheses. For a module it's "[module]", to
differentiate between a possible SCC with a function called "module".

To preserve D74814, we have to check if we're going to print anything at
all first. This is unfortunate, but I would consider this a special
case that shouldn't be handled in the core logic.

Reviewed By: jamieschmeiser

Differential Revision: https://reviews.llvm.org/D100231
2021-04-15 09:50:55 -07:00
Atmn Patel 04a0896487 Revert "[LoopDeletion] Allows deletion of possibly infinite side-effect free loops"
This reverts commit 0b17c6e447. This patch
causes a compile-time error in SCEV.
2020-11-07 00:32:12 -05:00
Atmn Patel 0b17c6e447 [LoopDeletion] Allows deletion of possibly infinite side-effect free loops
From C11 and C++11 onwards, a forward-progress requirement has been
introduced for both languages. In the case of C, loops with non-constant
conditionals that do not have any observable side-effects (as defined by
6.8.5p6) can be assumed by the implementation to terminate, and in the
case of C++, this assumption extends to all functions. The clang
frontend will emit the `mustprogress` function attribute for C++
functions (D86233, D85393, D86841) and emit the loop metadata
`llvm.loop.mustprogress` for every loop in C11 or later that has a
non-constant conditional.

This patch modifies LoopDeletion so that only loops with
the `llvm.loop.mustprogress` metadata or loops contained in functions
that are required to make progress (`mustprogress` or `willreturn`) are
checked for observable side-effects. If these loops do not have an
observable side-effect, then we delete them.

Loops without observable side-effects that do not satisfy the above
conditions will not be deleted.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D86844
2020-11-06 22:06:58 -05:00
Fedor Sergeev 2d94c2265e [NewPM] -print-module-scope -print-after now prints module even after invalidated Loop/SCC
-print-after IR printing generally can not print the IR unit (Loop or SCC)
which has just been invalidated by the pass. However, when working in -print-module-scope
mode even if Loop was invalidated there is still a valid module that we can print.

Since we can not access invalidated IR unit from AfterPassInvalidated instrumentation
point we can remember the module to be printed *before* pass. This change introduces
BeforePass instrumentation that stores all the information required for module printing
into the stack and then after pass (in AfterPassInvalidated) just print whatever
has been placed on stack.

Reviewed By: philip.pfaffe
Differential Revision: https://reviews.llvm.org/D55278

llvm-svn: 349896
2018-12-21 11:49:05 +00:00
Fedor Sergeev a1d95c3fc4 [NewPM] fixing asserts on deleted loop in -print-after-all
IR-printing AfterPass instrumentation might be called on a loop
that has just been invalidated. We should skip printing it to
avoid spurious asserts.

Reviewed By: chandlerc, philip.pfaffe
Differential Revision: https://reviews.llvm.org/D54740

llvm-svn: 348887
2018-12-11 19:05:35 +00:00