Commit Graph

5 Commits

Author SHA1 Message Date
Danila Kutenin 19e83a9b4c [ValueTracking] Pointer is known nonnull after load/store
If the pointer was loaded/stored before the null check, the check
is redundant and can be removed. For now the optimizers do not
remove the nullptr check, see https://gcc.godbolt.org/z/H2r5GG.
The patch allows to use more nonnull constraints. Also, it found
one more optimization in some PowerPC test. This is my first llvm
review, I am free to any comments.

Differential Revision: https://reviews.llvm.org/D71177
2019-12-11 20:32:29 +01:00
Danila Kutenin fc765698e0 [ValueTracking] Add tests for non-null check after load/store; NFC
Tests for D71177.
2019-12-11 20:26:31 +01:00
Piotr Padlewski d6f7346a4b Fix aliasing of launder.invariant.group
Summary:
Patch for capture tracking broke
bootstrap of clang with -fstict-vtable-pointers
which resulted in debbugging nightmare. It was fixed
https://reviews.llvm.org/D46900 but as it turned
out, there were other parts like inliner (computing of
noalias metadata) that I found after bootstraping with enabled
assertions.

Reviewers: hfinkel, rsmith, chandlerc, amharc, kuhar

Subscribers: JDevlieghere, eraman, llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D47088

llvm-svn: 333070
2018-05-23 09:16:44 +00:00
Sanjay Patel 97e4b98749 [ValueTracking] use nonnull argument attribute to eliminate null checks
Enhancing value tracking's analysis of null-ness was suggested in D27855, so here's a first attempt at that.

This is part of solving:
https://llvm.org/bugs/show_bug.cgi?id=28430

Differential Revision: https://reviews.llvm.org/D28204

llvm-svn: 294897
2017-02-12 15:35:34 +00:00
Sanjay Patel 5865d12e9f [ValueTracking] add tests for known-nonnull-at; NFC
llvm-svn: 290790
2016-12-31 19:23:26 +00:00