RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-22 18:54:02 +01:00
Code Issues Projects Releases Wiki Activity
Mirror of https://github.com/RPCS3/llvm-mirror
216,555 Commits 4 Branches 5 Tags 704 MiB
C++ 96.9%
C 1%
Python 1%
CMake 0.6%
OCaml 0.2%
Other 0.1%
f98f660050
Go to file
Hyeongyu Kim f98f660050 [InstCombine] Fix miscompile on GEP+load to icmp fold (PR45210) 
As noted in PR45210: https://bugs.llvm.org/show_bug.cgi?id=45210
...the bug is triggered as Eli say when sext(idx) * ElementSize overflows.

```
   // assume that GV is an array of 4-byte elements
   GEP = gep GV, 0, Idx // this is accessing Idx * 4
   L = load GEP
   ICI = icmp eq L, value
 =>
   ICI = icmp eq Idx, NewIdx
```

The foldCmpLoadFromIndexedGlobal function simplifies GEP+load operation to icmp.
And there is a problem because Idx * ElementSize can overflow.

Let's assume that the wanted value is at offset 0.
Then, there are actually four possible values for Idx to match offset 0: 0x00..00, 0x40..00, 0x80..00, 0xC0..00.
We should return true for all these values, but currently, the new icmp only returns true for 0x00..00.

This problem can be solved by masking off (trailing zeros of ElementSize) bits from Idx.

```
   ...
 =>
   Idx' = and Idx, 0x3F..FF
   ICI = icmp eq Idx', NewIdx
```

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D99481
2021-05-31 14:08:20 +09:00
benchmarks
bindings [SanitizeCoverage] Add support for NoSanitizeCoverage function attribute 2021-05-25 12:57:14 +02:00
cmake Pass -gcodeview-ghash when using clang-cl and lld-link 2021-05-27 20:49:17 -07:00
docs Revert "[TargetLowering] Only inspect attributes in the arguments for ArgListEntry" 2021-05-29 23:08:15 -07:00
examples [ORC] Update SpeculativeJIT example for dispatchTask changes in 5344c88dcb2. 2021-05-10 09:30:46 -07:00
include [InstCombine] fix miscompile from vector select substitution 2021-05-30 07:11:58 -04:00
lib [InstCombine] Fix miscompile on GEP+load to icmp fold (PR45210) 2021-05-31 14:08:20 +09:00
projects llvmbuildectomy - replace llvm-build by plain cmake 2020-11-13 10:35:24 +01:00
resources
runtimes [runtimes] Add the libc project to the list of runtimes. 2021-03-23 17:33:03 +00:00
test [InstCombine] Fix miscompile on GEP+load to icmp fold (PR45210) 2021-05-31 14:08:20 +09:00
tools [MCA] Refactor the InOrderIssueStage stage. NFCI 2021-05-27 22:28:04 +01:00
unittests [VP] Make getMaskParamPos/getVectorLengthParamPos return unsigned. Lowercase function names. 2021-05-28 11:28:47 -07:00
utils [NFCI] Move DEBUG_TYPE definition below #includes 2021-05-30 17:31:01 +08:00
.clang-format
.clang-tidy - Update .clang-tidy to ignore parameters of main like functions for naming violations in clang and llvm directory 2020-01-31 16:49:45 +00:00
.gitattributes Fix the "git modified" issue on the preserve-comments-crlf.s. 2019-09-10 12:17:49 +00:00
.gitignore Remove .gitignore entries not relevant in the monorepo. 2021-04-07 12:25:02 -07:00
CMakeLists.txt [CMake] Don't LTO optimize targets that aren't part of any distribution 2021-05-19 15:02:11 -07:00
CODE_OWNERS.TXT [M68k][CODE_OWNERS](0/8) Add code owner for the M68k target 2021-03-08 12:30:56 -08:00
configure
CREDITS.TXT Update personal info in CREDITS.TXT 2021-04-11 19:25:02 +08:00
LICENSE.TXT Fix typos throughout the license files that somehow I and my reviewers 2019-01-21 09:52:34 +00:00
llvm.spec.in Update structured references to the license to the new license. 2019-01-19 11:30:51 +00:00
README.txt Test commit. 2020-03-14 18:08:26 -07:00
RELEASE_TESTERS.TXT

README.txt 

The LLVM Compiler Infrastructure
================================

This directory and its subdirectories contain source code for LLVM,
a toolkit for the construction of highly optimized compilers,
optimizers, and runtime environments.

LLVM is open source software. You may freely distribute it under the terms of
the license agreement found in LICENSE.txt.

Please see the documentation provided in docs/ for further
assistance with LLVM, and in particular docs/GettingStarted.rst for getting
started with LLVM and docs/README.txt for an overview of LLVM's
documentation setup.

If you are writing a package for LLVM, see docs/Packaging.rst for our
suggestions.