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| author | Roman Lebedev <lebedev.ri@gmail.com> | 2020-01-03 16:14:29 +0300 |
|---|---|---|
| committer | Roman Lebedev <lebedev.ri@gmail.com> | 2020-01-03 17:55:47 +0300 |
| commit | 0727e2b90c7b11d5c6be55919c443628d8e2bc6e (patch) | |
| tree | 515030ecd57c6e08b3990d9c826a84b9658a20e4 /clang/unittests/Format/FormatTestJava.cpp | |
| parent | 473deaf34bc942f4ff50d4363e47ddcb510b56e0 (diff) | |
| download | llvm-0727e2b90c7b11d5c6be55919c443628d8e2bc6e.zip llvm-0727e2b90c7b11d5c6be55919c443628d8e2bc6e.tar.gz llvm-0727e2b90c7b11d5c6be55919c443628d8e2bc6e.tar.bz2 | |
[DAGCombiner][X86][AArch64] Generalize `A-(A&B)`->`A&(~B)` fold (PR44448)
The fold 'A - (A & (B - 1))' -> 'A & (0 - B)'
added in 8dab0a4a7d691f2704f1079538e0ef29548db159
is too specific. It should/can just be 'A - (A & B)' -> 'A & (~B)'
Even if we don't manage to fold `~` into B,
we have likely formed `ANDN` node.
Also, this way there's less similar-but-duplicate folds.
Name: X - (X & Y) -> X & (~Y)
%o = and i32 %X, %Y
%r = sub i32 %X, %o
=>
%n = xor i32 %Y, -1
%r = and i32 %X, %n
https://rise4fun.com/Alive/kOUl
See
https://bugs.llvm.org/show_bug.cgi?id=44448
https://reviews.llvm.org/D71499
Diffstat (limited to 'clang/unittests/Format/FormatTestJava.cpp')
0 files changed, 0 insertions, 0 deletions