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| author | Sanjay Patel <spatel@rotateright.com> | 2020-08-05 17:04:21 -0400 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2020-08-05 17:29:32 -0400 |
| commit | c66169136fe667d653ff40ba4bd9f6047702e93c (patch) | |
| tree | a41ae30926ee1293deacae145b6ddd8757fd4b06 /llvm/lib/Support/Compression.cpp | |
| parent | 0315571a19bb27da1b68088b07f1368747dd9438 (diff) | |
| download | llvm-c66169136fe667d653ff40ba4bd9f6047702e93c.zip llvm-c66169136fe667d653ff40ba4bd9f6047702e93c.tar.gz llvm-c66169136fe667d653ff40ba4bd9f6047702e93c.tar.bz2 | |
[InstCombine] fold icmp with 'mul nsw/nuw' and constant operands
This also removes a more specific fold that only handled icmp with 0.
https://rise4fun.com/Alive/sdM9
Name: mul nsw with icmp eq
Pre: (C1 != 0) && (C2 % C1) == 0
%a = mul nsw i8 %x, C1
%r = icmp eq i8 %a, C2
=>
%r = icmp eq i8 %x, C2 / C1
Name: mul nuw with icmp eq
Pre: (C1 != 0) && (C2 %u C1) == 0
%a = mul nuw i8 %x, C1
%r = icmp eq i8 %a, C2
=>
%r = icmp eq i8 %x, C2 /u C1
Name: mul nsw with icmp ne
Pre: (C1 != 0) && (C2 % C1) == 0
%a = mul nsw i8 %x, C1
%r = icmp ne i8 %a, C2
=>
%r = icmp ne i8 %x, C2 / C1
Name: mul nuw with icmp ne
Pre: (C1 != 0) && (C2 %u C1) == 0
%a = mul nuw i8 %x, C1
%r = icmp ne i8 %a, C2
=>
%r = icmp ne i8 %x, C2 /u C1
Diffstat (limited to 'llvm/lib/Support/Compression.cpp')
0 files changed, 0 insertions, 0 deletions