RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-11-29 22:30:33 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Know some simple identities. This improves codegen for (1LL << N).

Browse Source 
llvm-svn: 19698
This commit is contained in:
Chris Lattner 2005-01-19 17:29:49 +00:00
parent 6534e1ede3
commit 7114e8a527
1 changed files with 13 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
lib/CodeGen/SelectionDAG/SelectionDAG.cpp
View File

@ -615,6 +615,19 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
std::swap(N1, N2);
}
}
switch (Opcode) {
default: break;
case ISD::SHL: // shl 0, X -> 0
if (N1C->isNullValue()) return N1;
break;
case ISD::SRL: // srl 0, X -> 0
if (N1C->isNullValue()) return N1;
break;
case ISD::SRA: // sra -1, X -> -1
if (N1C->isAllOnesValue()) return N1;
break;
}
}
if (N2C) {