llvm /
llvm /
2d7ed2481d6c65bf20983414d1fbcf8d3a021bab Teach the DAGCombine to fold this pattern(c1 and c2 is constant).
// fold (sext (select cond, c1, c2)) -> (select cond, sext c1, sext c2)
// fold (zext (select cond, c1, c2)) -> (select cond, zext c1, zext c2)
// fold (aext (select cond, c1, c2)) -> (select cond, sext c1, sext c2)
Sign extend the operands if it is any_extend, to keep the signess of the operands that, the other combine rule would apply. The any_extend is handled as zero extend for constants. i.e.
t1: i8 = select t0, Constant:i8<-1>, Constant:i8<0>
t2: i64 = any_extend t1
-->
t3: i64 = select t0, Constant:i64<-1>, Constant:i64<0>
-->
t4: i64 = sign_extend_inreg t3
Differential Revision: https://reviews.llvm.org/D63318
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364382 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed