Juneyoung Lee 0441df94ad [InstCombine,InstSimplify] Optimize select followed by and/or/xor ...

This patch adds `A & (A && B)` -> `A && B`  (similarly for or + logical or)

Also, this patch adds `~(select C, (icmp pred X, Y), const)` -> `select C, (icmp pred' X, Y), ~const`.

Alive2 proof:
merge_and: https://alive2.llvm.org/ce/z/teMR97
merge_or: https://alive2.llvm.org/ce/z/b4yZUp
xor_and: https://alive2.llvm.org/ce/z/_-TXHi
xor_or: https://alive2.llvm.org/ce/z/2uYx_a

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D94861

2021-01-19 09:14:17 +09:00

227 KiB

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