[llvm-bugs] [Bug 40493] New: Fold "(12 * unsigned) % 8 == 0" ->"(unsigned & 1) == 0" missing

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=40493

            Bug ID: 40493
           Summary: Fold "(12 * unsigned) % 8 == 0" ->"(unsigned & 1) ==
                    0" missing
           Product: libraries
           Version: trunk
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: Scalar Optimizations
          Assignee: unassignedbugs at nondot.org
          Reporter: lebedev.ri at gmail.com
                CC: llvm-bugs at lists.llvm.org

Not sure how general this can be though.

https://godbolt.org/z/9bNnlb

https://rise4fun.com/Alive/O8a

  %mul = mul i32 %area, 12
  %rem = and i32 %mul, 4
  %cmp = icmp eq i32 %rem, 0
=>
  %and = and i32 %area, 1
  %cmp = icmp eq i32 %and, 0

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