[LoongArch] Pre-commit test for bstrins optimization

llvm/test/CodeGen/LoongArch/ir-instruction/and.ll

; LA64-NEXT:    ret
   %e = and i64 %b, 65520
   %f = and i64 %c, 65520
   %g = sub i64 %d, %e
   %h = mul i64 %e, %f
   %i = xor i64 %g, %h
   ret i64 %i
 }
 
+;; TODO: this can be codegened to bstrins.[wd] $a0, $zero, 23, 16.
+define i64 @and_i64_0xffffffffff00ffff(i64 %a) {
+; LA32-LABEL: and_i64_0xffffffffff00ffff:
+; LA32:       # %bb.0:
+; LA32-NEXT:    lu12i.w $a2, -4081
+; LA32-NEXT:    ori $a2, $a2, 4095
+; LA32-NEXT:    and $a0, $a0, $a2
+; LA32-NEXT:    ret
+;
+; LA64-LABEL: and_i64_0xffffffffff00ffff:
+; LA64:       # %bb.0:
+; LA64-NEXT:    lu12i.w $a1, -4081
+; LA64-NEXT:    ori $a1, $a1, 4095
+; LA64-NEXT:    and $a0, $a0, $a1
+; LA64-NEXT:    ret
+  %b = and i64 %a, 18446744073692839935
+  ret i64 %b
+}
+
 define i32 @and_add_lsr(i32 %x, i32 %y) {
 ; LA32-LABEL: and_add_lsr:
 ; LA32:       # %bb.0:
 ; LA32-NEXT:    addi.w $a0, $a0, -1
 ; LA32-NEXT:    srli.w $a1, $a1, 20
 ; LA32-NEXT:    and $a0, $a1, $a0
 ; LA32-NEXT:    ret
 ;