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package scala.tools.nsc
package backend.jvm
package opt
import org.junit.Assert._
import org.junit.Test
import org.junit.runner.RunWith
import org.junit.runners.JUnit4
import scala.tools.asm.tree.analysis._
import scala.tools.nsc.backend.jvm.analysis.{AliasingAnalyzer, AliasingFrame}
import scala.tools.nsc.backend.jvm.opt.BytecodeUtils._
import scala.tools.testing.BytecodeTesting
import scala.tools.testing.BytecodeTesting._
@RunWith(classOf[JUnit4])
class AnalyzerTest extends BytecodeTesting {
override def compilerArgs = "-Yopt:l:none"
import compiler._
@Test
def aliasingOfPrimitives(): Unit = {
val code =
"""class C {
| def f(a: Int, b: Long) = {
| val c = a - b // a is converted with i2l
| val d = c
| val e = a
| // locals: 0 this -- 1 a -- 2-3 b -- 4-5 c -- 6-7 d -- 8 e
| e + d // e is converted with i2l
| }
|}
""".stripMargin
val c = compileClass(code)
val a = new AliasingAnalyzer(new BasicInterpreter)
val f = getAsmMethod(c, "f")
a.analyze("C", f)
val List(_, i2l) = findInstrs(f, "I2L")
val aliasesAtI2l = a.frameAt(i2l, f).asInstanceOf[AliasingFrame[_]].aliases
assertEquals(aliasesAtI2l(1).iterator.toList, List(1, 8, 9)) // a, e and stack top
assertEquals(aliasesAtI2l(4).iterator.toList, List(4, 6))
val add = findInstr(f, "LADD")
val aliasesAtAdd = a.frameAt(add, f).asInstanceOf[AliasingFrame[_]].aliases
assertEquals(aliasesAtAdd(1).iterator.toList, List(1, 8)) // after i2l the value on the stack is no longer an alias
assertEquals(aliasesAtAdd(4).iterator.toList, List(4, 6, 10)) // c, d and stack top
}
}
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