Revert removal of bit extraction const prop for literals (#857)

See https://github.com/freechipsproject/chisel3/issues/867 for future API discussion

1 files changed, 19 insertions, 0 deletions

diff --git a/src/test/scala/chiselTests/SIntOps.scala b/src/test/scala/chiselTests/SIntOps.scala
index 2c8267af..9309c915 100644
--- a/src/test/scala/chiselTests/SIntOps.scala
+++ b/src/test/scala/chiselTests/SIntOps.scala
@@ -83,6 +83,20 @@ class SIntOpsTester(c: SIntOps) extends Tester(c) {
 }
 */
 
+class SIntLitExtractTester extends BasicTester {
+  assert(-5.S(1) === true.B)
+  assert(-5.S(2) === false.B)
+  assert(-5.S(100) === true.B)
+  assert(-5.S(3, 0) === "b1011".U)
+  assert(-5.S(9, 0) === "b1111111011".U)
+  assert(-5.S(4.W)(1) === true.B)
+  assert(-5.S(4.W)(2) === false.B)
+  assert(-5.S(4.W)(100) === true.B)
+  assert(-5.S(4.W)(3, 0) === "b1011".U)
+  assert(-5.S(4.W)(9, 0) === "b1111111011".U)
+  stop()
+}
+
 class SIntOpsSpec extends ChiselPropSpec {
 
   property("SIntOps should elaborate") {
@@ -94,4 +108,9 @@ class SIntOpsSpec extends ChiselPropSpec {
   }
 
   ignore("SIntOpsTester should return the correct result") { }
+
+  property("Bit extraction on literals should work for all non-negative indices") {
+    assertTesterPasses(new SIntLitExtractTester)
+  }
+
 }