fix(selectOldest): use === instead of isNotBefore

For instructions with vectors or other multiple `uop`, it is necessary to determine whether `robIdx` is the same before comparing `uopIdx`. Although there is no error if `isNotBefore` is used, we can use the clearer and more concise `===` to make the determination.
OpenXiangShan · Dec 9, 2024 · 049386d · 049386d
1 parent ddf3803
commit 049386d
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diff --git a/src/main/scala/xiangshan/mem/lsqueue/LoadExceptionBuffer.scala b/src/main/scala/xiangshan/mem/lsqueue/LoadExceptionBuffer.scala
@@ -81,7 +81,7 @@ class LqExceptionBuffer(implicit p: Parameters) extends XSModule with HasCircula
       }
       val oldest = Mux(valid(0) && valid(1),
         Mux(isAfter(bits(0).uop.robIdx, bits(1).uop.robIdx) ||
-          (isNotBefore(bits(0).uop.robIdx, bits(1).uop.robIdx) && bits(0).uop.uopIdx > bits(1).uop.uopIdx), res(1), res(0)),
+          (bits(0).uop.robIdx === bits(1).uop.robIdx && bits(0).uop.uopIdx > bits(1).uop.uopIdx), res(1), res(0)),
         Mux(valid(0) && !valid(1), res(0), res(1)))
       (Seq(oldest.valid), Seq(oldest.bits))
     } else {
@@ -95,7 +95,7 @@ class LqExceptionBuffer(implicit p: Parameters) extends XSModule with HasCircula
 
   when (req_valid) {
     req := Mux(
-      reqSel._1(0) && (isAfter(req.uop.robIdx, reqSel._2(0).uop.robIdx) || (isNotBefore(req.uop.robIdx, reqSel._2(0).uop.robIdx) && req.uop.uopIdx > reqSel._2(0).uop.uopIdx)),
+      reqSel._1(0) && (isAfter(req.uop.robIdx, reqSel._2(0).uop.robIdx) || (req.uop.robIdx === reqSel._2(0).uop.robIdx && req.uop.uopIdx > reqSel._2(0).uop.uopIdx)),
       reqSel._2(0),
       req)
   } .elsewhen (s2_enqueue.asUInt.orR) {

diff --git a/src/main/scala/xiangshan/mem/lsqueue/StoreQueue.scala b/src/main/scala/xiangshan/mem/lsqueue/StoreQueue.scala
@@ -123,7 +123,7 @@ class StoreExceptionBuffer(implicit p: Parameters) extends XSModule with HasCirc
       }
       val oldest = Mux(valid(0) && valid(1),
         Mux(isAfter(bits(0).uop.robIdx, bits(1).uop.robIdx) ||
-          (isNotBefore(bits(0).uop.robIdx, bits(1).uop.robIdx) && bits(0).uop.uopIdx > bits(1).uop.uopIdx), res(1), res(0)),
+          (bits(0).uop.robIdx === bits(1).uop.robIdx && bits(0).uop.uopIdx > bits(1).uop.uopIdx), res(1), res(0)),
         Mux(valid(0) && !valid(1), res(0), res(1)))
       (Seq(oldest.valid), Seq(oldest.bits))
     } else {