From 0c50a0b4fe3956f9d2e08e75d47c9cbd79bf0268 Mon Sep 17 00:00:00 2001 From: Rekai Gonzalez-Alberquilla Date: Mon, 6 Feb 2017 11:10:06 +0000 Subject: cpu: Fix the usage of const DynInstPtr Summary: Usage of const DynInstPtr& when possible and introduction of move operators to RefCountingPtr. In many places, scoped references to dynamic instructions do a copy of the DynInstPtr when a reference would do. This is detrimental to performance. On top of that, in case there is a need for reference tracking for debugging, the redundant copies make the process much more painful than it already is. Also, from the theoretical point of view, a function/method that defines a convenience name to access an instruction should not be considered an owner of the data, i.e., doing a copy and not a reference is not justified. On a related topic, C++11 introduces move semantics, and those are useful when, for example, there is a class modelling a HW structure that contains a list, and has a getHeadOfList function, to prevent doing a copy to an internal variable -> update pointer, remove from the list -> update pointer, return value making a copy to the assined variable -> update pointer, destroy the returned value -> update pointer. Change-Id: I3bb46c20ef23b6873b469fd22befb251ac44d2f6 Signed-off-by: Giacomo Gabrielli Reviewed-on: https://gem5-review.googlesource.com/c/13105 Reviewed-by: Andreas Sandberg Reviewed-by: Jason Lowe-Power Maintainer: Andreas Sandberg Maintainer: Jason Lowe-Power --- src/cpu/base_dyn_inst.hh | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'src/cpu/base_dyn_inst.hh') diff --git a/src/cpu/base_dyn_inst.hh b/src/cpu/base_dyn_inst.hh index 93cafd694..b4431da1f 100644 --- a/src/cpu/base_dyn_inst.hh +++ b/src/cpu/base_dyn_inst.hh @@ -827,7 +827,7 @@ class BaseDynInst : public ExecContext, public RefCounted /**Read the micro PC of this instruction. */ Addr microPC() const { return pc.microPC(); } - bool readPredicate() + bool readPredicate() const { return instFlags[Predicate]; } @@ -855,13 +855,13 @@ class BaseDynInst : public ExecContext, public RefCounted public: /** Returns whether or not the eff. addr. source registers are ready. */ - bool eaSrcsReady(); + bool eaSrcsReady() const; /** Is this instruction's memory access strictly ordered? */ bool strictlyOrdered() const { return instFlags[IsStrictlyOrdered]; } /** Has this instruction generated a memory request. */ - bool hasRequest() { return instFlags[ReqMade]; } + bool hasRequest() const { return instFlags[ReqMade]; } /** Returns iterator to this instruction in the list of all insts. */ ListIt &getInstListIt() { return instListIt; } -- cgit v1.2.3