Reorder the fields in ParameterBlock
This CL reorders the fields to group the hot fields together to increase data density. This CL doesn’t change functionality but expects to reduce cache misses and save CPU.
Change-Id: I313493a187ac6ebc607b311c39415c79a94f00c8
diff --git a/internal/ceres/parameter_block.h b/internal/ceres/parameter_block.h
index 96dd9de..65bb708 100644
--- a/internal/ceres/parameter_block.h
+++ b/internal/ceres/parameter_block.h
@@ -70,16 +70,16 @@
// The size is the size of the parameter block and the index is the position
// of the parameter block inside a Program (if any).
ParameterBlock(double* user_state, int size, int index)
- : user_state_(user_state),
- size_(size),
+ : size_(size),
state_(user_state),
- index_(index) {}
+ index_(index),
+ user_state_(user_state) {}
ParameterBlock(double* user_state, int size, int index, Manifold* manifold)
- : user_state_(user_state),
- size_(size),
+ : size_(size),
state_(user_state),
- index_(index) {
+ index_(index),
+ user_state_(user_state) {
if (manifold != nullptr) {
SetManifold(manifold);
}
@@ -339,11 +339,8 @@
return true;
}
- double* user_state_ = nullptr;
- int size_ = -1;
bool is_set_constant_ = false;
- Manifold* manifold_ = nullptr;
-
+ int size_ = -1;
// The "state" of the parameter. These fields are only needed while the
// solver is running. While at first glance using mutable is a bad idea, this
// ends up simplifying the internals of Ceres enough to justify the potential
@@ -351,18 +348,16 @@
mutable const double* state_ = nullptr;
mutable std::unique_ptr<double[]> plus_jacobian_;
- // The index of the parameter. This is used by various other parts of Ceres to
- // permit switching from a ParameterBlock* to an index in another array.
- int index_ = -1;
-
+ Manifold* manifold_ = nullptr;
// The offset of this parameter block inside a larger state vector.
int state_offset_ = -1;
// The offset of this parameter block inside a larger delta vector.
int delta_offset_ = -1;
- // If non-null, contains the residual blocks this parameter block is in.
- std::unique_ptr<ResidualBlockSet> residual_blocks_;
+ // The index of the parameter. This is used by various other parts of Ceres to
+ // permit switching from a ParameterBlock* to an index in another array.
+ int index_ = -1;
// Upper and lower bounds for the parameter block. SetUpperBound
// and SetLowerBound lazily initialize the upper_bounds_ and
@@ -378,6 +373,10 @@
std::unique_ptr<double[]> upper_bounds_;
std::unique_ptr<double[]> lower_bounds_;
+ // If non-null, contains the residual blocks this parameter block is in.
+ std::unique_ptr<ResidualBlockSet> residual_blocks_;
+ double* user_state_ = nullptr;
+
// Necessary so ProblemImpl can clean up the manifolds.
friend class ProblemImpl;
};
