Graphics Reference
In-Depth Information
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Hot fields
Cold fields
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[1]
[1]
[2]
[2]
Figure 13.2
Given an array of three structure instances (with frequently accessed “hot” fields
in light gray), hot/cold splitting rearranges the data so that cold fields are stored separately
and the array structure only contains hot fields (plus a link to where the cold fields are located).
for(inti=0;i<1000; i++)
if (elem[i].value > elem[index].value) index = i;
// Increment the count field of that element
elem[index].count++;
If this search is the predominant operation on this array of structures, it would
make sense to split the structure
S
into a hot part (
S1
) and a cold part (
S2
) and rewrite
the code as follows:
// Hot fields of S
struct S1 {
int32 value;
} elem1[1000];
// Cold fields of S
struct S2 {
int32 count;
...
} elem2[1000];
// Find the index of the element with largest value
int index = 0;
for(inti=0;i<1000; i++)
if (elem1[i].value > elem1[index].value) index = i;
