[PATCH] D15244: [PassManager] Tuning Memory Usage of AnalysisUsage

[Philip Reames via llvm-commits]

reames added a comment.

Here's the raw data for a single O3 pass pipeline.  Each line is a unique instance of AnalysisUsage.
#Required #Transitive #Preserved #Used

0 0 0 0
0 0 0 0
0 0 0 0
1 0 0 0
2 0 1 0
2 0 17 0
4 0 17 0
1 0 0 0
1 0 0 0
2 0 0 0
0 0 0 0
4 0 18 0
1 0 0 6
2 0 0 0
0 0 0 0
2 0 1 0
2 0 0 0
1 0 1 0
1 0 0 0
4 0 1 0
3 0 1 0
3 0 17 0
3 0 1 0
2 0 17 0
4 0 17 0
2 0 2 0
1 0 1 0
1 0 1 0
0 0 17 0
5 0 9 0
1 0 0 0
3 0 9 0
2 0 21 0
1 0 0 0
6 0 23 0
6 0 6 0
5 0 20 0
4 4 0 0
8 0 9 0
5 0 6 0
7 0 6 0
2 0 18 0
5 0 2 0
3 2 0 0
5 0 18 0
1 0 1 0
1 0 17 0
2 0 16 0
4 0 19 0
11 0 5 0
2 0 0 0
4 0 0 0
6 0 18 0
3 0 19 0

Observations:
#Used is always (?) zero
#Required is < 8
#Transative is < 2
#Preserved is bimodal

Reasonable numbers appear to be:
Required: 8
Transitive: 2
Preserved: 2
Used: 0


http://reviews.llvm.org/D15244