Bug 17707 - [4.0 Regression] O(N^2) in cgraph_reset_static_var_maps
Summary: [4.0 Regression] O(N^2) in cgraph_reset_static_var_maps
Status: RESOLVED FIXED
Alias: None
Product: gcc
Classification: Unclassified
Component: tree-optimization (show other bugs)
Version: 4.0.0
: P2 normal
Target Milestone: 4.0.0
Assignee: Not yet assigned to anyone
URL:
Keywords: compile-time-hog
Depends on:
Blocks: 15678 17278
  Show dependency tree / graph
 
Reported: 2004-09-28 08:06 UTC by Serge Belyshev
Modified: 2004-10-25 23:22 UTC (History)
2 users (show)

See Also:
Host:
Target:
Build:
Known to work:
Known to fail:
Last reconfirmed: 2004-09-28 11:37:05

Attachments
Add an attachment (proposed patch, testcase, etc.)

Note You need to log in before you can comment on or make changes to this bug.
Description Serge Belyshev 2004-09-28 08:06:13 UTC 
This testcase (from bug 15678) shows quadratic time in cgraph_reset_static_var_maps:

#define F0(a) void a(){}
#define F1(a) F0(a##0) F0(a##1) F0(a##2) F0(a##3) F0(a##4) F0(a##5) F0(a##6)
#define F2(a) F1(a##0) F1(a##1) F1(a##2) F1(a##3) F1(a##4) F1(a##5) F1(a##6)
#define F3(a) F2(a##0) F2(a##1) F2(a##2) F2(a##3) F2(a##4) F2(a##5) F2(a##6)
#define F4(a) F3(a##0) F3(a##1) F3(a##2) F3(a##3) F3(a##4) F3(a##5) F3(a##6)
#define F5(a) F4(a##0)/*F4(a##1) F4(a##2) F3(a##3) F3(a##4) F3(a##5) F3(a##6)*/

F5(f)
Comment 1 Serge Belyshev 2004-09-28 09:43:17 UTC 
(In reply to comment #0)

> #define F5(a) F4(a##0)/*F4(a##1) F4(a##2) F3(a##3) F3(a##4) F3(a##5) F3(a##6)*/
  	  			   	   ^^      ^^       ^^      ^^
					   these should be F4
Comment 2 Andrew Pinski 2004-09-28 11:37:04 UTC 
Confirmed, I think I know where the problem is, I will look into it later today.
Comment 3 Andrew Pinski 2004-10-25 23:22:37 UTC 
The code has been removed for 4.0.