https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64193
Bug ID: 64193
Summary: Decreased performance after r173250
Product: gcc
Version: 4.9.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: cederman at gaisler dot com
Target: i686-build_pc-linux-gnu
Created attachment 34196
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34196&action=edit
preprocessed source
When comparing version 4.4.2 with version 4.9.2 I noticed a performance
decrease for the Whetstone benchmark. It seems to have been introduced with
r173250. Compiling Whetstone with the latest master (r217599) I get the
following numbers:
Without r173250:
Loops: 5000000, Iterations: 1, Duration: 54 sec.
C Converted Double Precision Whetstones: 9259.3 MIPS
With r173250:
Loops: 5000000, Iterations: 1, Duration: 58 sec.
C Converted Double Precision Whetstones: 8620.7 MIPS
The assembly output has also increased in size.
I have attached a preprocessed copy of the Whetstone benchmark and assembly
output for i686-build_pc-linux-gnu compiled with -O3, with and without r173250.
Let me know if you need any more information.
