Date: Thu, 20 Feb 1997 15:34:34 -0800 (PST) From: "Jin Guojun[ITG]" <jin@adv-pc-1.lbl.gov> To: FreeBSD-gnats-submit@freebsd.org, iss-prog@adv-pc-1.lbl.gov Subject: gnu/2786: gcc version 2.7.2.1 C compiler slows down integer performance Message-ID: <199702202334.PAA00400@adv-pc-1.lbl.gov> Resent-Message-ID: <199702210000.QAA17052@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
>Number: 2786 >Category: gnu >Synopsis: gcc version 2.7.2.1 C compiler slows down integer performance >Confidential: no >Severity: serious >Priority: medium >Responsible: freebsd-bugs >State: open >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Thu Feb 20 16:00:01 PST 1997 >Last-Modified: >Originator: Jin Guojun[ITG] >Organization: >Release: FreeBSD 2.2-970215-GAMMA i386 >Environment: gcc version 2.7.2.1 under FreeBSD 2.2-GAMMA >Description: gcc version 2.7.2.1 slows down the integer instruction performance by 1/3 (33%). For details, please read ftp://george.lbl.gov/pub/ccs/performance.ps table-6 on page 7. Compare MIPS on column 4-5,6, and 7-8. Column 4 is a pure 2.1.7 system (same hardware for column 5-6). Column 5 is a pure 2.2-GAMMA system. Column 6 is a 2.2-GAMMA system using 2.1.6 compiler (gcc version 2.6.3) Column 7 is a 2.2-GAMMA system using 2.1.6 compiler (gcc version 2.6.3) Column 8 is a pure 2.2-GAMMA system (same hardware for column 7). >How-To-Repeat: I believe to wirte some integer arithmetic code can prove this. >Fix: to use gcc version 2.6.3 for a temporary solution. >Audit-Trail: >Unformatted:
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199702202334.PAA00400>