target/2427: Extra loop failures with -mcpu=athlon

[Joseph Myers <jsm28 at cam dot ac dot uk>]

>Number:         2427
>Category:       target
>Synopsis:       Extra loop failures with -mcpu=athlon
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 29 20:46:01 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     Joseph S. Myers
>Release:        3.0 20010328 (prerelease)
>Organization:
none
>Environment:
System: Linux digraph 2.2.19 #1 Wed Mar 28 16:01:38 UTC 2001 i686 unknown
Architecture: i686

	
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ../gcc-3cvs/configure --prefix=/opt/gcc/snapshot --disable-shared --enable-threads=posix --with-system-zlib
>Description:

Building a GCC with -mcpu=athlon as default tuning shows some extra
loop failures relative to one with -mcpu=pentiumpro as default.  These
may also be reproduced on an unmodified GCC using -mcpu=athlon.

Justification for priority "high": at least some of the failures also
occur with -mcpu=k6 but don't occur with -mcpu=k6 with GCC 2.95.3.
For example, loop-3c.c -O3 -mcpu=k6.

>How-To-Repeat:

Run the testsuite with -mcpu=athlon, or apply the obvious change to
config.gcc and configure for athlon-*-*-*.  Extra failures:

7992c7992
< PASS: gcc.c-torture/execute/loop-2b.c execution,  -O3 -fomit-frame-pointer 
---
> FAIL: gcc.c-torture/execute/loop-2b.c execution,  -O3 -fomit-frame-pointer 
7994c7994
< PASS: gcc.c-torture/execute/loop-2b.c execution,  -O3 -fomit-frame-pointer -funroll-loops 
---
> FAIL: gcc.c-torture/execute/loop-2b.c execution,  -O3 -fomit-frame-pointer -funroll-loops 
7996c7996
< PASS: gcc.c-torture/execute/loop-2b.c execution,  -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions 
---
> FAIL: gcc.c-torture/execute/loop-2b.c execution,  -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions 
7998c7998
< PASS: gcc.c-torture/execute/loop-2b.c execution,  -O3 -g 
---
> FAIL: gcc.c-torture/execute/loop-2b.c execution,  -O3 -g 
8000c8000
< PASS: gcc.c-torture/execute/loop-2b.c execution,  -Os 
---
> FAIL: gcc.c-torture/execute/loop-2b.c execution,  -Os 
8038c8038
< PASS: gcc.c-torture/execute/loop-2e.c execution,  -O2 
---
> FAIL: gcc.c-torture/execute/loop-2e.c execution,  -O2 
8040c8040
< PASS: gcc.c-torture/execute/loop-2e.c execution,  -O3 -fomit-frame-pointer 
---
> FAIL: gcc.c-torture/execute/loop-2e.c execution,  -O3 -fomit-frame-pointer 
8046c8046
< PASS: gcc.c-torture/execute/loop-2e.c execution,  -O3 -g 
---
> FAIL: gcc.c-torture/execute/loop-2e.c execution,  -O3 -g 
8048c8048
< PASS: gcc.c-torture/execute/loop-2e.c execution,  -Os 
---
> FAIL: gcc.c-torture/execute/loop-2e.c execution,  -Os 
8118c8118
< PASS: gcc.c-torture/execute/loop-3c.c execution,  -O2 
---
> FAIL: gcc.c-torture/execute/loop-3c.c execution,  -O2 
8120c8120
< PASS: gcc.c-torture/execute/loop-3c.c execution,  -O3 -fomit-frame-pointer 
---
> FAIL: gcc.c-torture/execute/loop-3c.c execution,  -O3 -fomit-frame-pointer 
8122c8122
< PASS: gcc.c-torture/execute/loop-3c.c execution,  -O3 -fomit-frame-pointer -funroll-loops 
---
> FAIL: gcc.c-torture/execute/loop-3c.c execution,  -O3 -fomit-frame-pointer -funroll-loops 
8124c8124
< PASS: gcc.c-torture/execute/loop-3c.c execution,  -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions 
---
> FAIL: gcc.c-torture/execute/loop-3c.c execution,  -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions 
8126c8126
< PASS: gcc.c-torture/execute/loop-3c.c execution,  -O3 -g 
---
> FAIL: gcc.c-torture/execute/loop-3c.c execution,  -O3 -g 
8128c8128
< PASS: gcc.c-torture/execute/loop-3c.c execution,  -Os 
---
> FAIL: gcc.c-torture/execute/loop-3c.c execution,  -Os 

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: