[Bug middle-end/53823] [4.8 Regression] FAIL: gcc.c-torture/execute/930921-1.c execution at -O0 and -O1

[dave.anglin at bell dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53823

--- Comment #19 from dave.anglin at bell dot net 2012-08-01 14:20:49 UTC ---
On 31-Jul-12, at 10:25 PM, rth at gcc dot gnu.org wrote:

> The cross-compile *ought* not to affect costs, which means that
> we ought to be making the same algorithm choices.  Which suggests
> that -- if this is a fully bootstrapped pa compiler -- you're
> looking at some part of expand_mult itself being mis-compiled.


I was afraid this might be the case.  However, I built a non bootstrap
compiler this morning with -g -O1.  The testcase still fails at -O0 and
O1, and works at -O2.

The compiler was configured as follows:

dave@mx3210:~/gnu/gcc/objdir/gcc$ ./xgcc -B./ -v
Reading specs from ./specs
COLLECT_GCC=./xgcc
COLLECT_LTO_WRAPPER=./lto-wrapper
Target: hppa-linux-gnu
Configured with: ../gcc/configure --with-gnu-as --with-gnu-ld --enable- 
shared --enable-multiarch --with-multiarch-defaults=hppa-linux-gnu -- 
enable-linker-build-id --build=hppa-linux-gnu --host=hppa-linux-gnu -- 
target=hppa-linux-gnu --prefix=/home/dave/opt/gnu/gcc/gcc-4.7.0 --with- 
local-prefix=/home/dave/opt/gnu --enable-threads=posix --enable- 
__cxa_atexit --build=hppa-linux-gnu --enable-clocale=gnu --enable-java- 
gc=boehm --enable-languages=c --disable-bootstrap
Thread model: posix
gcc version 4.8.0 20120801 (experimental) [trunk revision 190037] (GCC)

You probably would need to add --with-arch=1.1 to duplicate the  
default native settings with a cross.

The difference in extracts and deposits may not be the problem.  The - 
O2 code appears to have the same extracts as the
-O1 code.  I'll see if I can find where the real difference arises.

--
John David Anglin    dave.anglin@bell.net