[Bug rtl-optimization/44169] New: Wrong code while generating TLS offsets

["gcc at breakpoint dot cc" <gcc-bugzilla at gcc dot gnu dot org>]

libgomp testsuite fails with a segfault. It segfaults in
gomp_resolve_num_threads(), accessing the second TLS value.

The first access:
 .LBB28:
         .file 2 "../../../src/libgomp/libgomp.h"
         .loc 2 380 0
         bcl 20,31,$+8
         .long _GLOBAL_OFFSET_TABLE_-$
         mflr 9
         lwz 0,0(9)
         add 9,9,0
         lwz 9,gomp_tls_data@got@tprel(9)
         add 9,9,gomp_tls_data@tls
         lwz 9,40(9)

The second:
.LBE27:
         .loc 1 47 0
         cmpwi 7,3,1
         beq- 7,.L37
 .LVL32:
         .loc 1 49 0
         bcl 20,31,$+8
         .long _GLOBAL_OFFSET_TABLE_-$
         mflr 9
         add 9,9,0
         lwz 9,gomp_tls_data@got@tprel(9)
         add 9,9,gomp_tls_data@tls
         lwz 0,28(9)

After mflr, the lwz is missing. r0 has the offset from last lr which is wrong 
here.
The RTL in tc.c.185r.cprop_hardreg has the lwz included, the next pass  
tc.c.186r.dce does not anymore.

lwz gets not killed if I used -mcpu=power or -mcpu=e300c3. I used -mcpu=8540
which is default for powerpc-linux-gnuspe. -O1 was used in the test case.
The complete cmd line:

 /build/bigeasy/gcc-4.4-4.4.4/build/./gcc/xgcc   \
         -B/build/bigeasy/gcc-4.4-4.4.4/build/./gcc/ \
         -B/usr/powerpc-linux-gnuspe/bin/ \
         -B/usr/powerpc-linux-gnuspe/lib/ \
         -isystem \
         /usr/powerpc-linux-gnuspe/include \
         -isystem \
         /usr/powerpc-linux-gnuspe/sys-include \
         -Werror \
         -pthread \
         -ftls-model=initial-exec \
         -O2 \
         -pthread \
         -fPIC \
         -DPIC \
         tc.c \
         -o \
         tc.S \
         -S \
         -mcpu=8540 \
         -O1 \
         -fdump-rtl-all \
         -c \

A side note: the complete file (parallel.c from libgomp) was compiled with -O2
and the lwz was killed between parallel.c.174r.postreload and
parallel.c.176r.split2.


-- 
           Summary: Wrong code while generating TLS offsets
           Product: gcc
           Version: 4.4.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: gcc at breakpoint dot cc
 GCC build triplet: powerpc-linux-gnuspe
  GCC host triplet: powerpc-linux-gnuspe
GCC target triplet: powerpc-linux-gnuspe


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44169