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Re: [PATCH] Avoid crash compiling nonlocal gotos on ARM


> On Mon, Nov 17, 2003 at 01:56:17AM +0100, Waldek Hebisch wrote:
> > My finding was that 
> > on arm trampolines were created using library call (to 'memcpy').
> > That created additional basic block and requires calling 
> > `expand_end_target_temps' which calls `expand_nl_goto_receivers'. 
> 
> This description doesn't make sense.  There are no basic blocks at
> this point.  Indeed, a call to memcpy should not imply a basic block
> at all, whereas a loop to copy would.
> 
> Do ARM trampolines fail for C test cases?  If not, what's different
> about Pascal?
> 

Sorry for sloppy wiriting. What I mean is that `emit_block_move' inserts
a sequence of instructions outside normal program structure -- after
`expand_nl_goto_receivers' were called for current function. Expanding the
library call triggers call to `expand_end_target_temps' which int turn calls
`expand_nl_goto_receivers' again (wiping info gathered by the first 
call). Other variants of `emit_block_move' do not trigger extra call
to `expand_nl_goto_receivers'.

I included a C testcase in original message. With the testcase in file
`froc.c' I get:
hebisch@student:/arc/pom/gcc_t/gcc104/parm$ ../gcc-arm0/gcc/cc1 -O2 fproc.c
 print lvl1 eval
fproc.c:68: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
hebisch@student:/arc/pom/gcc_t/gcc104/parm$ ../gcc-arm0/gcc/cc1 --version
GNU C version 3.3.2 (arm-linux)
        compiled by GNU C version 3.3.1.
GGC heuristics: --param ggc-min-expand=98 --param ggc-min-heapsize=129147

The configure command was:
hebisch@student:/arc/pom/gcc_t/gcc104/gcc-arm0$ CFLAGS="-g -Dinhibit_libc" \
../gcc-3.3.2.orig/configure --enable-checking --enable-languages=c \
--disable-nls --disable-multilib --disable-shared --enable-threads=single \
--target=arm-linux

The host is i386-linux.

-- 
                              Waldek Hebisch
hebisch@math.uni.wroc.pl 


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