https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83705
--- Comment #7 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
> Of course, commenting out the part in simplify.c makes the repeat_7.f90
> test fail. Also, when compiling the testcase in this PR the compiler
> uses 1.7 GB RAM, so I do think it makes sense to have *some* limit
> where we give up and defer to runtime.
I agree, but the limit should probably not hardcoded. In order to test large
strings with our rebuilding gfortran, I have highjacked
flag_max_array_constructor with the following patch:
--- ../_clean/gcc/fortran/simplify.c 2018-01-05 20:02:38.000000000 +0100
+++ gcc/fortran/simplify.c 2018-01-07 12:20:45.000000000 +0100
@@ -6080,12 +6114,14 @@ gfc_simplify_repeat (gfc_expr *e, gfc_ex
len = e->value.character.length;
gfc_charlen_t nlen = ncop * len;
- /* Here's a semi-arbitrary limit. If the string is longer than 32 MB
- (8 * 2**20 elements * 4 bytes (wide chars) per element) defer to
+ /* Here's a semi-arbitrary limit. If the string is longer than 256 MB
+ (8 * 2**25 elements * 4 bytes (wide chars) per element) defer to
runtime instead of consuming (unbounded) memory and CPU at
compile time. */
- if (nlen > 8388608)
+ /* printf("nlen = %lld, limit = %lld\n", nlen, 4096ll *
flag_max_array_constructor); */
+ if (nlen > 4096ll * flag_max_array_constructor)
return NULL;
+ /* printf("result\n"); */
result = gfc_get_character_expr (e->ts.kind, &e->where, NULL, nlen);
for (size_t i = 0; i < (size_t) ncop; i++)
Note that on darwin repeat_7.f90 compiles, but does not link:
% time gfc repeat_7_db.f90 -fmax-array-constructor=1000000
final section layout:
__TEXT/__text addr=0x100000E2E, size=0x000000B0, fileOffset=0x00000E2E,
type=1
__TEXT/__stubs addr=0x100000EDE, size=0x0000001E, fileOffset=0x00000EDE,
type=28
__TEXT/__stub_helper addr=0x100000EFC, size=0x00000042,
fileOffset=0x00000EFC, type=32
__TEXT/__cstring addr=0x100000F3E, size=0x00000010, fileOffset=0x00000F3E,
type=13
__TEXT/__const addr=0x100000F50, size=0x8000001C, fileOffset=0x00000F50,
type=0
__TEXT/__eh_frame addr=0x180000F70, size=0x00000088, fileOffset=0x80000F70,
type=19
__DATA/__nl_symbol_ptr addr=0x180001000, size=0x00000010,
fileOffset=0x80001000, type=29
__DATA/__la_symbol_ptr addr=0x180001010, size=0x00000028,
fileOffset=0x80001010, type=27
__DATA/__huge addr=0x180001038, size=0x00000000, fileOffset=0x00000000,
type=25
ld: 32-bit RIP relative reference out of range (2147483784 max is +/-2GB): from
_main (0x100000EA1) to _options.1.3769 (0x180000F50) in '_main' from
/var/folders/8q/sh_swgz96r7f5vnn08f7fxr00000gn/T//ccs6xnfq.o for architecture
x86_64
collect2: error: ld returned 1 exit status
218.482u 16.499s 4:01.43 97.3% 0+0k 0+0io 2668pf+0w
