Eric Botcazou wrote:
>> A comment before the SETs and a testcase would be nice. IIRC
>> we do have stack size testcases via using -fstack-usage.
>
>Or -Wstack-usage, which might be more appropriate here.
Yes. good idea. I was not aware that we already have that kind of tests.
When trying to write this test. I noticed, that I did not try -Os so far.
But for -Os the stack is still the unchanged 3500 bytes.
However for embedded targets I am often inclined to use -Os, and
would certainly not expect the stack to explode...
I see in arm.md there are places like
/* If we're optimizing for size, we prefer the libgcc calls. */
if (optimize_function_for_size_p (cfun))
FAIL;
/* Expand operation using core-registers.
'FAIL' would achieve the same thing, but this is a bit smarter. */
scratch1 = gen_reg_rtx (SImode);
scratch2 = gen_reg_rtx (SImode);
arm_emit_coreregs_64bit_shift (LSHIFTRT, operands[0], operands[1],
operands[2], scratch1, scratch2);
.. that explains why this happens. I think it would be better to
use the emit_coreregs for shift count >= 32, because these are
effectively 32-bit shifts.
Will try if that can be improved, and come back with the
results.
Thanks
Bernd.
