Remove MODE_COMPOSITE_P test from simplify_gen_subreg [PR120718]HEADtrunkmaster

simplify_gen_subreg rejected subregs of literal constants if
MODE_COMPOSITE_P.  This was added by the fix for PR96648 in
g:c0f772894b6b3cd8ed5c5dd09d0c7917f51cf70f.  Jakub said:

  As for the simplify_gen_subreg change, I think it would be desirable
  to just avoid creating SUBREGs of constants on all targets and for all
  constants, if simplify_immed_subreg simplified, fine, otherwise punt,
  but as we are late in GCC11 development, the patch instead guards this
  behavior on MODE_COMPOSITE_P (outermode) - i.e. only conversions to
  powerpc{,64,64le} double double long double - and only for the cases where
  simplify_immed_subreg was called.

I'm not sure about relaxing the codes further, since subregs might
be wanted for CONST, SYMBOL_REF and LABEL_REF.  But removing the
MODE_COMPOSITE_P is needed to fix PR120718, where we get an ICE
from generating a subreg of a V2SI const_vector.

gcc/
	PR rtl-optimization/120718
	* simplify-rtx.cc (simplify_context::simplify_gen_subreg):
	Remove MODE_COMPOSITE_P condition.

gcc/testsuite/
	PR rtl-optimization/120718
	* gcc.target/aarch64/sve/acle/general/pr120718.c: New test.

0 files changed, 0 insertions, 0 deletions