[PATCH v2 2/7] bitint: Allow different limb_mode and abi_limb_mode in more cases

[Yang Yujie]

abi_limb_mode and limb_mode were asserted to be the same when
the target has different endianness for limbs in _BitInts
and words in objects.  Otherwise, this assertion also held when the
TYPE_PRECISION of _BitInt type being laid out is less than or equal
to the precision of abi_limb_mode.

But in the latter case it stops us from e.g. laying out _BitInt(65)
with abi_limb_mode == TImode for alignment or sizing while the actual
limb for lowering stays in DImode.  This patch removes this
limitation.

gcc/ChangeLog:

        * stor-layout.cc (layout_type): Reduce the conditions where
        the abi_limb_mode == limb_mode assertion applies.
---
 gcc/stor-layout.cc | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/gcc/stor-layout.cc b/gcc/stor-layout.cc
index 12071c96ca7..66a834faacc 100644
--- a/gcc/stor-layout.cc
+++ b/gcc/stor-layout.cc
@@ -2477,18 +2477,19 @@ layout_type (tree type)
        gcc_assert (ok);
        scalar_int_mode limb_mode
          = as_a <scalar_int_mode> (info.abi_limb_mode);
+
+       if (!info.big_endian != !WORDS_BIG_ENDIAN)
+         gcc_assert (info.abi_limb_mode == info.limb_mode);
+
        if (TYPE_PRECISION (type) <= GET_MODE_PRECISION (limb_mode))
          {
            SET_TYPE_MODE (type, limb_mode);
-           gcc_assert (info.abi_limb_mode == info.limb_mode);
            cnt = 1;
          }
        else
          {
            SET_TYPE_MODE (type, BLKmode);
            cnt = CEIL (TYPE_PRECISION (type), GET_MODE_PRECISION (limb_mode));
-           gcc_assert (info.abi_limb_mode == info.limb_mode
-                       || !info.big_endian == !WORDS_BIG_ENDIAN);
          }
        TYPE_SIZE (type) = bitsize_int (cnt * GET_MODE_BITSIZE (limb_mode));
        TYPE_SIZE_UNIT (type) = size_int (cnt * GET_MODE_SIZE (limb_mode));
-- 
2.46.0