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| author | Jakub Jelinek <jakub@redhat.com> | 2024-01-12 11:16:41 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2024-01-12 11:16:41 +0100 |
| commit | 4ff5e7cec91013f2b2e5c680d13bfd20e2a19763 (patch) | |
| tree | b3ebe769b99df7d6e6a2686f9ae7eaad04268712 /gcc | |
| parent | 109985343bcada8936cb83d1fd3cb9cad915fb4a (diff) | |
| download | gcc-4ff5e7cec91013f2b2e5c680d13bfd20e2a19763.zip gcc-4ff5e7cec91013f2b2e5c680d13bfd20e2a19763.tar.gz gcc-4ff5e7cec91013f2b2e5c680d13bfd20e2a19763.tar.bz2 | |
lower-bitint: Fix handling of casts on arches with abi_limb_mode != limb_mode
> > This patch is still work in progress, but posting to show failure with
> > bitint-7 test where handle_stmt called from lower_mergeable_stmt ICE's
> > because the idx (3) is out of range for the __BitInt(135) with a limb_prec
> > of 64.
>
> I can reproduce it, will debug it momentarily.
So, the problem was that in 2 spots I was comparing TYPE_SIZE of large/huge
BITINT_TYPEs to determine if it can be handled cheaply.
On x86_64 with limb_mode == abi_limb_mode (both DImode) that works fine,
if TYPE_SIZE is equal, it means it has the same number of limbs.
But on aarch64 TYPE_SIZE of say _BitInt(135) and _BitInt(193) is the same,
both are 256-bit storage, but because DImode is used as limb_mode, the
former actually needs just 3 limbs, while the latter needs 4 limbs.
And limb_access_type was asserting that we don't try to access 4th limb
on types which actually have a precision which needs just 3 limbs.
The following patch should fix that.
Note, for the info.extended targets (currently none, but I think arm 32-bit
in the ABI is meant like that), we'll need to do something different,
because the upper bits aren't just padding and should be zero/sign extended,
so if we say have limb_mode SImode, abi_limb_mode DImode, we'll need to
treat _BitInt(135) not as 5 SImode limbs, but 6. For !info.extended targets
I think treating _BitInt(135) as 3 DImode limbs rather than 4 is fine.
2024-01-12 Jakub Jelinek <jakub@redhat.com>
* gimple-lower-bitint.cc (mergeable_op): Instead of comparing
TYPE_SIZE (t) of large/huge BITINT_TYPEs, compare
CEIL (TYPE_PRECISION (t), limb_prec).
(bitint_large_huge::handle_cast): Likewise.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/gimple-lower-bitint.cc | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc index 8993a61..68e0189 100644 --- a/gcc/gimple-lower-bitint.cc +++ b/gcc/gimple-lower-bitint.cc @@ -231,7 +231,8 @@ mergeable_op (gimple *stmt) && TREE_CODE (rhs_type) == BITINT_TYPE && bitint_precision_kind (lhs_type) >= bitint_prec_large && bitint_precision_kind (rhs_type) >= bitint_prec_large - && tree_int_cst_equal (TYPE_SIZE (lhs_type), TYPE_SIZE (rhs_type))) + && (CEIL (TYPE_PRECISION (lhs_type), limb_prec) + == CEIL (TYPE_PRECISION (rhs_type), limb_prec))) { if (TYPE_PRECISION (rhs_type) >= TYPE_PRECISION (lhs_type)) return true; @@ -1263,8 +1264,8 @@ bitint_large_huge::handle_cast (tree lhs_type, tree rhs1, tree idx) if m_upwards_2limb * limb_prec is equal to lhs precision that is not the case. */ || (!m_var_msb - && tree_int_cst_equal (TYPE_SIZE (rhs_type), - TYPE_SIZE (lhs_type)) + && (CEIL (TYPE_PRECISION (lhs_type), limb_prec) + == CEIL (TYPE_PRECISION (rhs_type), limb_prec)) && (!m_upwards_2limb || (m_upwards_2limb * limb_prec < TYPE_PRECISION (lhs_type))))) |