On 6/29/20 7:19 PM, Roger Sayle wrote:
> This patch addresses the ICE in gcc.dg/attr-vector_size.c during make -k
> check on
> nvptx-none. The actual ICE looks like:
>
> testsuite/gcc.dg/attr-vector_size.c:29:1: internal compiler error: in
> tree_to_shwi, at tree.c:7321
> 0xf53bf2 tree_to_shwi(tree_node const*)
> ../../gcc/gcc/tree.c:7321
> 0xff1969 nvptx_vector_alignment
> ../../gcc/gcc/config/nvptx/nvptx.c:5105^M
>
> The problem is that the caller has ensured that TYPE_SIZE(type) is
> representable as
> an unsigned HOST_WIDE_INT, but nvptx_vector_alignment is accessing it as a
> signed HOST_WIDE_INT which overflows in pathological conditions. Amongst
> those
> pathological conditions is that a TYPE_SIZE of zero can sometimes reach this
> function,
> prior to an error being emitted. Making sure the result is not less than the
> mode's
> alignment and not greater than BIGGEST_ALIGNMENT fixes the ICEs, and
> generates
> the expected compile-time error messages.
>
> Tested on --target=nvptx-none, with a "make" and "make check" which results
> in four
> fewer unexpected failures and three more expected passes.
> Ok for mainline?
>
>
> 2020-06-29 Roger Sayle <ro...@nextmovesoftware.com>
>
> gcc/ChangeLog:
> * config/nvptx/nvptx.c (nvptx_vector_alignment): Use tree_to_uhwi
> to access TYPE_SIZE (type). Return at least the mode's alignment.
>
> Thanks,
> Roger
> --
> Roger Sayle
> NextMove Software
> Cambridge, UK
>
> diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
> index e3e84df..bfad91b 100644
> --- a/gcc/config/nvptx/nvptx.c
> +++ b/gcc/config/nvptx/nvptx.c
> @@ -5102,9 +5102,10 @@ static const struct attribute_spec
> nvptx_attribute_table[] =
> static HOST_WIDE_INT
> nvptx_vector_alignment (const_tree type)
> {
> - HOST_WIDE_INT align = tree_to_shwi (TYPE_SIZE (type));
> -
> - return MIN (align, BIGGEST_ALIGNMENT);
> + unsigned HOST_WIDE_INT align = tree_to_uhwi (TYPE_SIZE (type));
In the default target hook, we test tree_fits_uhwi_p, so I prefer we do
the same.
> + if (align > BIGGEST_ALIGNMENT)
> + return BIGGEST_ALIGNMENT;
I prefer using MIN to make code easier to read.
> + return MAX (align, GET_MODE_ALIGNMENT (TYPE_MODE (type)));
> }
>
> /* Indicate that INSN cannot be duplicated. */
Also, this is related to a PR, number included in commit log.
As of yet untested updated patch attached.
Thanks,
- Tom
nvptx: Fix ICE in nvptx_vector_alignment on gcc.dg/attr-vector_size.c
This patch addresses the ICE in gcc.dg/attr-vector_size.c during
make -k check on nvptx-none. The actual ICE looks like:
testsuite/gcc.dg/attr-vector_size.c:29:1: internal compiler error: \
in tree_to_shwi, at tree.c:7321
0xf53bf2 tree_to_shwi(tree_node const*)
../../gcc/gcc/tree.c:7321
0xff1969 nvptx_vector_alignment
../../gcc/gcc/config/nvptx/nvptx.c:5105^M
The problem is that the caller has ensured that TYPE_SIZE(type) is
representable as an unsigned HOST_WIDE_INT, but nvptx_vector_alignment is
accessing it as a signed HOST_WIDE_INT which overflows in pathological
conditions. Amongst those pathological conditions is that a TYPE_SIZE of
zero can sometimes reach this function, prior to an error being emitted.
Making sure the result is not less than the mode's alignment and not greater
than BIGGEST_ALIGNMENT fixes the ICEs, and generates the expected
compile-time error messages.
Tested on --target=nvptx-none, with a "make" and "make check" which results
in four fewer unexpected failures and three more expected passes.
2020-06-29 Roger Sayle <ro...@nextmovesoftware.com>
gcc/ChangeLog:
PR target/90932
* config/nvptx/nvptx.c (nvptx_vector_alignment): Use tree_to_uhwi
to access TYPE_SIZE (type). Return at least the mode's alignment.
---
gcc/config/nvptx/nvptx.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/gcc/config/nvptx/nvptx.c b/gcc/config/nvptx/nvptx.c
index e3e84dfd4e4..d2f321fcbcc 100644
--- a/gcc/config/nvptx/nvptx.c
+++ b/gcc/config/nvptx/nvptx.c
@@ -5102,9 +5102,22 @@ static const struct attribute_spec nvptx_attribute_table[] =
static HOST_WIDE_INT
nvptx_vector_alignment (const_tree type)
{
- HOST_WIDE_INT align = tree_to_shwi (TYPE_SIZE (type));
+ unsigned HOST_WIDE_INT align;
+ tree size = TYPE_SIZE (type);
+
+ /* Ensure align is not bigger than BIGGEST_ALIGNMENT. */
+ if (tree_fits_uhwi_p (size))
+ {
+ align = tree_to_uhwi (size);
+ align = MIN (align, BIGGEST_ALIGNMENT);
+ }
+ else
+ align = BIGGEST_ALIGNMENT;
+
+ /* Ensure align is not smaller than mode alignment. */
+ align = MAX (align, GET_MODE_ALIGNMENT (TYPE_MODE (type)));
- return MIN (align, BIGGEST_ALIGNMENT);
+ return align;
}
/* Indicate that INSN cannot be duplicated. */
