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));
+ if (align > BIGGEST_ALIGNMENT)
+ return BIGGEST_ALIGNMENT;
+ return MAX (align, GET_MODE_ALIGNMENT (TYPE_MODE (type)));
}
/* Indicate that INSN cannot be duplicated. */
