On Wed, Sep 27, 2023 at 11:15:26AM +0000, Richard Biener wrote:
> > tree-vect-patterns.cc:2947 unprom.quick_grow (nops);
> > T = vect_unpromoted_value
> > Go for quick_grow_cleared? Something else?
>
> The CTOR zero-initializes everything, so maybe it can go. In theory
> .set_op could also be changed to .push_op ...
So, I had a look at this and I think using quick_grow_cleared is best choice
here. The nops is 2 or 1 most of the time, worst case 3, so the price of
extra initialization of 4 pointer-sized-or-less members times 1, 2 or 3
doesn't seem worth bothering, it is similar to the bitmap_head case where
we already pay the price for just one structure anytime we do
vect_unpromoted_value unprom_diff;
(and later set_op on it) or even
vect_unpromoted_value unprom0[2];
With this patch and Richard S's poly_int_pod removal the static_assert can
be enabled as well and gcc builds.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
The second patch waits for the poly_int_pod removal commit and has been just
build tested but not bootstrapped yet.
2023-09-29 Jakub Jelinek <ja...@redhat.com>
* tree-vect-patterns.cc (vect_recog_over_widening_pattern): Use
quick_grow_cleared method on unprom rather than quick_grow.
--- gcc/tree-vect-patterns.cc.jj 2023-08-24 15:37:29.321410276 +0200
+++ gcc/tree-vect-patterns.cc 2023-09-29 09:45:27.980168865 +0200
@@ -2944,7 +2944,7 @@ vect_recog_over_widening_pattern (vec_in
/* Check the operands. */
unsigned int nops = gimple_num_ops (last_stmt) - first_op;
auto_vec <vect_unpromoted_value, 3> unprom (nops);
- unprom.quick_grow (nops);
+ unprom.quick_grow_cleared (nops);
unsigned int min_precision = 0;
bool single_use_p = false;
for (unsigned int i = 0; i < nops; ++i)
Jakub
2023-09-29 Jakub Jelinek <ja...@redhat.com>
* vec.h (quick_grow): Uncomment static_assert.
--- gcc/vec.h.jj 2023-09-29 10:39:09.327223861 +0200
+++ gcc/vec.h 2023-09-29 10:44:03.764108443 +0200
@@ -1396,7 +1396,7 @@ inline void
vec<T, A, vl_embed>::quick_grow (unsigned len)
{
gcc_checking_assert (length () <= len && len <= m_vecpfx.m_alloc);
-// static_assert (std::is_trivially_default_constructible <T>::value, "");
+ static_assert (std::is_trivially_default_constructible <T>::value, "");
m_vecpfx.m_num = len;
}
