Skip to content

Don't create a constant node for Vector64 #105538

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Jul 28, 2024
Merged

Don't create a constant node for Vector64 #105538

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
789917a
Don't create a constant node for Vector64
tannergooding Jul 26, 2024
1c9a79c
Ensure we process all arguments so the some_const case is correct
tannergooding Jul 26, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
18 changes: 5 additions & 13 deletions src/mono/mono/mini/simd-intrinsics.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1342,7 +1342,6 @@ emit_vector_create_elementwise (
// optimizations can be enabled. This includes recognizing partial constants
// and only performing the minimal number of inserts required

gboolean all_const = true;
gboolean some_const = false;

guint8 cns_vec[16];
Expand All @@ -1352,10 +1351,8 @@ emit_vector_create_elementwise (
if (vector_size == 16) {
for (int i = 0; i < param_count; ++i) {
if (!is_const (args[i])) {
all_const = false;
break;
Comment on lines -1355 to -1356
Copy link
Member Author

@tannergooding tannergooding Jul 26, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This was the remaining issue.

Mono only supports 128-bit xconst today, but we're still trying to handle the case where only some inputs are constant; such as Vector128.Create(1, 2, x, 4). This was early exiting in the case that not all inputs were constant so in the main loop below we ended up getting Vector128.Create(1, 2, x, 0) instead.

Fixed it to not early exit and only skip parameters if some were constant; which lets us get the correct value instead.

continue;
}

some_const = true;

if (type_enum_is_float (etype->type)) {
Expand Down Expand Up @@ -1418,10 +1415,6 @@ emit_vector_create_elementwise (
}
}

if (all_const) {
return emit_xconst_v128 (cfg, vklass, (guint8*)cns_vec);
}

MonoInst *ins;

if (some_const) {
Expand All @@ -1431,11 +1424,11 @@ emit_vector_create_elementwise (
}

for (int i = 0; i < param_count; ++i) {
if (!is_const (args[i]) || (vector_size != 16)) {
ins = emit_vector_insert_element (cfg, vklass, ins, etype->type, args[i], i, TRUE);
if (some_const && is_const (args[i])) {
continue;
}
ins = emit_vector_insert_element (cfg, vklass, ins, etype->type, args[i], i, TRUE);
}

return ins;
}

Expand Down Expand Up @@ -1484,8 +1477,7 @@ emit_vector_create_scalar (
} else {
g_assert (arg0->opcode == OP_I8CONST);
cns_val = arg0->inst_l;

}
}
switch (etype->type) {
case MONO_TYPE_I1:
case MONO_TYPE_U1: {
Expand Down