On Fri, 28 Nov 2014 04:36:42 +0100, Dave Airlie <airl...@gmail.com> wrote:
From: Dave Airlie <airl...@redhat.com>
Since 73dd50acf6d244979c2a657906aa56d3ac60d550
glsl: implement switch flow control using a loop
The SB backend was falling over in an assert or crashing.
Tracked this down to the loops having no repeats, but requiring
a working break, initial code just called the loop handler for
all non-if statements, but this caused a regression in
tests/shaders/dead-code-break-interaction.shader_test.
So I had to add further code to detect if all the departure
nodes are empty and avoid generating an empty loop for that case.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=86089
Signed-off-by: Dave Airlie <airl...@redhat.com>
---
src/gallium/drivers/r600/sb/sb_bc_finalize.cpp | 51
++++++++++++++++++--------
1 file changed, 36 insertions(+), 15 deletions(-)
diff --git a/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
b/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
index f0849ca..d91ffa5 100644
--- a/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
+++ b/src/gallium/drivers/r600/sb/sb_bc_finalize.cpp
@@ -46,15 +46,22 @@ int bc_finalizer::run() {
for (regions_vec::reverse_iterator I = rv.rbegin(), E = rv.rend(); I
!= E;
++I) {
region_node *r = *I;
-
+ bool is_if = false;
assert(r);
- bool loop = r->is_loop();
+ assert(r->first);
+ if (r->first->is_container()) {
+ container_node *repdep1 =
static_cast<container_node*>(r->first);
+ assert(repdep1->is_depart() || repdep1->is_repeat());
+ if_node *n_if = static_cast<if_node*>(repdep1->first);
+ if (n_if && n_if->is_if())
+ is_if = true;
+ }
- if (loop)
- finalize_loop(r);
- else
+ if (is_if)
finalize_if(r);
+ else
+ finalize_loop(r);
r->expand();
}
@@ -112,16 +119,31 @@ void bc_finalizer::finalize_loop(region_node* r) {
cf_node *loop_start = sh.create_cf(CF_OP_LOOP_START_DX10);
cf_node *loop_end = sh.create_cf(CF_OP_LOOP_END);
+ bool has_instr = false;
+
+ if (!r->is_loop()) {
+ for (depart_vec::iterator I = r->departs.begin(), E =
r->departs.end();
+ I != E; ++I) {
+ depart_node *dep = *I;
+ if (!dep->empty())
+ has_instr = true;
could break here
+ }
+ } else
+ has_instr = true;
- loop_start->jump_after(loop_end);
- loop_end->jump_after(loop_start);
+ if (has_instr) {
+ loop_start->jump_after(loop_end);
+ loop_end->jump_after(loop_start);
+ }
for (depart_vec::iterator I = r->departs.begin(), E = r->departs.end();
I != E; ++I) {
depart_node *dep = *I;
- cf_node *loop_break = sh.create_cf(CF_OP_LOOP_BREAK);
- loop_break->jump(loop_end);
- dep->push_back(loop_break);
+ if (has_instr) {
+ cf_node *loop_break = sh.create_cf(CF_OP_LOOP_BREAK);
+ loop_break->jump(loop_end);
+ dep->push_back(loop_break);
+ }
dep->expand();
}
@@ -137,8 +159,10 @@ void bc_finalizer::finalize_loop(region_node* r) {
rep->expand();
}
- r->push_front(loop_start);
- r->push_back(loop_end);
+ if (has_instr) {
+ r->push_front(loop_start);
+ r->push_back(loop_end);
+ }
}
void bc_finalizer::finalize_if(region_node* r) {
@@ -168,9 +192,6 @@ void bc_finalizer::finalize_if(region_node* r) {
if (n_if) {
-
- assert(n_if->is_if());
shouldn't need to remove this assertion
-
container_node *repdep2 =
static_cast<container_node*>(n_if->first);
assert(repdep2->is_depart() || repdep2->is_repeat());
I think i've managed to convince myself the above logic is correct, so
Reviewed-By: Glenn Kennard <glenn.kenn...@gmail.com>
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