Mesa (master): vc4: Emit a warning and proceed for handling loops in NIR.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 40e77741cf1e9a74b867c7d132ca2346fe1584e4
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=40e77741cf1e9a74b867c7d132ca2346fe1584e4

Author: Rhys Kidd <rhyskidd at gmail.com>
Date:   Tue Mar 15 23:00:28 2016 -0400

vc4: Emit a warning and proceed for handling loops in NIR.

We don't really suppor control flow yet, but it's a lot nicer to render
something and warn on stderr than to crash.

Fixes the following piglit tests:
- shaders/complex-loop-analysis-bug
- shaders/glsl-fs-discard-04

Converts the following piglit tests from crash to fail:
- shaders/glsl-fs-continue-inside-do-while
- shaders/glsl-fs-loop
- shaders/glsl-fs-loop-continue
- shaders/glsl-fs-loop-nested
- shaders/glsl-texcoord-array
- shaders/glsl-vs-continue-inside-do-while
- shaders/glsl-vs-loop
- shaders/glsl-vs-loop-continue
- shaders/glsl-vs-loop-nested

No piglit regressions.

v2 (Eric): Add stronger stderr warning.

Signed-off-by: Rhys Kidd <rhyskidd at gmail.com>
Reviewed-by: Eric Anholt <eric at anholt.net>

---

 src/gallium/drivers/vc4/vc4_program.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/vc4/vc4_program.c b/src/gallium/drivers/vc4/vc4_program.c
index 1439e1f..6a8fad9 100644
--- a/src/gallium/drivers/vc4/vc4_program.c
+++ b/src/gallium/drivers/vc4/vc4_program.c
@@ -1693,6 +1693,15 @@ ntq_emit_block(struct vc4_compile *c, nir_block *block)
         }
 }
 
+static void ntq_emit_cf_list(struct vc4_compile *c, struct exec_list *list);
+
+static void
+ntq_emit_loop(struct vc4_compile *c, nir_loop *nloop)
+{
+        fprintf(stderr, "LOOPS not fully handled. Rendering errors likely.\n");
+        ntq_emit_cf_list(c, &nloop->body);
+}
+
 static void
 ntq_emit_function(struct vc4_compile *c, nir_function_impl *func)
 {
@@ -1705,7 +1714,6 @@ ntq_emit_cf_list(struct vc4_compile *c, struct exec_list *list)
 {
         foreach_list_typed(nir_cf_node, node, node, list) {
                 switch (node->type) {
-                        /* case nir_cf_node_loop: */
                 case nir_cf_node_block:
                         ntq_emit_block(c, nir_cf_node_as_block(node));
                         break;
@@ -1714,6 +1722,10 @@ ntq_emit_cf_list(struct vc4_compile *c, struct exec_list *list)
                         ntq_emit_if(c, nir_cf_node_as_if(node));
                         break;
 
+                case nir_cf_node_loop:
+                        ntq_emit_loop(c, nir_cf_node_as_loop(node));
+                        break;
+
                 case nir_cf_node_function:
                         ntq_emit_function(c, nir_cf_node_as_function(node));
                         break;