From: Andrii Simiklit <andrii.simiklit@globallogic.com>
Date: Wed, 17 Jul 2019 12:05:49 +0000 (+0300)
Subject: glsl/nir: do not change an element index to have correct block name
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=be6d51e1e3a2b2165cd21fbdda2527d10f4ce9ff;p=mesa.git

glsl/nir: do not change an element index to have correct block name

When SSBO array is used with packed layout, both IR tree
and as a result, NIR tree will be incorrect.
In fact, the SSBO dereference indices won't
match the array size in some cases like the following:

"layout(packed, binding=1) buffer SSBO { vec4 a; } ssbo[3];
 out vec4 color;
 void main() {
   color = ssbo[2].a;
 }"

After linking the IR and then NIR will have an SSBO array
definition with size 1 but dereference still will have index 2
and linked_shader->Program->sh.ShaderStorageBlocks
will contain just SSBO with name "SSBO[2]"

So this line should be removed at least as a workaround for now
to avoid error like:
Failed to find the block by name "SSBO[0]"

Fixes: 810dde2a "glsl/nir: Add a pass to lower UBO and SSBO access"
Signed-off-by: Andrii Simiklit <andrii.simiklit@globallogic.com>
Reviewed-by: Kristian H. Kristensen <hoegsberg@google.com>
---

diff --git a/src/compiler/glsl/gl_nir_lower_buffers.c b/src/compiler/glsl/gl_nir_lower_buffers.c
index 59bb582069a..60ac1417355 100644
--- a/src/compiler/glsl/gl_nir_lower_buffers.c
+++ b/src/compiler/glsl/gl_nir_lower_buffers.c
@@ -49,7 +49,6 @@ get_block_array_index(nir_builder *b, nir_deref_instr *deref,
 
       if (nir_src_is_const(deref->arr.index)) {
          unsigned arr_index = nir_src_as_uint(deref->arr.index);
-         arr_index = MIN2(arr_index, arr_size - 1);
 
          /* We're walking the deref from the tail so prepend the array index */
          block_name = ralloc_asprintf(b->shader, "[%u]%s", arr_index,