There is some special-casing needed in a competent back-end. However, they
can do their special-casing easily enough based on whether or not the
offset is a constant. In the mean time, having the *_indirect variants
adds special cases a number of places where they don't need to be and, in
general, only complicates things. To complicate matters, NIR had no way to
convdert an indirect load/store to a direct one in the case that the
indirect was a constant so we would still not really get what the back-ends
wanted. The best solution seems to be to get rid of the *_indirect
variants entirely.
---
src/glsl/nir/nir_intrinsics.h | 81 +++++++++++++++++----------------
src/glsl/nir/nir_lower_phis_to_scalar.c | 4 --
src/glsl/nir/nir_print.c | 9 +---
3 files changed, 42 insertions(+), 52 deletions(-)
diff --git a/src/glsl/nir/nir_intrinsics.h b/src/glsl/nir/nir_intrinsics.h
index b2565c5..63df21e 100644
--- a/src/glsl/nir/nir_intrinsics.h
+++ b/src/glsl/nir/nir_intrinsics.h
@@ -228,54 +228,55 @@ SYSTEM_VALUE(num_work_groups, 3, 0)
SYSTEM_VALUE(helper_invocation, 1, 0)
/*
- * The format of the indices depends on the type of the load. For uniforms,
- * the first index is the base address and the second index is an offset that
- * should be added to the base address. (This way you can determine in the
- * back-end which variable is being accessed even in an array.) For inputs,
- * the one and only index corresponds to the attribute slot. UBO loads also
- * have a single index which is the base address to load from.
+ * Load operations pull data from some piece of GPU memory. All load
+ * operations operate in terms of offsets into some piece of theoretical
+ * memory. Loads from externally visible memory (UBO and SSBO) simply take a
+ * byte offset as a source. Loads from opaque memory (uniforms, inputs, etc.)
+ * take a base+offset pair where the base (const_index[0]) gives the location
+ * of the start of the variable being loaded and and the offset source is a
+ * offset into that variable.
*
- * UBO loads have a (possibly constant) source which is the UBO buffer index.
- * For each type of load, the _indirect variant has one additional source
- * (the second in the case of UBO's) that is the is an indirect to be added to
- * the constant address or base offset to compute the final offset.
+ * Some load operations such as UBO/SSBO load and per_vertex loads take an
+ * additional source to specify which UBO/SSBO/vertex to load from.
*
- * For vector backends, the address is in terms of one vec4, and so each array
- * element is +4 scalar components from the previous array element. For scalar
- * backends, the address is in terms of a single 4-byte float/int and arrays
- * elements begin immediately after the previous array element.
+ * The exact address type depends on the lowering pass that generates the
+ * load/store intrinsics. Typically, this is vec4 units for things such as
+ * varying slots and float units for fragment shader inputs. UBO and SSBO
+ * offsets are always in bytes.
*/
-#define LOAD(name, extra_srcs, indices, flags) \
- INTRINSIC(load_##name, extra_srcs, ARR(1), true, 0, 0, indices, flags) \
- INTRINSIC(load_##name##_indirect, extra_srcs + 1, ARR(1, 1), \
- true, 0, 0, indices, flags)
+#define LOAD(name, srcs, indices, flags) \
+ INTRINSIC(load_##name, srcs, ARR(1, 1, 1, 1), true, 0, 0, indices, flags)
-LOAD(uniform, 0, 2, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
-LOAD(ubo, 1, 1, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
-LOAD(input, 0, 1, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
-LOAD(per_vertex_input, 1, 1, NIR_INTRINSIC_CAN_ELIMINATE |
NIR_INTRINSIC_CAN_REORDER)
-LOAD(ssbo, 1, 1, NIR_INTRINSIC_CAN_ELIMINATE)
-LOAD(output, 0, 1, NIR_INTRINSIC_CAN_ELIMINATE)
-LOAD(per_vertex_output, 1, 1, NIR_INTRINSIC_CAN_ELIMINATE)
+/* src[] = { offset }. const_index[] = { base } */
+LOAD(uniform, 1, 1, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
+/* src[] = { buffer_index, offset }. No const_index */
+LOAD(ubo, 2, 0, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
+/* src[] = { offset }. const_index[0] = { base } */
+LOAD(input, 1, 1, NIR_INTRINSIC_CAN_ELIMINATE | NIR_INTRINSIC_CAN_REORDER)
+/* src[] = { vertex, offset }. const_index[] = { base } */
+LOAD(per_vertex_input, 2, 1, NIR_INTRINSIC_CAN_ELIMINATE |
NIR_INTRINSIC_CAN_REORDER)
+/* src[] = { buffer_index, offset }. No const_index */
+LOAD(ssbo, 2, 0, NIR_INTRINSIC_CAN_ELIMINATE)
+/* src[] = { offset }. const_index[] = { base } */
+LOAD(output, 1, 1, NIR_INTRINSIC_CAN_ELIMINATE)
+/* src[] = { vertex, offset }. const_index[] = { base } */
+LOAD(per_vertex_output, 2, 1, NIR_INTRINSIC_CAN_ELIMINATE)
/*
- * Stores work the same way as loads, except now the first register input is
- * the value or array to store and the optional second input is the indirect
- * offset. SSBO stores are similar, but they accept an extra source for the
- * block index and an extra index with the writemask to use.
+ * Stores work the same way as loads, except now the first source is the value
+ * to store and the second (and possibly third) source specify where to store
+ * the value. SSBO stores also have a write mask as const_index[0].
*/
-#define STORE(name, extra_srcs, extra_srcs_size, extra_indices, flags) \
- INTRINSIC(store_##name, 1 + extra_srcs, \
- ARR(0, extra_srcs_size, extra_srcs_size, extra_srcs_size), \
- false, 0, 0, 1 + extra_indices, flags) \
- INTRINSIC(store_##name##_indirect, 2 + extra_srcs, \
- ARR(0, 1, extra_srcs_size, extra_srcs_size), \
- false, 0, 0, 1 + extra_indices, flags)
+#define STORE(name, srcs, indices, flags) \
+ INTRINSIC(store_##name, srcs, ARR(0, 1, 1, 1), false, 0, 0, indices, flags)
-STORE(output, 0, 0, 0, 0)
-STORE(per_vertex_output, 1, 1, 0, 0)
-STORE(ssbo, 1, 1, 1, 0)
+/* src[] = { value, offset }. const_index[] = { base } */
+STORE(output, 2, 1, 0)
+/* src[] = { value, vertex, offset }. const_index[] = { base } */
+STORE(per_vertex_output, 3, 1, 0)
+/* src[] = { value, block_index, offset }. const_index[] = { write_mask } */
+STORE(ssbo, 3, 1, 0)
-LAST_INTRINSIC(store_ssbo_indirect)
+LAST_INTRINSIC(store_ssbo)
diff --git a/src/glsl/nir/nir_lower_phis_to_scalar.c
b/src/glsl/nir/nir_lower_phis_to_scalar.c
index aa124d9..2f5927f 100644
--- a/src/glsl/nir/nir_lower_phis_to_scalar.c
+++ b/src/glsl/nir/nir_lower_phis_to_scalar.c
@@ -91,13 +91,9 @@ is_phi_src_scalarizable(nir_phi_src *src,
case nir_intrinsic_interp_var_at_sample:
case nir_intrinsic_interp_var_at_offset:
case nir_intrinsic_load_uniform:
- case nir_intrinsic_load_uniform_indirect:
case nir_intrinsic_load_ubo:
- case nir_intrinsic_load_ubo_indirect:
case nir_intrinsic_load_ssbo:
- case nir_intrinsic_load_ssbo_indirect:
case nir_intrinsic_load_input:
- case nir_intrinsic_load_input_indirect:
return true;
default:
break;
diff --git a/src/glsl/nir/nir_print.c b/src/glsl/nir/nir_print.c
index c98a047..bb451f5 100644
--- a/src/glsl/nir/nir_print.c
+++ b/src/glsl/nir/nir_print.c
@@ -439,21 +439,15 @@ print_intrinsic_instr(nir_intrinsic_instr *instr,
print_state *state)
switch (instr->intrinsic) {
case nir_intrinsic_load_uniform:
- case nir_intrinsic_load_uniform_indirect:
var_list = &state->shader->uniforms;
break;
case nir_intrinsic_load_input:
- case nir_intrinsic_load_input_indirect:
case nir_intrinsic_load_per_vertex_input:
- case nir_intrinsic_load_per_vertex_input_indirect:
var_list = &state->shader->inputs;
break;
case nir_intrinsic_load_output:
- case nir_intrinsic_load_output_indirect:
case nir_intrinsic_store_output:
- case nir_intrinsic_store_output_indirect:
case nir_intrinsic_store_per_vertex_output:
- case nir_intrinsic_store_per_vertex_output_indirect:
var_list = &state->shader->outputs;
break;
default:
@@ -461,8 +455,7 @@ print_intrinsic_instr(nir_intrinsic_instr *instr,
print_state *state)
}
nir_foreach_variable(var, var_list) {
- if ((var->data.driver_location == instr->const_index[0]) &&
- var->name) {
+ if ((var->data.driver_location == instr->const_index[0]) && var->name) {
fprintf(fp, "\t/* %s */", var->name);
break;
}
--
2.5.0.400.gff86faf
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