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From 95b001cb190dbc0ec71d760e1d9c457c1a3e4f70 Mon Sep 17 00:00:00 2001 |
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From: Jason Ekstrand <jason.ekstrand@intel.com> |
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Date: Mon, 11 Mar 2019 20:43:15 -0500 |
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Subject: [PATCH 05/22] glsl/lower_vector_derefs: Don't use a temporary for TCS |
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outputs |
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|
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Tessellation control shader outputs act as if they have memory backing |
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them and you can have multiple writes to different components of the |
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same vector in-flight at the same time. When this happens, the load vec |
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store pattern that gets used by ir_triop_vector_insert doesn't yield the |
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correct results. Instead, just emit a sequence of conditional |
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assignments. |
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|
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Reviewed-by: Ian Romanick <ian.d.romanick@intel.com> |
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Cc: mesa-stable@lists.freedesktop.org |
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(cherry picked from commit bd17bdc56b34a08c421172df27fe07294c7a7024) |
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--- |
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src/compiler/glsl/lower_vector_derefs.cpp | 74 ++++++++++++++++++++--- |
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1 file changed, 64 insertions(+), 10 deletions(-) |
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|
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diff --git a/src/compiler/glsl/lower_vector_derefs.cpp b/src/compiler/glsl/lower_vector_derefs.cpp |
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index 6cd9a2d819a..2aae30d8201 100644 |
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--- a/src/compiler/glsl/lower_vector_derefs.cpp |
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+++ b/src/compiler/glsl/lower_vector_derefs.cpp |
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@@ -32,8 +32,9 @@ namespace { |
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|
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class vector_deref_visitor : public ir_rvalue_enter_visitor { |
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public: |
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- vector_deref_visitor() |
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- : progress(false) |
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+ vector_deref_visitor(void *mem_ctx, gl_shader_stage shader_stage) |
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+ : progress(false), shader_stage(shader_stage), |
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+ factory(&factory_instructions, mem_ctx) |
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{ |
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} |
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|
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@@ -45,6 +46,9 @@ public: |
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virtual ir_visitor_status visit_enter(ir_assignment *ir); |
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|
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bool progress; |
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+ gl_shader_stage shader_stage; |
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+ exec_list factory_instructions; |
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+ ir_factory factory; |
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}; |
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|
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} /* anonymous namespace */ |
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@@ -65,13 +69,63 @@ vector_deref_visitor::visit_enter(ir_assignment *ir) |
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ir_constant *old_index_constant = |
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deref->array_index->constant_expression_value(mem_ctx); |
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if (!old_index_constant) { |
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- ir->rhs = new(mem_ctx) ir_expression(ir_triop_vector_insert, |
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- new_lhs->type, |
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- new_lhs->clone(mem_ctx, NULL), |
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- ir->rhs, |
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- deref->array_index); |
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- ir->write_mask = (1 << new_lhs->type->vector_elements) - 1; |
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- ir->set_lhs(new_lhs); |
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+ if (shader_stage == MESA_SHADER_TESS_CTRL && |
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+ deref->variable_referenced()->data.mode == ir_var_shader_out) { |
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+ /* Tessellation control shader outputs act as if they have memory |
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+ * backing them and if we have writes from multiple threads |
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+ * targeting the same vec4 (this can happen for patch outputs), the |
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+ * load-vec-store pattern of ir_triop_vector_insert doesn't work. |
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+ * Instead, we have to lower to a series of conditional write-masked |
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+ * assignments. |
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+ */ |
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+ ir_variable *const src_temp = |
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+ factory.make_temp(ir->rhs->type, "scalar_tmp"); |
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+ |
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+ /* The newly created variable declaration goes before the assignment |
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+ * because we're going to set it as the new LHS. |
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+ */ |
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+ ir->insert_before(factory.instructions); |
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+ ir->set_lhs(new(mem_ctx) ir_dereference_variable(src_temp)); |
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+ |
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+ ir_variable *const arr_index = |
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+ factory.make_temp(deref->array_index->type, "index_tmp"); |
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+ factory.emit(assign(arr_index, deref->array_index)); |
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+ |
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+ for (unsigned i = 0; i < new_lhs->type->vector_elements; i++) { |
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+ ir_constant *const cmp_index = |
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+ ir_constant::zero(factory.mem_ctx, deref->array_index->type); |
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+ cmp_index->value.u[0] = i; |
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+ |
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+ ir_rvalue *const lhs_clone = new_lhs->clone(factory.mem_ctx, NULL); |
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+ ir_dereference_variable *const src_temp_deref = |
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+ new(mem_ctx) ir_dereference_variable(src_temp); |
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+ |
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+ if (new_lhs->ir_type != ir_type_swizzle) { |
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+ assert(lhs_clone->as_dereference()); |
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+ ir_assignment *cond_assign = |
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+ new(mem_ctx) ir_assignment(lhs_clone->as_dereference(), |
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+ src_temp_deref, |
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+ equal(arr_index, cmp_index), |
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+ WRITEMASK_X << i); |
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+ factory.emit(cond_assign); |
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+ } else { |
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+ ir_assignment *cond_assign = |
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+ new(mem_ctx) ir_assignment(swizzle(lhs_clone, i, 1), |
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+ src_temp_deref, |
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+ equal(arr_index, cmp_index)); |
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+ factory.emit(cond_assign); |
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+ } |
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+ } |
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+ ir->insert_after(factory.instructions); |
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+ } else { |
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+ ir->rhs = new(mem_ctx) ir_expression(ir_triop_vector_insert, |
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+ new_lhs->type, |
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+ new_lhs->clone(mem_ctx, NULL), |
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+ ir->rhs, |
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+ deref->array_index); |
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+ ir->write_mask = (1 << new_lhs->type->vector_elements) - 1; |
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+ ir->set_lhs(new_lhs); |
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+ } |
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} else if (new_lhs->ir_type != ir_type_swizzle) { |
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ir->set_lhs(new_lhs); |
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ir->write_mask = 1 << old_index_constant->get_uint_component(0); |
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@@ -105,7 +159,7 @@ vector_deref_visitor::handle_rvalue(ir_rvalue **rv) |
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bool |
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lower_vector_derefs(gl_linked_shader *shader) |
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{ |
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- vector_deref_visitor v; |
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+ vector_deref_visitor v(shader->ir, shader->Stage); |
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|
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visit_list_elements(&v, shader->ir); |
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|
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-- |
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2.21.0 |
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