r600/sfn: replace hand-backed literal check by NIR function

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6879>

src/gallium/drivers/r600/sfn/sfn_emitinstruction.cpp

@@ -134,15 +134,6 @@ int EmitInstruction::lookup_register_index(const nir_dest& dst)
    return m_proc.lookup_register_index(dst);
 }
 
-const nir_load_const_instr*
-EmitInstruction::get_literal_register(const nir_src& src) const
-{
-   if (src.is_ssa)
-      return m_proc.get_literal_constant(src.ssa->index);
-   else
-      return nullptr;
-}
-
 PValue EmitInstruction::get_temp_register(int channel)
 {
    return m_proc.get_temp_register(channel);

src/gallium/drivers/r600/sfn/sfn_emitinstruction.h

@@ -59,8 +59,6 @@ protected:
    PValue from_nir(const nir_alu_dest& v, unsigned component);
    PValue from_nir(const nir_dest& v, unsigned component);
 
-   const nir_load_const_instr* get_literal_register(const nir_src& src) const;
-
    int lookup_register_index(const nir_src& src) const;
    int lookup_register_index(const nir_dest& dst);
    PValue create_register_from_nir_src(const nir_src& src, unsigned comp);

src/gallium/drivers/r600/sfn/sfn_emittexinstruction.cpp

@@ -682,7 +682,7 @@ bool EmitTexInstruction::emit_tex_tg4(nir_tex_instr* instr, TexInputs& src)
 
    bool literal_offset = false;
    if (src.offset) {
-      literal_offset =  src.offset->is_ssa && get_literal_register(*src.offset);
+      literal_offset =  nir_src_as_const_value(*src.offset) != 0;
       r600::sfn_log << SfnLog::tex << " really have offsets and they are " <<
                        (literal_offset ? "literal" : "varying") <<
                        "\n";
@@ -976,11 +976,11 @@ void EmitTexInstruction::set_offsets(TexInstruction* ir, nir_src *offset)
       return;
 
    assert(offset->is_ssa);
-   auto literal = get_literal_register(*offset);
+   auto literal = nir_src_as_const_value(*offset);
    assert(literal);
 
    for (int i = 0; i < offset->ssa->num_components; ++i) {
-      ir->set_offset(i, literal->value[i].i32);
+      ir->set_offset(i, literal[i].i32);
    }
 }
 

src/gallium/drivers/r600/sfn/sfn_nir.cpp

@@ -246,8 +246,8 @@ bool ShaderFromNir::emit_instruction(nir_instr *instr)
       return impl->emit_deref_instruction(nir_instr_as_deref(instr));
    case nir_instr_type_intrinsic:
       return impl->emit_intrinsic_instruction(nir_instr_as_intrinsic(instr));
-   case nir_instr_type_load_const:
-      return impl->set_literal_constant(nir_instr_as_load_const(instr));
+   case nir_instr_type_load_const: /* const values are loaded when needed */
+      return true;
    case nir_instr_type_tex:
       return impl->emit_tex_instruction(instr);
    case nir_instr_type_jump:

src/gallium/drivers/r600/sfn/sfn_shader_geometry.cpp

@@ -291,18 +291,15 @@ bool GeometryShaderFromNir::emit_load_from_array(nir_intrinsic_instr* instr,
 {
    auto dest = vec_from_nir(instr->dest, instr->num_components);
 
-   const nir_load_const_instr* literal_index = nullptr;
-
-   if (array_deref.index->is_ssa)
-      literal_index = get_literal_constant(array_deref.index->ssa->index);
+   auto literal_index = nir_src_as_const_value(*array_deref.index);
 
    if (!literal_index) {
       sfn_log << SfnLog::err << "GS: Indirect input addressing not (yet) supported\n";
       return false;
    }
-   assert(literal_index->value[0].u32 < 6);
-   PValue addr = m_per_vertex_offsets[literal_index->value[0].u32];
+   assert(literal_index->u32 < 6);
 
+   PValue addr = m_per_vertex_offsets[literal_index->u32];
    auto fetch = new FetchInstruction(vc_fetch, no_index_offset, dest, addr,
                                      16 * array_deref.var->data.driver_location,
                                      R600_GS_RING_CONST_BUFFER, PValue(), bim_none, true);

src/gallium/drivers/r600/sfn/sfn_valuepool.cpp

@@ -113,18 +113,18 @@ PValue ValuePool::from_nir(const nir_src& v, unsigned component, unsigned swizzl
          return reg;
    }
 
-
-   auto literal_val = m_literal_constants.find(index);
-   if (literal_val != m_literal_constants.end()) {
-      switch (literal_val->second->def.bit_size) {
+   auto literal_val = nir_src_as_const_value(v);
+   if (literal_val) {
+      assert(v.is_ssa);
+      switch (v.ssa->bit_size) {
       case 1:
-         return PValue(new LiteralValue(literal_val->second->value[swizzled].b ? 0xffffffff : 0, component));
+         return PValue(new LiteralValue(literal_val[swizzled].b ? 0xffffffff : 0, component));
       case 32:
-         return literal(literal_val->second->value[swizzled].u32);
+         return literal(literal_val[swizzled].u32);
       default:
-         sfn_log << SfnLog::reg << "Unsupported bit size " << literal_val->second->def.bit_size
+         sfn_log << SfnLog::reg << "Unsupported bit size " << v.ssa->bit_size
                  << " fall back to 32\n";
-         return PValue(new LiteralValue(literal_val->second->value[swizzled].u32, component));
+         return PValue(new LiteralValue(literal_val[swizzled].u32, component));
       }
    }
 
@@ -481,38 +481,6 @@ bool ValuePool::create_undef(nir_ssa_undef_instr* instr)
    return true;
 }
 
-bool ValuePool::set_literal_constant(nir_load_const_instr* instr)
-{
-   sfn_log << SfnLog::reg << "Add literal " <<  instr->def.index << "\n";
-   m_literal_constants[instr->def.index] = instr;
-   return true;
-}
-
-const nir_load_const_instr* ValuePool::get_literal_constant(int index)
-{
-   sfn_log << SfnLog::reg << "Try to locate literal " << index  << "...";
-   auto literal = m_literal_constants.find(index);
-   if (literal == m_literal_constants.end()) {
-      sfn_log << SfnLog::reg << " not found\n";
-      return nullptr;
-   }
-   sfn_log << SfnLog::reg << " found\n";
-   return literal->second;
-}
-
-void ValuePool::add_uniform(unsigned index, const PValue& value)
-{
-   sfn_log << SfnLog::reg << "Reserve " << *value << " as " << index << "\n";
-   m_uniforms[index] = value;
-}
-
-PValue ValuePool::uniform(unsigned index)
-{
-   sfn_log << SfnLog::reg << "Search index " << index << "\n";
-   auto i = m_uniforms.find(index);
-   return i == m_uniforms.end() ? PValue() : i->second;
-}
-
 int ValuePool::allocate_with_mask(unsigned index, unsigned mask, bool pre_alloc)
 {
    int retval;

src/gallium/drivers/r600/sfn/sfn_valuepool.h

@@ -159,9 +159,6 @@ public:
     */
    bool create_undef(nir_ssa_undef_instr* instr);
 
-   bool set_literal_constant(nir_load_const_instr* instr);
-
-   const nir_load_const_instr *get_literal_constant(int index);
 
    void add_uniform(unsigned index, const PValue &value);
 
@@ -225,8 +222,6 @@ private:
 
    std::set<unsigned> m_ssa_undef;
 
-   LiteralBuffer m_literal_constants;
-
    std::map<unsigned, unsigned> m_local_register_map;
    std::map<unsigned, unsigned> m_ssa_register_map;