aco: use std::vector::reserve() more often

This removes the majority of vector re-allocations.

Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18105>

src/amd/compiler/aco_instruction_selection.cpp

@@ -10290,6 +10290,8 @@ visit_jump(isel_context* ctx, nir_jump_instr* instr)
 void
 visit_block(isel_context* ctx, nir_block* block)
 {
+   ctx->block->instructions.reserve(ctx->block->instructions.size() +
+                                    exec_list_length(&block->instr_list) * 2);
    nir_foreach_instr (instr, block) {
       switch (instr->type) {
       case nir_instr_type_alu: visit_alu_instr(ctx, nir_instr_as_alu(instr)); break;

src/amd/compiler/aco_instruction_selection_setup.cpp

@@ -934,6 +934,10 @@ setup_isel_context(Program* program, unsigned shader_count, struct nir_shader* c
 
    ctx.program->config->scratch_bytes_per_wave = align(scratch_size * ctx.program->wave_size, 1024);
 
+   unsigned nir_num_blocks = 0;
+   for (unsigned i = 0; i < shader_count; i++)
+      nir_num_blocks += nir_shader_get_entrypoint(shaders[i])->num_blocks;
+   ctx.program->blocks.reserve(nir_num_blocks * 2);
    ctx.block = ctx.program->create_and_insert_block();
    ctx.block->kind = block_kind_top_level;
 

src/amd/compiler/aco_lower_to_hw_instr.cpp

@@ -2009,6 +2009,7 @@ lower_to_hw_instr(Program* program)
       lower_context ctx;
       ctx.program = program;
       ctx.block = block;
+      ctx.instructions.reserve(block->instructions.size());
       Builder bld(program, &ctx.instructions);
 
       emit_set_mode_from_block(bld, *program, block, (block_idx == 0));
@@ -2520,7 +2521,7 @@ lower_to_hw_instr(Program* program)
             ctx.instructions.emplace_back(std::move(instr));
          }
       }
-      block->instructions.swap(ctx.instructions);
+      block->instructions = std::move(ctx.instructions);
    }
 }
 

src/amd/compiler/aco_optimizer.cpp

@@ -4828,11 +4828,11 @@ optimize(Program* program)
 
    /* 4. Add literals to instructions */
    for (Block& block : program->blocks) {
-      ctx.instructions.clear();
+      ctx.instructions.reserve(block.instructions.size());
       ctx.fp_mode = block.fp_mode;
       for (aco_ptr<Instruction>& instr : block.instructions)
          apply_literals(ctx, instr);
-      block.instructions.swap(ctx.instructions);
+      block.instructions = std::move(ctx.instructions);
    }
 }
 

src/amd/compiler/aco_register_allocation.cpp

@@ -2674,6 +2674,7 @@ register_allocation(Program* program, std::vector<IDSet>& live_out_per_block, ra
       ctx.war_hint.reset();
 
       std::vector<aco_ptr<Instruction>> instructions;
+      instructions.reserve(block.instructions.size());
 
       /* this is a slight adjustment from the paper as we already have phi nodes:
        * We consider them incomplete phis and only handle the definition. */