aco: Handle nir_debug_info_instr

Propagated debug info using p_debug_info and Program::debug_info.
Offsets into the shader binary are gathered during assembly.
This will be usefull for mapping back the disassembled shader to
nir, glsl or spirv.

Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29298>

src/amd/compiler/aco_assembler.cpp

@@ -1216,6 +1216,11 @@ emit_instruction(asm_context& ctx, std::vector<uint32_t>& out, Instruction* inst
       instr->opcode = aco_opcode::s_mov_b32;
       /* in case it's an inline constant, make it a literal */
       instr->operands[0] = Operand::literal32(0);
+   } else if (instr->opcode == aco_opcode::p_debug_info) {
+      assert(instr->operands[0].isConstant());
+      uint32_t index = instr->operands[0].constantValue();
+      ctx.program->debug_info[index].offset = (out.size() - 1) * 4;
+      return;
    }
 
    /* Promote VOP12C to VOP3 if necessary. */

src/amd/compiler/aco_instruction_selection.cpp

@@ -10539,6 +10539,30 @@ visit_jump(isel_context* ctx, nir_jump_instr* instr)
    }
 }
 
+void
+visit_debug_info(isel_context* ctx, nir_debug_info_instr* instr)
+{
+   ac_shader_debug_info info;
+   memset(&info, 0, sizeof(info));
+
+   switch (instr->type) {
+   case nir_debug_info_src_loc:
+      info.type = ac_shader_debug_info_src_loc;
+      info.src_loc.file = strdup(nir_src_as_string(instr->src_loc.filename));
+      info.src_loc.line = instr->src_loc.line;
+      info.src_loc.column = instr->src_loc.column;
+      info.src_loc.spirv_offset = instr->src_loc.spirv_offset;
+      break;
+   default:
+      return;
+   }
+
+   Builder bld(ctx->program, ctx->block);
+   bld.pseudo(aco_opcode::p_debug_info, Operand::c32(ctx->program->debug_info.size()));
+
+   ctx->program->debug_info.push_back(info);
+}
+
 void
 visit_block(isel_context* ctx, nir_block* block)
 {
@@ -10562,6 +10586,7 @@ visit_block(isel_context* ctx, nir_block* block)
       case nir_instr_type_undef: visit_undef(ctx, nir_instr_as_undef(instr)); break;
       case nir_instr_type_deref: break;
       case nir_instr_type_jump: visit_jump(ctx, nir_instr_as_jump(instr)); break;
+      case nir_instr_type_debug_info: visit_debug_info(ctx, nir_instr_as_debug_info(instr)); break;
       default: isel_err(instr, "Unknown NIR instr type");
       }
    }

src/amd/compiler/aco_ir.h

@@ -15,6 +15,7 @@
 
 #include "ac_binary.h"
 #include "ac_hw_stage.h"
+#include "ac_shader_debug_info.h"
 #include "ac_shader_util.h"
 #include "amd_family.h"
 #include <algorithm>
@@ -2131,6 +2132,8 @@ public:
    bool is_prolog = false;
    bool is_epilog = false;
 
+   std::vector<ac_shader_debug_info> debug_info;
+
    std::vector<uint8_t> constant_data;
    Temp private_segment_buffer;
    Temp scratch_offset;

src/amd/compiler/aco_lower_to_hw_instr.cpp

@@ -2246,7 +2246,8 @@ lower_to_hw_instr(Program* program)
          }
 
          aco_ptr<Instruction> mov;
-         if (instr->isPseudo() && instr->opcode != aco_opcode::p_unit_test) {
+         if (instr->isPseudo() && instr->opcode != aco_opcode::p_unit_test &&
+             instr->opcode != aco_opcode::p_debug_info) {
             Pseudo_instruction* pi = &instr->pseudo();
 
             switch (instr->opcode) {
@@ -2908,7 +2909,7 @@ lower_to_hw_instr(Program* program)
                              inst->isLDSDIR()) {
                      // TODO: GFX6-9 can use vskip
                      can_remove = prefer_remove;
-                  } else {
+                  } else if (inst->opcode != aco_opcode::p_debug_info) {
                      can_remove = false;
                      assert(false && "Pseudo instructions should be lowered by this point.");
                   }

src/amd/compiler/aco_opcodes.py

@@ -439,6 +439,8 @@ insn("p_end_with_regs")
 
 insn("p_shader_cycles_hi_lo_hi")
 
+insn("p_debug_info")
+
 # SOP2 instructions: 2 scalar inputs, 1 scalar output (+optional scc)
 SOP2 = {
    ("s_add_u32",            dst(1, SCC), src(1, 1), op(0x00)),

src/amd/compiler/aco_print_ir.cpp

@@ -899,6 +899,24 @@ print_stage(Stage stage, FILE* output)
    fprintf(output, ")\n");
 }
 
+void
+print_debug_info(const Program* program, const Instruction* instr, FILE* output)
+{
+   fprintf(output, "// ");
+
+   assert(instr->operands[0].isConstant());
+   const auto& info = program->debug_info[instr->operands[0].constantValue()];
+   switch (info.type) {
+   case ac_shader_debug_info_src_loc:
+      if (info.src_loc.spirv_offset)
+         fprintf(output, "0x%x ", info.src_loc.spirv_offset);
+      fprintf(output, "%s:%u:%u", info.src_loc.file, info.src_loc.line, info.src_loc.column);
+      break;
+   }
+
+   fprintf(output, "\n");
+}
+
 void
 aco_print_block(enum amd_gfx_level gfx_level, const Block* block, FILE* output, unsigned flags,
                 const Program* program)
@@ -926,6 +944,10 @@ aco_print_block(enum amd_gfx_level gfx_level, const Block* block, FILE* output,
 
    for (auto const& instr : block->instructions) {
       fprintf(output, "\t");
+      if (instr->opcode == aco_opcode::p_debug_info) {
+         print_debug_info(program, instr.get(), output);
+         continue;
+      }
       if (flags & print_live_vars) {
          RegisterDemand demand = instr->register_demand;
          fprintf(output, "(%3u vgpr, %3u sgpr)   ", demand.vgpr, demand.sgpr);