From 6e3446422f816d974a7cd5dfa27e8db3829e1cf0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Sch=C3=BCrmann?= <daniel@schuermann.dev>
Date: Mon, 8 Apr 2024 16:15:53 +0200
Subject: [PATCH] aco: introduce aco_opcode::p_boolean_phi

This opcode is only used during instruction selection and
immediately lowered to linear phis afterwards.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/28661>
---
 src/amd/compiler/aco_instruction_selection.cpp |  6 +++++-
 src/amd/compiler/aco_lower_phis.cpp            | 12 ++++++------
 src/amd/compiler/aco_opcodes.py                |  1 +
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/amd/compiler/aco_instruction_selection.cpp b/src/amd/compiler/aco_instruction_selection.cpp
index f98912d2980..3498f0fd144 100644
--- a/src/amd/compiler/aco_instruction_selection.cpp
+++ b/src/amd/compiler/aco_instruction_selection.cpp
@@ -10037,6 +10037,10 @@ visit_phi(isel_context* ctx, nir_phi_instr* instr)
    bool logical = !dst.is_linear() || instr->def.divergent;
    logical |= (ctx->block->kind & block_kind_merge) != 0;
    aco_opcode opcode = logical ? aco_opcode::p_phi : aco_opcode::p_linear_phi;
+   if (instr->def.bit_size == 1) {
+      logical = true;
+      opcode = aco_opcode::p_boolean_phi;
+   }
 
    /* we want a sorted list of sources, since the predecessor list is also sorted */
    std::map<unsigned, nir_def*> phi_src;
@@ -10432,7 +10436,7 @@ visit_loop(isel_context* ctx, nir_loop* loop)
             else
                instr->operands.back() =
                   create_continue_phis(ctx, loop_header_idx, ctx->block->index, instr, vals);
-         } else if (!is_phi(instr)) {
+         } else if (!is_phi(instr) && instr->opcode != aco_opcode::p_boolean_phi) {
             break;
          }
       }
diff --git a/src/amd/compiler/aco_lower_phis.cpp b/src/amd/compiler/aco_lower_phis.cpp
index c140aef5c4d..69d46fa743a 100644
--- a/src/amd/compiler/aco_lower_phis.cpp
+++ b/src/amd/compiler/aco_lower_phis.cpp
@@ -367,12 +367,12 @@ lower_phis(Program* program)
 
    for (Block& block : program->blocks) {
       for (aco_ptr<Instruction>& phi : block.instructions) {
-         if (phi->opcode == aco_opcode::p_phi) {
-            assert(program->wave_size == 64 ? phi->definitions[0].regClass() != s1
-                                            : phi->definitions[0].regClass() != s2);
-            if (phi->definitions[0].regClass() == program->lane_mask)
-               lower_divergent_bool_phi(program, &state, &block, phi);
-            else if (phi->definitions[0].regClass().is_subdword())
+         if (phi->opcode == aco_opcode::p_boolean_phi) {
+            assert(program->wave_size == 64 ? phi->definitions[0].regClass() == s2
+                                            : phi->definitions[0].regClass() == s1);
+            lower_divergent_bool_phi(program, &state, &block, phi);
+         } else if (phi->opcode == aco_opcode::p_phi) {
+            if (phi->definitions[0].regClass().is_subdword())
                lower_subdword_phis(program, &block, phi);
          } else if (!is_phi(phi)) {
             break;
diff --git a/src/amd/compiler/aco_opcodes.py b/src/amd/compiler/aco_opcodes.py
index e4ddb645195..a56f7147d28 100644
--- a/src/amd/compiler/aco_opcodes.py
+++ b/src/amd/compiler/aco_opcodes.py
@@ -329,6 +329,7 @@ insn("p_startpgm")
 insn("p_return")
 insn("p_phi")
 insn("p_linear_phi")
+insn("p_boolean_phi")
 insn("p_as_uniform")
 insn("p_unit_test")