[Mesa-dev] [PATCH 19/23] nir: Return progress from nir_convert_from_ssa().

[Matt Turner]

---
 src/compiler/nir/nir.h          |  2 +-
 src/compiler/nir/nir_from_ssa.c | 21 +++++++++++++++------
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
index db47699..0a127cd 100644
--- a/src/compiler/nir/nir.h
+++ b/src/compiler/nir/nir.h
@@ -2587,7 +2587,7 @@ void nir_convert_loop_to_lcssa(nir_loop *loop);
  * registers.  If false, convert all values (even those not involved in a phi
  * node) to registers.
  */
-void nir_convert_from_ssa(nir_shader *shader, bool phi_webs_only);
+bool nir_convert_from_ssa(nir_shader *shader, bool phi_webs_only);
 
 bool nir_lower_phis_to_regs_block(nir_block *block);
 bool nir_lower_ssa_defs_to_regs_block(nir_block *block);
diff --git a/src/compiler/nir/nir_from_ssa.c b/src/compiler/nir/nir_from_ssa.c
index d2646c6..07fcceb 100644
--- a/src/compiler/nir/nir_from_ssa.c
+++ b/src/compiler/nir/nir_from_ssa.c
@@ -524,18 +524,21 @@ rewrite_ssa_def(nir_ssa_def *def, void *void_state)
 static bool
 resolve_registers_block(nir_block *block, struct from_ssa_state *state)
 {
+   bool progress = false;
+
    nir_foreach_instr_safe(instr, block) {
       state->instr = instr;
-      nir_foreach_ssa_def(instr, rewrite_ssa_def, state);
+      progress |= nir_foreach_ssa_def(instr, rewrite_ssa_def, state);
 
       if (instr->type == nir_instr_type_phi) {
          nir_instr_remove(instr);
          ralloc_steal(state->dead_ctx, instr);
+         progress = true;
       }
    }
    state->instr = NULL;
 
-   return true;
+   return progress;
 }
 
 static void
@@ -756,10 +759,11 @@ resolve_parallel_copies_block(nir_block *block, struct from_ssa_state *state)
    return true;
 }
 
-static void
+static bool
 nir_convert_from_ssa_impl(nir_function_impl *impl, bool phi_webs_only)
 {
    struct from_ssa_state state;
+   bool progress = false;
 
    nir_builder_init(&state.builder, impl);
    state.dead_ctx = ralloc_context(NULL);
@@ -791,7 +795,7 @@ nir_convert_from_ssa_impl(nir_function_impl *impl, bool phi_webs_only)
    }
 
    nir_foreach_block(block, impl) {
-      resolve_registers_block(block, &state);
+      progress |= resolve_registers_block(block, &state);
    }
 
    nir_foreach_block(block, impl) {
@@ -804,15 +808,20 @@ nir_convert_from_ssa_impl(nir_function_impl *impl, bool phi_webs_only)
    /* Clean up dead instructions and the hash tables */
    _mesa_hash_table_destroy(state.merge_node_table, NULL);
    ralloc_free(state.dead_ctx);
+   return progress;
 }
 
-void
+bool
 nir_convert_from_ssa(nir_shader *shader, bool phi_webs_only)
 {
+   bool progress = false;
+
    nir_foreach_function(function, shader) {
       if (function->impl)
-         nir_convert_from_ssa_impl(function->impl, phi_webs_only);
+         progress |= nir_convert_from_ssa_impl(function->impl, phi_webs_only);
    }
+
+   return progress;
 }
 
 
-- 
2.10.2