[Mesa-dev] [PATCH 4/4] nir: Add some asserts that we don't put derefs in phis

[Jason Ekstrand]

The lcssa and phis_to_regs passes are used by various NIR optimizations
that modify the CFG.  Putting a couple of asserts will help ensure that
we don't accidentally put derefs in phis as part of an optimization
pass.
---
 src/compiler/nir/nir_from_ssa.c | 2 ++
 src/compiler/nir/nir_to_lcssa.c | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/src/compiler/nir/nir_from_ssa.c b/src/compiler/nir/nir_from_ssa.c
index 1aa35509b11..19d4bc33820 100644
--- a/src/compiler/nir/nir_from_ssa.c
+++ b/src/compiler/nir/nir_from_ssa.c
@@ -901,6 +901,8 @@ nir_lower_phis_to_regs_block(nir_block *block)
 
       nir_foreach_phi_src(src, phi) {
          assert(src->src.is_ssa);
+         /* We don't want derefs ending up in phi sources */
+         assert(!nir_src_as_deref(src->src));
          place_phi_read(shader, reg, src->src.ssa, src->pred);
       }
 
diff --git a/src/compiler/nir/nir_to_lcssa.c b/src/compiler/nir/nir_to_lcssa.c
index 9b3539193ea..0f62fc39400 100644
--- a/src/compiler/nir/nir_to_lcssa.c
+++ b/src/compiler/nir/nir_to_lcssa.c
@@ -111,6 +111,9 @@ convert_loop_exit_for_ssa(nir_ssa_def *def, void *void_state)
    if (all_uses_inside_loop)
       return true;
 
+   /* We don't want derefs ending up in phi sources */
+   assert(def->parent_instr->type != nir_instr_type_deref);
+
    /* Initialize a phi-instruction */
    nir_phi_instr *phi = nir_phi_instr_create(state->shader);
    nir_ssa_dest_init(&phi->instr, &phi->dest,
-- 
2.17.1