[Mesa-dev] [PATCH 1/6] nir/validate: Validated dests after sources

[Jason Ekstrand]

Previously, if someone accidentally made an instruction that refers to its
own SSA destination, the validator wouldn't catch it.  The reason for this
is that it validated the destination too early and, by the time it got to
the source, the destination SSA value was already added to the set of seen
SSA values so it would assume that it came from some previous instruction.
By moving destination validation to be after source validation, the SSA
value is not in the list of seen values and the validator will catch
self-referential instructions.
---
 src/glsl/nir/nir_validate.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/src/glsl/nir/nir_validate.c b/src/glsl/nir/nir_validate.c
index a42e830..349cccc 100644
--- a/src/glsl/nir/nir_validate.c
+++ b/src/glsl/nir/nir_validate.c
@@ -290,11 +290,11 @@ validate_alu_instr(nir_alu_instr *instr, validate_state *state)
 {
    assert(instr->op < nir_num_opcodes);
 
-   validate_alu_dest(&instr->dest, state);
-
    for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
       validate_alu_src(instr, i, state);
    }
+
+   validate_alu_dest(&instr->dest, state);
 }
 
 static void
@@ -375,6 +375,11 @@ validate_intrinsic_instr(nir_intrinsic_instr *instr, validate_state *state)
       validate_src(&instr->src[i], state);
    }
 
+   unsigned num_vars = nir_intrinsic_infos[instr->intrinsic].num_variables;
+   for (unsigned i = 0; i < num_vars; i++) {
+      validate_deref_var(instr, instr->variables[i], state);
+   }
+
    if (nir_intrinsic_infos[instr->intrinsic].has_dest) {
       unsigned components_written =
          nir_intrinsic_infos[instr->intrinsic].dest_components;
@@ -392,11 +397,6 @@ validate_intrinsic_instr(nir_intrinsic_instr *instr, validate_state *state)
       validate_dest(&instr->dest, state);
    }
 
-   unsigned num_vars = nir_intrinsic_infos[instr->intrinsic].num_variables;
-   for (unsigned i = 0; i < num_vars; i++) {
-      validate_deref_var(instr, instr->variables[i], state);
-   }
-
    switch (instr->intrinsic) {
    case nir_intrinsic_load_var: {
       const struct glsl_type *type =
@@ -432,8 +432,6 @@ validate_intrinsic_instr(nir_intrinsic_instr *instr, validate_state *state)
 static void
 validate_tex_instr(nir_tex_instr *instr, validate_state *state)
 {
-   validate_dest(&instr->dest, state);
-
    bool src_type_seen[nir_num_tex_src_types];
    for (unsigned i = 0; i < nir_num_tex_src_types; i++)
       src_type_seen[i] = false;
@@ -446,6 +444,8 @@ validate_tex_instr(nir_tex_instr *instr, validate_state *state)
 
    if (instr->sampler != NULL)
       validate_deref_var(instr, instr->sampler, state);
+
+   validate_dest(&instr->dest, state);
 }
 
 static void
-- 
2.5.0.400.gff86faf