panfrost/util: Move nir_undef_to_zero into core nir and add 'lower'

Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7565>

src/compiler/Makefile.sources

@@ -300,6 +300,7 @@ NIR_FILES = \
 	nir/nir_lower_two_sided_color.c \
 	nir/nir_lower_ubo_vec4.c \
 	nir/nir_lower_uniforms_to_ubo.c \
+	nir/nir_lower_undef_to_zero.c \
 	nir/nir_lower_vars_to_ssa.c \
 	nir/nir_lower_var_copies.c \
 	nir/nir_lower_vec_to_movs.c \

src/compiler/nir/meson.build

@@ -178,6 +178,7 @@ files_libnir = files(
   'nir_lower_tex.c',
   'nir_lower_to_source_mods.c',
   'nir_lower_two_sided_color.c',
+  'nir_lower_undef_to_zero.c',
   'nir_lower_vars_to_ssa.c',
   'nir_lower_var_copies.c',
   'nir_lower_vec_to_movs.c',

src/compiler/nir/nir.h

@@ -5124,6 +5124,8 @@ bool nir_opt_trivial_continues(nir_shader *shader);
 
 bool nir_opt_undef(nir_shader *shader);
 
+bool nir_lower_undef_to_zero(nir_shader *shader);
+
 bool nir_opt_uniform_atomics(nir_shader *shader);
 
 typedef bool (*nir_opt_vectorize_cb)(const nir_instr *a, const nir_instr *b,

src/compiler/nir/nir_lower_undef_to_zero.c

@@ -38,13 +38,10 @@
  * able to kick in to reduce stuff consuming the zero.
  */
 
-#include "compiler/nir/nir.h"
-#include "compiler/nir/nir_builder.h"
-
-bool nir_undef_to_zero(nir_shader *shader);
+#include "nir_builder.h"
 
 bool
-nir_undef_to_zero(nir_shader *shader)
+nir_lower_undef_to_zero(nir_shader *shader)
 {
    bool progress = false;
 

src/panfrost/Makefile.sources

@@ -94,7 +94,6 @@ util_FILES := \
         util/lcra.c \
         util/lcra.h \
         util/nir_mod_helpers.c \
-        util/nir_undef_to_zero.c \
         util/pan_ir.c \
         util/pan_ir.h \
         util/pan_liveness.c \

src/panfrost/bifrost/bifrost_compile.c

@@ -2406,7 +2406,7 @@ bi_optimize_nir(nir_shader *nir)
                 }
 
                 NIR_PASS(progress, nir, nir_opt_undef);
-                NIR_PASS(progress, nir, nir_undef_to_zero);
+                NIR_PASS(progress, nir, nir_lower_undef_to_zero);
 
                 NIR_PASS(progress, nir, nir_opt_loop_unroll,
                          nir_var_shader_in |

src/panfrost/midgard/midgard_compile.c

@@ -300,7 +300,7 @@ optimise_nir(nir_shader *nir, unsigned quirks, bool is_blend)
                 }
 
                 NIR_PASS(progress, nir, nir_opt_undef);
-                NIR_PASS(progress, nir, nir_undef_to_zero);
+                NIR_PASS(progress, nir, nir_lower_undef_to_zero);
 
                 NIR_PASS(progress, nir, nir_opt_loop_unroll,
                          nir_var_shader_in |

src/panfrost/util/meson.build

@@ -23,7 +23,6 @@ libpanfrost_util_files = files(
   'lcra.c',
   'lcra.h',
   'nir_mod_helpers.c',
-  'nir_undef_to_zero.c',
   'pan_ir.c',
   'pan_ir.h',
   'pan_liveness.c',

src/panfrost/util/pan_ir.h

@@ -81,9 +81,6 @@ panfrost_nir_assign_sysvals(struct panfrost_sysvals *ctx, void *memctx, nir_shad
 int
 panfrost_sysval_for_instr(nir_instr *instr, nir_dest *dest);
 
-bool
-nir_undef_to_zero(nir_shader *shader);
-
 typedef struct {
         int work_register_count;
         int uniform_cutoff;