llvmpipe: Handle nir_tex_src_min_lod

Reviewed-by: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33628>

src/gallium/auxiliary/gallivm/lp_bld_jit_sample.c

@@ -254,6 +254,8 @@ lp_bld_llvm_sampler_soa_emit_fetch_texel(const struct lp_build_sampler_soa *base
       enum lp_sampler_lod_control lod_control = (params->sample_key & LP_SAMPLER_LOD_CONTROL_MASK) >> LP_SAMPLER_LOD_CONTROL_SHIFT;
       if (lod_control == LP_SAMPLER_LOD_BIAS || lod_control == LP_SAMPLER_LOD_EXPLICIT)
          args[num_args++] = params->lod;
+      if (params->sample_key & LP_SAMPLER_MIN_LOD)
+         args[num_args++] = params->min_lod;
 
       if (params->type.length != lp_native_vector_width / 32)
          for (uint32_t i = 0; i < num_args; i++)

src/gallium/auxiliary/gallivm/lp_bld_jit_types.c

@@ -807,6 +807,9 @@ lp_build_sample_function_type(struct gallivm_state *gallivm, uint32_t sample_key
    if (lod_control == LP_SAMPLER_LOD_BIAS || lod_control == LP_SAMPLER_LOD_EXPLICIT)
       arg_types[num_params++] = coord_type;
 
+   if (sample_key & LP_SAMPLER_MIN_LOD)
+      arg_types[num_params++] = coord_type;
+
    val_type[0] = val_type[1] = val_type[2] = val_type[3] = lp_build_vec_type(gallivm, type);
    val_type[4] = lp_build_int_vec_type(gallivm, type);
    ret_type = LLVMStructTypeInContext(gallivm->context, val_type, 5, 0);

src/gallium/auxiliary/gallivm/lp_bld_nir_soa.c

@@ -5273,6 +5273,11 @@ lp_build_nir_sample_key(gl_shader_stage stage, nir_tex_instr *instr)
          explicit_lod = true;
          lod_src = i;
          break;
+      case nir_tex_src_min_lod:
+         sample_key |= LP_SAMPLER_MIN_LOD;
+         explicit_lod = true;
+         lod_src = i;
+         break;
       case nir_tex_src_offset:
          sample_key |= LP_SAMPLER_OFFSETS;
          break;
@@ -5364,6 +5369,9 @@ visit_tex(struct lp_build_nir_soa_context *bld, nir_tex_instr *instr)
          else
             explicit_lod = cast_type(bld, get_src(bld, &instr->src[i].src, 0), nir_type_float, 32);
          break;
+      case nir_tex_src_min_lod:
+         params.min_lod = cast_type(bld, get_src(bld, &instr->src[i].src, 0), nir_type_float, 32);
+         break;
       case nir_tex_src_ddx: {
          int deriv_cnt = instr->coord_components;
          if (instr->is_array)

src/gallium/auxiliary/gallivm/lp_bld_sample.c

@@ -827,6 +827,7 @@ lp_build_lod_selector(struct lp_build_sample_context *bld,
                       const struct lp_derivatives *derivs,
                       LLVMValueRef lod_bias, /* optional */
                       LLVMValueRef explicit_lod, /* optional */
+                      LLVMValueRef min_lod, /* optional */
                       enum pipe_tex_mipfilter mip_filter,
                       LLVMValueRef *out_lod,
                       LLVMValueRef *out_lod_ipart,
@@ -992,14 +993,17 @@ lp_build_lod_selector(struct lp_build_sample_context *bld,
          lod = lp_build_min(lodf_bld, lod, max_lod);
       }
       if (bld->static_sampler_state->apply_min_lod) {
-         LLVMValueRef min_lod =
+         LLVMValueRef desc_min_lod =
             dynamic_state->min_lod(bld->gallivm, bld->resources_type,
                                    bld->resources_ptr, sampler_unit);
-         min_lod = lp_build_broadcast_scalar(lodf_bld, min_lod);
+         desc_min_lod = lp_build_broadcast_scalar(lodf_bld, desc_min_lod);
 
-         lod = lp_build_max(lodf_bld, lod, min_lod);
+         lod = lp_build_max(lodf_bld, lod, desc_min_lod);
       }
 
+      if (min_lod)
+         lod = lp_build_max(lodf_bld, lod, min_lod);
+
       if (is_lodq) {
          *out_lod_fpart = lod;
          return;

src/gallium/auxiliary/gallivm/lp_bld_sample.h

@@ -99,7 +99,8 @@ enum lp_sampler_op_type {
 #define LP_SAMPLER_GATHER_COMP_MASK   (3 << 8)
 #define LP_SAMPLER_FETCH_MS          (1 << 10)
 #define LP_SAMPLER_RESIDENCY         (1 << 11)
-#define LP_SAMPLE_KEY_COUNT          (1 << 12)
+#define LP_SAMPLER_MIN_LOD           (1 << 12)
+#define LP_SAMPLE_KEY_COUNT          (1 << 13)
 
 
 /* Parameters used to handle TEX instructions */
@@ -118,6 +119,7 @@ struct lp_sampler_params
    const LLVMValueRef *offsets;
    LLVMValueRef ms_index;
    LLVMValueRef lod;
+   LLVMValueRef min_lod;
    const struct lp_derivatives *derivs;
    LLVMValueRef *texel;
 
@@ -666,6 +668,7 @@ lp_build_lod_selector(struct lp_build_sample_context *bld,
                       const struct lp_derivatives *derivs,
                       LLVMValueRef lod_bias, /* optional */
                       LLVMValueRef explicit_lod, /* optional */
+                      LLVMValueRef min_lod, /* optional */
                       enum pipe_tex_mipfilter mip_filter,
                       LLVMValueRef *out_lod,
                       LLVMValueRef *out_lod_ipart,
@@ -811,6 +814,7 @@ lp_build_sample_soa_code(struct gallivm_state *gallivm,
                          const LLVMValueRef *offsets,
                          const struct lp_derivatives *derivs, /* optional */
                          LLVMValueRef lod, /* optional */
+                         LLVMValueRef min_lod, /* optional */
                          LLVMValueRef ms_index, /* optional */
                          LLVMValueRef *texel_out);
 

src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c

@@ -2354,6 +2354,7 @@ lp_build_sample_common(struct lp_build_sample_context *bld,
                        const struct lp_derivatives *derivs, /* optional */
                        LLVMValueRef lod_bias, /* optional */
                        LLVMValueRef explicit_lod, /* optional */
+                       LLVMValueRef min_lod, /* optional */
                        LLVMValueRef *lod_pos_or_zero,
                        LLVMValueRef *lod,
                        LLVMValueRef *lod_fpart,
@@ -2455,7 +2456,7 @@ lp_build_sample_common(struct lp_build_sample_context *bld,
                             first_level_vec,
                             coords[0], coords[1], coords[2],
                             derivs, lod_bias, explicit_lod,
-                            mip_filter, lod,
+                            min_lod, mip_filter, lod,
                             &lod_ipart, lod_fpart, lod_pos_or_zero,
                             aniso_values);
       if (is_lodq) {
@@ -3162,6 +3163,7 @@ lp_build_sample_soa_code(struct gallivm_state *gallivm,
                          const LLVMValueRef *offsets,
                          const struct lp_derivatives *derivs, /* optional */
                          LLVMValueRef lod, /* optional */
+                         LLVMValueRef min_lod, /* optional */
                          LLVMValueRef ms_index, /* optional */
                          LLVMValueRef *texel_out)
 {
@@ -3611,7 +3613,7 @@ lp_build_sample_soa_code(struct gallivm_state *gallivm,
 
       lp_build_sample_common(&bld, op_is_lodq, texture_index, sampler_index,
                              newcoords, derivs, lod_bias, explicit_lod,
-                             &lod_positive, &lod, &lod_fpart,
+                             min_lod, &lod_positive, &lod, &lod_fpart,
                              &ilevel0, &ilevel1, &aniso_values);
 
       if (op_is_lodq) {
@@ -3987,6 +3989,7 @@ lp_build_sample_gen_func(struct gallivm_state *gallivm,
                             offsets,
                             deriv_ptr,
                             lod,
+                            NULL,
                             ms_index,
                             texel_out);
 
@@ -4251,6 +4254,7 @@ lp_build_sample_soa(const struct lp_static_texture_state *static_texture_state,
                                params->offsets,
                                params->derivs,
                                params->lod,
+                               NULL,
                                params->ms_index,
                                params->texel);
    }

src/gallium/drivers/llvmpipe/lp_texture_handle.c

@@ -536,6 +536,10 @@ compile_sample_function(struct llvmpipe_context *ctx, struct lp_static_texture_s
    if (lod_control == LP_SAMPLER_LOD_BIAS || lod_control == LP_SAMPLER_LOD_EXPLICIT)
       lod = LLVMGetParam(function, arg_index++);
 
+   LLVMValueRef min_lod = NULL;
+   if (sample_key & LP_SAMPLER_MIN_LOD)
+      min_lod = LLVMGetParam(function, arg_index++);
+
    LLVMBuilderRef old_builder = gallivm->builder;
    LLVMBasicBlockRef block = LLVMAppendBasicBlockInContext(gallivm->context, function, "entry");
    gallivm->builder = LLVMCreateBuilderInContext(gallivm->context);
@@ -545,7 +549,7 @@ compile_sample_function(struct llvmpipe_context *ctx, struct lp_static_texture_s
    if (supported) {
       lp_build_sample_soa_code(gallivm, texture, sampler, lp_build_sampler_soa_dynamic_state(sampler_soa),
                                type, sample_key, 0, 0, cs.jit_resources_type, NULL, cs.jit_cs_thread_data_type,
-                               NULL, coords, offsets, NULL, lod, ms_index, texel_out);
+                               NULL, coords, offsets, NULL, lod, min_lod, ms_index, texel_out);
    } else {
       lp_build_sample_nop(gallivm, lp_build_texel_type(type, util_format_description(texture->format)), coords, texel_out);
    }