gallivm,draw,llvmpipe: use base ptr + mip offsets instead of mip pointers

This might have a slight overhead but handling mip offsets more like
the width (and image) strides should make some things easier (mip level
being just part of the offset calculation) later.

Reviewed-by: Brian Paul <[email protected]>
Reviewed-by: José Fonseca <[email protected]>

3 files changed, 19 insertions, 9 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample.c b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
index 63cf610ecad..0727fd2b91a 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
@@ -733,12 +733,13 @@ lp_build_get_mipmap_level(struct lp_build_sample_context *bld,
                           LLVMValueRef level)
 {
    LLVMBuilderRef builder = bld->gallivm->builder;
-   LLVMValueRef indexes[2], data_ptr;
+   LLVMValueRef indexes[2], data_ptr, mip_offset;
 
    indexes[0] = lp_build_const_int32(bld->gallivm, 0);
    indexes[1] = level;
-   data_ptr = LLVMBuildGEP(builder, bld->data_array, indexes, 2, "");
-   data_ptr = LLVMBuildLoad(builder, data_ptr, "");
+   mip_offset = LLVMBuildGEP(builder, bld->mip_offsets, indexes, 2, "");
+   mip_offset = LLVMBuildLoad(builder, mip_offset, "");
+   data_ptr = LLVMBuildGEP(builder, bld->base_ptr, &mip_offset, 1, "");
    return data_ptr;
 }
 
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample.h b/src/gallium/auxiliary/gallivm/lp_bld_sample.h
index 0f3d8ae6cb5..d8a068d5497 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample.h
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample.h
@@ -157,12 +157,18 @@ struct lp_sampler_dynamic_state
                   struct gallivm_state *gallivm,
                   unsigned unit);
 
-   /** Obtain pointer to array of pointers to mimpap levels */
+   /** Obtain pointer to base of texture */
    LLVMValueRef
-   (*data_ptr)( const struct lp_sampler_dynamic_state *state,
+   (*base_ptr)( const struct lp_sampler_dynamic_state *state,
                 struct gallivm_state *gallivm,
                 unsigned unit);
 
+   /** Obtain pointer to array of mipmap offsets */
+   LLVMValueRef
+   (*mip_offsets)( const struct lp_sampler_dynamic_state *state,
+                   struct gallivm_state *gallivm,
+                   unsigned unit);
+
    /** Obtain texture min lod (returns float) */
    LLVMValueRef
    (*min_lod)(const struct lp_sampler_dynamic_state *state,
@@ -246,7 +252,8 @@ struct lp_build_sample_context
    /* Common dynamic state values */
    LLVMValueRef row_stride_array;
    LLVMValueRef img_stride_array;
-   LLVMValueRef data_array;
+   LLVMValueRef base_ptr;
+   LLVMValueRef mip_offsets;
 
    /** Integer vector with texture width, height, depth */
    LLVMValueRef int_size;
diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
index aaef7970635..00a5b187bcb 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
@@ -1298,8 +1298,9 @@ lp_build_sample_soa(struct gallivm_state *gallivm,
    tex_depth = dynamic_state->depth(dynamic_state, gallivm, unit);
    bld.row_stride_array = dynamic_state->row_stride(dynamic_state, gallivm, unit);
    bld.img_stride_array = dynamic_state->img_stride(dynamic_state, gallivm, unit);
-   bld.data_array = dynamic_state->data_ptr(dynamic_state, gallivm, unit);
-   /* Note that data_array is an array[level] of pointers to texture images */
+   bld.base_ptr = dynamic_state->base_ptr(dynamic_state, gallivm, unit);
+   bld.mip_offsets = dynamic_state->mip_offsets(dynamic_state, gallivm, unit);
+   /* Note that mip_offsets is an array[level] of offsets to texture images */
 
    s = coords[0];
    t = coords[1];
@@ -1439,7 +1440,8 @@ lp_build_sample_soa(struct gallivm_state *gallivm,
             bld4.dims = bld.dims;
             bld4.row_stride_array = bld.row_stride_array;
             bld4.img_stride_array = bld.img_stride_array;
-            bld4.data_array = bld.data_array;
+            bld4.base_ptr = bld.base_ptr;
+            bld4.mip_offsets = bld.mip_offsets;
             bld4.int_size = bld.int_size;
 
             bld4.vector_width = lp_type_width(type4);