gallivm: fix crash with seamless cube filtering with different min/mag filter

We are not allowed to modify the incoming coords values, or things may
crash (as we may be inside a llvm conditional and the values may be used
in another branch).
I recently broke this when fixing an issue with NaNs and seamless cube
map filtering, and it causes crashes when doing cubemap filtering
if the min and mag filters are different.
Add const to the pointers passed in to prevent this mishap in the future.

Fixes: a485ad0bcd ("gallivm: fix an issue with NaNs with seamless cube filtering")

Reviewed-by: Jose Fonseca <[email protected]>
(cherry picked from commit 4fe662c58f6453b3558de479e7c2bfe4158dc26c)

1 files changed, 21 insertions, 17 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
index ff8cbf604c0..8f760f59fed 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample_soa.c
@@ -857,7 +857,7 @@ lp_build_sample_image_nearest(struct lp_build_sample_context *bld,
                               LLVMValueRef img_stride_vec,
                               LLVMValueRef data_ptr,
                               LLVMValueRef mipoffsets,
-                              LLVMValueRef *coords,
+                              const LLVMValueRef *coords,
                               const LLVMValueRef *offsets,
                               LLVMValueRef colors_out[4])
 {
@@ -1004,7 +1004,7 @@ lp_build_sample_image_linear(struct lp_build_sample_context *bld,
                              LLVMValueRef img_stride_vec,
                              LLVMValueRef data_ptr,
                              LLVMValueRef mipoffsets,
-                             LLVMValueRef *coords,
+                             const LLVMValueRef *coords,
                              const LLVMValueRef *offsets,
                              LLVMValueRef colors_out[4])
 {
@@ -1106,7 +1106,7 @@ lp_build_sample_image_linear(struct lp_build_sample_context *bld,
       struct lp_build_if_state edge_if;
       LLVMTypeRef int1t;
       LLVMValueRef new_faces[4], new_xcoords[4][2], new_ycoords[4][2];
-      LLVMValueRef coord, have_edge, have_corner;
+      LLVMValueRef coord0, coord1, have_edge, have_corner;
       LLVMValueRef fall_off_ym_notxm, fall_off_ym_notxp, fall_off_x, fall_off_y;
       LLVMValueRef fall_off_yp_notxm, fall_off_yp_notxp;
       LLVMValueRef x0, x1, y0, y1, y0_clamped, y1_clamped;
@@ -1130,20 +1130,20 @@ lp_build_sample_image_linear(struct lp_build_sample_context *bld,
        * other values might be bogus in the end too).
        * So kill off the NaNs here.
        */
-      coords[0] = lp_build_max_ext(coord_bld, coords[0], coord_bld->zero,
-                                   GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN);
-      coords[1] = lp_build_max_ext(coord_bld, coords[1], coord_bld->zero,
-                                   GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN);
-      coord = lp_build_mul(coord_bld, coords[0], flt_width_vec);
+      coord0 = lp_build_max_ext(coord_bld, coords[0], coord_bld->zero,
+                                GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN);
+      coord0 = lp_build_mul(coord_bld, coord0, flt_width_vec);
       /* instead of clamp, build mask if overflowed */
-      coord = lp_build_sub(coord_bld, coord, half);
+      coord0 = lp_build_sub(coord_bld, coord0, half);
       /* convert to int, compute lerp weight */
       /* not ideal with AVX (and no AVX2) */
-      lp_build_ifloor_fract(coord_bld, coord, &x0, &s_fpart);
+      lp_build_ifloor_fract(coord_bld, coord0, &x0, &s_fpart);
       x1 = lp_build_add(ivec_bld, x0, ivec_bld->one);
-      coord = lp_build_mul(coord_bld, coords[1], flt_height_vec);
-      coord = lp_build_sub(coord_bld, coord, half);
-      lp_build_ifloor_fract(coord_bld, coord, &y0, &t_fpart);
+      coord1 = lp_build_max_ext(coord_bld, coords[1], coord_bld->zero,
+                                GALLIVM_NAN_RETURN_OTHER_SECOND_NONNAN);
+      coord1 = lp_build_mul(coord_bld, coord1, flt_height_vec);
+      coord1 = lp_build_sub(coord_bld, coord1, half);
+      lp_build_ifloor_fract(coord_bld, coord1, &y0, &t_fpart);
       y1 = lp_build_add(ivec_bld, y0, ivec_bld->one);
 
       fall_off[0] = lp_build_cmp(ivec_bld, PIPE_FUNC_LESS, x0, ivec_bld->zero);
@@ -1747,7 +1747,7 @@ lp_build_sample_mipmap(struct lp_build_sample_context *bld,
                        unsigned img_filter,
                        unsigned mip_filter,
                        boolean is_gather,
-                       LLVMValueRef *coords,
+                       const LLVMValueRef *coords,
                        const LLVMValueRef *offsets,
                        LLVMValueRef ilevel0,
                        LLVMValueRef ilevel1,
@@ -1820,6 +1820,7 @@ lp_build_sample_mipmap(struct lp_build_sample_context *bld,
                                       PIPE_FUNC_GREATER,
                                       lod_fpart, bld->lodf_bld.zero);
          need_lerp = lp_build_any_true_range(&bld->lodi_bld, bld->num_lods, need_lerp);
+         lp_build_name(need_lerp, "need_lerp");
       }
 
       lp_build_if(&if_ctx, bld->gallivm, need_lerp);
@@ -1888,7 +1889,7 @@ static void
 lp_build_sample_mipmap_both(struct lp_build_sample_context *bld,
                             LLVMValueRef linear_mask,
                             unsigned mip_filter,
-                            LLVMValueRef *coords,
+                            const LLVMValueRef *coords,
                             const LLVMValueRef *offsets,
                             LLVMValueRef ilevel0,
                             LLVMValueRef ilevel1,
@@ -1945,6 +1946,7 @@ lp_build_sample_mipmap_both(struct lp_build_sample_context *bld,
        * should be able to merge the branches in this case.
        */
       need_lerp = lp_build_any_true_range(&bld->lodi_bld, bld->num_lods, lod_positive);
+      lp_build_name(need_lerp, "need_lerp");
 
       lp_build_if(&if_ctx, bld->gallivm, need_lerp);
       {
@@ -2422,7 +2424,7 @@ static void
 lp_build_sample_general(struct lp_build_sample_context *bld,
                         unsigned sampler_unit,
                         boolean is_gather,
-                        LLVMValueRef *coords,
+                        const LLVMValueRef *coords,
                         const LLVMValueRef *offsets,
                         LLVMValueRef lod_positive,
                         LLVMValueRef lod_fpart,
@@ -2483,7 +2485,8 @@ lp_build_sample_general(struct lp_build_sample_context *bld,
          struct lp_build_if_state if_ctx;
 
          lod_positive = LLVMBuildTrunc(builder, lod_positive,
-                                       LLVMInt1TypeInContext(bld->gallivm->context), "");
+                                       LLVMInt1TypeInContext(bld->gallivm->context),
+                                       "lod_pos");
 
          lp_build_if(&if_ctx, bld->gallivm, lod_positive);
          {
@@ -2519,6 +2522,7 @@ lp_build_sample_general(struct lp_build_sample_context *bld,
          }
          need_linear = lp_build_any_true_range(&bld->lodi_bld, bld->num_lods,
                                                linear_mask);
+         lp_build_name(need_linear, "need_linear");
 
          if (bld->num_lods != bld->coord_type.length) {
             linear_mask = lp_build_unpack_broadcast_aos_scalars(bld->gallivm,