llvmpipe: fix using wrong format with MRT in blend code

We were passing in the rt index however this was always 0 for non-independent
blend case. (The format was only actually used to decide if the color mask
covered all channels so this went unnoticed and was discovered by accident.)
Additionally, there was a second problem because we do fixups in the key based
on color buffer format we cannot use non-independent blend anyway as the fixed
up values would never get used.
So always turn non-independent blending into independent.

Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: José Fonseca <jfonseca@vmware.com>

4 files changed, 26 insertions, 11 deletions

diff --git a/src/gallium/drivers/llvmpipe/lp_bld_blend.h b/src/gallium/drivers/llvmpipe/lp_bld_blend.h
index 0a1cea1153c..3a3be815aee 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_blend.h
+++ b/src/gallium/drivers/llvmpipe/lp_bld_blend.h
@@ -56,7 +56,7 @@ lp_build_blend(struct lp_build_context *bld,
 LLVMValueRef
 lp_build_blend_aos(struct gallivm_state *gallivm,
                    const struct pipe_blend_state *blend,
-                   const enum pipe_format *cbuf_format,
+                   const enum pipe_format cbuf_format,
                    struct lp_type type,
                    unsigned rt,
                    LLVMValueRef src,
diff --git a/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c b/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c
index 641c253bfe3..65f66e0df01 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c
+++ b/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c
@@ -266,7 +266,7 @@ lp_build_blend_factor(struct lp_build_blend_aos_context *bld,
  * @param blend         the blend state of the shader variant
  * @param cbuf_format   format of the colour buffer
  * @param type          data type of the pixel vector
- * @param rt            rt number
+ * @param rt            render target index
  * @param src           blend src
  * @param dst           blend dst
  * @param mask          optional mask to apply to the blending result
@@ -278,7 +278,7 @@ lp_build_blend_factor(struct lp_build_blend_aos_context *bld,
 LLVMValueRef
 lp_build_blend_aos(struct gallivm_state *gallivm,
                    const struct pipe_blend_state *blend,
-                   const enum pipe_format *cbuf_format,
+                   const enum pipe_format cbuf_format,
                    struct lp_type type,
                    unsigned rt,
                    LLVMValueRef src,
@@ -298,7 +298,7 @@ lp_build_blend_aos(struct gallivm_state *gallivm,
    unsigned alpha_swizzle = UTIL_FORMAT_SWIZZLE_NONE;
    unsigned i;
 
-   desc = util_format_description(cbuf_format[rt]);
+   desc = util_format_description(cbuf_format);
 
    /* Setup build context */
    memset(&bld, 0, sizeof bld);
diff --git a/src/gallium/drivers/llvmpipe/lp_state_fs.c b/src/gallium/drivers/llvmpipe/lp_state_fs.c
index 5a8351bff67..3eae162d6b6 100644
--- a/src/gallium/drivers/llvmpipe/lp_state_fs.c
+++ b/src/gallium/drivers/llvmpipe/lp_state_fs.c
@@ -1645,12 +1645,21 @@ generate_unswizzled_blend(struct gallivm_state *gallivm,
    /*
     * Blending
     */
+   /* XXX this is broken for RGB8 formats -
+    * they get expanded from 12 to 16 elements (to include alpha)
+    * by convert_to_blend_type then reduced to 15 instead of 12
+    * by convert_from_blend_type (a simple fix though breaks A8...).
+    * R16G16B16 also crashes differently however something going wrong
+    * inside llvm handling npot vector sizes seemingly.
+    * It seems some cleanup could be done here (like skipping conversion/blend
+    * when not needed).
+    */
    convert_to_blend_type(gallivm, out_format_desc, dst_type, row_type, dst, src_count);
 
    for (i = 0; i < src_count; ++i) {
       dst[i] = lp_build_blend_aos(gallivm,
                                   &variant->key.blend,
-                                  variant->key.cbuf_format,
+                                  out_format,
                                   row_type,
                                   rt,
                                   src[i],
@@ -1999,7 +2008,6 @@ generate_fragment(struct llvmpipe_context *lp,
       LLVMValueRef color_ptr;
       LLVMValueRef stride;
       LLVMValueRef index = lp_build_const_int32(gallivm, cbuf);
-      unsigned rt = key->blend.independent_blend_enable ? cbuf : 0;
 
       boolean do_branch = ((key->depth.enabled
                             || key->stencil[0].enabled
@@ -2016,7 +2024,7 @@ generate_fragment(struct llvmpipe_context *lp,
                              LLVMBuildGEP(builder, stride_ptr, &index, 1, ""),
                              "");
 
-      generate_unswizzled_blend(gallivm, rt, variant, key->cbuf_format[cbuf],
+      generate_unswizzled_blend(gallivm, cbuf, variant, key->cbuf_format[cbuf],
                                 num_fs, fs_type, fs_mask, fs_out_color[cbuf],
                                 context_ptr, color_ptr, stride, partial_mask, do_branch);
    }
@@ -2505,6 +2513,15 @@ make_variant_key(struct llvmpipe_context *lp,
    }
 
    key->nr_cbufs = lp->framebuffer.nr_cbufs;
+
+   if (!key->blend.independent_blend_enable) {
+      /* we always need independent blend otherwise the fixups below won't work */
+      for (i = 1; i < key->nr_cbufs; i++) {
+         memcpy(&key->blend.rt[i], &key->blend.rt[0], sizeof(key->blend.rt[0]));
+      }
+      key->blend.independent_blend_enable = 1;
+   }
+
    for (i = 0; i < lp->framebuffer.nr_cbufs; i++) {
       enum pipe_format format = lp->framebuffer.cbufs[i]->format;
       struct pipe_rt_blend_state *blend_rt = &key->blend.rt[i];
@@ -2516,8 +2533,6 @@ make_variant_key(struct llvmpipe_context *lp,
       assert(format_desc->colorspace == UTIL_FORMAT_COLORSPACE_RGB ||
              format_desc->colorspace == UTIL_FORMAT_COLORSPACE_SRGB);
 
-      blend_rt->colormask = lp->blend->rt[i].colormask;
-
       /*
        * Mask out color channels not present in the color buffer.
        */
@@ -2539,7 +2554,7 @@ make_variant_key(struct llvmpipe_context *lp,
        * Also, force rgb/alpha func/factors match, to make AoS blending easier.
        */
       if (format_desc->swizzle[3] > UTIL_FORMAT_SWIZZLE_W ||
-	  format_desc->swizzle[3] == format_desc->swizzle[0]) {
+          format_desc->swizzle[3] == format_desc->swizzle[0]) {
          blend_rt->rgb_src_factor   = force_dst_alpha_one(blend_rt->rgb_src_factor);
          blend_rt->rgb_dst_factor   = force_dst_alpha_one(blend_rt->rgb_dst_factor);
          blend_rt->alpha_func       = blend_rt->rgb_func;
diff --git a/src/gallium/drivers/llvmpipe/lp_test_blend.c b/src/gallium/drivers/llvmpipe/lp_test_blend.c
index 9c0a076fd89..754434d3dfd 100644
--- a/src/gallium/drivers/llvmpipe/lp_test_blend.c
+++ b/src/gallium/drivers/llvmpipe/lp_test_blend.c
@@ -172,7 +172,7 @@ add_blend_test(struct gallivm_state *gallivm,
    dst = LLVMBuildLoad(builder, dst_ptr, "dst");
    con = LLVMBuildLoad(builder, const_ptr, "const");
 
-   res = lp_build_blend_aos(gallivm, blend, &format, type, rt, src, NULL, dst, NULL, con, NULL, swizzle, 4);
+   res = lp_build_blend_aos(gallivm, blend, format, type, rt, src, NULL, dst, NULL, con, NULL, swizzle, 4);
 
    lp_build_name(res, "res");