llvmpipe: Unified common code between AoS and SoA blending.

Added a new file lp_bld_blend.c for the common code.
Merged and added some simple optimisations.

Reviewed-by: Jose Fonseca <[email protected]>

6 files changed, 290 insertions, 162 deletions

diff --git a/src/gallium/drivers/llvmpipe/Makefile b/src/gallium/drivers/llvmpipe/Makefile
index 1a4e93d7ce3..26fbde9a169 100644
--- a/src/gallium/drivers/llvmpipe/Makefile
+++ b/src/gallium/drivers/llvmpipe/Makefile
@@ -5,6 +5,7 @@ LIBNAME = llvmpipe
 
 C_SOURCES = \
 	lp_bld_alpha.c \
+	lp_bld_blend.c \
 	lp_bld_blend_aos.c \
 	lp_bld_blend_logicop.c \
 	lp_bld_blend_soa.c \
diff --git a/src/gallium/drivers/llvmpipe/SConscript b/src/gallium/drivers/llvmpipe/SConscript
index c1a63ee877f..85560a1c716 100644
--- a/src/gallium/drivers/llvmpipe/SConscript
+++ b/src/gallium/drivers/llvmpipe/SConscript
@@ -32,6 +32,7 @@ llvmpipe = env.ConvenienceLibrary(
 	target = 'llvmpipe',
 	source = [
 		'lp_bld_alpha.c',
+		'lp_bld_blend.c',
 		'lp_bld_blend_aos.c',
 		'lp_bld_blend_logicop.c',
 		'lp_bld_blend_soa.c',
diff --git a/src/gallium/drivers/llvmpipe/lp_bld_blend.c b/src/gallium/drivers/llvmpipe/lp_bld_blend.c
new file mode 100644
index 00000000000..a87a220ea48
--- /dev/null
+++ b/src/gallium/drivers/llvmpipe/lp_bld_blend.c
@@ -0,0 +1,191 @@
+/**************************************************************************
+ *
+ * Copyright 2012 VMware, Inc.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+#include "pipe/p_state.h"
+#include "util/u_debug.h"
+
+#include "gallivm/lp_bld_type.h"
+#include "gallivm/lp_bld_arit.h"
+
+#include "lp_bld_blend.h"
+
+/**
+ * Is (a OP b) == (b OP a)?
+ */
+boolean
+lp_build_blend_func_commutative(unsigned func)
+{
+   switch (func) {
+   case PIPE_BLEND_ADD:
+   case PIPE_BLEND_MIN:
+   case PIPE_BLEND_MAX:
+      return TRUE;
+   case PIPE_BLEND_SUBTRACT:
+   case PIPE_BLEND_REVERSE_SUBTRACT:
+      return FALSE;
+   default:
+      assert(0);
+      return TRUE;
+   }
+}
+
+
+/**
+ * Whether the blending functions are the reverse of each other.
+ */
+boolean
+lp_build_blend_func_reverse(unsigned rgb_func, unsigned alpha_func)
+{
+   if(rgb_func == alpha_func)
+      return FALSE;
+   if(rgb_func == PIPE_BLEND_SUBTRACT && alpha_func == PIPE_BLEND_REVERSE_SUBTRACT)
+      return TRUE;
+   if(rgb_func == PIPE_BLEND_REVERSE_SUBTRACT && alpha_func == PIPE_BLEND_SUBTRACT)
+      return TRUE;
+   return FALSE;
+}
+
+
+/**
+ * Whether the blending factors are complementary of each other.
+ */
+static INLINE boolean
+lp_build_blend_factor_complementary(unsigned src_factor, unsigned dst_factor)
+{
+   return dst_factor == (src_factor ^ 0x10);
+}
+
+
+/**
+ * @sa http://www.opengl.org/sdk/docs/man/xhtml/glBlendEquationSeparate.xml
+ */
+LLVMValueRef
+lp_build_blend_func(struct lp_build_context *bld,
+                    unsigned func,
+                    LLVMValueRef term1,
+                    LLVMValueRef term2)
+{
+   switch (func) {
+   case PIPE_BLEND_ADD:
+      return lp_build_add(bld, term1, term2);
+   case PIPE_BLEND_SUBTRACT:
+      return lp_build_sub(bld, term1, term2);
+   case PIPE_BLEND_REVERSE_SUBTRACT:
+      return lp_build_sub(bld, term2, term1);
+   case PIPE_BLEND_MIN:
+      return lp_build_min(bld, term1, term2);
+   case PIPE_BLEND_MAX:
+      return lp_build_max(bld, term1, term2);
+   default:
+      assert(0);
+      return bld->zero;
+   }
+}
+
+
+/**
+ * Performs optimisations and blending independent of SoA/AoS
+ *
+ * @param func                   the blend function
+ * @param factor_src             PIPE_BLENDFACTOR_xxx
+ * @param factor_dst             PIPE_BLENDFACTOR_xxx
+ * @param src                    source rgba
+ * @param dst                    dest rgba
+ * @param src_factor             src factor computed value
+ * @param dst_factor             dst factor computed value
+ * @param not_alpha_dependent    same factors accross all channels of src/dst
+ *
+ * not_alpha_dependent should be:
+ *  SoA: always true as it is only one channel at a time
+ *  AoS: rgb_src_factor == alpha_src_factor && rgb_dst_factor == alpha_dst_factor
+ *
+ * Note that pretty much every possible optimisation can only be done on non-unorm targets
+ * due to unorm values not going above 1.0 meaning factorisation can change results.
+ * e.g. (0.9 * 0.9) + (0.9 * 0.9) != 0.9 * (0.9 + 0.9) as result of + is always <= 1.
+ */
+LLVMValueRef
+lp_build_blend(struct lp_build_context *bld,
+               unsigned func,
+               unsigned factor_src,
+               unsigned factor_dst,
+               LLVMValueRef src,
+               LLVMValueRef dst,
+               LLVMValueRef src_factor,
+               LLVMValueRef dst_factor,
+               boolean not_alpha_dependent,
+               boolean optimise_only)
+{
+   LLVMValueRef result, src_term, dst_term;
+
+   /* If we are not alpha dependent we can mess with the src/dst factors */
+   if (not_alpha_dependent) {
+      if (lp_build_blend_factor_complementary(factor_src, factor_dst)) {
+         if (func == PIPE_BLEND_ADD) {
+            if (factor_src < factor_dst) {
+               return lp_build_lerp(bld, src_factor, dst, src);
+            } else {
+               return lp_build_lerp(bld, dst_factor, src, dst);
+            }
+         } else if(bld->type.floating && func == PIPE_BLEND_SUBTRACT) {
+            result = lp_build_add(bld, src, dst);
+            result = lp_build_mul(bld, result, src_factor);
+
+            if (factor_src < factor_dst) {
+               return lp_build_sub(bld, result, dst);
+            } else {
+               return lp_build_sub(bld, src, result);
+            }
+         } else if(bld->type.floating && func == PIPE_BLEND_REVERSE_SUBTRACT) {
+            result = lp_build_add(bld, src, dst);
+            result = lp_build_mul(bld, result, src_factor);
+
+            if (factor_src < factor_dst) {
+               return lp_build_sub(bld, dst, result);
+            } else {
+               return lp_build_sub(bld, result, src);
+            }
+         }
+      }
+
+      if (bld->type.floating && factor_src == factor_dst) {
+         if (func == PIPE_BLEND_ADD ||
+             func == PIPE_BLEND_SUBTRACT ||
+             func == PIPE_BLEND_REVERSE_SUBTRACT) {
+            LLVMValueRef result;
+            result = lp_build_blend_func(bld, func, src, dst);
+            return lp_build_mul(bld, result, src_factor);
+         }
+      }
+   }
+
+   if (optimise_only)
+      return NULL;
+
+   src_term = lp_build_mul(bld, src, src_factor);
+   dst_term = lp_build_mul(bld, dst, dst_factor);
+   return lp_build_blend_func(bld, func, src_term, dst_term);
+}
diff --git a/src/gallium/drivers/llvmpipe/lp_bld_blend.h b/src/gallium/drivers/llvmpipe/lp_bld_blend.h
index c0c95a27129..68e55ac05b3 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_blend.h
+++ b/src/gallium/drivers/llvmpipe/lp_bld_blend.h
@@ -40,25 +40,17 @@ struct lp_type;
 struct lp_build_context;
 
 
-/**
- * Whether the blending function is commutative or not.
- */
-boolean
-lp_build_blend_func_commutative(unsigned func);
-
-
-/**
- * Whether the blending functions are the reverse of each other.
- */
-boolean
-lp_build_blend_func_reverse(unsigned rgb_func, unsigned alpha_func);
-
-
 LLVMValueRef
-lp_build_blend_func(struct lp_build_context *bld,
-                    unsigned func,
-                    LLVMValueRef term1,
-                    LLVMValueRef term2);
+lp_build_blend(struct lp_build_context *bld,
+               unsigned func,
+               unsigned factor_src,
+               unsigned factor_dst,
+               LLVMValueRef src,
+               LLVMValueRef dst,
+               LLVMValueRef src_factor,
+               LLVMValueRef dst_factor,
+               boolean not_alpha_dependent,
+               boolean optimise_only);
 
 
 LLVMValueRef
@@ -98,4 +90,20 @@ lp_build_logicop(LLVMBuilderRef builder,
                  LLVMValueRef dst);
 
 
+LLVMValueRef
+lp_build_blend_func(struct lp_build_context *bld,
+                    unsigned func,
+                    LLVMValueRef term1,
+                    LLVMValueRef term2);
+
+
+boolean
+lp_build_blend_func_reverse(unsigned rgb_func,
+                            unsigned alpha_func);
+
+
+boolean
+lp_build_blend_func_commutative(unsigned func);
+
+
 #endif /* !LP_BLD_BLEND_H */
diff --git a/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c b/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c
index 59d5f545966..66df662711c 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c
+++ b/src/gallium/drivers/llvmpipe/lp_bld_blend_aos.c
@@ -220,84 +220,21 @@ lp_build_blend_swizzle(struct lp_build_blend_aos_context *bld,
  */
 static LLVMValueRef
 lp_build_blend_factor(struct lp_build_blend_aos_context *bld,
-                      LLVMValueRef factor1,
                       unsigned rgb_factor,
                       unsigned alpha_factor,
                       unsigned alpha_swizzle)
 {
-   LLVMValueRef rgb_factor_;
-   LLVMValueRef alpha_factor_;
-   LLVMValueRef factor2;
+   LLVMValueRef rgb_factor_, alpha_factor_;
    enum lp_build_blend_swizzle rgb_swizzle;
 
-   rgb_factor_   = lp_build_blend_factor_unswizzled(bld, rgb_factor,   FALSE);
-   alpha_factor_ = lp_build_blend_factor_unswizzled(bld, alpha_factor, TRUE);
+   rgb_factor_ = lp_build_blend_factor_unswizzled(bld, rgb_factor, FALSE);
 
-   rgb_swizzle = lp_build_blend_factor_swizzle(rgb_factor);
-
-   factor2 = lp_build_blend_swizzle(bld, rgb_factor_, alpha_factor_, rgb_swizzle, alpha_swizzle);
-
-   return lp_build_mul(&bld->base, factor1, factor2);
-}
-
-
-/**
- * Is (a OP b) == (b OP a)?
- */
-boolean
-lp_build_blend_func_commutative(unsigned func)
-{
-   switch (func) {
-   case PIPE_BLEND_ADD:
-   case PIPE_BLEND_MIN:
-   case PIPE_BLEND_MAX:
-      return TRUE;
-   case PIPE_BLEND_SUBTRACT:
-   case PIPE_BLEND_REVERSE_SUBTRACT:
-      return FALSE;
-   default:
-      assert(0);
-      return TRUE;
-   }
-}
-
-
-boolean
-lp_build_blend_func_reverse(unsigned rgb_func, unsigned alpha_func)
-{
-   if(rgb_func == alpha_func)
-      return FALSE;
-   if(rgb_func == PIPE_BLEND_SUBTRACT && alpha_func == PIPE_BLEND_REVERSE_SUBTRACT)
-      return TRUE;
-   if(rgb_func == PIPE_BLEND_REVERSE_SUBTRACT && alpha_func == PIPE_BLEND_SUBTRACT)
-      return TRUE;
-   return FALSE;
-}
-
-
-/**
- * @sa http://www.opengl.org/sdk/docs/man/xhtml/glBlendEquationSeparate.xml
- */
-LLVMValueRef
-lp_build_blend_func(struct lp_build_context *bld,
-                    unsigned func,
-                    LLVMValueRef term1, 
-                    LLVMValueRef term2)
-{
-   switch (func) {
-   case PIPE_BLEND_ADD:
-      return lp_build_add(bld, term1, term2);
-   case PIPE_BLEND_SUBTRACT:
-      return lp_build_sub(bld, term1, term2);
-   case PIPE_BLEND_REVERSE_SUBTRACT:
-      return lp_build_sub(bld, term2, term1);
-   case PIPE_BLEND_MIN:
-      return lp_build_min(bld, term1, term2);
-   case PIPE_BLEND_MAX:
-      return lp_build_max(bld, term1, term2);
-   default:
-      assert(0);
-      return bld->zero;
+   if (alpha_swizzle != UTIL_FORMAT_SWIZZLE_NONE) {
+      rgb_swizzle   = lp_build_blend_factor_swizzle(rgb_factor);
+      alpha_factor_ = lp_build_blend_factor_unswizzled(bld, alpha_factor, TRUE);
+      return lp_build_blend_swizzle(bld, rgb_factor_, alpha_factor_, rgb_swizzle, alpha_swizzle);
+   } else {
+      return rgb_factor_;
    }
 }
 
@@ -329,9 +266,9 @@ lp_build_blend_aos(struct gallivm_state *gallivm,
                    LLVMValueRef const_,
                    const unsigned char swizzle[4])
 {
+   const struct pipe_rt_blend_state * state = &blend->rt[rt];
    struct lp_build_blend_aos_context bld;
-   LLVMValueRef src_term;
-   LLVMValueRef dst_term;
+   LLVMValueRef src_factor, dst_factor;
    LLVMValueRef result;
    unsigned alpha_swizzle = swizzle[3];
    boolean fullcolormask;
@@ -343,45 +280,60 @@ lp_build_blend_aos(struct gallivm_state *gallivm,
    bld.dst = dst;
    bld.const_ = const_;
 
-   if (!blend->rt[rt].blend_enable) {
+   if (swizzle[3] > UTIL_FORMAT_SWIZZLE_W || swizzle[3] == swizzle[0])
+      alpha_swizzle = UTIL_FORMAT_SWIZZLE_NONE;
+
+   if (!state->blend_enable) {
       result = src;
    } else {
-
-      /* TODO: There are still a few optimization opportunities here. For certain
-       * combinations it is possible to reorder the operations and therefore saving
-       * some instructions. */
-
-      src_term = lp_build_blend_factor(&bld, src, blend->rt[rt].rgb_src_factor,
-                                       blend->rt[rt].alpha_src_factor, alpha_swizzle);
-      dst_term = lp_build_blend_factor(&bld, dst, blend->rt[rt].rgb_dst_factor,
-                                       blend->rt[rt].alpha_dst_factor, alpha_swizzle);
-
-      lp_build_name(src_term, "src_term");
-      lp_build_name(dst_term, "dst_term");
-
-      if(blend->rt[rt].rgb_func == blend->rt[rt].alpha_func) {
-         result = lp_build_blend_func(&bld.base, blend->rt[rt].rgb_func, src_term, dst_term);
-      }
-      else {
-         /* Seperate RGB / A functions */
-
-         LLVMValueRef rgb;
+      boolean rgb_alpha_same = state->rgb_src_factor == state->rgb_dst_factor && state->alpha_src_factor == state->alpha_dst_factor;
+      assert(rgb_alpha_same || alpha_swizzle != UTIL_FORMAT_SWIZZLE_NONE);
+
+      src_factor = lp_build_blend_factor(&bld, state->rgb_src_factor,
+                                         state->alpha_src_factor, alpha_swizzle);
+      dst_factor = lp_build_blend_factor(&bld, state->rgb_dst_factor,
+                                         state->alpha_dst_factor, alpha_swizzle);
+
+      result = lp_build_blend(&bld.base,
+                              state->rgb_func,
+                              state->rgb_src_factor,
+                              state->rgb_dst_factor,
+                              src,
+                              dst,
+                              src_factor,
+                              dst_factor,
+                              rgb_alpha_same,
+                              false);
+
+      if(state->rgb_func != state->alpha_func && alpha_swizzle != UTIL_FORMAT_SWIZZLE_NONE) {
          LLVMValueRef alpha;
 
-         rgb   = lp_build_blend_func(&bld.base, blend->rt[rt].rgb_func,   src_term, dst_term);
-         alpha = lp_build_blend_func(&bld.base, blend->rt[rt].alpha_func, src_term, dst_term);
-
-         result = lp_build_blend_swizzle(&bld, rgb, alpha, LP_BUILD_BLEND_SWIZZLE_RGBA, alpha_swizzle);
+         alpha = lp_build_blend(&bld.base,
+                                state->alpha_func,
+                                state->alpha_src_factor,
+                                state->alpha_dst_factor,
+                                src,
+                                dst,
+                                src_factor,
+                                dst_factor,
+                                rgb_alpha_same,
+                                false);
+
+         result = lp_build_blend_swizzle(&bld,
+                                         result,
+                                         alpha,
+                                         LP_BUILD_BLEND_SWIZZLE_RGBA,
+                                         alpha_swizzle);
       }
    }
 
    /* Check if color mask is necessary */
-   fullcolormask = util_format_colormask_full(util_format_description(cbuf_format[rt]), blend->rt[rt].colormask);
+   fullcolormask = util_format_colormask_full(util_format_description(cbuf_format[rt]), state->colormask);
 
    if (!fullcolormask) {
       LLVMValueRef color_mask;
 
-      color_mask = lp_build_const_mask_aos_swizzled(gallivm, bld.base.type, blend->rt[rt].colormask, swizzle);
+      color_mask = lp_build_const_mask_aos_swizzled(gallivm, bld.base.type, state->colormask, swizzle);
       lp_build_name(color_mask, "color_mask");
 
       /* Combine with input mask if necessary */
diff --git a/src/gallium/drivers/llvmpipe/lp_bld_blend_soa.c b/src/gallium/drivers/llvmpipe/lp_bld_blend_soa.c
index 4d5bc9642d9..bba58b10492 100644
--- a/src/gallium/drivers/llvmpipe/lp_bld_blend_soa.c
+++ b/src/gallium/drivers/llvmpipe/lp_bld_blend_soa.c
@@ -196,13 +196,6 @@ lp_build_blend_soa_factor(struct lp_build_blend_soa_context *bld,
 }
 
 
-static boolean
-lp_build_blend_factor_complementary(unsigned src_factor, unsigned dst_factor)
-{
-   return dst_factor == (src_factor ^ 0x10);
-}
-
-
 /**
  * Generate blend code in SOA mode.
  * \param rt  render target index (to index the blend / colormask state)
@@ -252,42 +245,6 @@ lp_build_blend_soa(struct gallivm_state *gallivm,
             unsigned func = i < 3 ? blend->rt[rt].rgb_func : blend->rt[rt].alpha_func;
             boolean func_commutative = lp_build_blend_func_commutative(func);
 
-	    if (func == PIPE_BLEND_ADD &&
-		lp_build_blend_factor_complementary(src_factor, dst_factor) && 0) {
-               /*
-                * Special case linear interpolation, (i.e., complementary factors).
-                */
-
-	       LLVMValueRef weight;
-	       if (src_factor < dst_factor) {
-		  weight = lp_build_blend_soa_factor(&bld, src_factor, i);
-		  res[i] = lp_build_lerp(&bld.base, weight, dst[i], src[i]);
-	       } else {
-		  weight = lp_build_blend_soa_factor(&bld, dst_factor, i);
-		  res[i] = lp_build_lerp(&bld.base, weight, src[i], dst[i]);
-	       }
-	       continue;
-	    }
-
-	    if ((func == PIPE_BLEND_ADD ||
-                 func == PIPE_BLEND_SUBTRACT ||
-                 func == PIPE_BLEND_REVERSE_SUBTRACT) &&
-		src_factor == dst_factor &&
-                type.floating) {
-               /*
-                * Special common factor.
-                *
-                * XXX: Only for floating points for now, since saturation will
-                * cause different results.
-                */
-
-	       LLVMValueRef factor;
-               factor = lp_build_blend_soa_factor(&bld, src_factor, i);
-               res[i] = lp_build_blend_func(&bld.base, func, src[i], dst[i]);
-               res[i] = lp_build_mul(&bld.base, res[i], factor);
-	       continue;
-	    }
-
             /*
              * Compute src/dst factors.
              */
@@ -298,6 +255,24 @@ lp_build_blend_soa(struct gallivm_state *gallivm,
             bld.factor[1][1][i] = lp_build_blend_soa_factor(&bld, dst_factor, i);
 
             /*
+             * Check if lp_build_blend can perform any optimisations
+             */
+            res[i] = lp_build_blend(&bld.base,
+                                    func,
+                                    src_factor,
+                                    dst_factor,
+                                    bld.factor[0][0][i],
+                                    bld.factor[1][0][i],
+                                    bld.factor[0][1][i],
+                                    bld.factor[1][1][i],
+                                    true,
+                                    true);
+
+            if (res[i]) {
+               continue;
+            }
+
+            /*
              * Compute src/dst terms
              */
 
@@ -311,7 +286,7 @@ lp_build_blend_soa(struct gallivm_state *gallivm,
                      break;
                }
 
-               if(j < i)
+               if(j < i && bld.term[k][j])
                   bld.term[k][i] = bld.term[k][j];
                else
                   bld.term[k][i] = lp_build_mul(&bld.base, bld.factor[k][0][i], bld.factor[k][1][i]);