TC-2020: Implement blorp color clear on Gen6+submit/tizen/20141203.084028accepted/tizen/mobile/20141205.122758accepted/tizen/ivi/20141208.101821accepted/tizen/common/20141203.182728

This patch fix a glmark2 performance regression introduced by
commit f9dc7aabb3273d6d8a54c6778a5695a8527f4454
Author: Kristian Høgsberg <krh@bitplanet.net>
Date:   Mon Jul 7 15:27:17 2014 -0700

   i965: Add optimization pass to let us use the replicate data message

BugZilla: https://bugs.tizen.org/jira/browse/TC-2020

Change-Id: Ib7bcc8bbefd4dc8d1befd274480bf380f635f8c3
Signed-off-by: Xiong Zhang <xiong.y.zhang@intel.com>

4 files changed, 636 insertions, 5 deletions

diff --git a/src/mesa/drivers/dri/i965/Makefile.sources b/src/mesa/drivers/dri/i965/Makefile.sources
index b91b81397bf..0ca896e7a88 100644
--- a/src/mesa/drivers/dri/i965/Makefile.sources
+++ b/src/mesa/drivers/dri/i965/Makefile.sources
@@ -28,6 +28,7 @@ i965_FILES = \
 	brw_blorp.cpp \
 	brw_blorp_blit.cpp \
 	brw_blorp_blit_eu.cpp \
+	brw_blorp_clear.cpp \
 	brw_cc.c \
 	brw_cfg.cpp \
 	brw_clear.c \
diff --git a/src/mesa/drivers/dri/i965/brw_blorp.h b/src/mesa/drivers/dri/i965/brw_blorp.h
index ff68000a294..782321e9d54 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp.h
+++ b/src/mesa/drivers/dri/i965/brw_blorp.h
@@ -49,6 +49,13 @@ brw_blorp_blit_miptrees(struct brw_context *brw,
                         float dst_x1, float dst_y1,
                         GLenum filter, bool mirror_x, bool mirror_y);
 
+bool
+brw_blorp_clear_color(struct brw_context *brw, struct gl_framebuffer *fb,
+					  GLbitfield mask, bool partial_clear);
+
+void
+brw_blorp_resolve_color(struct brw_context *brw,
+						struct intel_mipmap_tree *mt);
 #ifdef __cplusplus
 } /* end extern "C" */
 
diff --git a/src/mesa/drivers/dri/i965/brw_blorp_clear.cpp b/src/mesa/drivers/dri/i965/brw_blorp_clear.cpp
new file mode 100644
index 00000000000..e8bdc9dc09c
--- /dev/null
+++ b/src/mesa/drivers/dri/i965/brw_blorp_clear.cpp
@@ -0,0 +1,616 @@
+/*
+ * Copyright © 2013 Intel Corporation
+ *
+ * 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, sublicense,
+ * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS 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.
+ */
+
+extern "C" {
+#include "main/teximage.h"
+#include "main/blend.h"
+#include "main/fbobject.h"
+#include "main/renderbuffer.h"
+}
+
+#include "util/ralloc.h"
+
+#include "intel_fbo.h"
+
+#include "brw_blorp.h"
+#include "brw_context.h"
+#include "brw_eu.h"
+#include "brw_state.h"
+
+#define FILE_DEBUG_FLAG DEBUG_BLORP
+
+struct brw_blorp_const_color_prog_key
+{
+   bool use_simd16_replicated_data;
+   bool pad[3];
+};
+
+/**
+ * Parameters for a blorp operation where the fragment shader outputs a
+ * constant color.  This is used for both fast color clears and color
+ * resolves.
+ */
+class brw_blorp_const_color_params : public brw_blorp_params
+{
+public:
+   virtual uint32_t get_wm_prog(struct brw_context *brw,
+                                brw_blorp_prog_data **prog_data) const;
+
+   brw_blorp_const_color_prog_key wm_prog_key;
+};
+
+class brw_blorp_clear_params : public brw_blorp_const_color_params
+{
+public:
+   brw_blorp_clear_params(struct brw_context *brw,
+                          struct gl_framebuffer *fb,
+                          struct gl_renderbuffer *rb,
+                          GLubyte *color_mask,
+                          bool partial_clear,
+                          unsigned layer);
+};
+
+
+/**
+ * Parameters for a blorp operation that performs a "render target resolve".
+ * This is used to resolve pending fast clear pixels before a color buffer is
+ * used for texturing, ReadPixels, or scanout.
+ */
+class brw_blorp_rt_resolve_params : public brw_blorp_const_color_params
+{
+public:
+   brw_blorp_rt_resolve_params(struct brw_context *brw,
+                               struct intel_mipmap_tree *mt);
+};
+
+
+class brw_blorp_const_color_program
+{
+public:
+   brw_blorp_const_color_program(struct brw_context *brw,
+                                 const brw_blorp_const_color_prog_key *key);
+   ~brw_blorp_const_color_program();
+
+   const GLuint *compile(struct brw_context *brw, GLuint *program_size);
+
+   brw_blorp_prog_data prog_data;
+
+private:
+   void alloc_regs();
+
+   void *mem_ctx;
+   const brw_blorp_const_color_prog_key *key;
+   struct brw_compile func;
+
+   /* Thread dispatch header */
+   struct brw_reg R0;
+
+   /* Pixel X/Y coordinates (always in R1). */
+   struct brw_reg R1;
+
+   /* Register with push constants (a single vec4) */
+   struct brw_reg clear_rgba;
+
+   /* MRF used for render target writes */
+   GLuint base_mrf;
+};
+
+brw_blorp_const_color_program::brw_blorp_const_color_program(
+      struct brw_context *brw,
+      const brw_blorp_const_color_prog_key *key)
+   : mem_ctx(ralloc_context(NULL)),
+     key(key),
+     R0(),
+     R1(),
+     clear_rgba(),
+     base_mrf(0)
+{
+   prog_data.first_curbe_grf = 0;
+   prog_data.persample_msaa_dispatch = false;
+   brw_init_compile(brw, &func, mem_ctx);
+}
+
+brw_blorp_const_color_program::~brw_blorp_const_color_program()
+{
+   ralloc_free(mem_ctx);
+}
+
+
+/**
+ * Determine if fast color clear supports the given clear color.
+ *
+ * Fast color clear can only clear to color values of 1.0 or 0.0.  At the
+ * moment we only support floating point, unorm, and snorm buffers.
+ */
+static bool
+is_color_fast_clear_compatible(struct brw_context *brw,
+                               mesa_format format,
+                               const union gl_color_union *color)
+{
+   if (_mesa_is_format_integer_color(format))
+      return false;
+
+   for (int i = 0; i < 4; i++) {
+      if (color->f[i] != 0.0 && color->f[i] != 1.0 &&
+          _mesa_format_has_color_component(format, i)) {
+         return false;
+      }
+   }
+   return true;
+}
+
+
+/**
+ * Convert the given color to a bitfield suitable for ORing into DWORD 7 of
+ * SURFACE_STATE.
+ */
+static uint32_t
+compute_fast_clear_color_bits(const union gl_color_union *color)
+{
+   uint32_t bits = 0;
+   for (int i = 0; i < 4; i++) {
+      if (color->f[i] != 0.0)
+         bits |= 1 << (GEN7_SURFACE_CLEAR_COLOR_SHIFT + (3 - i));
+   }
+   return bits;
+}
+
+
+brw_blorp_clear_params::brw_blorp_clear_params(struct brw_context *brw,
+                                               struct gl_framebuffer *fb,
+                                               struct gl_renderbuffer *rb,
+                                               GLubyte *color_mask,
+                                               bool partial_clear,
+                                               unsigned layer)
+{
+   struct gl_context *ctx = &brw->ctx;
+   struct intel_renderbuffer *irb = intel_renderbuffer(rb);
+
+   /* Override the surface format according to the context's sRGB rules. */
+   mesa_format format = _mesa_get_render_format(ctx, irb->mt->format);
+   dst.set(brw, irb->mt, irb->mt_level, layer, format, true);
+   dst.brw_surfaceformat = brw->render_target_format[format];
+
+   x0 = fb->_Xmin;
+   x1 = fb->_Xmax;
+   if (rb->Name != 0) {
+      y0 = fb->_Ymin;
+      y1 = fb->_Ymax;
+   } else {
+      y0 = rb->Height - fb->_Ymax;
+      y1 = rb->Height - fb->_Ymin;
+   }
+
+   memcpy(&wm_push_consts.dst_x0, ctx->Color.ClearColor.f, sizeof(float) * 4);
+
+   use_wm_prog = true;
+
+   memset(&wm_prog_key, 0, sizeof(wm_prog_key));
+
+   wm_prog_key.use_simd16_replicated_data = true;
+
+   /* From the SNB PRM (Vol4_Part1):
+    *
+    *     "Replicated data (Message Type = 111) is only supported when
+    *      accessing tiled memory.  Using this Message Type to access linear
+    *      (untiled) memory is UNDEFINED."
+    */
+   if (irb->mt->tiling == I915_TILING_NONE)
+      wm_prog_key.use_simd16_replicated_data = false;
+
+   /* Constant color writes ignore everyting in blend and color calculator
+    * state.  This is not documented.
+    */
+   for (int i = 0; i < 4; i++) {
+      if (_mesa_format_has_color_component(irb->mt->format, i) &&
+          !color_mask[i]) {
+         color_write_disable[i] = true;
+         wm_prog_key.use_simd16_replicated_data = false;
+      }
+   }
+
+   /* If we can do this as a fast color clear, do so.
+    *
+    * Note that the condition "!partial_clear" means we only try to do full
+    * buffer clears using fast color clear logic.  This is necessary because
+    * the fast color clear alignment requirements mean that we typically have
+    * to clear a larger rectangle than (x0, y0) to (x1, y1).  Restricting fast
+    * color clears to the full-buffer condition guarantees that the extra
+    * memory locations that get written to are outside the image boundary (and
+    * hence irrelevant).  Note that the rectangle alignment requirements are
+    * never larger than the size of a tile, so there is no danger of
+    * overflowing beyond the memory belonging to the region.
+    */
+   if (irb->mt->fast_clear_state != INTEL_FAST_CLEAR_STATE_NO_MCS &&
+       !partial_clear && wm_prog_key.use_simd16_replicated_data &&
+       is_color_fast_clear_compatible(brw, format, &ctx->Color.ClearColor)) {
+      memset(&wm_push_consts, 0xff, 4*sizeof(float));
+      fast_clear_op = GEN7_FAST_CLEAR_OP_FAST_CLEAR;
+
+      /* Figure out what the clear rectangle needs to be aligned to, and how
+       * much it needs to be scaled down.
+       */
+      unsigned x_align, y_align, x_scaledown, y_scaledown;
+
+      if (irb->mt->msaa_layout == INTEL_MSAA_LAYOUT_NONE) {
+         /* From the Ivy Bridge PRM, Vol2 Part1 11.7 "MCS Buffer for Render
+          * Target(s)", beneath the "Fast Color Clear" bullet (p327):
+          *
+          *     Clear pass must have a clear rectangle that must follow
+          *     alignment rules in terms of pixels and lines as shown in the
+          *     table below. Further, the clear-rectangle height and width
+          *     must be multiple of the following dimensions. If the height
+          *     and width of the render target being cleared do not meet these
+          *     requirements, an MCS buffer can be created such that it
+          *     follows the requirement and covers the RT.
+          *
+          * The alignment size in the table that follows is related to the
+          * alignment size returned by intel_get_non_msrt_mcs_alignment(), but
+          * with X alignment multiplied by 16 and Y alignment multiplied by 32.
+          */
+         intel_get_non_msrt_mcs_alignment(brw, irb->mt, &x_align, &y_align);
+         x_align *= 16;
+         y_align *= 32;
+
+         /* From the Ivy Bridge PRM, Vol2 Part1 11.7 "MCS Buffer for Render
+          * Target(s)", beneath the "Fast Color Clear" bullet (p327):
+          *
+          *     In order to optimize the performance MCS buffer (when bound to
+          *     1X RT) clear similarly to MCS buffer clear for MSRT case,
+          *     clear rect is required to be scaled by the following factors
+          *     in the horizontal and vertical directions:
+          *
+          * The X and Y scale down factors in the table that follows are each
+          * equal to half the alignment value computed above.
+          */
+         x_scaledown = x_align / 2;
+         y_scaledown = y_align / 2;
+
+         /* From BSpec: 3D-Media-GPGPU Engine > 3D Pipeline > Pixel > Pixel
+          * Backend > MCS Buffer for Render Target(s) [DevIVB+] > Table "Color
+          * Clear of Non-MultiSampled Render Target Restrictions":
+          *
+          *   Clear rectangle must be aligned to two times the number of
+          *   pixels in the table shown below due to 16x16 hashing across the
+          *   slice.
+          */
+         x_align *= 2;
+         y_align *= 2;
+      } else {
+         /* From the Ivy Bridge PRM, Vol2 Part1 11.7 "MCS Buffer for Render
+          * Target(s)", beneath the "MSAA Compression" bullet (p326):
+          *
+          *     Clear pass for this case requires that scaled down primitive
+          *     is sent down with upper left co-ordinate to coincide with
+          *     actual rectangle being cleared. For MSAA, clear rectangle’s
+          *     height and width need to as show in the following table in
+          *     terms of (width,height) of the RT.
+          *
+          *     MSAA  Width of Clear Rect  Height of Clear Rect
+          *      4X     Ceil(1/8*width)      Ceil(1/2*height)
+          *      8X     Ceil(1/2*width)      Ceil(1/2*height)
+          *
+          * The text "with upper left co-ordinate to coincide with actual
+          * rectangle being cleared" is a little confusing--it seems to imply
+          * that to clear a rectangle from (x,y) to (x+w,y+h), one needs to
+          * feed the pipeline using the rectangle (x,y) to
+          * (x+Ceil(w/N),y+Ceil(h/2)), where N is either 2 or 8 depending on
+          * the number of samples.  Experiments indicate that this is not
+          * quite correct; actually, what the hardware appears to do is to
+          * align whatever rectangle is sent down the pipeline to the nearest
+          * multiple of 2x2 blocks, and then scale it up by a factor of N
+          * horizontally and 2 vertically.  So the resulting alignment is 4
+          * vertically and either 4 or 16 horizontally, and the scaledown
+          * factor is 2 vertically and either 2 or 8 horizontally.
+          */
+         switch (irb->mt->num_samples) {
+         case 4:
+            x_scaledown = 8;
+            break;
+         case 8:
+            x_scaledown = 2;
+            break;
+         default:
+            unreachable("Unexpected sample count for fast clear");
+         }
+         y_scaledown = 2;
+         x_align = x_scaledown * 2;
+         y_align = y_scaledown * 2;
+      }
+
+      /* Do the alignment and scaledown. */
+      x0 = ROUND_DOWN_TO(x0,  x_align) / x_scaledown;
+      y0 = ROUND_DOWN_TO(y0, y_align) / y_scaledown;
+      x1 = ALIGN(x1, x_align) / x_scaledown;
+      y1 = ALIGN(y1, y_align) / y_scaledown;
+   }
+}
+
+
+brw_blorp_rt_resolve_params::brw_blorp_rt_resolve_params(
+      struct brw_context *brw,
+      struct intel_mipmap_tree *mt)
+{
+	struct gl_context *ctx = &brw->ctx;
+   mesa_format format = _mesa_get_render_format(ctx, mt->format);
+   dst.set(brw, mt, 0 /* level */, 0 /* layer */, format, true);
+
+   /* From the Ivy Bridge PRM, Vol2 Part1 11.9 "Render Target Resolve":
+    *
+    *     A rectangle primitive must be scaled down by the following factors
+    *     with respect to render target being resolved.
+    *
+    * The scaledown factors in the table that follows are related to the
+    * alignment size returned by intel_get_non_msrt_mcs_alignment(), but with
+    * X and Y alignment each divided by 2.
+    */
+   unsigned x_align, y_align;
+   intel_get_non_msrt_mcs_alignment(brw, mt, &x_align, &y_align);
+   unsigned x_scaledown = x_align / 2;
+   unsigned y_scaledown = y_align / 2;
+   x0 = y0 = 0;
+   x1 = ALIGN(mt->logical_width0, x_scaledown) / x_scaledown;
+   y1 = ALIGN(mt->logical_height0, y_scaledown) / y_scaledown;
+
+   fast_clear_op = GEN7_FAST_CLEAR_OP_RESOLVE;
+
+   /* Note: there is no need to initialize push constants because it doesn't
+    * matter what data gets dispatched to the render target.  However, we must
+    * ensure that the fragment shader delivers the data using the "replicated
+    * color" message.
+    */
+   use_wm_prog = true;
+   memset(&wm_prog_key, 0, sizeof(wm_prog_key));
+   wm_prog_key.use_simd16_replicated_data = true;
+}
+
+
+uint32_t
+brw_blorp_const_color_params::get_wm_prog(struct brw_context *brw,
+                                          brw_blorp_prog_data **prog_data)
+   const
+{
+   uint32_t prog_offset = 0;
+   if (!brw_search_cache(&brw->cache, BRW_BLORP_CONST_COLOR_PROG,
+                         &this->wm_prog_key, sizeof(this->wm_prog_key),
+                         &prog_offset, prog_data)) {
+      brw_blorp_const_color_program prog(brw, &this->wm_prog_key);
+      GLuint program_size;
+      const GLuint *program = prog.compile(brw, &program_size);
+      brw_upload_cache(&brw->cache, BRW_BLORP_CONST_COLOR_PROG,
+                       &this->wm_prog_key, sizeof(this->wm_prog_key),
+                       program, program_size,
+                       &prog.prog_data, sizeof(prog.prog_data),
+                       &prog_offset, prog_data);
+   }
+   return prog_offset;
+}
+
+void
+brw_blorp_const_color_program::alloc_regs()
+{
+   int reg = 0;
+   this->R0 = retype(brw_vec8_grf(reg++, 0), BRW_REGISTER_TYPE_UW);
+   this->R1 = retype(brw_vec8_grf(reg++, 0), BRW_REGISTER_TYPE_UW);
+
+   prog_data.first_curbe_grf = reg;
+   clear_rgba = retype(brw_vec4_grf(reg++, 0), BRW_REGISTER_TYPE_F);
+   reg += BRW_BLORP_NUM_PUSH_CONST_REGS;
+
+   /* Make sure we didn't run out of registers */
+   assert(reg <= GEN7_MRF_HACK_START);
+
+   this->base_mrf = 2;
+}
+
+const GLuint *
+brw_blorp_const_color_program::compile(struct brw_context *brw,
+                                       GLuint *program_size)
+{
+   /* Set up prog_data */
+   memset(&prog_data, 0, sizeof(prog_data));
+   prog_data.persample_msaa_dispatch = false;
+
+   alloc_regs();
+
+   brw_set_default_compression_control(&func, BRW_COMPRESSION_NONE);
+
+   struct brw_reg mrf_rt_write =
+      retype(vec16(brw_message_reg(base_mrf)), BRW_REGISTER_TYPE_F);
+
+   uint32_t mlen, msg_type;
+   if (key->use_simd16_replicated_data) {
+      /* The message payload is a single register with the low 4 floats/ints
+       * filled with the constant clear color.
+       */
+      brw_set_default_mask_control(&func, BRW_MASK_DISABLE);
+      brw_MOV(&func, vec4(brw_message_reg(base_mrf)), clear_rgba);
+      brw_set_default_mask_control(&func, BRW_MASK_ENABLE);
+
+      msg_type = BRW_DATAPORT_RENDER_TARGET_WRITE_SIMD16_SINGLE_SOURCE_REPLICATED;
+      mlen = 1;
+   } else {
+      for (int i = 0; i < 4; i++) {
+         /* The message payload is pairs of registers for 16 pixels each of r,
+          * g, b, and a.
+          */
+         brw_set_default_compression_control(&func, BRW_COMPRESSION_COMPRESSED);
+         brw_MOV(&func,
+                 brw_message_reg(base_mrf + i * 2),
+                 brw_vec1_grf(clear_rgba.nr, i));
+         brw_set_default_compression_control(&func, BRW_COMPRESSION_NONE);
+      }
+
+      msg_type = BRW_DATAPORT_RENDER_TARGET_WRITE_SIMD16_SINGLE_SOURCE;
+      mlen = 8;
+   }
+
+   /* Now write to the render target and terminate the thread */
+   brw_fb_WRITE(&func,
+                16 /* dispatch_width */,
+                base_mrf /* msg_reg_nr */,
+                mrf_rt_write /* src0 */,
+                msg_type,
+                BRW_BLORP_RENDERBUFFER_BINDING_TABLE_INDEX,
+                mlen,
+                0 /* response_length */,
+                true /* eot */,
+                false /* header present */);
+
+   if (unlikely(INTEL_DEBUG & DEBUG_BLORP)) {
+      fprintf(stderr, "Native code for BLORP clear:\n");
+      brw_disassemble(brw, func.store, 0, func.next_insn_offset, stderr);
+      fprintf(stderr, "\n");
+   }
+
+   brw_compact_instructions(&func, 0, 0, NULL);
+   return brw_get_program(&func, program_size);
+}
+
+
+bool
+do_single_blorp_clear(struct brw_context *brw, struct gl_framebuffer *fb,
+                      struct gl_renderbuffer *rb, unsigned buf,
+                      bool partial_clear, unsigned layer)
+{
+   struct gl_context *ctx = &brw->ctx;
+   struct intel_renderbuffer *irb = intel_renderbuffer(rb);
+
+   brw_blorp_clear_params params(brw, fb, rb, ctx->Color.ColorMask[buf],
+                                 partial_clear, layer);
+
+   bool is_fast_clear =
+      (params.fast_clear_op == GEN7_FAST_CLEAR_OP_FAST_CLEAR);
+   if (is_fast_clear) {
+      /* Record the clear color in the miptree so that it will be
+       * programmed in SURFACE_STATE by later rendering and resolve
+       * operations.
+       */
+      uint32_t new_color_value =
+         compute_fast_clear_color_bits(&ctx->Color.ClearColor);
+      if (irb->mt->fast_clear_color_value != new_color_value) {
+         irb->mt->fast_clear_color_value = new_color_value;
+         brw->state.dirty.brw |= BRW_NEW_SURFACES;
+      }
+
+      /* If the buffer is already in INTEL_FAST_CLEAR_STATE_CLEAR, the clear
+       * is redundant and can be skipped.
+       */
+      if (irb->mt->fast_clear_state == INTEL_FAST_CLEAR_STATE_CLEAR)
+         return true;
+
+      /* If the MCS buffer hasn't been allocated yet, we need to allocate
+       * it now.
+       */
+      if (!irb->mt->mcs_mt) {
+         if (!intel_miptree_alloc_non_msrt_mcs(brw, irb->mt)) {
+            /* MCS allocation failed--probably this will only happen in
+             * out-of-memory conditions.  But in any case, try to recover
+             * by falling back to a non-blorp clear technique.
+             */
+            return false;
+         }
+         brw->state.dirty.brw |= BRW_NEW_SURFACES;
+      }
+   }
+
+   const char *clear_type;
+   if (is_fast_clear)
+      clear_type = "fast";
+   else if (params.wm_prog_key.use_simd16_replicated_data)
+      clear_type = "replicated";
+   else
+      clear_type = "slow";
+
+   DBG("%s (%s) to mt %p level %d layer %d\n", __FUNCTION__, clear_type,
+       irb->mt, irb->mt_level, irb->mt_layer);
+
+   brw_blorp_exec(brw, &params);
+
+   if (is_fast_clear) {
+      /* Now that the fast clear has occurred, put the buffer in
+       * INTEL_FAST_CLEAR_STATE_CLEAR so that we won't waste time doing
+       * redundant clears.
+       */
+      irb->mt->fast_clear_state = INTEL_FAST_CLEAR_STATE_CLEAR;
+   }
+
+   return true;
+}
+
+
+extern "C" {
+bool
+brw_blorp_clear_color(struct brw_context *brw, struct gl_framebuffer *fb,
+                      GLbitfield mask, bool partial_clear)
+{
+   for (unsigned buf = 0; buf < fb->_NumColorDrawBuffers; buf++) {
+      struct gl_renderbuffer *rb = fb->_ColorDrawBuffers[buf];
+      struct intel_renderbuffer *irb = intel_renderbuffer(rb);
+
+      /* Only clear the buffers present in the provided mask */
+      if (((1 << fb->_ColorDrawBufferIndexes[buf]) & mask) == 0)
+         continue;
+
+      /* If this is an ES2 context or GL_ARB_ES2_compatibility is supported,
+       * the framebuffer can be complete with some attachments missing.  In
+       * this case the _ColorDrawBuffers pointer will be NULL.
+       */
+      if (rb == NULL)
+         continue;
+
+      if (fb->MaxNumLayers > 0) {
+         unsigned layer_multiplier =
+            (irb->mt->msaa_layout == INTEL_MSAA_LAYOUT_UMS ||
+             irb->mt->msaa_layout == INTEL_MSAA_LAYOUT_CMS) ?
+            irb->mt->num_samples : 1;
+         unsigned num_layers = irb->layer_count;
+         for (unsigned layer = 0; layer < num_layers; layer++) {
+            if (!do_single_blorp_clear(brw, fb, rb, buf, partial_clear,
+                                       irb->mt_layer + layer * layer_multiplier)) {
+               return false;
+            }
+         }
+      } else {
+         unsigned layer = irb->mt_layer;
+         if (!do_single_blorp_clear(brw, fb, rb, buf, partial_clear, layer))
+            return false;
+      }
+
+      irb->need_downsample = true;
+   }
+
+   return true;
+}
+
+void
+brw_blorp_resolve_color(struct brw_context *brw, struct intel_mipmap_tree *mt)
+{
+   DBG("%s to mt %p\n", __FUNCTION__, mt);
+
+   brw_blorp_rt_resolve_params params(brw, mt);
+   brw_blorp_exec(brw, &params);
+   mt->fast_clear_state = INTEL_FAST_CLEAR_STATE_RESOLVED;
+}
+
+} /* extern "C" */
diff --git a/src/mesa/drivers/dri/i965/brw_clear.c b/src/mesa/drivers/dri/i965/brw_clear.c
index 0e5fef59e9f..f76dd1ccaa8 100644
--- a/src/mesa/drivers/dri/i965/brw_clear.c
+++ b/src/mesa/drivers/dri/i965/brw_clear.c
@@ -241,12 +241,19 @@ brw_clear(struct gl_context *ctx, GLbitfield mask)
       }
    }
 
+   /* BLORP is currently only supported on Gen6+. */
+   if (brw->gen >= 6 && brw->gen < 8 &&
+	   mask & BUFFER_BITS_COLOR) {
+	   if (brw_blorp_clear_color(brw, fb, mask, partial_clear)) {
+		   debug_mask("blorp color", mask & BUFFER_BITS_COLOR);
+		   mask &= ~BUFFER_BITS_COLOR;
+	   }
+   } else if (brw->gen >= 8 && mask & BUFFER_BITS_COLOR) {
    /* Clear color buffers with fast clear or at least rep16 writes. */
-   if (brw->gen >= 6 && mask & BUFFER_BITS_COLOR) {
-      if (brw_meta_fast_clear(brw, fb, mask, partial_clear)) {
-         debug_mask("blorp color", mask & BUFFER_BITS_COLOR);
-         mask &= ~BUFFER_BITS_COLOR;
-      }
+	   if (brw_meta_fast_clear(brw, fb, mask, partial_clear)) {
+		   debug_mask("blorp color", mask & BUFFER_BITS_COLOR);
+		   mask &= ~BUFFER_BITS_COLOR;
+	   }
    }
 
    GLbitfield tri_mask = mask & (BUFFER_BITS_COLOR |