Don't issue texture barriers for RT's with separate storage

BUG=skia:

Review URL: https://codereview.chromium.org/1137663004

7 files changed, 22 insertions, 8 deletions

diff --git a/src/gpu/GrCommandBuilder.cpp b/src/gpu/GrCommandBuilder.cpp
index 2ff59bcecd..106e78185d 100644
--- a/src/gpu/GrCommandBuilder.cpp
+++ b/src/gpu/GrCommandBuilder.cpp
@@ -82,7 +82,7 @@ GrCommandBuilder::recordXferBarrierIfNecessary(const GrPipeline& pipeline,
         return NULL;
     }
 
-    XferBarrier* xb = GrNEW_APPEND_TO_RECORDER(*this->cmdBuffer(), XferBarrier, ());
+    XferBarrier* xb = GrNEW_APPEND_TO_RECORDER(*this->cmdBuffer(), XferBarrier, (rt));
     xb->fBarrierType = barrierType;
     return xb;
 }
diff --git a/src/gpu/GrGpu.h b/src/gpu/GrGpu.h
index 83f6c992fc..f2ad10f417 100644
--- a/src/gpu/GrGpu.h
+++ b/src/gpu/GrGpu.h
@@ -277,7 +277,7 @@ public:
                              const SkIPoint& dstPoint) = 0;
 
     // Called before certain draws in order to guarantee coherent results from dst reads.
-    virtual void xferBarrier(GrXferBarrierType) = 0;
+    virtual void xferBarrier(GrRenderTarget*, GrXferBarrierType) = 0;
 
     struct DrawArgs {
         DrawArgs(const GrPrimitiveProcessor* primProc,
diff --git a/src/gpu/GrTargetCommands.cpp b/src/gpu/GrTargetCommands.cpp
index 7e57c03291..096d429dea 100644
--- a/src/gpu/GrTargetCommands.cpp
+++ b/src/gpu/GrTargetCommands.cpp
@@ -111,5 +111,5 @@ void GrTargetCommands::CopySurface::execute(GrGpu* gpu) {
 }
 
 void GrTargetCommands::XferBarrier::execute(GrGpu* gpu) {
-    gpu->xferBarrier(fBarrierType);
+    gpu->xferBarrier(fRenderTarget.get(), fBarrierType);
 }
diff --git a/src/gpu/GrTargetCommands.h b/src/gpu/GrTargetCommands.h
index 5e35e50bbf..2f9909bb02 100644
--- a/src/gpu/GrTargetCommands.h
+++ b/src/gpu/GrTargetCommands.h
@@ -242,11 +242,17 @@ private:
     };
 
     struct XferBarrier : public Cmd {
-        XferBarrier() : Cmd(kXferBarrier_CmdType) {}
+        XferBarrier(GrRenderTarget* rt)
+            : Cmd(kXferBarrier_CmdType)
+            , fRenderTarget(rt) {
+        }
 
         void execute(GrGpu*) override;
 
         GrXferBarrierType   fBarrierType;
+
+    private:
+        GrPendingIOResource<GrRenderTarget, kWrite_GrIOType> fRenderTarget;
     };
 
     static const int kCmdBufferInitialSizeInBytes = 8 * 1024;
diff --git a/src/gpu/GrTest.cpp b/src/gpu/GrTest.cpp
index 1017273031..0b3d030cdb 100644
--- a/src/gpu/GrTest.cpp
+++ b/src/gpu/GrTest.cpp
@@ -169,7 +169,7 @@ public:
         return false;
     }
 
-    void xferBarrier(GrXferBarrierType) override {}
+    void xferBarrier(GrRenderTarget*, GrXferBarrierType) override {}
 
 private:
     void onResetContext(uint32_t resetBits) override {}
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 3d7d6918f1..6d97804fc6 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -2787,12 +2787,20 @@ bool GrGLGpu::canCopySurface(const GrSurface* dst,
     return false;
 }
 
-void GrGLGpu::xferBarrier(GrXferBarrierType type) {
+void GrGLGpu::xferBarrier(GrRenderTarget* rt, GrXferBarrierType type) {
     switch (type) {
-        case kTexture_GrXferBarrierType:
+        case kTexture_GrXferBarrierType: {
+            GrGLRenderTarget* glrt = static_cast<GrGLRenderTarget*>(rt);
+            if (glrt->textureFBOID() != glrt->renderFBOID()) {
+                // The render target uses separate storage so no need for glTextureBarrier.
+                // FIXME: The render target will resolve automatically when its texture is bound,
+                // but we could resolve only the bounds that will be read if we do it here instead.
+                return;
+            }
             SkASSERT(this->caps()->textureBarrierSupport());
             GL_CALL(TextureBarrier());
             return;
+        }
         case kBlend_GrXferBarrierType:
             SkASSERT(GrDrawTargetCaps::kAdvanced_BlendEquationSupport ==
                      this->caps()->blendEquationSupport());
diff --git a/src/gpu/gl/GrGLGpu.h b/src/gpu/gl/GrGLGpu.h
index 4409b0c8fc..3323ece079 100644
--- a/src/gpu/gl/GrGLGpu.h
+++ b/src/gpu/gl/GrGLGpu.h
@@ -106,7 +106,7 @@ public:
                         const SkIRect& srcRect,
                         const SkIPoint& dstPoint) override;
 
-    void xferBarrier(GrXferBarrierType) override;
+    void xferBarrier(GrRenderTarget*, GrXferBarrierType) override;
 
     void buildProgramDesc(GrProgramDesc*,
                           const GrPrimitiveProcessor&,