Remove gpu shader optimatization for solid white or trans black colors

Running test on the added bench which draws a grid of all white paths, all blue paths, or alternating checkered white/blue paths.

With optimization in (ms):
         White       Blue        Checkered
Linux    ~80         ~80         ~160
N7       ~800        ~1100       ~1500
Moto-e   ~830        ~1100       ~2500

Without optimization in (ms):
         White       Blue        Checkered
Linux    ~80         ~80         ~80
N7       ~1100       ~1100       ~1100
Moto-e   ~1100       ~1100       ~1500

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/5f78d2251a440443c9eaa321dad058d7a32bfef7

R=bsalomon@google.com

Author: egdaniel@google.com

Review URL: https://codereview.chromium.org/375823005

7 files changed, 26 insertions, 29 deletions

diff --git a/src/gpu/GrDrawState.cpp b/src/gpu/GrDrawState.cpp
index 14ba6fad5d..02c7920f5d 100644
--- a/src/gpu/GrDrawState.cpp
+++ b/src/gpu/GrDrawState.cpp
@@ -409,6 +409,15 @@ GrDrawState::BlendOptFlags GrDrawState::calcBlendOpts(bool forceCoverage,
     return kNone_BlendOpt;
 }
 
+bool GrDrawState::canIgnoreColorAttribute() const {
+    if (fBlendOptFlags & kInvalid_BlendOptFlag) {
+        this->getBlendOpts();
+    }
+    return SkToBool(fBlendOptFlags & (GrDrawState::kEmitTransBlack_BlendOptFlag |
+                                      GrDrawState::kEmitCoverage_BlendOptFlag));
+}
+
+
 ////////////////////////////////////////////////////////////////////////////////
 
 void GrDrawState::AutoViewMatrixRestore::restore() {
diff --git a/src/gpu/GrDrawState.h b/src/gpu/GrDrawState.h
index cef21af880..c1dd9dcd36 100644
--- a/src/gpu/GrDrawState.h
+++ b/src/gpu/GrDrawState.h
@@ -551,6 +551,12 @@ public:
     }
 
     /**
+     * We don't use suplied vertex color attributes if our blend mode is EmitCoverage or
+     * EmitTransBlack
+     */
+    bool canIgnoreColorAttribute() const;
+
+    /**
      * Determines what optimizations can be applied based on the blend. The coefficients may have
      * to be tweaked in order for the optimization to work. srcCoeff and dstCoeff are optional
      * params that receive the tweaked coefficients. Normally the function looks at the current
diff --git a/src/gpu/gl/GrGLProgram.cpp b/src/gpu/gl/GrGLProgram.cpp
index 435d0cdb02..5bc7d0b277 100644
--- a/src/gpu/gl/GrGLProgram.cpp
+++ b/src/gpu/gl/GrGLProgram.cpp
@@ -154,7 +154,7 @@ void GrGLProgram::setColor(const GrDrawState& drawState,
                            GrColor color,
                            SharedGLState* sharedState) {
     const GrGLProgramDesc::KeyHeader& header = fDesc.getHeader();
-    if (!drawState.hasColorVertexAttribute()) {
+    if (!drawState.hasColorVertexAttribute() || drawState.canIgnoreColorAttribute()) {
         switch (header.fColorInput) {
             case GrGLProgramDesc::kAttribute_ColorInput:
                 SkASSERT(-1 != header.fColorAttributeIndex);
@@ -178,12 +178,8 @@ void GrGLProgram::setColor(const GrDrawState& drawState,
                 }
                 sharedState->fConstAttribColorIndex = -1;
                 break;
-            case GrGLProgramDesc::kSolidWhite_ColorInput:
-            case GrGLProgramDesc::kTransBlack_ColorInput:
-                sharedState->fConstAttribColorIndex = -1;
-                break;
             default:
-                SkFAIL("Unknown color type.");
+                SkFAIL("Unexpected color type.");
         }
     } else {
         sharedState->fConstAttribColorIndex = -1;
@@ -218,11 +214,10 @@ void GrGLProgram::setCoverage(const GrDrawState& drawState,
                 sharedState->fConstAttribCoverageIndex = -1;
                 break;
             case GrGLProgramDesc::kSolidWhite_ColorInput:
-            case GrGLProgramDesc::kTransBlack_ColorInput:
                 sharedState->fConstAttribCoverageIndex = -1;
                 break;
             default:
-                SkFAIL("Unknown coverage type.");
+                SkFAIL("Unexpected coverage type.");
         }
     } else {
         sharedState->fConstAttribCoverageIndex = -1;
diff --git a/src/gpu/gl/GrGLProgramDesc.cpp b/src/gpu/gl/GrGLProgramDesc.cpp
index 27a1fab1e0..e1a319104d 100644
--- a/src/gpu/gl/GrGLProgramDesc.cpp
+++ b/src/gpu/gl/GrGLProgramDesc.cpp
@@ -66,6 +66,7 @@ bool GrGLProgramDesc::Build(const GrDrawState& drawState,
 
     bool skipColor = SkToBool(blendOpts & (GrDrawState::kEmitTransBlack_BlendOptFlag |
                                            GrDrawState::kEmitCoverage_BlendOptFlag));
+
     int firstEffectiveColorStage = 0;
     bool inputColorIsUsed = true;
     if (!skipColor) {
@@ -99,11 +100,6 @@ bool GrGLProgramDesc::Build(const GrDrawState& drawState,
     bool requiresLocalCoordAttrib = !(skipCoverage  && skipColor) &&
                                     drawState.hasLocalCoordAttribute();
 
-    bool colorIsTransBlack = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);
-    bool colorIsSolidWhite = (blendOpts & GrDrawState::kEmitCoverage_BlendOptFlag) ||
-                             (!requiresColorAttrib && 0xffffffff == drawState.getColor()) ||
-                             (!inputColorIsUsed);
-
     bool readsDst = false;
     bool readFragPosition = false;
     // We use vertexshader-less shader programs only when drawing paths.
@@ -192,11 +188,7 @@ bool GrGLProgramDesc::Build(const GrDrawState& drawState,
 #endif
     bool defaultToUniformInputs = GR_GL_NO_CONSTANT_ATTRIBUTES || gpu->caps()->pathRenderingSupport();
 
-    if (colorIsTransBlack) {
-        header->fColorInput = kTransBlack_ColorInput;
-    } else if (colorIsSolidWhite) {
-        header->fColorInput = kSolidWhite_ColorInput;
-    } else if (defaultToUniformInputs && !requiresColorAttrib) {
+    if (defaultToUniformInputs && !requiresColorAttrib && inputColorIsUsed) {
         header->fColorInput = kUniform_ColorInput;
     } else {
         header->fColorInput = kAttribute_ColorInput;
@@ -205,11 +197,9 @@ bool GrGLProgramDesc::Build(const GrDrawState& drawState,
 
     bool covIsSolidWhite = !requiresCoverageAttrib && 0xffffffff == drawState.getCoverageColor();
 
-    if (skipCoverage) {
-        header->fCoverageInput = kTransBlack_ColorInput;
-    } else if (covIsSolidWhite || !inputCoverageIsUsed) {
+    if ((covIsSolidWhite || !inputCoverageIsUsed) && !skipCoverage) {
         header->fCoverageInput = kSolidWhite_ColorInput;
-    } else if (defaultToUniformInputs && !requiresCoverageAttrib) {
+    } else if (defaultToUniformInputs && !requiresCoverageAttrib && inputCoverageIsUsed) {
         header->fCoverageInput = kUniform_ColorInput;
     } else {
         header->fCoverageInput = kAttribute_ColorInput;
diff --git a/src/gpu/gl/GrGLProgramDesc.h b/src/gpu/gl/GrGLProgramDesc.h
index a8d27ab269..cccdee9ce2 100644
--- a/src/gpu/gl/GrGLProgramDesc.h
+++ b/src/gpu/gl/GrGLProgramDesc.h
@@ -100,7 +100,6 @@ private:
     // Specifies where the initial color comes from before the stages are applied.
     enum ColorInput {
         kSolidWhite_ColorInput,
-        kTransBlack_ColorInput,
         kAttribute_ColorInput,
         kUniform_ColorInput,
 
diff --git a/src/gpu/gl/GrGLShaderBuilder.cpp b/src/gpu/gl/GrGLShaderBuilder.cpp
index 7a57d8e32e..8d1e66be7c 100644
--- a/src/gpu/gl/GrGLShaderBuilder.cpp
+++ b/src/gpu/gl/GrGLShaderBuilder.cpp
@@ -164,10 +164,6 @@ bool GrGLShaderBuilder::genProgram(const GrEffectStage* colorStages[],
             this->addUniform(GrGLShaderBuilder::kFragment_Visibility, kVec4f_GrSLType, "Color",
                              &name);
         inputColor = GrGLSLExpr4(name);
-    } else if (GrGLProgramDesc::kSolidWhite_ColorInput == header.fColorInput) {
-        inputColor = GrGLSLExpr4(1);
-    } else if (GrGLProgramDesc::kTransBlack_ColorInput == header.fColorInput) {
-        inputColor = GrGLSLExpr4(0);
     }
 
     if (GrGLProgramDesc::kUniform_ColorInput == header.fCoverageInput) {
@@ -178,8 +174,6 @@ bool GrGLShaderBuilder::genProgram(const GrEffectStage* colorStages[],
         inputCoverage = GrGLSLExpr4(name);
     } else if (GrGLProgramDesc::kSolidWhite_ColorInput == header.fCoverageInput) {
         inputCoverage = GrGLSLExpr4(1);
-    } else if (GrGLProgramDesc::kTransBlack_ColorInput == header.fCoverageInput) {
-        inputCoverage = GrGLSLExpr4(0);
     }
 
     if (k110_GrGLSLGeneration != fGpu->glslGeneration()) {
diff --git a/src/gpu/gl/GrGpuGL_program.cpp b/src/gpu/gl/GrGpuGL_program.cpp
index 9e1b6f5c2b..45181c25a8 100644
--- a/src/gpu/gl/GrGpuGL_program.cpp
+++ b/src/gpu/gl/GrGpuGL_program.cpp
@@ -353,9 +353,12 @@ void GrGpuGL::setupGeometry(const DrawInfo& info, size_t* indexOffsetInBytes) {
         uint32_t usedAttribArraysMask = 0;
         const GrVertexAttrib* vertexAttrib = this->getDrawState().getVertexAttribs();
 
+        bool canIgnoreColorAttrib = this->getDrawState().canIgnoreColorAttribute();
+
         for (int vertexAttribIndex = 0; vertexAttribIndex < vertexAttribCount;
              ++vertexAttribIndex, ++vertexAttrib) {
 
+            if (kColor_GrVertexAttribBinding != vertexAttrib->fBinding || !canIgnoreColorAttrib) {
             usedAttribArraysMask |= (1 << vertexAttribIndex);
             GrVertexAttribType attribType = vertexAttrib->fType;
             attribState->set(this,
@@ -367,6 +370,7 @@ void GrGpuGL::setupGeometry(const DrawInfo& info, size_t* indexOffsetInBytes) {
                              stride,
                              reinterpret_cast<GrGLvoid*>(
                                  vertexOffsetInBytes + vertexAttrib->fOffset));
+            }
         }
         attribState->disableUnusedArrays(this, usedAttribArraysMask);
     }