Move willUseInputColor check to computeInvariantOutput

src/gpu/GrOptDrawState.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrOptDrawState.h"
 
 #include "GrDrawState.h"
@@ skipping 226 matching lines @@
             inout.fValidFlags = kA_GrColorComponentFlag;
         } else {
             inout.fValidFlags = 0;
             // not strictly necessary but we get false alarms from tools about uninit.
             inout.fColor = 0;
         }
     }
 
     for (int i = 0; i < ds.numColorStages(); ++i) {
         const GrFragmentProcessor* fp = ds.getColorStage(i).getProcessor();
-        if (!fp->willUseInputColor()) {
+        fp->computeInvariantOutput(&inout);
+        if (!inout.fWillUseInputColor) {
             *firstColorStageIdx = i;
             fInputColorIsUsed = false;
         }
-        fp->computeInvariantOutput(&inout);
         if (kRGBA_GrColorComponentFlags == inout.fValidFlags) {
             *firstColorStageIdx = i + 1;
             fColor = inout.fColor;
             fInputColorIsUsed = true;
             *fixedFunctionVAToRemove |= 0x1 << kColor_GrVertexAttribBinding;
+            // Since we are clearing all previous color stages we are in a state where we have found
+            // zero stages that don't multiply the inputColor.
+            inout.fNonMulStageFound = false;
         }
     }
 }
 
 void GrOptDrawState::computeEffectiveCoverageStages(const GrDrawState& ds,
                                                     int* firstCoverageStageIdx) {
     // We do not try to optimize out constantColor coverage effects here. It is extremely rare
     // to have a coverage effect that returns a constant value for all four channels. Thus we
     // save having to make extra virtual calls by not checking for it.
 
     // Don't do any optimizations on coverage stages. It should not be the case where we do not use
     // input coverage in an effect
 #ifdef OptCoverageStages
+    GrProcessor::InvariantOutput inout;
     for (int i = 0; i < ds.numCoverageStages(); ++i) {
-        const GrProcessor* processor = ds.getCoverageStage(i).getProcessor();
-        if (!processor->willUseInputColor()) {
+        const GrFragmentProcessor* fp = ds.getCoverageStage(i).getProcessor();
+        fp->computeInvariantOutput(&inout);
+        if (!inout.fWillUseInputColor) {
             *firstCoverageStageIdx = i;
             fInputCoverageIsUsed = false;
         }
     }
 #endif
 }
 
 static void get_stage_stats(const GrFragmentStage& stage, bool* readsDst, bool* readsFragPosition) {
     if (stage.getProcessor()->willReadDstColor()) {
         *readsDst = true;
@@ skipping 85 matching lines @@
         }
     }
 
     SkASSERT(0 == memcmp(this->fFixedFunctionVertexAttribIndices,
                          that.fFixedFunctionVertexAttribIndices,
                          sizeof(this->fFixedFunctionVertexAttribIndices)));
 
     return true;
 }