Remove memcmp from GrProgramDesc op== and Less

src/gpu/GrProgramDesc.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrProgramDesc_DEFINED
 #define GrProgramDesc_DEFINED
 
@@ skipping 21 matching lines @@
     // Gets the a checksum of the key. Can be used as a hash value for a fast lookup in a cache.
     uint32_t getChecksum() const { return *this->atOffset<uint32_t, kChecksumOffset>(); }
 
     GrProgramDesc& operator= (const GrProgramDesc& other) {
         uint32_t keyLength = other.keyLength();
         fKey.reset(SkToInt(keyLength));
         memcpy(fKey.begin(), other.fKey.begin(), keyLength);
         return *this;
     }
 
-    bool operator== (const GrProgramDesc& other) const {
-        // The length is masked as a hint to the compiler that the address will be 4 byte aligned.
-        return 0 == memcmp(this->asKey(), other.asKey(), this->keyLength() & ~0x3);
+    bool operator== (const GrProgramDesc& that) const {
+        SkASSERT(SkIsAlign4(this->keyLength()));
+        int l = this->keyLength() >> 2;
+        const uint32_t* aKey = this->asKey();
+        const uint32_t* bKey = that.asKey();
+        for (int i = 0; i < l; ++i) {
+            if (aKey[i] != bKey[i]) {
+                return false;
+            }
+        }
+        return true;
     }
 
     bool operator!= (const GrProgramDesc& other) const {
         return !(*this == other);
     }
 
     static bool Less(const GrProgramDesc& a, const GrProgramDesc& b) {
-        return memcmp(a.asKey(), b.asKey(), a.keyLength() & ~0x3) < 0;
+        SkASSERT(SkIsAlign4(a.keyLength()));
+        int l = a.keyLength() >> 2;
+        const uint32_t* aKey = a.asKey();
+        const uint32_t* bKey = b.asKey();
+        for (int i = 0; i < l; ++i) {
+            if (aKey[i] != bKey[i]) {
+                return aKey[i] < bKey[i] ? true : false;
+            }
+        }
+        return false;
     }
 
     struct KeyHeader {
         uint8_t                     fFragPosKey;   // set by GrGLShaderBuilder if there are
                                                    // effects that read the fragment position.
                                                    // Otherwise, 0.
         uint8_t                     fSnapVerticesToPixelCenters;
         int8_t                      fColorEffectCnt;
         int8_t                      fCoverageEffectCnt;
     };
@@ skipping 54 matching lines @@
     };
 
     SkSTArray<kPreAllocSize, uint8_t, true>& key() { return fKey; }
     const SkSTArray<kPreAllocSize, uint8_t, true>& key() const { return fKey; }
 
 private:
     SkSTArray<kPreAllocSize, uint8_t, true> fKey;
 };
 
 #endif