Add instruction alignment tests to unit tests.

src/PNaClTranslator.cpp

 //===- subzero/src/PNaClTranslator.cpp - ICE from bitcode -----------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the PNaCl bitcode file to Ice, to machine code
@@ skipping 1156 matching lines @@
   void popTimerIfTimingEachFunction() const {
     if (ALLOW_DUMP && getFlags().TimeEachFunction) {
       getTranslator().getContext()->popTimer(
           getTranslator().getContext()->getTimerID(
               Ice::GlobalContext::TSK_Funcs, Func->getFunctionName()),
           Ice::GlobalContext::TSK_Funcs);
     }
   }
 
   // Extracts the corresponding Alignment to use, given the AlignPower
-  // (i.e. 2**AlignPower, or 0 if AlignPower == 0). InstName is the
+  // (i.e. 2**(AlignPower-1), or 0 if AlignPower == 0). InstName is the
   // name of the instruction the alignment appears in.
   void extractAlignment(const char *InstName, uint32_t AlignPower,
                         uint32_t &Alignment) {
-    if (AlignPower <= AlignPowerLimit) {
+    if (AlignPower <= AlignPowerLimit + 1) {
       Alignment = (1 << AlignPower) >> 1;
       return;
     }
     std::string Buffer;
     raw_string_ostream StrBuf(Buffer);
     StrBuf << InstName << " alignment greater than 2**" << AlignPowerLimit
            << ". Found: 2**" << AlignPower;

[jvoung (off chromium), 2015/01/12 18:10:06]

"2**... AlignPower - 1"

[Karl, 2015/01/14 22:03:07]

Done.

     Error(StrBuf.str());
     // Error recover with value that is always acceptable.
     Alignment = 1;
   }
 
   bool ParseBlock(unsigned BlockID) override;
 
   void ProcessRecord() override;
 
   void ExitBlock() override;
@@ skipping 1802 matching lines @@
 
   if (TopLevelBlocks != 1) {
     errs() << IRFilename
            << ": Contains more than one module. Found: " << TopLevelBlocks
            << "\n";
     ErrorStatus = true;
   }
 }
 
 } // end of namespace Ice