[llvm] r259399 - Fix infinite recursion in MCAsmStreamer::EmitValueImpl.

[Rafael Espindola via llvm-commits]

Author: rafael
Date: Mon Feb  1 14:36:49 2016
New Revision: 259399

URL: http://llvm.org/viewvc/llvm-project?rev=259399&view=rev
Log:
Fix infinite recursion in MCAsmStreamer::EmitValueImpl.

If a target can only emit 8-bits data, we would loop in EmitValueImpl
since it will try to split a 32-bits data in 1 chunk of 32-bits.

No test since all current targets can emit 32bits at a time.

Patch by Alexandru Guduleasa!

Modified:
    llvm/trunk/lib/MC/MCAsmStreamer.cpp

Modified: llvm/trunk/lib/MC/MCAsmStreamer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/MC/MCAsmStreamer.cpp?rev=259399&r1=259398&r2=259399&view=diff
==============================================================================
--- llvm/trunk/lib/MC/MCAsmStreamer.cpp (original)
+++ llvm/trunk/lib/MC/MCAsmStreamer.cpp Mon Feb  1 14:36:49 2016
@@ -720,17 +720,15 @@ void MCAsmStreamer::EmitValueImpl(const
       report_fatal_error("Don't know how to emit this value.");
 
     // We couldn't handle the requested integer size so we fallback by breaking
-    // the request down into several, smaller, integers.  Since sizes greater
-    // than eight are invalid and size equivalent to eight should have been
-    // handled earlier, we use four bytes as our largest piece of granularity.
+    // the request down into several, smaller, integers.
+    // Since sizes greater or equal to "Size" are invalid, we use the greatest
+    // power of 2 that is less than "Size" as our largest piece of granularity.
     bool IsLittleEndian = MAI->isLittleEndian();
     for (unsigned Emitted = 0; Emitted != Size;) {
       unsigned Remaining = Size - Emitted;
       // The size of our partial emission must be a power of two less than
-      // eight.
-      unsigned EmissionSize = PowerOf2Floor(Remaining);
-      if (EmissionSize > 4)
-        EmissionSize = 4;
+      // Size.
+      unsigned EmissionSize = PowerOf2Floor(std::min(Remaining, Size - 1));
       // Calculate the byte offset of our partial emission taking into account
       // the endianness of the target.
       unsigned ByteOffset =