Reviewers: Erik Corry,

Description:
Avoid trashing the FPSCR when calculating Math.floor

The restoring of FPSCR could restore a random value as the restore point could
be jumped to from before FPSCR was loaded.

Please review this at http://codereview.chromium.org/6344002/

SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/

Affected files:
  M     src/arm/stub-cache-arm.cc


Index: src/arm/stub-cache-arm.cc
===================================================================
--- src/arm/stub-cache-arm.cc   (revision 6330)
+++ src/arm/stub-cache-arm.cc   (working copy)
@@ -1952,7 +1952,7 @@
   __ cmp(r7, Operand(HeapNumber::kMantissaBits));
   // If greater or equal, the argument is already round and in r0.
   __ b(&restore_fpscr_and_return, ge);
-  __ b(&slow);
+  __ b(&wont_fit_smi);

   __ bind(&no_vfp_exception);
   // Move the result back to general purpose register r0.
@@ -1980,10 +1980,10 @@
   __ Ret();

   __ bind(&wont_fit_smi);
-  __ bind(&slow);
   // Restore FPCSR and fall to slow case.
   __ vmsr(r3);

+  __ bind(&slow);
   // Tail call the full function. We do not have to patch the receiver
   // because the function makes no use of it.
   __ InvokeFunction(function, arguments(), JUMP_FUNCTION);


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