x86: Fix loading of floating point constants

This changeset actually fixes two issues:

 * The lfpimm instruction didn't work correctly when applied to a
   floating point constant (it did work for integers containing the
   bit string representation of a constant) since it used
   reinterpret_cast to convert a double to a uint64_t. This caused a
   compilation error, at least, in gcc 4.6.3.

 * The instructions loading floating point constants in the x87
   processor didn't work correctly since they just stored a truncated
   integer instead of a double in the floating point register. This
   changeset fixes the old microcode by using lfpimm instruction
   instead of the limm instructions.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/arch/x86/utility.hh b/src/arch/x86/utility.hh
index 6fc802f2f..48840ac77 100644
--- a/src/arch/x86/utility.hh
+++ b/src/arch/x86/utility.hh
@@ -134,6 +134,13 @@ namespace X86ISA
      * @param val New rflags value to store in TC
      */
     void setRFlags(ThreadContext *tc, uint64_t val);
+
+    /**
+     * Extract the bit string representing a double value.
+     */
+    inline uint64_t getDoubleBits(double val) {
+        return *(uint64_t *)(&val);
+    }
 }
 
 #endif // __ARCH_X86_UTILITY_HH__