diff options
author | Andreas Sandberg <andreas@sandberg.pp.se> | 2013-06-18 16:30:06 +0200 |
---|---|---|
committer | Andreas Sandberg <andreas@sandberg.pp.se> | 2013-06-18 16:30:06 +0200 |
commit | a8e8c4f433fb3cce354950ba72136b84abb78015 (patch) | |
tree | c1b93c2399e0474da011b9aaaa324d4bd14b919e /src/arch/x86/utility.hh | |
parent | c9c02efb99c0a982c116c7d1d8ed9a984c174198 (diff) | |
download | gem5-a8e8c4f433fb3cce354950ba72136b84abb78015.tar.xz |
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.
Diffstat (limited to 'src/arch/x86/utility.hh')
-rw-r--r-- | src/arch/x86/utility.hh | 7 |
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__ |