Intel CORE 2 DUO E4000 - SPECIFICATION UPDATE 3-2008 Specification page 30

• FST m64real
• FSTP m32real
• FSTP m64real
• FSTP m80real
• FIST m16int
• FIST m32int
• FISTP m16int
• FISTP m32int
• FISTP m64int
• FISTTP m16int
• FISTTP m32int
• FISTTP m64int
Note that even if this combination of instructions is encountered, there is also a
dependency on the internal pipelining and execution state of both instructions in the
processor.
Implication: Inexact-result exceptions are commonly masked or ignored by applications,
as it happens frequently, and produces a rounded result acceptable to most
applications. The PE bit of the FPU status word may not always be set upon
receiving an inexact-result exception. Thus, if these exceptions are
unmasked, a floating-point error exception handler may not recognize that a
precision exception occurred. Note that this is a "sticky" bit, i.e., once set by
an inexact-result condition, it remains set until cleared by software.
Workaround: This condition can be avoided by inserting either three NOPs or three non-
floating-point non-Jcc instructions between the two floating-point
instructions.
For the steppings affected, see the Summary Tables of Changes.
Status:
AI21. Global Pages in the Data Translation Look-Aside Buffer (DTLB) May
Not Be Flushed by RSM instruction before Restoring the Architectural
State from SMRAM
The Resume from System Management Mode (RSM) instruction does not
Problem:
flush global pages from the Data Translation Look-Aside Buffer (DTLB) prior
to reloading the saved architectural state.
Implication: If SMM turns on paging with global paging enabled and then maps any of
linear addresses of SMRAM using global pages, RSM load may load data from
the wrong location.
Workaround: Do not use global pages in system management mode.
For the steppings affected, see the Summary Tables of Changes.
Status:
30 Intel
Intel® Core™2 Duo Desktop Processor E6000 and E4000 Sequence
®
Core™2 Extreme Processor X6800 and
Specification Update
Errata