Intel 2ND GENERATION CORE PROCESSOR FAMILY DESKTOP - SPECIFICATION UPDATE 01-2011 Specification page 26

Workaround: Software should avoid memory accesses that wrap around the respective 16-bit and
32-bit mode memory limits.
Status: For the steppings affected, see the Summary Tables of Changes.
BJ37. Performance Monitor SSE Retired Instructions May Return Incorrect
Values
Problem: Performance Monitoring counter SIMD_INST_RETIRED (Event: C7H) is used to track
retired SSE instructions. Due to this erratum, the processor may also count other types
of instructions resulting in higher than expected values.
Implication: Performance Monitoring counter SIMD_INST_RETIRED may report count higher than
expected.
Workaround: None identified
Status: For the steppings affected, see the Summary Tables of Changes.
BJ38. FP Data Operand Pointer May Be Incorrectly Calculated After an FP
Access Which Wraps a 4-Gbyte Boundary in Code That Uses 32-Bit
Address Size in 64-bit Mode
Problem: The FP (Floating Point) Data Operand Pointer is the effective address of the operand
associated with the last non-control FP instruction executed by the processor. If an 80-
bit FP access (load or store) uses a 32-bit address size in 64-bit mode and the memory
access wraps a 4-Gbyte boundary and the FP environment is subsequently saved, the
value contained in the FP Data Operand Pointer may be incorrect.
Implication: Due to this erratum, the FP Data Operand Pointer may be incorrect. Wrapping an 80-bit
FP load around a 4-Gbyte boundary in this way is not a normal programming practice.
Intel has not observed this erratum with any commercially available software.
Workaround: If the FP Data Operand Pointer is used in a 64-bit operating system which may run code
accessing 32-bit addresses, care must be taken to ensure that no 80-bit FP accesses
are wrapped around a 4-Gbyte boundary.
Status: For the steppings affected, see the Summary Tables of Changes.
26 Specification Update