Advanced Micro Devices Corporation

Michael E Tuuk

Teik-Chung Tan

Wing-Shek Wong

Benjamin T Sander

Michael T Clark

Gregory William Smaus

Matthew Andrew Rafacz

Faisal A Syed

Matthew M Crum

Christopher Svec

A processor includes a store queue that stores information representing store instructions. In response to retirement of a store instruction, the processor invalidates the corresponding entry in the store queue, thereby indicating that the entry is available to store a subsequent store instruction. The store address is not removed from the queue until the subsequent store instruction is stored. Accordingly, the store address is available for comparison to a dependent load address.

Confirming store-to-load forwards

A data processing device employs a first translation look-aside buffer (TLB) to translate virtual addresses to physical addresses. If a virtual address to be translated is not located in the first TLB, the physical address is requested from a set of page tables. When the data processing device is in a hypervisor mode, a second TLB is accessed in response to the request to access the page tables. If the virtual address is located in the second TLB, the hypervisor page tables are bypassed and the second TLB provides a physical address or information to access another table in the set of page tables. By bypassing the hypervisor page tables, the time to translate an address in the hypervisor mode is reduced, thereby improving the efficiency of the data processing device.

Address translation with multiple translation look aside buffers

A method and circuit for fast flag generation. The circuit is coupled to receive data to be shifted, the data including a first plurality of bits. A shift count value (including a second plurality of bits) is also received by the circuit, as well as an indication of a direction the data is to be shifted. Based on the shift count value and the indication of direction, the position of a bit within the data is determined. The bit is then output as a flag bit.

Fast flag generation

A technique for reducing stack pointer adjustment operations when stack dependent operations, which correspond to stack dependent instructions, are encountered includes setting a stack pointer to an initial value for a stack. A number of bytes associated with the stack dependent operation is determined. A stack pointer delta is then modified based upon the number of bytes associated with the stack dependent operation. A current location in the stack is determined based on the stack pointer and the stack pointer delta.

Determination of current stack pointer value using architectural and speculative stack pointer delta values

A method and mechanism for performing division. A processor includes a divider configured to perform arithmetic division operations. Prior to dividing a dividend by a divisor, the divider manipulates the dividend and divisor to reduce the number of bits considered and the computations required to perform the division. The divisor is normalized by eliminating sign bits. The dividend is prescaled to eliminate one or more sign bits. Prescaling of the dividend may not be precise as sign bits of the dividend may be shifted out as groups of bits, rather than individual bits. Prescaling of the dividend may be adjusted to account for the fact that the divider considers multiple bits of the dividend at a time. Subsequent to prescaling and adjustment, the dividend may be adjusted in dependence upon the normalization of the divisor. Further adjustment may be utilized to maintain a significance relationship between the divisor and dividend. Subsequent to further adjustment, the division operation may be completed.

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Michael E Tuuk