This preview shows page 1. Sign up to view the full content.
Unformatted text preview: akes this value and the value of %ecx at the start of the loop and produces a new value for %ecx. As this example illustrates, tags can be associated with intermediate values that are never written to the register ﬁle. The operation
incl %edx.0 %edx.1 indicates that the increment operation adds one to the value of %edx at the start of the loop to generate a new value for this register. The operation
cmpl %esi, %edx.1 cc.1 indicates that the compare operation (performed by either integer unit) compares the value in %esi (which does not change in the loop) with the newly computed value for %edx. It then sets the condition codes, identiﬁed with the explicit label cc.1. As this example illustrates, the processor can use renaming to track changes to the condition code registers. Finally, the jump instruction was predicted taken. The jump operation
jl-taken cc.1 5.7. UNDERSTANDING MODERN PROCESSORS
%edx.0 227 incl %edx.1 Execution Unit Operations load (%eax, %edx.0, 4) imull t.1, %ecx.0...
View Full Document
- Spring '10
- The American