RISC means reduced instruction set: a small set of simple (atomic) instructions that may be combined into more complex operations. RISC指精简指令集:由简单(原子的)指令构成的小指令集合,由它们可以组合成更复杂的操作。 2.3 x86内存管理 1. What is the range of addressable memory in protected mode?
The presence of wide SIMD registers means that existing x86 processors can load or store up to 128 bits of memory data in a single instruction and also perform bitwise operations (although not integer arithmetic[15]) on full 128-bits quantities in parallel. Intel's Sandy Bridge processors added...
This means that while X86S is dead, some of the proposed changes may still make it into future x86 processors, much like how AMD’s 64-bit extensions to the ISA, except this time it’d be done in cooperation. In an industry where competition from ARM especially is getting much stronger...
(2) Bit fields occupy as many bits as you assign them, up to 4 bytes, and their length need not be a multiple of 8 bits (1 byte) Table 6 Scalar Alignment Data Type char short int enum pointer float double long double long double (64-bit operating system) long [int] 32-bit on...
Following is a table that will provide you with a good summary of what each string means: Reading from left to right is the preference of using that term to describe the CPU architecture over the other, alternatively used terms on its right. ...
The Intel x86 processor uses complex instruction set computer (CISC) architecture, which means there is a modest number of special-purpose registers instead of large quantities of general-purpose registers. It also means that complex special-purpose instructions will predominate. The x86 processor ...
⁵ It also means that the x86-32 pun of interpretingnopasxchg eax, eaxdoes not work in x86-64. The self-exchange zeroes out the high 32 bits as a side effect. The Windows debugger doesn’t realize this, and if you ask it to assemblexchg eax, eax, it encodes it as90, using the...
According to the Intel notation (of which section 3.1.1 in volume 2 of the Intel manuals will give you a comprehensive run through), +rd at the end of a byte value means the same thing that I described earlier: the three least significant bits will indicate the operand register. You ...
all instructions are 32-bits long unless you're in thumb mode, which means that all instructions are 16-bit long, but the same sort of trade-offs that come from a fixed length instruction encoding still apply. Thumb-2 is a variable length ISA, so in some sense the same trade-offs appl...
The integration of those libraries into libc means that additional symbols become available by default. This can cause applications that contain weak references to take unexpected code paths that would only have been used in previous glibc versions when e.g. preloading libpthread.so.0, potentially ...