diff --git a/llvm/docs/CodeGenerator.html b/llvm/docs/CodeGenerator.html index 009ecd676788..66d793dfa03c 100644 --- a/llvm/docs/CodeGenerator.html +++ b/llvm/docs/CodeGenerator.html @@ -1718,7 +1718,7 @@ processors, and includes support for ISA extensions such as MMX and SSE.
x86 has the ability to perform loads and stores to different address spaces +via the x86 segment registers. A segment override prefix byte on an instruction +causes the instruction's memory access to go to the specified segment. LLVM +address space 0 is the default address space, which includes the stack, and +any unqualified memory accesses in a program. Address spaces 1-255 are +currently reserved for user-defined code. The GS-segment is represented by +address space 256. Other x86 segments have yet to be allocated address space +numbers. + +
Some operating systems use the GS-segment to implement TLS, so care should be +taken when reading and writing to address space 256 on these platforms. + +