[llvm-commits] [llvm] r72894 - in /llvm/trunk: include/llvm/Attributes.h include/llvm/Target/TargetOptions.h lib/AsmParser/LLLexer.cpp lib/AsmParser/LLParser.cpp lib/AsmParser/LLToken.h lib/Target/PowerPC/PPCRegisterInfo.cpp lib/Target/TargetMachine.cpp lib/Target/X86/X86RegisterInfo.cpp lib/VMCore/Attributes.cpp test/CodeGen/X86/red-zone2.ll tools/llc/llc.cpp

[Devang Patel]

On Jun 7, 2009, at 11:05 AM, Nick Lewycky wrote:

> This attribute needs an entry in LangRef. Please add one.

Yes. I am going to add one or two additional attributes. I'll document  
all of them together.
>
>
> Also, I'm now getting "noredzone" notes on all my functions all the  
> time when building x86-32 Linux. I suppose that's technically true  
> but do we really need this everywhere?

llvm-gcc sets this when -mno-red-zone is set by GCC's target machinery.

>
>
> Why disable the redzone anyways? Isn't it an ABI feature?

GCC man page says,

        -mno-red-zone
            Do not use a so called red zone for x86-64 code.  The red  
zone is
            mandated by the x86-64 ABI, it is a 128-byte area beyond the
            location of the stack pointer that will not be modified by  
signal
            or interrupt handlers and therefore can be used for  
temporary data
            without adjusting the stack pointer.  The flag -mno-red-zone
            disables this red zone.


>
>
> Nick
-
Devang