llvm dev - Aug 2010 - [LLVMdev] Purpose of PROLOG_LABEL in function prologue?

I've been building/dumping some x86_64 code and I've noticed that each
of the routines has 3 temporary symbols, à la:

_main:
	pushq	%rbp
Ltmp18:
	movq	%rsp, %rbp
Ltmp19:
	subq	$320, %rsp
Ltmp20:
	movl	%ecx, -276(%rbp)

I've tracked them back to emitPrologue in X86RegisterInfo.cpp.  I'm
wonder what's their purpose?

They're filling up my symbol table...

Cameron Esfahani
dirty at apple.com

"All that is necessary for the triumph of evil is that good men do
nothing."

Edmund Burke

On Aug 3, 2010, at 3:04 PM, Cameron Esfahani wrote:
> I've been building/dumping some x86_64 code and I've noticed that
each of the routines has 3 temporary symbols, à la:
> 
> _main:
> 	pushq	%rbp
> Ltmp18:
> 	movq	%rsp, %rbp
> Ltmp19:
> 	subq	$320, %rsp
> Ltmp20:
> 	movl	%ecx, -276(%rbp)
> 
> I've tracked them back to emitPrologue in X86RegisterInfo.cpp.  I'm
wonder what's their purpose?
> 
> They're filling up my symbol table...

EH ranges for unwind info.  If you look later on in the file for the symbols
you'll see them.

-eric

On Aug 3, 2010, at 3:12 PM, Eric Christopher wrote:
> 
> On Aug 3, 2010, at 3:04 PM, Cameron Esfahani wrote:
> 
>> I've been building/dumping some x86_64 code and I've noticed
that each of the routines has 3 temporary symbols, à la:
>> 
>> _main:
>> 	pushq	%rbp
>> Ltmp18:
>> 	movq	%rsp, %rbp
>> Ltmp19:
>> 	subq	$320, %rsp
>> Ltmp20:
>> 	movl	%ecx, -276(%rbp)
>> 
>> I've tracked them back to emitPrologue in X86RegisterInfo.cpp. 
I'm wonder what's their purpose?
>> 
>> They're filling up my symbol table...
> 
> 
> EH ranges for unwind info.  If you look later on in the file for the
symbols you'll see them.
Oh, though they should be local and not exported at all.

-eric

I don't see any references to them, that's why I brought it up...

On Aug 3, 2010, at 3:12 PM, Eric Christopher wrote:
> 
> On Aug 3, 2010, at 3:04 PM, Cameron Esfahani wrote:
> 
>> I've been building/dumping some x86_64 code and I've noticed
that each of the routines has 3 temporary symbols, à la:
>> 
>> _main:
>> 	pushq	%rbp
>> Ltmp18:
>> 	movq	%rsp, %rbp
>> Ltmp19:
>> 	subq	$320, %rsp
>> Ltmp20:
>> 	movl	%ecx, -276(%rbp)
>> 
>> I've tracked them back to emitPrologue in X86RegisterInfo.cpp. 
I'm wonder what's their purpose?
>> 
>> They're filling up my symbol table...
> 
> 
> EH ranges for unwind info.  If you look later on in the file for the
symbols you'll see them.
> 
> -eric
Cameron Esfahani
dirty at apple.com

"You only live once, and the way I live, once is enough"

Frank Sinatra