This is the mail archive of the
gcc-help@gcc.gnu.org
mailing list for the GCC project.
Re: Abt an RTL expression
- From: Andrew Haley <aph at redhat dot com>
- To: "Mohamed Shafi" <shafitvm at gmail dot com>
- Cc: gcc-help at gcc dot gnu dot org
- Date: Tue, 31 Oct 2006 10:21:15 +0000
- Subject: Re: Abt an RTL expression
- References: <ba0bd44d0610310201n42443c7doa72c150eef2c8a66@mail.gmail.com>
This should not be posted to the gcc list. You want gcc-help.
Mohamed Shafi writes:
> Hello all,
>
> Can anyone tell me what the below expression means ?
It's a memory clobber. It doesn't actually do anything itself, but it
prevents expressions that touch memory from being moved over it.
> (insn 38 37 40 4 (parallel [
> (asm_operands/v ("") ("") 0 [ //line 2
> (reg:SI 32 [ s5.1 ])
> //line 3
> ]
> [
> (asm_input:SI ("r"))
> //line 6
> ] ("test55.c") 42)
> //line 7
> (clobber (mem:BLK (scratch) [0 A8]))
> //line 8
> ]) -1 (nil)
> (nil))
>
> in line 2, what is the 0 for?
>
> what does line 3 mean?what is it purpose ?
>
> In line 7 test55.c is the file name . why is it needed and what is 42?
> In line 8 what does [0 A8] mean?
Why is the filename needed? For debugging.
As for the rest: I can't remember. Read the source.
Andrew.