Re: [Linux-ia64] Compiler warnings.

[Steffen Persvold <sp@scali.com>]

On Sat, 22 Jun 2002, Steffen Persvold wrote:

> 
> Hi all,
> 
> For some time I've been compiling applications and kernels on IA64. 
> Sometimes the assembler gives me warnings about "RAW dependencies" which 
> makes me wonder about the quality of the gcc compiler. Is this something 
> that should be paid attention to ?
> 
> Here's a warning (and not the only one) I get when I compile the latest 
> 2.4.18 patchset with gcc 2.96 (gcc version 2.96 20000731 (Debian GNU/Linux 
> IA64 experimental)) :
> 
> gcc -D__KERNEL__ -I/usr/src/linux-2.4.18-020622/include 
> -Wall -Wstrict-prototypes -Wno-trigraphs -g -O2 -fomit-frame-pointer 
> -fno-strict-aliasing -fno-common -pipe  -ffixed-r13 
> -mfixed-rangeñ0-f15,f32-f127 -falign-functions2 -mconstant-gp  
> -DKBUILD_BASENAME=vmscan  -c -o vmscan.o vmscan.c
> {standard input}: Assembler messages:
> {standard input}:594: Warning: Use of 'st8' violates RAW dependency 'DTC' (data)
> {standard input}:594: Warning: Only the first path encountering the conflict is reported
> {standard input}:581: Warning: This is the location of the conflicting usage
> 
> I haven't tried the 3.0.1 compiler yet.
> 

I forgot, I've also been seeing "WAW dependencies" :

gcc -D__KERNEL__ -I/usr/src/linux-2.4.18-020622/include -Wall 
-Wstrict-prototypes -Wno-trigraphs -g -O2 -fomit-frame-pointer 
-fno-strict-aliasing -fno-common -pipe  -ffixed-r13 
-mfixed-rangeñ0-f15,f32-f127 -falign-functions2 -DMODULE -DMODVERSIONS 
-include /usr/src/linux-2.4.18-020622/include/linux/modversions.h -DDBG=0 
-DT3_JUMBO_RCV_RCB_ENTRY_COUNT%6 -DNICE_SUPPORT 
-DPCIX_TARGET_WORKAROUND=1 -DINCLUDE_TBI_SUPPORT -DINCLUDE_5701_AX_FIX=1 
-DKBUILD_BASENAMEµ7um  -c -o b57um.o b57um.c
{standard input}: Assembler messages:
{standard input}:13085: Warning: Use of 'cmp.ne' violates WAW dependency 'PR%, % in 1 - 15' (impliedf), specific resource number is 7
{standard input}:13085: Warning: Only the first path encountering the conflict is reported
{standard input}:13081: Warning: This is the location of the conflicting usage

Regards,
 -- 
  Steffen Persvold   | Scalable Linux Systems |   Try out the world's best
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