[Qemu-devel] [PATCH] [ARM] Fix C-flag for ASR <reg> when shift==0

[Qemu-devel] [PATCH] [ARM] Fix C-flag for ASR <reg> when shift==0

[Matthew Howkins]

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There is a bug in the ARM emulation of data-processing instructions with
ASR <reg> when the shift==0. The current QEMU CVS incorrectly modifies
the C-flag, when it should be preserved.

The attached patch corrects this.

Matthew



[-- Attachment #2: qemu_arm_asr_reg.patch --]
[-- Type: text/x-patch, Size: 525 bytes --]

Index: target-arm/op.c
===================================================================
RCS file: /sources/qemu/qemu/target-arm/op.c,v
retrieving revision 1.21
diff -u -r1.21 op.c
--- target-arm/op.c	26 Jun 2006 19:55:19 -0000	1.21
+++ target-arm/op.c	11 Feb 2007 16:08:22 -0000
@@ -667,7 +667,7 @@
     if (shift >= 32) {
         env->CF = (T1 >> 31) & 1;
         T1 = (int32_t)T1 >> 31;
-    } else {
+    } else if (shift != 0) {
         env->CF = (T1 >> (shift - 1)) & 1;
         T1 = (int32_t)T1 >> shift;
     }

Re: [Qemu-devel] [PATCH] [ARM] Fix C-flag for ASR <reg> when shift==0

[Aurelien Jarno]

Matthew Howkins a écrit :
> There is a bug in the ARM emulation of data-processing instructions with
> ASR <reg> when the shift==0. The current QEMU CVS incorrectly modifies
> the C-flag, when it should be preserved.
> 
> The attached patch corrects this.
> 

This patch is consistent with the reference manual, I think it should be
applied. Has it been lost?

> ------------------------------------------------------------------------
> 
> Index: target-arm/op.c
> ===================================================================
> RCS file: /sources/qemu/qemu/target-arm/op.c,v
> retrieving revision 1.21
> diff -u -r1.21 op.c
> --- target-arm/op.c	26 Jun 2006 19:55:19 -0000	1.21
> +++ target-arm/op.c	11 Feb 2007 16:08:22 -0000
> @@ -667,7 +667,7 @@
>      if (shift >= 32) {
>          env->CF = (T1 >> 31) & 1;
>          T1 = (int32_t)T1 >> 31;
> -    } else {
> +    } else if (shift != 0) {
>          env->CF = (T1 >> (shift - 1)) & 1;
>          T1 = (int32_t)T1 >> shift;
>      }
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://lists.nongnu.org/mailman/listinfo/qemu-devel


-- 
  .''`.  Aurelien Jarno	            | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   aurel32@debian.org         | aurelien@aurel32.net
   `-    people.debian.org/~aurel32 | www.aurel32.net

Re: [Qemu-devel] [PATCH] [ARM] Fix C-flag for ASR <reg> when shift==0

[Aurelien Jarno]

Aurelien Jarno a écrit :
> Matthew Howkins a écrit :
>> There is a bug in the ARM emulation of data-processing instructions with
>> ASR <reg> when the shift==0. The current QEMU CVS incorrectly modifies
>> the C-flag, when it should be preserved.
>>
>> The attached patch corrects this.
>>
> 
> This patch is consistent with the reference manual, I think it should be
> applied. Has it been lost?

Still no news about this patch...


>> ------------------------------------------------------------------------
>>
>> Index: target-arm/op.c
>> ===================================================================
>> RCS file: /sources/qemu/qemu/target-arm/op.c,v
>> retrieving revision 1.21
>> diff -u -r1.21 op.c
>> --- target-arm/op.c	26 Jun 2006 19:55:19 -0000	1.21
>> +++ target-arm/op.c	11 Feb 2007 16:08:22 -0000
>> @@ -667,7 +667,7 @@
>>      if (shift >= 32) {
>>          env->CF = (T1 >> 31) & 1;
>>          T1 = (int32_t)T1 >> 31;
>> -    } else {
>> +    } else if (shift != 0) {
>>          env->CF = (T1 >> (shift - 1)) & 1;
>>          T1 = (int32_t)T1 >> shift;
>>      }
>>
>>
>> ------------------------------------------------------------------------
>>
>> _______________________________________________
>> Qemu-devel mailing list
>> Qemu-devel@nongnu.org
>> http://lists.nongnu.org/mailman/listinfo/qemu-devel
> 
> 


-- 
  .''`.  Aurelien Jarno	            | GPG: 1024D/F1BCDB73
 : :' :  Debian developer           | Electrical Engineer
 `. `'   aurel32@debian.org         | aurelien@aurel32.net
   `-    people.debian.org/~aurel32 | www.aurel32.net