[Mesa-dev] [PATCH] intel/decoder: Use gen_group::dw_length when available

[Lionel Landwerlin]

On 23/04/18 12:20, Topi Pohjolainen wrote:
> Otherwise gen_group_get_length() will try to use first fields
> of, for example, CC_VIEWPORT and SF_CLIP to determine the
> group size. These packets are not present in the state with
> full header but simply with their contents while equivalent
> state pointers (3DSTATE_VIEWPORT_STATE_POINTERS_CC and
> 3DSTATE_VIEWPORT_STATE_POINTERS_SF_CLIP respectively) telling
> their starting points.
>
> Before:
> -------
>
> 0xfffef540:  0x78230000:  3DSTATE_VIEWPORT_STATE_POINTERS_CC
>
> 0xfffef540:  0x78230000 : Dword 0
>      DWord Length: 0
> 0xfffef544:  0x00000180 : Dword 1
>      CC Viewport Pointer: 0x00000180
> CC_VIEWPORT 0
> 0xfffea180:  0x00000000 : Dword 0
>      Minimum Depth: 0.000000
> 0xfffef548:  0x78210000:  3DSTATE_VIEWPORT_STATE_POINTERS_SF_CLIP
> 0xfffef548:  0x78210000 : Dword 0
>      DWord Length: 0
> 0xfffef54c:  0x000001c0 : Dword 1
>      SF Clip Viewport Pointer: 0x000001c0
> SF_CLIP_VIEWPORT 0
> 0xfffea1c0:  0x41000000 : Dword 0
>      Viewport Matrix Element m00: 0.000000
> 0xfffea1c4:  0x3f000000 : Dword 1
>      Viewport Matrix Element m11: 0.500000
> 0xfffef550:  0x78240000:  3DSTATE_BLEND_STATE_POINTERS
>
> After:
> ------
>
> 0xfffef540:  0x78230000:  3DSTATE_VIEWPORT_STATE_POINTERS_CC
>
> 0xfffef540:  0x78230000 : Dword 0
>      DWord Length: 0
> 0xfffef544:  0x00000180 : Dword 1
>      CC Viewport Pointer: 0x00000180
> CC_VIEWPORT 0
> 0xfffea180:  0x00000000 : Dword 0
>      Minimum Depth: 0.000000
> 0xfffea184:  0x3f800000 : Dword 1
>      Maximum Depth: 1.000000
> 0xfffef548:  0x78210000:  3DSTATE_VIEWPORT_STATE_POINTERS_SF_CLIP
> 0xfffef548:  0x78210000 : Dword 0
>      DWord Length: 0
> 0xfffef54c:  0x000001c0 : Dword 1
>      SF Clip Viewport Pointer: 0x000001c0
> SF_CLIP_VIEWPORT 0
> 0xfffea1c0:  0x41000000 : Dword 0
>      Viewport Matrix Element m00: 0.000000
> 0xfffea1c4:  0x3f000000 : Dword 1
>      Viewport Matrix Element m11: 0.500000
> 0xfffea1c8:  0x3f000000 : Dword 2
>      Viewport Matrix Element m22: 0.500000
> 0xfffea1cc:  0x41000000 : Dword 3
>      Viewport Matrix Element m30: 8.000000
> 0xfffea1d0:  0x3f000000 : Dword 4
>      Viewport Matrix Element m31: 0.500000
> 0xfffea1d4:  0x3f000000 : Dword 5
>      Viewport Matrix Element m32: 0.500000
> 0xfffea1d8:  0x00000000 : Dword 6
> 0xfffea1dc:  0x00000000 : Dword 7
> 0xfffea1e0:  0xc5000000 : Dword 8
>      X Min Clip Guardband: -2048.000000
> 0xfffea1e4:  0x45000000 : Dword 9
>      X Max Clip Guardband: 2048.000000
> 0xfffea1e8:  0xc7000000 : Dword 10
>      Y Min Clip Guardband: -32768.000000
> 0xfffea1ec:  0x47000000 : Dword 11
>      Y Max Clip Guardband: 32768.000000
> 0xfffea1f0:  0x00000000 : Dword 12
>      X Min ViewPort: 0.000000
> 0xfffea1f4:  0x41700000 : Dword 13
>      X Max ViewPort: 15.000000
> 0xfffea1f8:  0x00000000 : Dword 14
>      Y Min ViewPort: 0.000000
> 0xfffea1fc:  0x00000000 : Dword 15
>      Y Max ViewPort: 0.000000
>
> CC: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> CC: Kenneth Graunke <kenneth at whitecape.org>
> Signed-off-by: Topi Pohjolainen <topi.pohjolainen at intel.com>
> ---
>   src/intel/common/gen_decoder.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/src/intel/common/gen_decoder.c b/src/intel/common/gen_decoder.c
> index 1b8123b..cc212cc 100644
> --- a/src/intel/common/gen_decoder.c
> +++ b/src/intel/common/gen_decoder.c
> @@ -713,6 +713,9 @@ gen_group_find_field(struct gen_group *group, const char *name)
>   int
>   gen_group_get_length(struct gen_group *group, const uint32_t *p)
>   {
> +   if (group->dw_length)
> +      return group->dw_length;

I don't think that'll work. Some instructions have length (as default 
value) too but might have a variable DWord Length field as well.
I think the best approach is to flag <struct> & <register> elements in 
the decoder and in get_length() have a if (group->is_struct || 
group->is_register) return group->dw_length;.

> +
>      uint32_t h = p[0];
>      uint32_t type = field_value(h, 29, 31);
>