Bug 94459

Summary:	FLT_TO_INT rounding issues on pre R800 cards
Product:	Mesa	Reporter:	Patrick Rudolph <siro>
Component:	Drivers/Gallium/r600	Assignee:	Default DRI bug account <dri-devel>
Status:	RESOLVED MOVED	QA Contact:	Default DRI bug account <dri-devel>
Severity:	minor
Priority:	medium
Version:	unspecified
Hardware:	All
OS:	All
Whiteboard:
i915 platform:		i915 features:
Attachments:	patch r600_shader.c to insert a ALU_OP1_RNDNE instruction on pre r8xx cards for TGSI_OPCODE_ARR

Description Patrick Rudolph 2016-03-09 09:23:36 UTC

Running WINE tests with Gallium Nine enabled I found the following test to fail on pre R800 cards.
The failing test is from wine d3d9/tests/visual.c test_mova().
It can be found here: https://source.winehq.org/ident?_i=test_mova&_remember=1

To issue doesn't exists on radeonsi, softpipe and R800+.

The problem seems to be TGSI_OPCODE_ARR that should round on FLT_TO_INT, but pre R800 cards truncate instead.
This might result in wrong addressing, as TGSI_OPCODE_ARR is expected to round.
If the card doesn't support rounding on FLT_TO_INT, r600 driver should insert a rounding instruction.

Tested with latest mesa git on RV770.

Comment 1 Patrick Rudolph 2016-03-09 11:33:49 UTC

Created attachment 122172 [details] [review]
patch r600_shader.c to insert a ALU_OP1_RNDNE instruction on pre r8xx cards for TGSI_OPCODE_ARR

Comment 2 Roland Scheidegger 2016-03-09 13:49:46 UTC

The code in question isn't used by anything non-r600/r700, thus a switch isn't warranted.
(I think it would look nicer if the arl/arr cases were merged and use a conditional to select the rounding instruction too.)

Comment 3 GitLab Migration User 2019-09-18 19:21:11 UTC

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