Bug 94459 - FLT_TO_INT rounding issues on pre R800 cards
Summary: FLT_TO_INT rounding issues on pre R800 cards
Alias: None
Product: Mesa
Classification: Unclassified
Component: Drivers/Gallium/r600 (show other bugs)
Version: unspecified
Hardware: All All
: medium minor
Assignee: Default DRI bug account
QA Contact: Default DRI bug account
Depends on:
Reported: 2016-03-09 09:23 UTC by Patrick Rudolph
Modified: 2019-09-18 19:21 UTC (History)
0 users

See Also:
i915 platform:
i915 features:

patch r600_shader.c to insert a ALU_OP1_RNDNE instruction on pre r8xx cards for TGSI_OPCODE_ARR (2.04 KB, patch)
2016-03-09 11:33 UTC, Patrick Rudolph
Details | Splinter Review

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
-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

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