Bug 105105 - Suffixless KHR_robustness functions aren't exposed in ES 3.2
Summary: Suffixless KHR_robustness functions aren't exposed in ES 3.2
Status: RESOLVED NOTOURBUG
Alias: None
Product: Mesa
Classification: Unclassified
Component: Mesa core (show other bugs)
Version: git
Hardware: Other All
: medium major
Assignee: Tapani Pälli
QA Contact: mesa-dev
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2018-02-15 00:15 UTC by Kenneth Graunke
Modified: 2018-04-12 04:08 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:


Attachments

Description Kenneth Graunke 2018-02-15 00:15:18 UTC
These two tests fail on i965:

   KHR-NoContext.es32.robustness.readnpixels
   KHR-NoContext.es32.robustness.getnuniform

The readnpixels test does:

   PFNGLREADNPIXELS pReadnPixels = (PFNGLREADNPIXELS)context->getRenderContext().getProcAddress("glReadnPixels");

and then calls that function pointer...but ends up in generic_nop().

It looks like the suffixless versions aren't getting exposed correctly, despite being part of ES 3.2.

There's a fair bit of complex aliasing going on for ARB/KHR/suffixless, and I'm getting a bit lost trying to figure out the right mapi/glapi/gen XML snippets to do the right thing.
Comment 1 Tapani Pälli 2018-02-15 12:54:32 UTC
It looks like these 2 tests fail for different reasons:

- 'readnpix' hits generic_nop (glapi issue)

- 'getnuniform', problem seems to be that according to Mesa these uniforms are inactive and therefore no uniformstorage is available. I can see that linker reserves explicit locations correctly (inputf : 11, inputi : 12, inputu : 13) but opt_dead_code removes the variables:

--- 8< ---
Removed declaration of inputf@0x34f1f80
Removed declaration of inputu@0x34f26b0
Removed declaration of inputi@0x34f2540
--- 8< ---

If I modify opt_dead_code to not remove those variables the test passes. I hacked it like this:

--- 8< ---
+            if (entry->var->data.explicit_location)
+               continue;
--- 8< ---

It seems compiler/linker should realize that they are written to shared values so we should not optimize those away.
Comment 2 Tapani Pälli 2018-02-15 13:04:24 UTC
(In reply to Tapani Pälli from comment #1)
> It seems compiler/linker should realize that they are written to shared
> values so we should not optimize those away.

and alternative theory: since we never write these out to any buffer maybe it is just ok to optimize these away and test should be changed instead :)
Comment 3 Tapani Pälli 2018-02-26 08:19:04 UTC
(In reply to Tapani Pälli from comment #2)
> (In reply to Tapani Pälli from comment #1)
> > It seems compiler/linker should realize that they are written to shared
> > values so we should not optimize those away.
> 
> and alternative theory: since we never write these out to any buffer maybe
> it is just ok to optimize these away and test should be changed instead :)

I've created issue about this and sent a fix proposal for getnuniform test:
https://gitlab.khronos.org/Tracker/vk-gl-cts/issues/1036
Comment 4 Tapani Pälli 2018-03-01 11:19:07 UTC
(In reply to Kenneth Graunke from comment #0)
> The readnpixels test does:
> 
>    PFNGLREADNPIXELS pReadnPixels =
> (PFNGLREADNPIXELS)context->getRenderContext().
> getProcAddress("glReadnPixels");
> 
> and then calls that function pointer...but ends up in generic_nop().

It does not actually call it, instead it calls api via "gl.readnPixels", gl contains the API functions that have been resolved already earlier. The pReadnPixels would actually work if it would be utilized, I changed test to use that and it passes.

I'm wanted to write this down here so that I won't forget this. Will need to figure out how context functions in 'gl.*' get resolved.
Comment 5 Tapani Pälli 2018-04-03 10:16:11 UTC
Updating status ... my fix to dEQP went in and now we pass 'getnuniform' test, but readnpixels still fails.

I did a separate GLES 3.2 app that utilizes these entrypoints, they are being exposed and work correctly. Also dEQP has tests that call these entrypoints and those tests are passing. So, as said in comment #4 there seems to be something going wrong with how the api functions are resolved by the test suite.
Comment 6 Tapani Pälli 2018-04-03 11:41:21 UTC
OK .. after yet another gdb session I think now I got it. What is happening is that when the test suite generates functions from khronos xml, it first sets gl.readnPixels to glReadnPixelsKHR but later on replaces this same pointer with glReadnPixelsEXT (which Mesa does not support). This is a bit unfortunate, maybe it should check if the function was already succesfully resolved. Will attempt this.
Comment 7 Tapani Pälli 2018-04-03 12:10:22 UTC
OK, sent a fix to vk-gl-cts suite to reorder EXT and KHR resolving so that KHR is preferred over EXT. It might be this is not the only case where such reordering is required and maybe more elegant fix to generator scripts is required.
Comment 8 Tapani Pälli 2018-04-12 04:08:35 UTC
This is now fixed in opengl-es-cts-3.2.4 by following commit, resolving this one as NOTOURBUG.

--- 8< ---
commit c693c85a5f9983caab94c3973e6dc0efaae57b0c
Author: Tapani Pälli <tapani.palli@intel.com>
Date:   Thu Apr 5 08:13:46 2018 +0300

    Prefer KHR entrypoints instead of EXT for robustness tests
    
    When resolving function entrypoints, framework resolves EXT
    entrypoints after KHR to the same pointers. There are drivers that
    implement only KHR entrypoints, prefer KHR over EXT so that KHR
    entrypoints will be the ones used if both extensions are supported
    by the driver.
    
    Components: OpenGL ES
    VK-GL-CTS issue: 1107
    
    Affects:
    KHR-NoContext.es32.robustness.getnuniform
    KHR-NoContext.es32.robustness.readnpixels
    
    Change-Id: Iec5f7cbdd53061e105b3445f7613ee41fccc4553
    Signed-off-by: Tapani Pälli <tapani.palli@intel.com>


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