Bug 107734

Summary:	[GLSL] glsl-fface-invariant, glsl-fcoord-invariant and glsl-pcoord-invariant should fail
Product:	Mesa	Reporter:	vadym <vadym.shovkoplias>
Component:	glsl-compiler	Assignee:	mesa-dev
Status:	RESOLVED FIXED	QA Contact:	Intel 3D Bugs Mailing List <intel-3d-bugs>
Severity:	normal
Priority:	medium	CC:	mark.a.janes
Version:	unspecified
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:

Description vadym 2018-08-29 09:12:06 UTC

GLSL ES 1.0 linker tests glsl-fface-invariant, glsl-fcoord-invariant and glsl-pcoord-invariant have to fail as specified in spec: 

4.6.4 Invariance and Linkage
The invariance of varyings that are declared in both the vertex and fragment shaders must match.For the built-in special variables, gl_FragCoord can only be declared invariant if and only if gl_Position is declared invariant. Similarly gl_PointCoord can only be declared invariant if and only if gl_PointSize is
declared invariant. It is an error to declare gl_FrontFacing as invariant. The invariance of gl_FrontFacing is the same as the invariance of gl_Position.

Comment 1 vadym 2018-08-29 12:13:14 UTC

Patch: https://patchwork.freedesktop.org/patch/246321/

Comment 2 Tapani Pälli 2018-09-03 08:00:48 UTC

Seems a bit like : https://patchwork.freedesktop.org/patch/36417/

IIRC there was some issue with that patch ... or not. Vadym, please check if this fixes the WebGL tests also?

Comment 3 vadym 2018-09-04 08:22:01 UTC

Hi Tapani,

Yep, looks like patches are almost the same. I didn't expected that some patches can be on review since 2014 :)

I checked following WebGL tests which are related to invariance:

1) conformance/glsl/bugs/global-invariant-does-not-leak-across-shaders.html (Passed: 3/3 in 100.0 ms)

2) conformance/glsl/bugs/invariant-does-not-leak-across-shaders.html (Passed: 3/3 in 84.0 ms)

3) conformance/glsl/misc/fragcolor-fragdata-invariant.html (Passed: 1/2 Failed: 1/2 in 98.0 ms)
    failed: [unexpected fragment shader compile status] (expected: true) Declaring both gl_FragColor and gl_FragData invariant should succeed.

4) conformance/glsl/misc/shaders-with-invariance.html (Passed: 19/19 in 116.0 ms)

5) deqp/functional/gles3/shaderbuiltinvar.html (Passed: 27/31 Failed: 4/31 in 944.0 ms)
    failed: builtin_variable.max_vertex_output_vectors_vertex: Invalid builtin constant value
    failed: builtin_variable.max_vertex_output_vectors_fragment: Invalid builtin constant value
    failed: builtin_variable.max_fragment_input_vectors_vertex: Invalid builtin constant value
    failed: builtin_variable.max_fragment_input_vectors_fragment: Invalid builtin constant value

6) conformance2/glsl3/invalid-invariant.html (Passed: 3/3 in 82.0 ms)

7) conformance2/glsl3/valid-invariant.html (Passed: 4/4 in 92.0 ms)


and got the same results without and with the patch. So looks like this change doesn't affect WebGL.

Comment 4 Tapani Pälli 2018-09-12 10:05:49 UTC

Resolved by
--- 8< ---
commit 9b5c0c520f6e41f19b3568a4e0532c836bc522e4
Author: Vadym Shovkoplias <vadim.shovkoplias@gmail.com>
Date:   Fri Sep 7 15:14:52 2018 +0300

    glsl/linker: Check the invariance of built-in special variables

Comment 5 vadym 2018-09-12 16:52:32 UTC

Hi Mark,

Following shader tests are fixed now:

    * glsl-pcoord-invariant.shader_test
    * glsl-fcoord-invariant.shader_test
    * glsl-fface-invariant.shader_test

I think those tests can be moved from [expected-failures] to [fixed-tests] in mesa CI.

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