Fix race in ShaderBallotFunctionRead test

The original code contained a race to write an SSBO, since it wasn't
using atomics. This change replaces that code with a much simpler
reimplementation of readFirstInvocationARB() by using findLSB() and
ballotARB() to provide an argument to readInvocationARB().

This change also strips out a now-unused argument and related code
from the shader-builder helper class, which is shared with the other
shader_ballot tests.

Components: OpenGL

VK-GL-CTS issue: 665

Affects:
* KHR-GL43/44/45.shader_ballot_tests.ShaderBallotAvailability
* KHR-GL43/44/45.shader_ballot_tests.ShaderBallotBitmasks
* KHR-GL43/44/45.shader_ballot_tests.ShaderBallotFunctionBallot
* KHR-GL43/44/45.shader_ballot_tests.ShaderBallotFunctionRead

Change-Id: Iaf121ab07e13bf450533c96c95f1b7745631c0c8

diff --git a/external/openglcts/modules/gl/gl4cShaderBallotTests.cpp b/external/openglcts/modules/gl/gl4cShaderBallotTests.cpp
index 5f97bd2..b5562db 100644 (file)
--- a/external/openglcts/modules/gl/gl4cShaderBallotTests.cpp
+++ b/external/openglcts/modules/gl/gl4cShaderBallotTests.cpp
@@ -39,13 +39,11 @@ namespace gl4cts
 
 ShaderBallotBaseTestCase::ShaderPipeline::ShaderPipeline(glu::ShaderType       testedShader,
                                                                                                                 const std::string& contentSnippet,
-                                                                                                                const std::string& headSnippet,
                                                                                                                 std::map<std::string, std::string> specMap)
        : m_programRender(NULL), m_programCompute(NULL), m_testedShader(testedShader), m_specializationMap(specMap)
 {
        std::string testedHeadPart = "#extension GL_ARB_shader_ballot : enable\n"
                                                                 "#extension GL_ARB_gpu_shader_int64 : enable\n";
-       testedHeadPart += headSnippet;
 
        std::string testedContentPart = contentSnippet;
 
@@ -551,7 +549,7 @@ ShaderBallotBitmasksTestCase::ShaderBallotBitmasksTestCase(deqp::Context& contex
                        std::map<std::string, std::string> specMap;
                        specMap["MASK_VAR"]              = maskIter->first;
                        specMap["MASK_OPERATOR"] = maskIter->second;
-                       m_shaderPipelines.push_back(new ShaderPipeline((glu::ShaderType)i, colorShaderSnippet, "", specMap));
+                       m_shaderPipelines.push_back(new ShaderPipeline((glu::ShaderType)i, colorShaderSnippet, specMap));
                }
        }
 }
@@ -688,21 +686,20 @@ ShaderBallotFunctionReadTestCase::ShaderBallotFunctionReadTestCase(deqp::Context
        std::string readFirstInvSnippet = "float color = 1.0f - (gl_SubGroupInvocationARB / float(gl_SubGroupSizeARB));\n"
                                                                          "outColor = readFirstInvocationARB(vec4(color, color, color, 1.0f));\n";
 
-       std::string readInvSnippetHead = "layout(std430, binding = 0) buffer invocationBuffer {\n"
-                                                                        "  int invocation;\n"
-                                                                        "};";
-
        std::string readInvSnippet = "float color = 1.0 - (gl_SubGroupInvocationARB / float(gl_SubGroupSizeARB));\n"
-                                                                "if(invocation == -1)\n"
-                                                                "{\n"
-                                                                "      invocation = int(gl_SubGroupInvocationARB);\n"
+                                                                "uvec2 parts = unpackUint2x32(ballotARB(true));\n"
+                                                                "uint invocation;\n"
+                                                                "if (parts.x != 0) {\n"
+                                                                "    invocation = findLSB(parts.x);\n"
+                                                                "} else {\n"
+                                                                "    invocation = findLSB(parts.y) + 32;\n"
                                                                 "}\n"
-                                                                "outColor = readInvocationARB(vec4(color, color, color, 1.0f), uint(invocation));\n";
+                                                                "outColor = readInvocationARB(vec4(color, color, color, 1.0f), invocation);\n";
 
        for (unsigned int i = 0; i < glu::SHADERTYPE_LAST; ++i)
        {
                m_shaderPipelines.push_back(new ShaderPipeline((glu::ShaderType)i, readFirstInvSnippet));
-               m_shaderPipelines.push_back(new ShaderPipeline((glu::ShaderType)i, readInvSnippet, readInvSnippetHead));
+               m_shaderPipelines.push_back(new ShaderPipeline((glu::ShaderType)i, readInvSnippet));
        }
 }
 
@@ -741,26 +738,10 @@ tcu::TestNode::IterateResult ShaderBallotFunctionReadTestCase::iterate()
        {
                gl.clear(GL_COLOR_BUFFER_BIT);
 
-               glw::GLuint invocationBufferID;
-               gl.genBuffers(1, &invocationBufferID);
-               GLU_EXPECT_NO_ERROR(gl.getError(), "genBuffers failed");
-               gl.bindBuffer(GL_SHADER_STORAGE_BUFFER, invocationBufferID);
-               GLU_EXPECT_NO_ERROR(gl.getError(), "bindBuffer failed");
-
-               int invocationID = -1;
-               gl.bufferData(GL_SHADER_STORAGE_BUFFER, sizeof(int), &invocationID, GL_DYNAMIC_COPY);
-               GLU_EXPECT_NO_ERROR(gl.getError(), "bufferData failed");
-               gl.bindBufferBase(GL_SHADER_STORAGE_BUFFER, 0, invocationBufferID);
-               GLU_EXPECT_NO_ERROR(gl.getError(), "bindBufferBase failed");
-               gl.bindBuffer(GL_SHADER_STORAGE_BUFFER, 0);
-               GLU_EXPECT_NO_ERROR(gl.getError(), "bindBuffer failed");
-
                (*pipelineIter)->test(m_context);
 
                gl.flush();
 
-               gl.deleteBuffers(1, &invocationBufferID);
-
                bool validationResult =
                        ShaderBallotBaseTestCase::validateScreenPixelsSameColor(m_context, tcu::Vec4(1.0f, 0.0f, 0.0f, 1.0f));
                TCU_CHECK_MSG(validationResult, "Read functions result is not correct");

diff --git a/external/openglcts/modules/gl/gl4cShaderBallotTests.hpp b/external/openglcts/modules/gl/gl4cShaderBallotTests.hpp
index 74b066f..4f12a6c 100644 (file)
--- a/external/openglcts/modules/gl/gl4cShaderBallotTests.hpp
+++ b/external/openglcts/modules/gl/gl4cShaderBallotTests.hpp
@@ -52,7 +52,6 @@ public:
 
        public:
                ShaderPipeline(glu::ShaderType testedShader, const std::string& contentSnippet,
-                                          const std::string& headSnippet = "",
                                           std::map<std::string, std::string> specMap = std::map<std::string, std::string>());
                ~ShaderPipeline();