From bce4b9f85777346d6c512bdb59c02a2b22c906a5 Mon Sep 17 00:00:00 2001
From: Geoff Lang <geofflang@chromium.org>
Date: Wed, 19 Jun 2019 16:20:09 -0400
Subject: [PATCH] Always scalarize mat and vec constructor arguments.

This workaround is always enabled in Chrome, do the same in ANGLE.

BUG=882580

Change-Id: I2c01f34a589b07bd0035d7408be884f7a51b1706
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1666699
Reviewed-by: Jonah Ryan-Davis <jonahr@google.com>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
---
 include/platform/FrontendFeatures.h | 5 +++++
 src/libANGLE/Display.cpp            | 1 +
 src/libANGLE/Shader.cpp             | 6 ++++++
 3 files changed, 12 insertions(+)

diff --git a/include/platform/FrontendFeatures.h b/include/platform/FrontendFeatures.h
index d9eec66bc..2c0ad3381 100644
--- a/include/platform/FrontendFeatures.h
+++ b/include/platform/FrontendFeatures.h
@@ -44,6 +44,11 @@ struct FrontendFeatures : angle::FeatureSetBase
         "On Windows Intel OpenGL drivers TexImage sometimes seems to interact "
         "with the Framebuffer",
         &members};
+
+    angle::Feature scalarizeVecAndMatConstructorArgs = {
+        "scalarize_vec_and_mat_constructor_args", angle::FeatureCategory::FrontendWorkarounds,
+        "Always rewrite vec/mat constructors to be consistent", &members,
+        "http://crbug.com/398694"};
 };
 
 inline FrontendFeatures::FrontendFeatures()  = default;
diff --git a/src/libANGLE/Display.cpp b/src/libANGLE/Display.cpp
index ccccc0740..fe7cbfd13 100644
--- a/src/libANGLE/Display.cpp
+++ b/src/libANGLE/Display.cpp
@@ -1350,6 +1350,7 @@ void Display::initializeFrontendFeatures()
 {
     // Enable on all Impls
     mFrontendFeatures.loseContextOnOutOfMemory.enabled = true;
+    mFrontendFeatures.scalarizeVecAndMatConstructorArgs.enabled = true;
 
     mImplementation->initializeFrontendFeatures(&mFrontendFeatures);
 
diff --git a/src/libANGLE/Shader.cpp b/src/libANGLE/Shader.cpp
index b1007310d..29f9097bf 100644
--- a/src/libANGLE/Shader.cpp
+++ b/src/libANGLE/Shader.cpp
@@ -22,6 +22,7 @@
 #include "libANGLE/ResourceManager.h"
 #include "libANGLE/renderer/GLImplFactory.h"
 #include "libANGLE/renderer/ShaderImpl.h"
+#include "platform/FrontendFeatures.h"
 
 namespace gl
 {
@@ -342,6 +343,11 @@ void Shader::compile(const Context *context)
         options |= SH_VALIDATE_LOOP_INDEXING;
     }
 
+    if (context->getFrontendFeatures().scalarizeVecAndMatConstructorArgs.enabled)
+    {
+        options |= SH_SCALARIZE_VEC_AND_MAT_CONSTRUCTOR_ARGS;
+    }
+
     mCurrentMaxComputeWorkGroupInvocations = context->getCaps().maxComputeWorkGroupInvocations;
 
     ASSERT(mBoundCompiler.get());