Fix block size calculation w.r.t variable-size arrays

In SSBOs, there can be a last array whose size is not specified (i.e. can take any size). This is especially prevalent in Compute shaders that process a buffer. In the shader translator, the size of this array is given as 0. HLSL register offset calculation was tripped up by this as it used (arraySize - 1). The optimization in [1] effectively removed a test that would perform this calculation only when the size is positive. This change adds back this guard. [1] https://chromium-review.googlesource.com/c/angle/angle/+/684742 Bug: angleproject:2516 Change-Id: If45ac934f542c5ffcad67f962eebe45a3aeba70b Reviewed-on: https://chromium-review.googlesource.com/c/1409403 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>

Fix block size calculation w.r.t variable-size arrays
5f82dde6 · Shahbaz Youssefi · Commit Bot · d3e0e84c · 5f82dde6
Commit 5f82dde6 authored Jan 14, 2019 by Shahbaz Youssefi Committed by Commit Bot Jan 15, 2019
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blocklayoutHLSL.cpp src/compiler/translator/blocklayoutHLSL.cpp +5 -1

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--- a/src/compiler/translator/blocklayoutHLSL.cpp
+++ b/src/compiler/translator/blocklayoutHLSL.cpp
@@ -85,7 +85,11 @@ void HLSLBlockEncoder::advanceOffset(GLenum typeIn,
    if (!arraySizes.empty())
    {
-        mCurrentOffset += arrayStride * (gl::ArraySizeProduct(arraySizes) - 1);
+        unsigned int arraySize = gl::ArraySizeProduct(arraySizes);
+        if (arraySize > 0)
+        {
+            mCurrentOffset += arrayStride * (arraySize - 1);
+        }
    }
    if (gl::IsMatrixType(type))