Fix interpolation functions for push constants

When using push constants, we end up having dynamic offsets on the input parameter of the interpolation functions, so we need to be able to handle this case. Since this is for push constants, we assume that all dynamic offsets will be the same, for simplicity. Bug: b/171415086 Change-Id: I5de1720e383c234c9392421d507a66e6d7ba2445 Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/52930 Presubmit-Ready: Alexis Hétu <sugoi@google.com> Reviewed-by: Nicolas Capens <nicolascapens@google.com> Kokoro-Result: kokoro <noreply+kokoro@google.com> Tested-by: Alexis Hétu <sugoi@google.com> Commit-Queue: Alexis Hétu <sugoi@google.com>

Fix interpolation functions for push constants
c09e3d9f · Alexis Hetu · swiftshader-scoped@luci-project-accounts.iam.gserviceaccount.com · 0320eab6 · c09e3d9f
Commit c09e3d9f authored Feb 17, 2021 by Alexis Hetu Committed by swiftshader-scoped@luci-project-accounts.iam.gserviceaccount.com Feb 17, 2021
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Showing with 27 additions and 4 deletions

SpirvShaderGLSLstd450.cpp src/Pipeline/SpirvShaderGLSLstd450.cpp +27 -4

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--- a/src/Pipeline/SpirvShaderGLSLstd450.cpp
+++ b/src/Pipeline/SpirvShaderGLSLstd450.cpp
@@ -54,6 +54,16 @@ uint32_t ComputeInterpolantOffset(uint32_t offset, uint32_t components_per_row, 
 	return offset;
 }

+rr::Int ComputeInterpolantOffset(rr::Int offset, uint32_t components_per_row, bool useArrayOffset)
+{
+	if(useArrayOffset)
+	{
+		rr::Int interpolant_offset = offset / rr::Int(components_per_row);
+		offset = (interpolant_offset << 2) + (offset - interpolant_offset * rr::Int(components_per_row));
+	}
+	return offset;
+}
+
 }  // namespace

 namespace sw {
@@ -1064,13 +1074,26 @@ SIMD::Float SpirvShader::Interpolate(SIMD::Pointer const &ptr, int32_t location,
 			return SIMD::Float(0.0f);
 	}

-	uint32_t offset = ComputeInterpolantOffset((ptr.staticOffsets[0] >> 2) + component, components_per_row, useArrayOffset);
-	if((interpolant + offset) >= inputs.size())
+	Pointer<Byte> planeEquation = interpolationData.primitive + OFFSET(Primitive, V[interpolant]);
+	if(ptr.hasDynamicOffsets)
 	{
-		return SIMD::Float(0.0f);
+		// This code assumes all dynamic offsets are equal
+		Int offset = ComputeInterpolantOffset(((Extract(ptr.dynamicOffsets, 0) + ptr.staticOffsets[0]) >> 2) + component, components_per_row, useArrayOffset);
+		offset = Min(offset, Int(inputs.size() - interpolant - 1));
+		planeEquation += (offset * sizeof(PlaneEquation));
+	}
+	else
+	{
+		ASSERT(ptr.hasStaticEqualOffsets());
+
+		uint32_t offset = ComputeInterpolantOffset((ptr.staticOffsets[0] >> 2) + component, components_per_row, useArrayOffset);
+		if((interpolant + offset) >= inputs.size())
+		{
+			return SIMD::Float(0.0f);
+		}
+		planeEquation += offset * sizeof(PlaneEquation);
 	}

-	Pointer<Byte> planeEquation = interpolationData.primitive + OFFSET(Primitive, V[interpolant]) + offset * sizeof(PlaneEquation);
 	return SpirvRoutine::interpolateAtXY(x, y, rhw, planeEquation, false, true);
 }