Clamp _SNORM formats to -1.0

Following the Vulkan 1.1 specification Section 2.9.1. "Conversion from Normalized Fixed-Point to Floating-Point": Note that while zero is exactly expressible in this representation, one value (-128 in the example) is outside the representable range, and must be clamped before use. https://www.khronos.org/registry/vulkan/specs/1.1/html/vkspec.html#fundamentals-fixedfpconv Bug: dawn:283 Change-Id: Id548c6d67132ac36f33bc020954c5511de624ffc Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/43648 Kokoro-Result: kokoro <noreply+kokoro@google.com> Reviewed-by: Nicolas Capens <nicolascapens@google.com> Tested-by: Corentin Wallez <cwallez@google.com>

Clamp _SNORM formats to -1.0
5c883d3c · Corentin Wallez · Corentin Wallez · 3cfa8e28 · 5c883d3c · 5c883d3c
Commit 5c883d3c authored Apr 08, 2020 by Corentin Wallez Committed by Corentin Wallez Apr 09, 2020
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Showing with 16 additions and 16 deletions

SamplerCore.cpp src/Pipeline/SamplerCore.cpp +8 -8

VertexRoutine.cpp src/Pipeline/VertexRoutine.cpp +8 -8

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--- a/src/Pipeline/SamplerCore.cpp
+++ b/src/Pipeline/SamplerCore.cpp
@@ -183,10 +183,10 @@ Vector4f SamplerCore::sampleTexture(Pointer<Byte> &texture, Float4 uvw[4], Float
 				case VK_FORMAT_R8G8_SNORM:
 				case VK_FORMAT_R8G8B8A8_SNORM:
 				case VK_FORMAT_A8B8G8R8_SNORM_PACK32:
-					c.x *= Float4(1.0f / 0x7F00);
+					c.x = Max(c.x * Float4(1.0f / 0x7F00), Float4(-1.0f));
-					c.y *= Float4(1.0f / 0x7F00);
+					c.y = Max(c.y * Float4(1.0f / 0x7F00), Float4(-1.0f));
-					c.z *= Float4(1.0f / 0x7F00);
+					c.z = Max(c.z * Float4(1.0f / 0x7F00), Float4(-1.0f));
-					c.w *= Float4(1.0f / 0x7F00);
+					c.w = Max(c.w * Float4(1.0f / 0x7F00), Float4(-1.0f));
 					break;
 				case VK_FORMAT_R8_UNORM:
 				case VK_FORMAT_R8G8_UNORM:
@@ -237,10 +237,10 @@ Vector4f SamplerCore::sampleTexture(Pointer<Byte> &texture, Float4 uvw[4], Float
 			case VK_FORMAT_R8G8_SNORM:
 			case VK_FORMAT_R8G8B8A8_SNORM:
 			case VK_FORMAT_A8B8G8R8_SNORM_PACK32:
-				c.x = Float4(cs.x) * Float4(1.0f / 0x7F00);
+				c.x = Max(Float4(cs.x) * Float4(1.0f / 0x7F00), Float4(-1.0f));
-				c.y = Float4(cs.y) * Float4(1.0f / 0x7F00);
+				c.y = Max(Float4(cs.y) * Float4(1.0f / 0x7F00), Float4(-1.0f));
-				c.z = Float4(cs.z) * Float4(1.0f / 0x7F00);
+				c.z = Max(Float4(cs.z) * Float4(1.0f / 0x7F00), Float4(-1.0f));
-				c.w = Float4(cs.w) * Float4(1.0f / 0x7F00);
+				c.w = Max(Float4(cs.w) * Float4(1.0f / 0x7F00), Float4(-1.0f));
 				break;
 			case VK_FORMAT_R8_UNORM:
 			case VK_FORMAT_R8G8_UNORM:

--- a/src/Pipeline/VertexRoutine.cpp
+++ b/src/Pipeline/VertexRoutine.cpp
@@ -269,10 +269,10 @@ Vector4f VertexRoutine::readStream(Pointer<Byte> &buffer, UInt &stride, const St
 			transpose4xN(v.x, v.y, v.z, v.w, componentCount);
-			if(componentCount >= 1) v.x *= *Pointer<Float4>(constants + OFFSET(Constants, unscaleSByte));
+			if(componentCount >= 1) v.x = Max(v.x * *Pointer<Float4>(constants + OFFSET(Constants, unscaleSByte)), Float4(-1.0f));
-			if(componentCount >= 2) v.y *= *Pointer<Float4>(constants + OFFSET(Constants, unscaleSByte));
+			if(componentCount >= 2) v.y = Max(v.y * *Pointer<Float4>(constants + OFFSET(Constants, unscaleSByte)), Float4(-1.0f));
-			if(componentCount >= 3) v.z *= *Pointer<Float4>(constants + OFFSET(Constants, unscaleSByte));
+			if(componentCount >= 3) v.z = Max(v.z * *Pointer<Float4>(constants + OFFSET(Constants, unscaleSByte)), Float4(-1.0f));
-			if(componentCount >= 4) v.w *= *Pointer<Float4>(constants + OFFSET(Constants, unscaleSByte));
+			if(componentCount >= 4) v.w = Max(v.w * *Pointer<Float4>(constants + OFFSET(Constants, unscaleSByte)), Float4(-1.0f));
 			break;
 		case VK_FORMAT_R8_SINT:
 		case VK_FORMAT_R8G8_SINT:
@@ -295,10 +295,10 @@ Vector4f VertexRoutine::readStream(Pointer<Byte> &buffer, UInt &stride, const St
 			transpose4xN(v.x, v.y, v.z, v.w, componentCount);
-			if(componentCount >= 1) v.x *= *Pointer<Float4>(constants + OFFSET(Constants, unscaleShort));
+			if(componentCount >= 1) v.x = Max(v.x * *Pointer<Float4>(constants + OFFSET(Constants, unscaleShort)), Float4(-1.0f));
-			if(componentCount >= 2) v.y *= *Pointer<Float4>(constants + OFFSET(Constants, unscaleShort));
+			if(componentCount >= 2) v.y = Max(v.y * *Pointer<Float4>(constants + OFFSET(Constants, unscaleShort)), Float4(-1.0f));
-			if(componentCount >= 3) v.z *= *Pointer<Float4>(constants + OFFSET(Constants, unscaleShort));
+			if(componentCount >= 3) v.z = Max(v.z * *Pointer<Float4>(constants + OFFSET(Constants, unscaleShort)), Float4(-1.0f));
-			if(componentCount >= 4) v.w *= *Pointer<Float4>(constants + OFFSET(Constants, unscaleShort));
+			if(componentCount >= 4) v.w = Max(v.w * *Pointer<Float4>(constants + OFFSET(Constants, unscaleShort)), Float4(-1.0f));
 			break;
 		case VK_FORMAT_R16_SINT:
 		case VK_FORMAT_R16G16_SINT: