Rename ImageInstructionState to ImageInstructionSignature

This structure contains all the information about an Image Instruction's
opcode and parameter types, so "signature" is much more descriptive than
"state".

Bug: b/203730083
Change-Id: Ia334850127ffb0e6958fecee3486b537e2ac1802
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/59448
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
diff --git a/src/Pipeline/SpirvShader.hpp b/src/Pipeline/SpirvShader.hpp
index f6a3443..a3a4b45 100644
--- a/src/Pipeline/SpirvShader.hpp
+++ b/src/Pipeline/SpirvShader.hpp
@@ -511,18 +511,18 @@
 
 	// Compact representation of image instruction state that is passed to the
 	// trampoline function for retrieving/generating the corresponding sampling routine.
-	struct ImageInstructionState
+	struct ImageInstructionSignature
 	{
-		ImageInstructionState(Variant variant, SamplerMethod samplerMethod)
-		    : state(0)
+		ImageInstructionSignature(Variant variant, SamplerMethod samplerMethod)
+		    : signature(0)
 		{
 			this->variant = variant;
 			this->samplerMethod = samplerMethod;
 		}
 
 		// Unmarshal from raw 32-bit data
-		explicit ImageInstructionState(uint32_t state)
-		    : state(state)
+		explicit ImageInstructionSignature(uint32_t signature)
+		    : signature(signature)
 		{}
 
 		SamplerFunction getSamplerFunction() const
@@ -567,14 +567,14 @@
 				uint32_t sample : 1;            // 0-1 scalar integer
 			};
 
-			uint32_t state;
+			uint32_t signature;
 		};
 	};
 
 	// This gets stored as a literal in the generated code, so it should be compact.
-	static_assert(sizeof(ImageInstructionState) == sizeof(uint32_t), "ImageInstructionState must be 32-bit");
+	static_assert(sizeof(ImageInstructionSignature) == sizeof(uint32_t), "ImageInstructionSignature must be 32-bit");
 
-	struct ImageInstruction : public ImageInstructionState
+	struct ImageInstruction : public ImageInstructionSignature
 	{
 		ImageInstruction(InsnIterator insn, const SpirvShader &spirv);
 
@@ -594,7 +594,7 @@
 		Object::ID sampleId = 0;
 
 	private:
-		static ImageInstructionState parseVariantAndMethod(InsnIterator insn);
+		static ImageInstructionSignature parseVariantAndMethod(InsnIterator insn);
 		static uint32_t getImageOperandsIndex(InsnIterator insn);
 		static uint32_t getImageOperandsMask(InsnIterator insn);
 	};
@@ -1376,8 +1376,8 @@
 	// Returns the pair <significand, exponent>
 	std::pair<SIMD::Float, SIMD::Int> Frexp(RValue<SIMD::Float> val) const;
 
-	static ImageSampler *getImageSampler(const vk::Device *device, uint32_t instruction, uint32_t samplerId, uint32_t imageViewId);
-	static std::shared_ptr<rr::Routine> emitSamplerRoutine(ImageInstructionState instruction, const Sampler &samplerState);
+	static ImageSampler *getImageSampler(const vk::Device *device, uint32_t signature, uint32_t samplerId, uint32_t imageViewId);
+	static std::shared_ptr<rr::Routine> emitSamplerRoutine(ImageInstructionSignature instruction, const Sampler &samplerState);
 
 	// TODO(b/129523279): Eliminate conversion and use vk::Sampler members directly.
 	static sw::FilterType convertFilterMode(const vk::SamplerState *samplerState, VkImageViewType imageViewType, SamplerMethod samplerMethod);
diff --git a/src/Pipeline/SpirvShaderImage.cpp b/src/Pipeline/SpirvShaderImage.cpp
index ab34cd2..346c506 100644
--- a/src/Pipeline/SpirvShaderImage.cpp
+++ b/src/Pipeline/SpirvShaderImage.cpp
@@ -88,7 +88,7 @@
 namespace sw {
 
 SpirvShader::ImageInstruction::ImageInstruction(InsnIterator insn, const SpirvShader &spirv)
-    : ImageInstructionState(parseVariantAndMethod(insn))
+    : ImageInstructionSignature(parseVariantAndMethod(insn))
     , position(insn.distanceFrom(spirv.begin()))
 {
 	if(samplerMethod == Write)
@@ -209,7 +209,7 @@
 	}
 }
 
-SpirvShader::ImageInstructionState SpirvShader::ImageInstruction::parseVariantAndMethod(InsnIterator insn)
+SpirvShader::ImageInstructionSignature SpirvShader::ImageInstruction::parseVariantAndMethod(InsnIterator insn)
 {
 	uint32_t imageOperands = getImageOperandsMask(insn);
 	bool bias = imageOperands & spv::ImageOperandsBiasMask;
@@ -330,7 +330,7 @@
 	If(!cacheHit)
 	{
 		rr::Int imageViewId = *Pointer<rr::Int>(imageDescriptor + OFFSET(vk::SampledImageDescriptor, imageViewId));
-		cache.function = Call(getImageSampler, state->routine->device, instruction.state, samplerId, imageViewId);
+		cache.function = Call(getImageSampler, state->routine->device, instruction.signature, samplerId, imageViewId);
 		cache.imageDescriptor = imageDescriptor;
 		cache.samplerId = samplerId;
 	}
diff --git a/src/Pipeline/SpirvShaderSampling.cpp b/src/Pipeline/SpirvShaderSampling.cpp
index 2d1a071..11d468f 100644
--- a/src/Pipeline/SpirvShaderSampling.cpp
+++ b/src/Pipeline/SpirvShaderSampling.cpp
@@ -30,16 +30,16 @@
 
 namespace sw {
 
-SpirvShader::ImageSampler *SpirvShader::getImageSampler(const vk::Device *device, uint32_t inst, uint32_t samplerId, uint32_t imageViewId)
+SpirvShader::ImageSampler *SpirvShader::getImageSampler(const vk::Device *device, uint32_t signature, uint32_t samplerId, uint32_t imageViewId)
 {
-	ImageInstructionState instruction(inst);
+	ImageInstructionSignature instruction(signature);
 	ASSERT(imageViewId != 0 && (samplerId != 0 || instruction.samplerMethod == Fetch));
 	ASSERT(device);
 
-	vk::Device::SamplingRoutineCache::Key key = { inst, samplerId, imageViewId };
+	vk::Device::SamplingRoutineCache::Key key = { signature, samplerId, imageViewId };
 
 	auto createSamplingRoutine = [&device](const vk::Device::SamplingRoutineCache::Key &key) {
-		ImageInstructionState instruction(key.instruction);
+		ImageInstructionSignature instruction(key.instruction);
 		const vk::Identifier::State imageViewState = vk::Identifier(key.imageView).getState();
 		const vk::SamplerState *vkSamplerState = (key.sampler != 0) ? device->findSampler(key.sampler) : nullptr;
 
@@ -121,7 +121,7 @@
 	return (ImageSampler *)(routine->getEntry());
 }
 
-std::shared_ptr<rr::Routine> SpirvShader::emitSamplerRoutine(ImageInstructionState instruction, const Sampler &samplerState)
+std::shared_ptr<rr::Routine> SpirvShader::emitSamplerRoutine(ImageInstructionSignature instruction, const Sampler &samplerState)
 {
 	// TODO(b/129523279): Hold a separate mutex lock for the sampler being built.
 	rr::Function<Void(Pointer<Byte>, Pointer<SIMD::Float>, Pointer<SIMD::Float>, Pointer<Byte>)> function;