aded symtable for loading vars and params to local memory

package/src/ExpressionProcessing.jl

@@ -30,6 +30,7 @@ function expr_to_postfix(expr::Expr)::PostfixType
 		if typeof(arg) === Expr
 			append!(postfix, expr_to_postfix(arg))
 		elseif typeof(arg) === Symbol # variables/parameters
+			# maybe TODO: replace the parameters with their respective values, as this might make the expr evaluation faster
 			exprElement = convert_to_ExpressionElement(convert_var_to_int(arg))
 			push!(postfix, exprElement)
 		else

package/src/Transpiler.jl

@@ -74,9 +74,9 @@ function get_kernel_signature(kernelName::String, parameters::Vector{DataType}):
 	for i in eachindex(parameters)
 		print(signatureBuffer, "  .param .u32", " ", "param_", i)
 
-		parameterRegister = get_next_free_register("r")
+		parameterRegister = get_next_free_register!("r")
 		println(paramLoadingBuffer, "ld.param.u32   $parameterRegister, [param_$i];")
-		println(paramLoadingBuffer, "cvta.to.global.u32   $(get_next_free_register("parameter")), $parameterRegister;")
+		println(paramLoadingBuffer, "cvta.to.global.u32   $(get_next_free_register!("parameter")), $parameterRegister;")
 		if i != lastindex(parameters)
 			println(signatureBuffer, ",")
 		end
@@ -94,18 +94,18 @@ Constructs the PTX code used for handling the case where too many threads are st
 function get_guard_clause(exitJumpLocation::String, nrOfVarSetsRegister::String)::String
 	guardBuffer = IOBuffer()
 
-	threadIds = get_next_free_register("r")
-	threadsPerCTA = get_next_free_register("r")
-	currentThreadId = get_next_free_register("r")
+	threadIds = get_next_free_register!("r")
+	threadsPerCTA = get_next_free_register!("r")
+	currentThreadId = get_next_free_register!("r")
 
 	# load data into above defined registers
 	println(guardBuffer, "mov.u32    $threadIds, %ntid.x;")
 	println(guardBuffer, "mov.u32    $threadsPerCTA, %ctaid.x;")
 	println(guardBuffer, "mov.u32    $currentThreadId, %tid.x;")
 
-	globalThreadId = get_next_free_register("r") # basically the index of the thread in the variable set
-	breakCondition = get_next_free_register("p")
-	nrOfVarSets = get_next_free_register("i")
+	globalThreadId = get_next_free_register!("r") # basically the index of the thread in the variable set
+	breakCondition = get_next_free_register!("p")
+	nrOfVarSets = get_next_free_register!("i")
 	println(guardBuffer, "ld.global.u32  $nrOfVarSets, $nrOfVarSetsRegister;")
 	println(guardBuffer, "mad.lo.s32     $globalThreadId, $threadIds, $threadsPerCTA, $currentThreadId;")
 	println(guardBuffer, "setp.ge.s32    $breakCondition, $globalThreadId, $nrOfVarSets;") # guard clause = index > nrOfVariableSets
@@ -143,10 +143,14 @@ function generate_calculation_code(expression::ExpressionProcessing.PostfixType,
 			# TODO
 			# %parameter1 + startIndex + Index * bytes
 			# startIndex: should be calculateable by global threadId and size of variables
+			# startIndex: threadId (==var-set/param) * size of var/params
 			if token.Value > 0 # varaibles
-				var = get_next_free_register("f")
-				#TODO: investigate how best to load var from global to local memory, especially when var used multiple times. (probably kind of symtable)
+				var, first_access = get_register_for_name!("x$(token.Value)")
+				#TODO: if first_access is true -> generate code for loading from global to local memory
 				push!(operands, "[$variablesRegister+$(token.Value*sizeof(token.Value))]") # missing: startIndex
+			else
+				param, first_access = get_register_for_name!("x$(token.Value)")
+				#TODO: if first_access is true -> generate code for loading from global to local memory
 			end
 		end
 	end
@@ -167,7 +171,7 @@ function type_to_ptx_type(type::DataType)::String
 end
 
 function get_operation(operator::Operator, left::Operand, right::Union{Operand, Nothing} = nothing)::Tuple{String, String}
-	resultRegister = get_next_free_register("f")
+	resultRegister = get_next_free_register!("f")
 	resultCode = ""
 
 	if is_binary_operator(operator) && isnothing(right)
@@ -209,16 +213,15 @@ function get_operation(operator::Operator, left::Operand, right::Union{Operand,
 end
 
 let registers = Dict() # stores the count of the register already used.
-	global get_next_free_register
+	global get_next_free_register!
 	global get_register_definitions
 
 	# By convention these names correspond to the following types:
 	# - p -> pred
 	# - f -> float32
 	# - r -> 32 bit
-	# - var -> float32
-	# - param -> float32 !! although, they might get inserted as fixed number and not be sent to gpu?
-	function get_next_free_register(name::String)::String
+	# - var -> float32 (used for variables and params)
+	function get_next_free_register!(name::String)::String
 		if haskey(registers, name)
 			registers[name] += 1
 		else
@@ -257,5 +260,20 @@ let registers = Dict() # stores the count of the register already used.
 	end
 end
 
+let symtable = Dict()
+	global get_register_for_name!
+
+	"Returns the register for this variable/parameter and true if it is used for the first time and false otherwise."
+	function get_register_for_name!(varName::String)
+		if haskey(symtable, varName)
+			return (symtable[varName], false)
+		else
+			reg = get_next_free_register!("var")
+			symtable[varName] = reg
+			return (reg, true)
+		end
+	end
+end
+
 end
 

thesis/chapters/introduction.tex

@@ -1,10 +1,13 @@
 \chapter{Introduction}
 \label{cha:Introduction}
 
-Introduction into topic and why someone would want to evaluate expressions on the GPU. Also include "Non-Goals"
+This chapter provides an entry point for this thesis. First the motivation of exploring this topic is presented. Next are the research questions that will be answered in this thesis are outlined. Lastly the methodology on how to answer these questions will be explained.
 
-\section[Research Question]{Research Question and Methodology}
+\section{Background and Motivation}
+
+
+\section{Research Question}
 What are the research questions and how they will be answered
 
-\section{Overview}
+\section{Methodology}
 Will give an overview of the chapters and what to expect