52 lines
991 B
Go
52 lines
991 B
Go
package core
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import (
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"git.akyoto.dev/cli/q/src/ast"
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"git.akyoto.dev/cli/q/src/cpu"
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"git.akyoto.dev/cli/q/src/expression"
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"git.akyoto.dev/cli/q/src/token"
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)
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// UsesRegister returns true if evaluating the expression would write or read the given register.
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func (f *Function) UsesRegister(expr *expression.Expression, register cpu.Register) bool {
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if expr.IsLeaf() {
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if expr.Token.Kind != token.Identifier {
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return false
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}
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variable := f.VariableByName(expr.Token.Text(f.File.Bytes))
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if variable == nil || variable.Register != register {
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return false
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}
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return true
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}
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if ast.IsFunctionCall(expr) {
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if register == f.CPU.Output[0] {
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return true
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}
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for i, parameter := range expr.Children[1:] {
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if register == f.CPU.Input[i] {
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return true
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}
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if f.UsesRegister(parameter, register) {
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return true
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}
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}
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return false
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}
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for _, child := range expr.Children {
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if f.UsesRegister(child, register) {
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return true
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}
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}
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return false
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}
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