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58 lines
1.2 KiB
Plaintext
58 lines
1.2 KiB
Plaintext
//
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// MintermTests.m
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// Clock SignalTests
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//
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// Created by Thomas Harte on 20/09/2021.
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// Copyright © 2021 Thomas Harte. All rights reserved.
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//
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#import <XCTest/XCTest.h>
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#include <cstdint>
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#include "Minterms.hpp"
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namespace {
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/// Implements the Amiga minterm algorithm in a bit-by-bit form.
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template <typename IntT> IntT slow_minterm(IntT a, IntT b, IntT c, uint8_t minterm) {
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constexpr int top_shift = sizeof(IntT) * 8 - 1;
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IntT result = 0;
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for(int i = 0; i < 8*sizeof(IntT); i++) {
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int index = ((c&1) << 0) | ((b&1) << 1) | ((a&1) << 2);
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result >>= 1;
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result |= ((minterm >> index) & 1) << top_shift;
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a >>= 1;
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b >>= 1;
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c >>= 1;
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}
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return result;
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}
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}
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@interface MintermTests: XCTestCase
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@end
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@implementation MintermTests
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- (void)testAll {
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// These three are selected just to ensure that all combinations of
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// bit pattern exist in the input.
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constexpr uint8_t a = 0xaa;
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constexpr uint8_t b = 0xcc;
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constexpr uint8_t c = 0xf0;
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for(int minterm = 0; minterm < 256; minterm++) {
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const uint8_t slow = slow_minterm(a, b, c, minterm);
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const uint8_t fast = Amiga::apply_minterm(a, b, c, minterm);
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XCTAssertEqual(slow, fast, "Mismatch found between naive and fast implementations for %02x", minterm);
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}
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}
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@end
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