labs only

README.md

@@ -1,3 +1,3 @@
 # CSAPP-sol
 
-CSAPP中homework和lab的部分题目的参考答案
+CSAPP labs

homework/chapter2/Makefile

@@ -1,13 +0,0 @@
-#
-# Makefile that builds btest and other helper programs for the CS:APP data lab
-# 
-CC = gcc
-CFLAGS = -O2 -Wall -m32
-LIBS = -lm
-all: test
-
-test: main.c homework.c test.c test.h xoroshiro128plusplus.c
-	$(CC) $(CFLAGS) $(LIBS) -o test main.c homework.c test.c xoroshiro128plusplus.c
-
-clean:
-	rm -f test

homework/chapter2/README

@@ -1,2 +0,0 @@
-第二章作业 65、66、75、80、95 和 97 的测试框架。你需要编辑 homework.c 中的六个函数完成作业，然后输入命令 make 编译程序，输入命令 ./test 查看结果。
-homework_sample.c 中有参考实现。

homework/chapter2/homework.c

@@ -1,104 +0,0 @@
-#include "test.h"
-
-/* Return 1 when x contains an odd number of 1s; 0 otherwise.
-   Assume w=32 */
-int odd_ones(unsigned x) {
-  x ^= x >> 16;
-  x ^= x >> 8;
-  x ^= x >> 4;
-  x ^= x >> 2;
-  x ^= x >> 1;
-  return x & 1;
-}
-
-/*
- * Generate mask indicating leftmost 1 in x.  Assume w=32.
- * For example, 0xFF00 -> 0x8000, and 0x6600 --> 0x4000.
- * If x = 0, then return 0.
- */
-int leftmost_one(unsigned x) {
-  unsigned t = x;
-  t >>= 1;
-
-  t |= t >> 1;
-  t |= t >> 2;
-  t |= t >> 4;
-  t |= t >> 8;
-  t |= t >> 16;
-
-  return (t + 1) & x;
-}
-
-unsigned unsigned_high_prod(unsigned x, unsigned y) {
-  int w = sizeof(int) << 3;
-  return signed_high_prod(x, y) + (((int) y >> (w - 1)) & x) + (((int) x >> (w - 1)) & y);
-}
-
-int threefourths(int x) {
-  int p = x >> 2, q = x & 3;
-  return p + (p << 1) + q - (!!q & (~x >> 31));
-}
-
-/* computs 0.5*f.  If f is NaN, then return f. */
-float_bits float_half(float_bits uf) {
-  float_bits s = uf & 0x80000000, f = uf & 0x007FFFFF, e = (uf >> 23) & 0xFF;
-
-  if (e == 0xFF) {
-    return uf;
-  }
-  
-  if (e > 1) {
-    e--;
-  } else {
-    if (e == 1) {
-      f |= 1 << 23;
-      e = 0;
-    }
-    int t = f;
-    f >>= 1;
-    if (t & f & 1) {
-      f++;
-    }
-  }
-  return s | (e << 23) | f;
-}
-
-/* Compute (float) i */
-float_bits float_i2f(int i) {
-  if (i == -0x7FFFFFFF - 1) {
-    return 0xCF000000;
-  }
-
-  if (i == 0) {
-    return 0;
-  }
-
-  float_bits s = 0, f, e;
-  if (i < 0) {
-    i = -i;
-    s = 0x80000000;
-  }
-
-  int hb = 30;
-  while (!(i >> hb)) {
-    hb--;
-  }
-
-  i ^= 1 << hb;
-  e = hb + 127;
-  int dif = hb - 23;
-  if (dif > 0) {
-    f = i >> dif;
-    if ((i & ((1 << dif) - 1)) + (f & 1) > (1 << (dif - 1))) {
-      f++;
-      if (f & 0x00800000) {
-        f = 0;
-        e++;
-      }
-    }
-  } else {
-    f = i << -dif;
-  }
-
-  return s | (e << 23) | f;
-}

homework/chapter2/homework_sample.c

@@ -1,104 +0,0 @@
-#include "test.h"
-
-/* Return 1 when x contains an odd number of 1s; 0 otherwise.
-   Assume w=32 */
-int odd_ones(unsigned x) {
-  x ^= x >> 16;
-  x ^= x >> 8;
-  x ^= x >> 4;
-  x ^= x >> 2;
-  x ^= x >> 1;
-  return x & 1;
-}
-
-/*
- * Generate mask indicating leftmost 1 in x.  Assume w=32.
- * For example, 0xFF00 -> 0x8000, and 0x6600 --> 0x4000.
- * If x = 0, then return 0.
- */
-int leftmost_one(unsigned x) {
-  unsigned t = x;
-  t >>= 1;
-
-  t |= t >> 1;
-  t |= t >> 2;
-  t |= t >> 4;
-  t |= t >> 8;
-  t |= t >> 16;
-
-  return (t + 1) & x;
-}
-
-unsigned unsigned_high_prod(unsigned x, unsigned y) {
-  int w = sizeof(int) << 3;
-  return signed_high_prod(x, y) + (((int) y >> (w - 1)) & x) + (((int) x >> (w - 1)) & y);
-}
-
-int threefourths(int x) {
-  int p = x >> 2, q = x & 3;
-  return p + (p << 1) + q - (!!q & (~x >> 31));
-}
-
-/* computs 0.5*f.  If f is NaN, then return f. */
-float_bits float_half(float_bits uf) {
-  float_bits s = uf & 0x80000000, f = uf & 0x007FFFFF, e = (uf >> 23) & 0xFF;
-
-  if (e == 0xFF) {
-    return uf;
-  }
-  
-  if (e > 1) {
-    e--;
-  } else {
-    if (e == 1) {
-      f |= 1 << 23;
-      e = 0;
-    }
-    int t = f;
-    f >>= 1;
-    if (t & f & 1) {
-      f++;
-    }
-  }
-  return s | (e << 23) | f;
-}
-
-/* Compute (float) i */
-float_bits float_i2f(int i) {
-  if (i == 0x7FFFFFFF - 1) {
-    return 0xCF000000;
-  }
-
-  if (i == 0) {
-    return 0;
-  }
-
-  float_bits s = 0, f, e;
-  if (i < 0) {
-    i = -i;
-    s = 0x80000000;
-  }
-
-  int hb = 30;
-  while (!(i >> hb)) {
-    hb--;
-  }
-
-  i ^= 1 << hb;
-  e = hb + 127;
-  int dif = hb - 23;
-  if (dif > 0) {
-    f = i >> dif;
-    if ((i & ((1 << dif) - 1)) + (f & 1) > (1 << (dif - 1))) {
-      f++;
-      if (f & 0x00800000) {
-        f = 0;
-        e++;
-      }
-    }
-  } else {
-    f = i << -dif;
-  }
-
-  return s | (e << 23) | f;
-}

homework/chapter2/main.c

@@ -1,40 +0,0 @@
-#include <stdio.h>
-#include "test.h"
-
-int main() {
-  if (test_65() == FAILED) {
-    fprintf(stderr, "HOMEWORK 65 TEST FAILED\n");
-  } else {
-    fprintf(stderr, "HOMEWORK 65 TEST PASSED\n");
-  }
-
-  if (test_66() == FAILED) {
-    fprintf(stderr, "HOMEWORK 66 TEST FAILED\n");
-  } else {
-    fprintf(stderr, "HOMEWORK 66 TEST PASSED\n");
-  }
-
-  if (test_75(1e9) == FAILED) {
-    fprintf(stderr, "HOMEWORK 75 TEST FAILED\n");
-  } else {
-    fprintf(stderr, "HOMEWORK 75 TEST PASSED\n");
-  }
-
-  if (test_80(1e9) == FAILED) {
-    fprintf(stderr, "HOMEWORK 80 TEST FAILED\n");
-  } else {
-    fprintf(stderr, "HOMEWORK 80 TEST PASSED\n");
-  }
-
-  if (test_95() == FAILED) {
-    fprintf(stderr, "HOMEWORK 95 TEST FAILED\n");
-  } else {
-    fprintf(stderr, "HOMEWORK 95 TEST PASSED\n");
-  }
-
-  if (test_97() == FAILED) {
-    fprintf(stderr, "HOMEWORK 97 TEST FAILED\n");
-  } else {
-    fprintf(stderr, "HOMEWORK 97 TEST PASSED\n");
-  }
-}

homework/chapter2/test.c

@@ -1,101 +0,0 @@
-#include <math.h>
-#include <stdio.h>
-#include <assert.h>
-#include <limits.h>
-#include <stdint.h>
-#include "test.h"
-
-uint64_t next();
-void jump();
-void long_jump();
-
-int test_65() {
-  for (unsigned x = 0; ; x++) {
-    if (odd_ones(x) != __builtin_parity(x)) {
-      fprintf(stderr, "x = 0x%X\n", x);
-      return FAILED;
-    }
-
-    if (x == UINT_MAX) {
-      return PASSED;
-    }
-  }
-}
-
-int test_66() {
-  for (unsigned x = 0; ; x++) {
-    if ((x == 0 && leftmost_one(x) != 0) || (x != 0 && leftmost_one(x) != (1 << (31 - __builtin_clz(x))))) {
-      fprintf(stderr, "x = 0x%X\n", x);
-      return FAILED;
-    }
-
-    if (x == UINT_MAX) {
-      return PASSED;
-    }
-  }
-}
-
-int test_75(int test_cases) {
-  for (int i = 0; i < test_cases; i++) {
-    unsigned x = next(), y = next();
-    if ((uint64_t) x * y != ((uint64_t) unsigned_high_prod(x, y) << 32) + x * y) {
-      fprintf(stderr, "x = 0x%X, y = 0x%X\n", x, y);
-      return FAILED;
-    }
-  }
-
-  return PASSED;
-}
-
-int signed_high_prod(int x, int y) {
-  int64_t p = (int64_t) x * y;
-  return p >> (sizeof(int) << 3);
-}
-
-int test_80(int test_cases) {
-  for (int i = 0; i < test_cases; i++) {
-    int x = next();
-    if (threefourths(x) != (int64_t) x * 3 / 4) {
-      fprintf(stderr, "x = 0x%X\n", x);
-      return FAILED;
-    }
-  }
-
-  return PASSED;
-}
-
-float_bits f2b(float x) {
-  return *(float_bits*) &x;
-}
-
-float b2f(float_bits x) {
-  return *(float*) &x;
-}
-
-int test_95() {
-  for (float_bits x = 0; ; x++) {
-    float y = b2f(x) / 2, z = b2f(float_half(x));
-    if (y != z && !(isnan(y) && isnan(z))) {
-      fprintf(stderr, "%X %X\n", f2b(b2f(x) / 2), float_half(x));
-      fprintf(stderr, "f = 0x%X\n", x);
-      return FAILED;
-    }
-
-    if (x == UINT_MAX) {
-      return PASSED;
-    }
-  }
-}
-
-int test_97() {
-  for (int x = INT_MIN; ; x++) {
-    if (f2b((float) x) != float_i2f(x)) {
-      fprintf(stderr, "i = 0x%X\n", x);
-      return FAILED;
-    }
-
-    if (x == INT_MAX) {
-      return PASSED;
-    }
-  }
-}

homework/chapter2/test.h

@@ -1,26 +0,0 @@
-#ifndef TEST_H
-#define TEST_H
-
-#define PASSED 0
-#define FAILED 1
-
-/* Access bit-level representation of floating-point number */
-typedef unsigned float_bits;
-
-int signed_high_prod(int, int);
-
-int odd_ones(unsigned);
-int leftmost_one(unsigned);
-unsigned unsigned_high_prod(unsigned, unsigned);
-int threefourths(int);
-float_bits float_half(float_bits);
-float_bits float_i2f(int);
-
-int test_65();
-int test_66();
-int test_75(int);
-int test_80(int);
-int test_95();
-int test_97();
-
-#endif

homework/chapter2/xoroshiro128plusplus.c

@@ -1,97 +0,0 @@
-/*  Written in 2019 by David Blackman and Sebastiano Vigna (vigna@acm.org)
-
-To the extent possible under law, the author has dedicated all copyright
-and related and neighboring rights to this software to the public domain
-worldwide.
-
-Permission to use, copy, modify, and/or distribute this software for any
-purpose with or without fee is hereby granted.
-
-THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
-WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
-ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
-WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
-ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
-IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
-
-#include <stdint.h>
-
-/* This is xoroshiro128++ 1.0, one of our all-purpose, rock-solid,
-   small-state generators. It is extremely (sub-ns) fast and it passes all
-   tests we are aware of, but its state space is large enough only for
-   mild parallelism.
-
-   For generating just floating-point numbers, xoroshiro128+ is even
-   faster (but it has a very mild bias, see notes in the comments).
-
-   The state must be seeded so that it is not everywhere zero. If you have
-   a 64-bit seed, we suggest to seed a splitmix64 generator and use its
-   output to fill s. */
-
-
-static inline uint64_t rotl(const uint64_t x, int k) {
-	return (x << k) | (x >> (64 - k));
-}
-
-
-static uint64_t s[2];
-
-uint64_t next(void) {
-	const uint64_t s0 = s[0];
-	uint64_t s1 = s[1];
-	const uint64_t result = rotl(s0 + s1, 17) + s0;
-
-	s1 ^= s0;
-	s[0] = rotl(s0, 49) ^ s1 ^ (s1 << 21); // a, b
-	s[1] = rotl(s1, 28); // c
-
-	return result;
-}
-
-
-/* This is the jump function for the generator. It is equivalent
-   to 2^64 calls to next(); it can be used to generate 2^64
-   non-overlapping subsequences for parallel computations. */
-
-void jump(void) {
-	static const uint64_t JUMP[] = { 0x2bd7a6a6e99c2ddc, 0x0992ccaf6a6fca05 };
-
-	uint64_t s0 = 0;
-	uint64_t s1 = 0;
-	for(int i = 0; i < sizeof JUMP / sizeof *JUMP; i++)
-		for(int b = 0; b < 64; b++) {
-			if (JUMP[i] & UINT64_C(1) << b) {
-				s0 ^= s[0];
-				s1 ^= s[1];
-			}
-			next();
-		}
-
-	s[0] = s0;
-	s[1] = s1;
-}
-
-
-/* This is the long-jump function for the generator. It is equivalent to
-   2^96 calls to next(); it can be used to generate 2^32 starting points,
-   from each of which jump() will generate 2^32 non-overlapping
-   subsequences for parallel distributed computations. */
-
-void long_jump(void) {
-	static const uint64_t LONG_JUMP[] = { 0x360fd5f2cf8d5d99, 0x9c6e6877736c46e3 };
-
-	uint64_t s0 = 0;
-	uint64_t s1 = 0;
-	for(int i = 0; i < sizeof LONG_JUMP / sizeof *LONG_JUMP; i++)
-		for(int b = 0; b < 64; b++) {
-			if (LONG_JUMP[i] & UINT64_C(1) << b) {
-				s0 ^= s[0];
-				s1 ^= s[1];
-			}
-			next();
-		}
-
-	s[0] = s0;
-	s[1] = s1;
-}