Initial commit

Makefile

+CC = gcc
+CFLAGS = -Wall -Werror
+
+all: factmain 
+
+# perhaps use this as you develop further parts 
+# of the assignment
+#all: factmain gcdmain 
+
+factmain.o:	fact.h factmain.c
+fact.o:	fact.s
+
+gcdmain.o:	gcd.h gcdmain.c
+gcd.o:	gcd.s
+
+
+factmain:	fact.o factmain.o
+	$(CC) $(CFLAGS) -o factmain fact.o factmain.o
+
+gcdmain:	gcd.o gcdmain.o
+	$(CC) $(CFLAGS) -o gcdmain gcd.o gcdmain.o
+
+
+clean:
+	rm -f *.o factmain gcdmain
+
+
+.PHONY: all clean
+

bookprob3.6.txt

+Answers to Practice Problem 3.6, CS:APP3e pp.192-193
+----------------------------------------------------
+
+

bookprob3.63.txt

+Answer to Problem 3.63, CS:APP3e pp.314-315
+-------------------------------------------
+
+

example.c

+int ex(int a, int b, int c, int d) {
+    int res;
+    res = a * (b - c) + d;
+    return res;
+}

fact.h

+/*
+ * This is a stub header for fact.s
+ */
+extern int fact(int n);

fact.s

+#=============================================================================
+# The fact(n) function recursively computes n! (n factorial).
+#
+.globl fact
+fact:
+        orl     $0, %edi        # Sets zero flag if arg equals zero
+        jnz     fact_continue   # Compute factorial if nonzero
+        movl    $1, %eax        # Otherwise return 1
+        jmp     fact_return
+
+fact_continue:
+        pushq   %rdi            # Save our argument n before recursive call
+        decl    %edi            # Compute n-1 for arg in recursive call
+        call    fact            # Make recursive call; answer will be in eax
+
+fact_resume:
+        popq    %rdi            # Restore our argument n into rdi
+
+        # fact(n-1) is in %eax; multiply %edi (n) into that for our answer!
+        imull   %edi, %eax
+
+fact_return:
+        ret     # All done
+

math.s

+/* This file contains x86-64 assembly-language implementations of three
+ * basic, very common math operations.
+ */
+
+        .text
+
+/*====================================================================
+ * int f1(int x, int y)
+ */
+.globl f1
+f1:
+        movl    %edi, %edx
+        movl    %esi, %eax
+        cmpl    %edx, %eax
+        cmovg   %edx, %eax
+        ret
+
+
+/*====================================================================
+ * int f2(int x)
+ */
+.globl f2
+f2:
+        movl    %edi, %eax
+        movl    %eax, %edx
+        sarl    $31, %edx
+        xorl    %edx, %eax
+        subl    %edx, %eax
+        ret
+
+
+/*====================================================================
+ * int f3(int x)
+ */
+.globl f3
+f3:
+        movl    %edi, %edx
+        movl    %edx, %eax
+        sarl    $31, %eax
+        testl   %edx, %edx
+        movl    $1, %edx
+        cmovg   %edx, %eax
+        ret
+

problem1.txt

+What does the assembly code do?
+-------------------------------
+
+
+

stackframe.txt

+Stack Contents of fact(3)
+-------------------------
+
+Address     Value       Description
+--------    --------    ------------------------------------
+0x1008
+

tokens.txt

+Late tokens applied to this assignment:  0