diff options
Diffstat (limited to '3')
| -rw-r--r-- | 3/6_control/27_while_for.c | 46 | ||||
| -rw-r--r-- | 3/6_control/28_fun_b.c | 33 | ||||
| -rw-r--r-- | 3/6_control/29_continue.c | 5 | ||||
| -rw-r--r-- | 3/6_control/30_switch2.c | 37 | ||||
| -rw-r--r-- | 3/6_control/31_the_switcher.c | 29 | ||||
| -rw-r--r-- | 3/7_procedures/32_functions.c | 14 | ||||
| -rw-r--r-- | 3/7_procedures/33_procprob.c | 21 | ||||
| -rw-r--r-- | 3/7_procedures/34_long_p.c | 34 |
8 files changed, 219 insertions, 0 deletions
diff --git a/3/6_control/27_while_for.c b/3/6_control/27_while_for.c new file mode 100644 index 0000000..f7f73f7 --- /dev/null +++ b/3/6_control/27_while_for.c @@ -0,0 +1,46 @@ +#include <stdio.h> + +long fact_for(long n) { + long i; + long result = 1; + for (i = 2; i <= n; i++) { + result *= i; + } + return result; +} + +// guarded do +// +// init-s +// t = test-e; +// if (!t) goto done; +// +// loop: +// body-s +// update-e; +// t = test-e; +// if (t) goto loop; +// +// done: + +long fact_for_gd_goto(long n) { + long i = 2; + long result = 1; + + int t = i<=n; + if (!t) { + goto done; + } +loop: + result *= i; + i++; + t = i<=n; + if (t) goto loop; +done: + return result; +} + +int main() { + printf("for: %ld, goto: %ld\n", fact_for(5), fact_for_gd_goto(5)); + return 0; +} diff --git a/3/6_control/28_fun_b.c b/3/6_control/28_fun_b.c new file mode 100644 index 0000000..5ecf7d2 --- /dev/null +++ b/3/6_control/28_fun_b.c @@ -0,0 +1,33 @@ +#include <stdio.h> + +// x in rdi +// fun_b: +// movl $64, %edx i <- 64 (32 bits?, long presumably) +// movl $0, %eax val <- 0 +// .L10: +// movq %rdi, %rcx tmp <- x +// andl $1, %ecx tmp <- tmp & 1 +// addq %rax, %rax val <- val + val +// orq %rcx, %rax val <- val | tmp +// shrq %rdi +// subq $1, %rdx i <- i-1 +// jne .L10 if i != 0 then goto .L10 +// rep; ret +long fun_b(unsigned long x) { + long val = 0; + long i; + for (i = 64; i!=0; i--) { + long tmp = x; + tmp &= 1; // check 1 bit + val += val; // multiply by two + val |= tmp; // add 1 bit if present + x >>= 1; // shift next bit into 1 bit + } + return val; +} + +// Seems to compute the value shifted to the left (63 - nbit), (or in other words the mirror image) +int main() { + printf("val: %ld, computed: %ld, bits: %lb\n", fun_b(10), (long) 10 << 59, 10); + return 0; +} diff --git a/3/6_control/29_continue.c b/3/6_control/29_continue.c new file mode 100644 index 0000000..175f57b --- /dev/null +++ b/3/6_control/29_continue.c @@ -0,0 +1,5 @@ +#include <stdio.h> + +int main() { + return 0; +} diff --git a/3/6_control/30_switch2.c b/3/6_control/30_switch2.c new file mode 100644 index 0000000..0c8cc85 --- /dev/null +++ b/3/6_control/30_switch2.c @@ -0,0 +1,37 @@ +#include <stdio.h> + +// x in %rdi +// switch2: +// addq $1, %rdi +// cmpq $8, %rdi +// ja .L2 if (x + 1) > 8 then goto default +// jmp *.L4(,%rdi,8) take the address at x*8 from .L4 +void switch2(long x, long *dest) { + long val = 0; + switch (x) { + case -1: + printf(".L9"); + break; + case 0: + case 7: + printf(".L5"); + break; + case 1: + printf(".L6"); + break; + case 2: + case 4: + printf(".L7"); + break; + case 5: + printf(".L8"); + break; + + } + *dest = val; +} + +int main(void) { + printf("val: %ld\n"); + return 0; +} diff --git a/3/6_control/31_the_switcher.c b/3/6_control/31_the_switcher.c new file mode 100644 index 0000000..c8b0a4a --- /dev/null +++ b/3/6_control/31_the_switcher.c @@ -0,0 +1,29 @@ +#include <stdio.h> + +// a in %rdi, b in %rsi, c in %rdx, dest in %rcx +void switcher(long a, long b, long c, long *dest) { + long val; + switch (a) { + case 5: /* Case A .L7 */ + c = 15 ^ a; + /* Fall through */ + case 0: /* Case B .L3 */ + val = 112 + c; + break; + case 2: /* Case C .L5 */ + case 7: /* Case D .L5 */ + val = (c + b)<<2; + break; + case 4: /* Case E */ + val = a; + break; + default: /* .L2 */ + val = b; + } + *dest = val; /* .L6 */ +} + +int main(void) { + printf("val: %ld\n"); + return 0; +} diff --git a/3/7_procedures/32_functions.c b/3/7_procedures/32_functions.c new file mode 100644 index 0000000..ebf4405 --- /dev/null +++ b/3/7_procedures/32_functions.c @@ -0,0 +1,14 @@ +// Label PC Instruction %rdi %rsi %rax %rsp *%rsp Description +// M1 400560 callq 10 7fffffffe820 Call first(10) +// +// F1 400548 lea 10 7fffffffe818 400565 v <- x + 1 +// F2 40054c sub 10 11 7fffffffe818 400565 u <- x - 1 +// F3 400550 callq 9 11 7fffffffe818 400565 Call last(9, 11) +// +// L1 400540 mov 9 11 7fffffffe810 400555 rax <- u +// L2 400543 imul 9 11 9 7fffffffe810 400555 rax <- rax * v +// L3 400547 retq 9 11 99 7fffffffe810 400555 return +// +// F4 400555 retq 9 11 99 7fffffffe818 400565 return +// +// M2 400565 mov 9 11 99 Resume diff --git a/3/7_procedures/33_procprob.c b/3/7_procedures/33_procprob.c new file mode 100644 index 0000000..4c68855 --- /dev/null +++ b/3/7_procedures/33_procprob.c @@ -0,0 +1,21 @@ +// procprob +// movslq %edi, %rdi movslq==Move and sign extend 32bit to 64bit two's complement number, +// Basically seems to convert the first signed argument to 64bit size. +// A singed 32bit number is an int? +// addq %rdi, (%rdx) *u <- (long) u + (long) a +// addb %sil, (%rcx) *v <- (char) *v + (?) b +// movl $6, %eax sizeof(a) + sizeof(b) = 6 = 4 + 2 +// +// procprob +// movslq %edi, %rdi movslq==Move and sign extend 32bit to 64bit two's complement number, +// Basically seems to convert the first signed argument to 64bit size. +// A singed 32bit number is an int? +// addq %rdi, (%rdx) *u <- (long) u + (long) a +// addb %sil, (%rcx) *v <- (char) *v + (?) b +// movl $6, %eax sizeof(a) + sizeof(b) = 6 = 2 + 4 +// +int procprob(int a, short b, long *u, char *v) { + *u += a; + *v += b; + return sizeof(b) + sizeof(b) +} diff --git a/3/7_procedures/34_long_p.c b/3/7_procedures/34_long_p.c new file mode 100644 index 0000000..d058b77 --- /dev/null +++ b/3/7_procedures/34_long_p.c @@ -0,0 +1,34 @@ +// long P(long x) +// x in %rdi +// bx and bp, r12-15 are callee saved +// +// P: +// pushq %r15 +// pushq %r14 +// pushq %r13 +// pushq %r12 +// pushq %rbp +// pushq %rbx +// subq $24, %rsp Allocate 24 extra bytes +// +// movq %rdi, %rbx move first arg into rbx +// leaq 1(%rdi), %r15 move first arg into rbx +// leaq 2(%rdi), %r14 move first arg into rbx +// leaq 3(%rdi), %r13 move first arg into rbx +// leaq 4(%rdi), %r12 move first arg into rbx +// leaq 5(%rdi), %rbp move first arg into rbx +// leaq 6(%rdi), %rax move first arg into rbx +// movq %rax, (%rsp) save %rax in one of the three 8byte spots +// leaq 7(%rdi), %rdx move first arg into rdx +// movq %rdx, 8(%rsp) save %rdx in the second of the three 8byte spots +// movl $0, %eax set ax to zero? +// call Q +// ... +// +// A. x, x + 1, x + 2, x + 3, x + 4, x + 5 +// B. x + 6, x + 7 +// C. There were more than 6? +// +long P(long x) { + return 0; +} |