fix 3.md and update Makefile

This commit is contained in:
2025-10-20 21:54:07 +09:00
parent b04b68a339
commit 99628ab532
2 changed files with 76 additions and 13 deletions

View File

@@ -1,2 +1,4 @@
all:
rm ./notes/*.out
rm -f ./notes/*.out
rm -f ./notes/*.o
rm -f ./notes/*.s

View File

@@ -52,7 +52,7 @@ void sumstore(long x, long y, long *dest) {
```
```sh {cmd hide}
while ! [ -f 3_1.o ]; do sleep .1; done; objdump -d 3_1.o
while ! [ -r 3_1.o ]; do sleep .1; done; objdump -d 3_1.o
```
### Integer Registers
@@ -267,12 +267,12 @@ long absdiff(long x, long y) {
```
```sh { cmd hide }
while ! [ -f 3_3.o ]; do sleep .1; done; objdump -d 3_3.o -Msuffix
while ! [ -r 3_3.o ]; do sleep .1; done; objdump -d 3_3.o -Msuffix
```
**expressing with `goto`**
```c {cmd=gcc args=[-Og -x c -fno-if-conversion -c $input_file -o 3_4.o]}
```c {cmd=gcc args=[-Og -x c -rno-if-conversion -c $input_file -o 3_4.o]}
long absdiff_j(long x, long y) {
long result;
int ntest = x <= y;
@@ -300,7 +300,7 @@ long absdiff(long x, long y) {
```
```sh {cmd hide}
while ! [ -f 3_5.o ]; do sleep .1; done; objdump -d 3_5.o -Msuffix
while ! [ -r 3_5.o ]; do sleep .1; done; objdump -d 3_5.o -Msuffix
```
However, there are several *bad cases* for conditional move.
@@ -357,7 +357,7 @@ loop:
</table>
```sh {cmd hide}
while ! [ -f 3_6.o ]; do sleep .1; done; objdump -d 3_6.o -Msuffix
while ! [ -r 3_6.o ]; do sleep .1; done; objdump -d 3_6.o -Msuffix
```
**general do-while translation**
@@ -426,7 +426,7 @@ long pcount_while(unsigned long x) {
```
```sh {cmd hide}
echo "jmp-to-middle translation"
while ! [ -f 3_7.o ]; do sleep .1; done; objdump -d 3_7.o -Msuffix
while ! [ -r 3_7.o ]; do sleep .1; done; objdump -d 3_7.o -Msuffix
```
**general while translation#2**
@@ -478,7 +478,7 @@ long pcount_while(unsigned long x) {
```
```sh {cmd hide}
echo "while to do-while conversion"
while ! [ -f 3_8.o ]; do sleep .1; done; objdump -d 3_8.o -Msuffix
while ! [ -r 3_8.o ]; do sleep .1; done; objdump -d 3_8.o -Msuffix
```
#### for loop form
@@ -560,13 +560,13 @@ long pcount_for(unsigned long x) {
<td>
```sh {cmd hide}
while ! [ -f 3_9.o ]; do sleep .1; done; objdump -d 3_9.o -Msuffix
while ! [ -r 3_9.o ]; do sleep .1; done; objdump -d 3_9.o -Msuffix
```
</td>
<td>
```sh {cmd hide}
while ! [ -f 3_10.o ]; do sleep .1; done; objdump -d 3_10.o -Msuffix
while ! [ -r 3_10.o ]; do sleep .1; done; objdump -d 3_10.o -Msuffix
```
</td>
</tr>
@@ -614,7 +614,7 @@ long switch_eg (long x, long y, long z) {
<td>
```sh {cmd hide}
while ! [ -f 3_11.s ]; do sleep .1; done; cat 3_11.s
while ! [ -r 3_11.s ]; do sleep .1; done; cat 3_11.s
```
</td>
</tr>
@@ -667,7 +667,7 @@ void multstore(long x, long y, long *dest) {
```
```sh {cmd hide}
while ! [ -f 3_12.o ]; do sleep .1; done; objdump -d 3_12.o -Msuffix
while ! [ -r 3_12.o ]; do sleep .1; done; objdump -d 3_12.o -Msuffix
```
Procedure call `call label`
@@ -676,3 +676,64 @@ Procedure call `call label`
Return address:
* Address of the next instruction right after call
Procedure return: `ret`
### Procedure Data Flow
* registers
* first 6 args: `%rdi`, `%rsi`, `%rdx`, `%rcx`, `%r8`, `%r9`
* return value: `rax`
* stack
for example with above example
```sh {cmd hide}
while ! [ -r 3_12.o ]; do sleep .1; done; objdump -d 3_12.o -Msuffix
```
* with above `mult2` variable `t` is already stored in `%rax`
* so `movq %rax,(%rbx)` where `%rbx` is `long*dest`
### Managing local data
**Stack-Based Languages**
In languages that support recursion
* Code must be "reentrant", which means multiple simultaneous instantiations of single procedure.
* Need some place to store ***state*** of each instantiation: (**args**, **local variables**, **return pointer**)
In order to get this, **stack discipline** is used. state for given procedure needed for limited time(from called to return): Calle returns before caller does.
Stack allocated in **frames**, state for single procdure instantiation.
When function is called, a new stack frame is created above stack top. And then when the function is returned, a corresponding frame is popped. and return to previous call state.
#### Stack Frame
is consist of **return information**, **local storage(if needed)** and **temporary space(if needed)**.
* `%rbp` frame pointer
* `%rsp` stack pointer
Space allocated when enter procedure, "set-up" code and includes push by `call`.
Deallocated when return, "finish" code and includes pop by `ret`.
#### x86-64/Linux Stack Frame
* for compile w/o *stack canary*, add option `-fno-stack-protector`
```c {cmd=gcc args=[-Og -x c -fno-stack-protector -c $input_file -o 3_13.o]}
long incr(long *p, long val) {
long x = *p;
long y = x + val;
*p = y;
return x;
}
long call_incr() {
long v1 = 15213;
long v2 = incr(&v1, 3000);
return v1 + v2;
}
```
```sh {cmd hide}
while ! [ -r 3_13.o ]; do sleep .1; done; objdump -d 3_13.o -Msuffix
```