From f463d544793ff83efd8b95d0bce5ec80fd8170f3 Mon Sep 17 00:00:00 2001 From: Miquel Sabaté Solà Date: Wed, 4 Dec 2024 21:42:37 +0100 Subject: Remove old test code MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There is some code that I had there after messing with some of the topics on Uros' blog (https://popovicu.com/), but that became irrelevant after working on some other projects (e.g. fbos) or on other examples. This commit also brings about a major overhaul on the structure of the project. Hopefully it's now at a more ready state. Signed-off-by: Miquel Sabaté Solà --- arch/riscv/usr/Makefile | 19 ------ arch/riscv/usr/basics.c | 162 --------------------------------------------- arch/riscv/usr/factorial.S | 28 -------- arch/riscv/usr/float.S | 40 ----------- arch/riscv/usr/string.S | 111 ------------------------------- 5 files changed, 360 deletions(-) delete mode 100644 arch/riscv/usr/Makefile delete mode 100644 arch/riscv/usr/basics.c delete mode 100644 arch/riscv/usr/factorial.S delete mode 100644 arch/riscv/usr/float.S delete mode 100644 arch/riscv/usr/string.S (limited to 'arch/riscv/usr') diff --git a/arch/riscv/usr/Makefile b/arch/riscv/usr/Makefile deleted file mode 100644 index b4752a3..0000000 --- a/arch/riscv/usr/Makefile +++ /dev/null @@ -1,19 +0,0 @@ -CC = $(CROSS_COMPILE)gcc -CCFLAGS = -EXE = basics - -DEBUG = -ifneq ($(strip $(DEBUG)),) - CCFLAGS += -g -endif - -.PHONY: all -all: clean $(EXE) - -.PHONY: $(EXE) -$(EXE): - $(CC) $(CCFLAGS) -o $(EXE) basics.c factorial.S string.S float.S - -.PHONY: clean -clean: - @rm -f $(EXE) diff --git a/arch/riscv/usr/basics.c b/arch/riscv/usr/basics.c deleted file mode 100644 index 1d822c3..0000000 --- a/arch/riscv/usr/basics.c +++ /dev/null @@ -1,162 +0,0 @@ -#include -#include -#include -#include -#include - -/* - * Returns the factorial for the given unsigned 64-bit integer. - * - * Implemented in factorial.S - */ -int factorial(uint64_t n); - -void test_factorial(void) -{ - assert(factorial(0) == 0); - assert(factorial(1) == 1); - assert(factorial(2) == 2); - assert(factorial(3) == 6); - assert(factorial(4) == 24); - - printf("factorial:\t\tOK\n"); -} - -/* - * Returns a pointer with the same given string but reversed. Note that the - * string cannot be in read-only space since the reversal is done in-place. - * - * Implemented in string.S - */ -char *reverse_string(char *str); - -void test_reverse_string(void) -{ - assert(reverse_string(NULL) == NULL); - assert(strlen(reverse_string("")) == 0); - - char s1[] = "This is a string."; - assert(strcmp(reverse_string(s1), ".gnirts a si sihT") == 0); - - char s2[] = "."; - assert(strcmp(reverse_string(s2), ".") == 0); - - printf("reverse_string:\t\tOK\n"); -} - -/* - * Returns true if the given string is a palindrome, false otherwise. - * - * Implemented in string.S - */ -bool is_palindrome(char *str); - -void test_is_palindrome(void) -{ - assert(is_palindrome(NULL) == 0); - assert(is_palindrome("") == 0); - assert(is_palindrome("aba") == 1); - assert(is_palindrome("aaa") == 1); - assert(is_palindrome("This is a a si sihT") == 1); - - printf("is_palindrome:\t\tOK\n"); -} - -/* - * This function computes the following: ((a + b) * b) + b. Don't try to make - * sense of it, that's the computation I ended up while messing with RISC-V - * floating point instructions. Anyways, with this in mind, it will return if - * the computed value is greater than 10. - * - * Implemented in float.S - */ -bool greater_than_ten(double a, uint64_t b); - -void test_greater_than_ten(void) -{ - assert(!greater_than_ten(2.3, 1)); // 4.3 - assert(greater_than_ten(2.3, 2)); // 10.6 - - printf("greater_than_ten:\tOK\n"); -} - -/* - * Atomically add the integer pointed by `a` with the given `value`. - * this is a function, I've checked that the assembly produced by GCC on a - * decent optimization level actually inlines this. - */ -static inline void atomic_add(uint64_t *a, uint64_t value) -{ - /* - * The execution is a mere `amoadd` instruction, but it will set on `t0` the - * result. If it fails (e.g. the address was already being used), then `t0 = - * 0` and `beqz` will instruct it to try again. - * - * Note that on the board I'm using the 'Zawrs' extension is not available. - * Otherwise I could have re-arranged to code to something like this: - * - * amoadd.d t0, %1, %0 - * bnez t0, .Latomic_add_done - * wrs.nto - * .Latomic_add_done: - * - * This is an extra instruction but it saves on power if the memory address - * happens to be used at access time. - * - * As for the 'A' RISC-V specific constraint, it means "An address that is - * held in a general-purpose register". GCC will then do the magic and - * convert it to `amoadd.d t0, a1, (a0)` or something like that. Note that - * we have to pass the '+' constraint modifier because the address will be - * both read and written atomically. - * - * See: https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html. - */ - asm volatile(".Latomic_add_retry:\n\t" - "amoadd.d t0, %1, %0\n\t" - "beqz t0, .Latomic_add_retry" - : "+A"(*a) - : "r"(value) - : "t0", "memory"); -} - -void test_atomic_add(void) -{ - uint64_t i = 4; - - atomic_add(&i, 0); - assert(i == 4); - - atomic_add(&i, 2); - assert(i == 6); - - printf("atomic_add:\t\tOK\n"); -} - -extern int mstrcmp(const char *s1, const char *s2); - -void test_mstrcmp(void) -{ - char *strings[] = { - "hello", "", "iello", "helloa", "contammusaaquellhomedegranarditquetantissimerra", - }; - - for (uint64_t i = 0; i < 1000000000; i++) { - assert(mstrcmp(strings[0], strings[0]) == 0); - assert(mstrcmp(strings[0], strings[1]) > 0); - assert(mstrcmp(strings[0], strings[2]) < 0); - assert(mstrcmp(strings[0], strings[3]) < 0); - assert(mstrcmp(strings[0], strings[4]) > 0); - } - - printf("mstrcmp:\t\tOK\n"); -} - -int main() -{ - test_factorial(); - test_reverse_string(); - test_is_palindrome(); - test_greater_than_ten(); - test_atomic_add(); - test_mstrcmp(); -} diff --git a/arch/riscv/usr/factorial.S b/arch/riscv/usr/factorial.S deleted file mode 100644 index 7e3df12..0000000 --- a/arch/riscv/usr/factorial.S +++ /dev/null @@ -1,28 +0,0 @@ -.text -.globl factorial -.type factorial, @function - -factorial: - // If input <= 1, just return the given thing. - addi t0, zero, 1 - bgt a0, t0, else - jr ra -else: - // Preserve the argument and the return address before the call. - addi sp, sp, -16 - sd a0, 0(sp) - sd ra, 8(sp) - - // Call the same function but with a value of argument-1. - addi a0, a0, -1 - call factorial - - // Restore back the original argument and the return address. Then multiply - // the original argument with the returned one from the previous call. - ld t1, 0(sp) - ld ra, 8(sp) - addi sp, sp, 16 - mul a0, t1, a0 - - // And return to the caller. - jr ra diff --git a/arch/riscv/usr/float.S b/arch/riscv/usr/float.S deleted file mode 100644 index f481f3e..0000000 --- a/arch/riscv/usr/float.S +++ /dev/null @@ -1,40 +0,0 @@ -.text -.globl greater_than_ten -.type greater_than_ten, @function - -// bool greater_than_ten(double a, uint64_t b); -greater_than_ten: - // Upon entry a -> fa0; and b -> a0. That is, the ABI increments the - //(f)a register per argument type. - - // Change the rounding to "Rounds Towards Zero" (bits: 0b001). - li t0, 0b001 - fsrm t0 - - // Convert the second parameter to double. - fcvt.d.lu ft0, a0 - - // ret = a + b - fadd.d fa0, fa0, ft0 - - // ret = (ret * b) + b - fmv.d ft1, ft0 - fmadd.d fa0, fa0, ft0, ft1 - - // Now we need to compare the number with 10.0. There are multiple ways to - // load a floating point immediate: - // 1. Loading an integer immediate and then convert it into a double. This - // is discouraged on the RISC-V assembly manual. - // 2. Load a double with `fld` from a memory location on the data section. - // 3. Load a floating point immediate with `fli` (requires the `Zfa` - // extension). - // I don't have the `Zfa` extension on my board, so I'm opting for the - // second way. - fld ft1, .TEN, t0 - fle.d a0, ft1, fa0 - - ret - -.data -.TEN: - .double 10.0 diff --git a/arch/riscv/usr/string.S b/arch/riscv/usr/string.S deleted file mode 100644 index 3878074..0000000 --- a/arch/riscv/usr/string.S +++ /dev/null @@ -1,111 +0,0 @@ -.text - -.globl reverse_string -.type reverse_string, @function - -// char * reverse_string(char *str); -reverse_string: - // Return early on null pointer. - beq a0, zero, end - - // Preserve the original pointer. - addi sp, sp, -8 - sd a0, 0(sp) - - // Set `t0` to point to the end of the string. - add t0, a0, zero -set_end_ptr: - lbu t2, 0(t0) - beq t2, zero, end_ptr_done - addi t0, t0, 1 - j set_end_ptr - - // We are done iterating, if `a0` and `t0` are equal, then there's nothing - // to be done and we can return early. Otherwise decrement `t0` so it points - // to the byte right before the null termination. -end_ptr_done: - beq a0, t0, reverse_done - addi t0, t0, -1 - -reverse_loop: - // Swap values between the two pointers. - lb t1, 0(a0) - lb t2, 0(t0) - sb t1, 0(t0) - sb t2, 0(a0) - - // Move pointers and check whether the pointers have already crossed. If - // they have not crossed yet there is still looping to be done. Otherwise - // we are done. - addi a0, a0, 1 - addi t0, t0, -1 - bltu a0, t0, reverse_loop - -reverse_done: - // Restore things back and return to the caller. - ld a0, 0(sp) - addi sp, sp, 8 -end: - jr ra - -.globl is_palindrome -.type is_palindrome, @function - -// bool is_palindrome(char *str); -is_palindrome: - // Return early on null pointer. - beq a0, zero, palindrome_no - - // Set `t0` to point to the end of the string. - add t0, a0, zero -pal_set_end_ptr: - lbu t2, 0(t0) - beq t2, zero, pal_end_ptr_done - addi t0, t0, 1 - j pal_set_end_ptr - - // We are done iterating, if `a0` and `t0` are equal, then there's nothing - // to be done and we can return early. Otherwise decrement `t0` so it points - // to the byte right before the null termination. -pal_end_ptr_done: - beq a0, t0, palindrome_no - addi t0, t0, -1 - -pal_loop: - // Swap values between the two pointers. - lb t1, 0(a0) - lb t2, 0(t0) - bne t1, t2, palindrome_no - - // Move pointers and check whether the pointers have already crossed. If - // they have not crossed yet there is still looping to be done. Otherwise - // we are done. - addi a0, a0, 1 - addi t0, t0, -1 - bleu a0, t0, pal_loop - -palindrome_yes: - li a0, 1 - jr ra - -palindrome_no: - li a0, 0 - jr ra - -.globl mstrcmp -.type mstrcmp, @function - -// int mstrcmp(const char *, const char *); -mstrcmp: -1: - lbu t0, 0(a0) - lbu t1, 0(a1) - bne t0, t1, 2f - addi a0, a0, 1 - addi a1, a1, 1 - bnez t0, 1b - li a0, 0 - ret -2: - sub a0, t0, t1 - ret -- cgit v1.2.3