Add all-your-base exercise

config.json

@@ -121,6 +121,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 4
+      },
+      {
+        "slug": "all-your-base",
+        "name": "All Your Base",
+        "uuid": "4e3f2d32-a052-45c2-ba97-2e2584d55650",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 5
       }
     ]
   },

exercises/practice/all-your-base/.docs/instructions.md

@@ -0,0 +1,28 @@
+# Instructions
+
+Convert a sequence of digits in one base, representing a number, into a sequence of digits in another base, representing the same number.
+
+~~~~exercism/note
+Try to implement the conversion yourself.
+Do not use something else to perform the conversion for you.
+~~~~
+
+## About [Positional Notation][positional-notation]
+
+In positional notation, a number in base **b** can be understood as a linear combination of powers of **b**.
+
+The number 42, _in base 10_, means:
+
+`(4 × 10¹) + (2 × 10⁰)`
+
+The number 101010, _in base 2_, means:
+
+`(1 × 2⁵) + (0 × 2⁴) + (1 × 2³) + (0 × 2²) + (1 × 2¹) + (0 × 2⁰)`
+
+The number 1120, _in base 3_, means:
+
+`(1 × 3³) + (1 × 3²) + (2 × 3¹) + (0 × 3⁰)`
+
+_Yes. Those three numbers above are exactly the same. Congratulations!_
+
+[positional-notation]: https://en.wikipedia.org/wiki/Positional_notation

exercises/practice/all-your-base/.docs/introduction.md

@@ -0,0 +1,8 @@
+# Introduction
+
+You've just been hired as professor of mathematics.
+Your first week went well, but something is off in your second week.
+The problem is that every answer given by your students is wrong!
+Luckily, your math skills have allowed you to identify the problem: the student answers _are_ correct, but they're all in base 2 (binary)!
+Amazingly, it turns out that each week, the students use a different base.
+To help you quickly verify the student answers, you'll be building a tool to translate between bases.

exercises/practice/all-your-base/.meta/config.json

@@ -0,0 +1,17 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "all_your_base.s"
+    ],
+    "test": [
+      "all_your_base_test.c"
+    ],
+    "example": [
+      ".meta/example.s"
+    ]
+  },
+  "blurb": "Convert a number, represented as a sequence of digits in one base, to any other base."
+}

exercises/practice/all-your-base/.meta/example.s

@@ -0,0 +1,58 @@
+.equ BAD_BASE, -1
+.equ BAD_DIGIT, -2
+
+.text
+.globl rebase
+
+/* extern int rebase(int32_t in_base, const int32_t* in_digits, int in_digit_count, int32_t out_base, int32_t* out_digits); */
+rebase:
+        cmp     w0, #2                  /* minimum valid base */
+        blt     .bad_base
+
+        cmp     w3, #2
+        blt     .bad_base
+
+        mov     x5, #0                  /* value represented by digits */
+        mov     x7, x4                  /* output pointer */
+
+.read:
+        cbz     x2, .write
+        ldr     w6, [x1], 4             /* load input digit, post-increment */
+        cmp     w6, w0
+        bhs     .bad_digit              /* unsigned >= */
+
+        madd    x5, x0, x5, x6          /* in_base * value + digit */
+        sub     x2, x2, #1              /* decrement number of digits remaining */
+        b       .read
+
+.bad_base:
+        mov     x0, BAD_BASE
+        ret
+
+.bad_digit:
+        mov     x0, BAD_DIGIT
+        ret
+
+.write:
+        udiv    x1, x5, x3              /* divide value by out_base */
+        msub    x6, x1, x3, x5          /* remainder, i.e. output digit */
+        str     w6, [x7], #4            /* store, post-increment */
+        mov     x5, x1
+        cbnz    x5, .write              /* loop until value is 0 */
+
+        sub     x0, x7, x4              /* length of output, in bytes */
+        lsr     x0, x0, #2
+
+.reverse:
+        ldr     w1, [x7, #-4]!          /* load, pre-decrement */
+        cmp     x7, x4
+        beq     .return
+
+        ldr     w2, [x4]
+        str     w2, [x7]
+        str     w1, [x4], #4            /* store, post-increment */
+        cmp     x7, x4
+        bne     .reverse
+
+.return:
+        ret

exercises/practice/all-your-base/.meta/tests.toml

@@ -0,0 +1,73 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[5ce422f9-7a4b-4f44-ad29-49c67cb32d2c]
+description = "single bit one to decimal"
+
+[0cc3fea8-bb79-46ac-a2ab-5a2c93051033]
+description = "binary to single decimal"
+
+[f12db0f9-0d3d-42c2-b3ba-e38cb375a2b8]
+description = "single decimal to binary"
+
+[2c45cf54-6da3-4748-9733-5a3c765d925b]
+description = "binary to multiple decimal"
+
+[65ddb8b4-8899-4fcc-8618-181b2cf0002d]
+description = "decimal to binary"
+
+[8d418419-02a7-4824-8b7a-352d33c6987e]
+description = "trinary to hexadecimal"
+
+[d3901c80-8190-41b9-bd86-38d988efa956]
+description = "hexadecimal to trinary"
+
+[5d42f85e-21ad-41bd-b9be-a3e8e4258bbf]
+description = "15-bit integer"
+
+[d68788f7-66dd-43f8-a543-f15b6d233f83]
+description = "empty list"
+
+[5e27e8da-5862-4c5f-b2a9-26c0382b6be7]
+description = "single zero"
+
+[2e1c2573-77e4-4b9c-8517-6c56c5bcfdf2]
+description = "multiple zeros"
+
+[3530cd9f-8d6d-43f5-bc6e-b30b1db9629b]
+description = "leading zeros"
+
+[a6b476a1-1901-4f2a-92c4-4d91917ae023]
+description = "input base is one"
+
+[e21a693a-7a69-450b-b393-27415c26a016]
+description = "input base is zero"
+
+[54a23be5-d99e-41cc-88e0-a650ffe5fcc2]
+description = "input base is negative"
+
+[9eccf60c-dcc9-407b-95d8-c37b8be56bb6]
+description = "negative digit"
+
+[232fa4a5-e761-4939-ba0c-ed046cd0676a]
+description = "invalid positive digit"
+
+[14238f95-45da-41dc-95ce-18f860b30ad3]
+description = "output base is one"
+
+[73dac367-da5c-4a37-95fe-c87fad0a4047]
+description = "output base is zero"
+
+[13f81f42-ff53-4e24-89d9-37603a48ebd9]
+description = "output base is negative"
+
+[0e6c895d-8a5d-4868-a345-309d094cfe8d]
+description = "both bases are negative"

exercises/practice/all-your-base/Makefile

@@ -0,0 +1,36 @@
+AS = aarch64-linux-gnu-as
+CC = aarch64-linux-gnu-gcc
+
+CFLAGS = -g -Wall -Wextra -pedantic -Werror
+LDFLAGS =
+
+ALL_LDFLAGS = -pie -Wl,--fatal-warnings
+
+ALL_CFLAGS = -std=c99 -fPIE $(CFLAGS)
+ALL_LDFLAGS += $(LDFLAGS)
+
+C_OBJS = $(patsubst %.c,%.o,$(wildcard *.c))
+AS_OBJS = $(patsubst %.s,%.o,$(wildcard *.s))
+ALL_OBJS = $(filter-out example.o,$(C_OBJS) $(AS_OBJS) vendor/unity.o)
+
+CC_CMD = $(CC) $(ALL_CFLAGS) -c -o $@ $<
+
+all: tests
+	qemu-aarch64 -L /usr/aarch64-linux-gnu ./$<
+
+tests: $(ALL_OBJS)
+	@$(CC) $(ALL_CFLAGS) $(ALL_LDFLAGS) -o $@ $(ALL_OBJS)
+
+%.o: %.s
+	@$(AS) -o $@ $<
+
+%.o: %.c
+	@$(CC_CMD)
+
+vendor/unity.o: vendor/unity.c vendor/unity.h vendor/unity_internals.h
+	@$(CC_CMD)
+
+clean:
+	@rm -f *.o vendor/*.o tests
+
+.PHONY: all clean

exercises/practice/all-your-base/all_your_base.s

@@ -0,0 +1,8 @@
+.equ BAD_BASE, -1
+.equ BAD_DIGIT, -2
+
+.text
+.globl rebase
+
+rebase:
+    ret