wip

- Remove printf() call on release builds. This is more deterministic
  than printf() modifiers. We only use it printing u64, f32 variables.
- Add unit tests.

.github/workflows/compile.yml

@@ -15,7 +15,7 @@ jobs:
     - name: install packages
       run: sudo apt-get install -y --no-install-recommends --no-install-suggests
            meson ninja-build
-           libevdev-dev liburing-dev
+           liburing-dev
            libwayland-dev libwayland-client0 wayland-protocols 
 
     - name: configure

.github/workflows/test.yml

@@ -0,0 +1,25 @@
+name: test
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: install packages
+      run: sudo apt-get install -y --no-install-recommends --no-install-suggests
+           meson ninja-build
+           liburing-dev
+           libwayland-dev libwayland-client0 wayland-protocols 
+
+    - name: configure
+      run: meson setup build --buildtype release -Dtest=true
+
+    - name: test
+      run: meson test -C build

include/assert.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#if GAMEPAD_IDLE_INHIBIT_DEBUG
+#define debug_assert(x)                                                                                                \
+  if (!(x)) {                                                                                                          \
+    __builtin_debugtrap();                                                                                             \
+  }
+#else
+#define debug_assert(x)
+#endif
+
+#define runtime_assert(x)                                                                                              \
+  if (!(x)) {                                                                                                          \
+    __builtin_trap();                                                                                                  \
+  }

include/math.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include "type.h"
+
+/*
+ * Returns binary logarithm of 𝑥.
+ *
+ *                           ctz(𝑥)         31^clz(𝑥)   clz(𝑥)
+ *       uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
+ *     0x00000000      wut       32        0      wut       32
+ *     0x00000001        0        0        1        0       31
+ *     0x80000001        0        0        1       31        0
+ *     0x80000000       31       31       32       31        0
+ *     0x00000010        4        4        5        4       27
+ *     0x08000010        4        4        5       27        4
+ *     0x08000000       27       27       28       27        4
+ *     0xffffffff        0        0        1       31        0
+ *
+ * @param x is a 64-bit integer
+ * @return number in range 0..63 or undefined if 𝑥 is 0
+ *
+ * @note Adapted from https://github.com/jart/cosmopolitan/blob/master/libc/intrin/bsrl.c
+ * @copyright
+ * ╒══════════════════════════════════════════════════════════════════════════════╕
+ * │ Copyright 2023 Justine Alexandra Roberts Tunney                              │
+ * │                                                                              │
+ * │ Permission to use, copy, modify, and/or distribute this software for         │
+ * │ any purpose with or without fee is hereby granted, provided that the         │
+ * │ above copyright notice and this permission notice appear in all copies.      │
+ * │                                                                              │
+ * │ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+ * │ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+ * │ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+ * │ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+ * │ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+ * │ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+ * │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+ * │ PERFORMANCE OF THIS SOFTWARE.                                                │
+ * └──────────────────────────────────────────────────────────────────────────────┘
+ */
+static inline u8
+bsrl(s64 x)
+{
+  static const u8 kDebruijn[64] = {
+      0,  47, 1,  56, 48, 27, 2,  60, 57, 49, 41, 37, 28, 16, 3,  61, 54, 58, 35, 52, 50, 42,
+      21, 44, 38, 32, 29, 23, 17, 11, 4,  62, 46, 55, 26, 59, 40, 36, 15, 53, 34, 51, 20, 43,
+      31, 22, 10, 45, 25, 39, 14, 33, 19, 30, 9,  24, 13, 18, 8,  12, 7,  6,  5,  63,
+  };
+
+  x |= x >> 1;
+  x |= x >> 2;
+  x |= x >> 4;
+  x |= x >> 8;
+  x |= x >> 16;
+  x |= x >> 32;
+  return kDebruijn[(x * 0x03f79d71b4cb0a89ull) >> 58];
+}