6793

1 files changed, 83 insertions, 0 deletions

diff --git a/406try-divide.mu b/406try-divide.mu
new file mode 100644
index 00000000..9c7a0229
--- /dev/null
+++ b/406try-divide.mu
@@ -0,0 +1,83 @@
+# slow, iterative divide instruction
+# preconditions: _nr >= 0, _dr > 0
+fn try-divide _nr: int, _dr: int -> result/eax: int {
+  # x = next power-of-2 multiple of _dr after _nr
+  var x/ecx: int <- copy 1
+  {
+#?     print-int32-hex 0, x
+#?     print-string 0, "\n"
+    var tmp/edx: int <- copy _dr
+    tmp <- multiply x
+    compare tmp, _nr
+    break-if->
+    x <- shift-left 1
+    loop
+  }
+#?   print-string 0, "--\n"
+  # min, max = x/2, x
+  var max/ecx: int <- copy x
+  var min/edx: int <- copy max
+  min <- shift-right 1
+  # narrow down result between min and max
+  var i/eax: int <- copy min
+  {
+#?     print-int32-hex 0, i
+#?     print-string 0, "\n"
+    var foo/ebx: int <- copy _dr
+    foo <- multiply i
+    compare foo, _nr
+    break-if->
+    i <- increment
+    loop
+  }
+  result <- copy i
+  result <- decrement
+#?   print-string 0, "=> "
+#?   print-int32-hex 0, result
+#?   print-string 0, "\n"
+}
+
+fn test-try-divide-1 {
+  var result/eax: int <- try-divide 0, 2
+  check-ints-equal result, 0, "F - try-divide-1\n"
+}
+
+fn test-try-divide-2 {
+  var result/eax: int <- try-divide 1, 2
+  check-ints-equal result, 0, "F - try-divide-2\n"
+}
+
+fn test-try-divide-3 {
+  var result/eax: int <- try-divide 2, 2
+  check-ints-equal result, 1, "F - try-divide-3\n"
+}
+
+fn test-try-divide-4 {
+  var result/eax: int <- try-divide 4, 2
+  check-ints-equal result, 2, "F - try-divide-4\n"
+}
+
+fn test-try-divide-5 {
+  var result/eax: int <- try-divide 6, 2
+  check-ints-equal result, 3, "F - try-divide-5\n"
+}
+
+fn test-try-divide-6 {
+  var result/eax: int <- try-divide 9, 3
+  check-ints-equal result, 3, "F - try-divide-6\n"
+}
+
+fn test-try-divide-7 {
+  var result/eax: int <- try-divide 0xc, 4
+  check-ints-equal result, 3, "F - try-divide-7\n"
+}
+
+fn test-try-divide-8 {
+  var result/eax: int <- try-divide 0x1b, 3  # 27/3
+  check-ints-equal result, 9, "F - try-divide-8\n"
+}
+
+fn test-try-divide-9 {
+  var result/eax: int <- try-divide 0x1c, 3  # 28/3
+  check-ints-equal result, 9, "F - try-divide-9\n"
+}