libnum: num8 optimizations

libnum/include/num/num.h

@@ -98,16 +98,16 @@ struct num8
     /* Comparisons with int */
 
     inline constexpr bool operator==(int const &i) {
-        return i == 0 && v == 0;
+        return (v | i) == 0;
     }
     inline constexpr bool operator<(int const &i) {
         return i >= 1;
     }
     inline constexpr bool operator<=(int const &i) {
-        return *this < i || *this == i;
+        return i + !v > 0;
     }
     inline constexpr bool operator>(int const &i) {
-        return i + (v == 0) <= 0;
+        return i + !v <= 0;
     }
     inline constexpr bool operator>=(int const &i) {
         return i <= 0;
@@ -346,8 +346,8 @@ concept is_num =
 inline constexpr num8::num8(num16 n): v(n.v) {}
 /* Casting to unsigned allows the use of shlr instead of shad */
 inline constexpr num8::num8(num32 n): v((uint32_t)n.v >> 8) {}
-/* Slightly inefficient; acceses both longwords of n.v, only one is needed */
-inline constexpr num8::num8(num64 n): v(n.v >> 24) {}
+/* Casting to 32-bit eliminates the unused high word */
+inline constexpr num8::num8(num64 n): v((uint32_t)n.v >> 24) {}
 
 inline constexpr num16::num16(num8 n): v(n.v) {}
 /* Casting to unsigned allows the use of shlr instead of shad */

libnum/test/isel.py

@@ -416,7 +416,7 @@ def printRawFunction(asm, sybl):
     # Eliminate labels that are defined but unused
     RE_LABEL = re.compile(r"^(\.[a-zA-Z_][a-zA-Z0-9_]*):$", re.MULTILINE)
     for label in RE_LABEL.findall(func):
-        if func.count(f"{label}:\n") == 1:
+        if func.count(label) == 1:
             func = func.replace(f"{label}:\n", "")
 
     print(func.strip())

libnum/test/isel_num8.cpp

@@ -16,4 +16,35 @@ num8 num8_of_num32(num32 x)
     return num8(x);
 }
 
+// num8_of_num64: %<=2 && %=[shlr*||shad]
+num8 num8_of_num64(num64 x)
+{
+    return num8(x);
 }
+
+/* This requires sign extensions because we care about high bits */
+// num8_mul: %<=5
+num8 num8_mul(num8 x, num8 y)
+{
+    return x * y;
+}
+
+// num8_eq: [or] && ![bt* || bf*]
+bool num8_eq(num8 x, int i)
+{
+    return x == i;
+}
+
+// num8_le: ![bt* || bf*] && %<=4
+bool num8_le(num8 x, int i)
+{
+    return x <= i;
+}
+
+// num8_gt: ![bt* || bf*] && %<=4
+bool num8_gt(num8 x, int i)
+{
+    return x > i;
+}
+
+} /* extern "C" */