Hardcode templating ~800ms

1 files changed, 15 insertions, 0 deletions

diff --git a/itoa_gen.py b/itoa_gen.py
new file mode 100644
index 0000000..0437c62
--- /dev/null
+++ b/itoa_gen.py
@@ -0,0 +1,15 @@
+with open("itoa_lut.h", "w") as f:
+    f.write("#include <stdint.h>\n")
+    f.write("typedef union { struct { char chars[3]; uint8_t len; } fields; uint32_t bits; } LutEntry;\n")
+    f.write("const uint32_t itoa_lut[256] = {")
+    out = []
+    for i in range(0, 256):
+        running=len(str(i))
+        for j in reversed(range(3)):
+            running = running << 8
+            if j < len(str(i)):
+                running += ord(str(i)[j])
+        out.append(hex(running))
+    f.write(", ".join(out))
+    f.write("};")
+