[hackers] [st] optimize column width calculation and utf-8 encode for ASCII || Hiltjo Posthuma

[git]

commit cde480c6939e62771ba3b60ef4eb848031aee9f9
Author:     Hiltjo Posthuma <hil...@codemadness.org>
AuthorDate: Sat May 9 14:03:14 2020 +0200
Commit:     Hiltjo Posthuma <hil...@codemadness.org>
CommitDate: Sat May 9 14:11:25 2020 +0200

    optimize column width calculation and utf-8 encode for ASCII
    
    In particular on OpenBSD and on glibc wcwidth() is quite expensive.
    On musl there is little difference.

diff --git a/st.c b/st.c
index 5d4054f..1414f98 100644
--- a/st.c
+++ b/st.c
@@ -2307,7 +2307,7 @@ tputc(Rune u)
        Glyph *gp;
 
        control = ISCONTROL(u);
-       if (!IS_SET(MODE_UTF8 | MODE_SIXEL)) {
+       if (u < 127 || !IS_SET(MODE_UTF8 | MODE_SIXEL)) {
                c[0] = u;
                width = len = 1;
        } else {