From 11f3e33f9bbb31330b1dc4a51c07f8c58aef2fdd Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Fri, 13 Apr 2012 04:38:56 -0400 Subject: [PATCH] use fast version of the int reading code for the high-order digits too this increases code size slightly, but it's considerably faster, especially for power-of-2 bases. --- src/internal/intparse.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/src/internal/intparse.c b/src/internal/intparse.c index e30a1a58..fba38c0a 100644 --- a/src/internal/intparse.c +++ b/src/internal/intparse.c @@ -83,9 +83,19 @@ int __intparse(struct intparse *v, const void *buf, size_t n) v->state++; v->val = v->small; case 5: - llim = UINTMAX_MAX/b; - for (; n && (d=digits[*s])val<=llim && d<=UINTMAX_MAX-v->val*b; n--, s++) - v->val = v->val * b + d; + if (b==10) { + for (; n && *s-'0'<10U && v->val<=UINTMAX_MAX/10 && (*s-'0')<=UINTMAX_MAX-10*v->val; n--, s++) + v->val = v->val * 10 + (*s-'0'); + } else if ((b&-b) == b) { + int bs = "\0\1\2\4\7\3\6\5"[(0x17*b)>>5&7]; + llim = UINTMAX_MAX>>bs; + for (; n && (d=digits[*s])val<=llim; n--, s++) + v->val = (v->val<val<=llim && d<=UINTMAX_MAX-b*v->val; n--, s++) + v->val = v->val * b + d; + } if (!n) return 1; if (d >= b) goto finished; v->state++; -- 2.20.1