From 5e5cce81240b39c6068380cd786ac59c2ce88c07 Mon Sep 17 00:00:00 2001 From: "David A. Mellis" Date: Sat, 7 May 2011 18:17:32 -0400 Subject: Optimizing printing of numbers (writing a single buffer). Fix from Bill Greiman via Limor. --- cores/arduino/Print.cpp | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) (limited to 'cores/arduino/Print.cpp') diff --git a/cores/arduino/Print.cpp b/cores/arduino/Print.cpp index eac145f..0a580b7 100755 --- a/cores/arduino/Print.cpp +++ b/cores/arduino/Print.cpp @@ -179,25 +179,23 @@ void Print::println(double n, int digits) // Private Methods ///////////////////////////////////////////////////////////// -void Print::printNumber(unsigned long n, uint8_t base) -{ - unsigned char buf[8 * sizeof(long)]; // Assumes 8-bit chars. - unsigned long i = 0; +void Print::printNumber(unsigned long n, uint8_t base) { + char buf[8 * sizeof(long) + 1]; // Assumes 8-bit chars plus zero byte. + char *str = &buf[sizeof(buf) - 1]; - if (n == 0) { - print('0'); - return; - } + *str = '\0'; + + // prevent crash if called with base == 1 + if (base < 2) base = 10; - while (n > 0) { - buf[i++] = n % base; + do { + unsigned long m = n; n /= base; - } + char c = m - base * n; + *--str = c < 10 ? c + '0' : c + 'A' - 10; + } while(n); - for (; i > 0; i--) - print((char) (buf[i - 1] < 10 ? - '0' + buf[i - 1] : - 'A' + buf[i - 1] - 10)); + write(str); } void Print::printFloat(double number, uint8_t digits) -- cgit v1.2.3-18-g5258