From 292eb365c6175f996dff4a9ef94f0bdf2c4b3dfe Mon Sep 17 00:00:00 2001 From: AnHardt Date: Thu, 15 Dec 2016 12:50:22 +0100 Subject: [PATCH] Optimize handling of block_buffer_runtime() millis_t is long - divisions take for ever. Return a kind of millisecond instead of microsecond - divided by 1024 instead of 1000 for speed. (2.4% error) That does not matter because block_buffer_runtime is already a too short estimation. Shrink the return-type. --- Marlin/planner.h | 8 +++++++- Marlin/ultralcd.cpp | 9 +++++---- 2 files changed, 12 insertions(+), 5 deletions(-) diff --git a/Marlin/planner.h b/Marlin/planner.h index d9b87afc63..aeacedba25 100644 --- a/Marlin/planner.h +++ b/Marlin/planner.h @@ -395,10 +395,16 @@ class Planner { #if ENABLED(ULTRA_LCD) - static millis_t block_buffer_runtime() { + static uint16_t block_buffer_runtime() { CRITICAL_SECTION_START millis_t bbru = block_buffer_runtime_us; CRITICAL_SECTION_END + // To translate µs to ms a division by 1000 would be required. + // We introduce 2.4% error here by dividing by 1024. + // Doesn't matter because block_buffer_runtime_us is already too small an estimation. + bbru >>= 10; + // limit to about a minute. + NOMORE(bbru, 0xfffful); return bbru; } diff --git a/Marlin/ultralcd.cpp b/Marlin/ultralcd.cpp index 4da0ae4ebd..e234c27bad 100755 --- a/Marlin/ultralcd.cpp +++ b/Marlin/ultralcd.cpp @@ -64,7 +64,7 @@ void lcd_status_screen(); millis_t next_lcd_update_ms; uint8_t lcdDrawUpdate = LCDVIEW_CLEAR_CALL_REDRAW; // Set when the LCD needs to draw, decrements after every draw. Set to 2 in LCD routines so the LCD gets at least 1 full redraw (first redraw is partial) -millis_t max_display_update_time = 0; +uint16_t max_display_update_time = 0; #if ENABLED(DOGLCD) bool drawing_screen = false; @@ -2978,12 +2978,13 @@ void lcd_update() { lcdDrawUpdate = LCDVIEW_REDRAW_NOW; } - millis_t bbr = planner.block_buffer_runtime(); + // then we want to use 1/2 of the time only. + uint16_t bbr2 = planner.block_buffer_runtime() >> 1; #if ENABLED(DOGLCD) - if ((lcdDrawUpdate || drawing_screen) && (!bbr || (bbr > 2 * max_display_update_time * 1000))) + if ((lcdDrawUpdate || drawing_screen) && (!bbr2 || (bbr2 > max_display_update_time))) #else - if (lcdDrawUpdate && (!bbr || (bbr > 2 * max_display_update_time * 1000))) + if (lcdDrawUpdate && (!bbr2 || (bbr2 > max_display_update_time))) #endif { #if ENABLED(DOGLCD)