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7c7720a3ab
With this assumption, we can replace 'a % b' with 'a & (b - 1)'. In terms of instructions, this means a fast 'and' instead of a slow 'div'. Further optimize scrolling by: * not double-initializing empty rows. Previously, grid_row_alloc() called calloc(), which was then followed by a memset() when scrolling. This is of course unnecessary. * Don't loop the entire set of visible rows (this was done to ensure all visible rows had been allocated, and to prefetch the cell contents). This isn't necessary; only newly pulled in rows can be NULL. For now, don't prefetch at all.
55 lines
1.2 KiB
C
55 lines
1.2 KiB
C
#include "grid.h"
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//#include <string.h>
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#include <assert.h>
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#define LOG_MODULE "grid"
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#define LOG_ENABLE_DBG 0
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#include "log.h"
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void
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grid_swap_row(struct grid *grid, int row_a, int row_b, bool initialize)
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{
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assert(grid->offset >= 0);
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assert(row_a != row_b);
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int real_a = (grid->offset + row_a) & (grid->num_rows - 1);
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int real_b = (grid->offset + row_b) & (grid->num_rows - 1);
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struct row *a = grid->rows[real_a];
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struct row *b = grid->rows[real_b];
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#if 0
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if (a == NULL)
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a = grid_row_alloc(grid->num_cols, initialize);
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if (b == NULL)
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b = grid_row_alloc(grid->num_cols, initialize);
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#endif
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grid->rows[real_a] = b;
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grid->rows[real_b] = a;
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}
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struct row *
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grid_row_alloc(int cols, bool initialize)
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{
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struct row *row = malloc(sizeof(*row));
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row->dirty = false;
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if (initialize) {
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row->cells = calloc(cols, sizeof(row->cells[0]));
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for (size_t c = 0; c < cols; c++)
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row->cells[c].attrs.clean = 1;
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} else
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row->cells = malloc(cols * sizeof(row->cells[0]));
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return row;
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}
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void
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grid_row_free(struct row *row)
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{
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if (row == NULL)
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return;
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free(row->cells);
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free(row);
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}
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