From 17416eaff2bee8f81a094fb2805a2f1920c81a5e Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sun, 2 Jun 2019 00:04:50 +0200 Subject: [PATCH] disk: part: avoid undefined reference to `__udivmoddi4' When compiling with FTRACE=1 an error ld.bfd: disk/built-in.o: in function `lba512_muldiv': disk/part.c:114: undefined reference to `__udivmoddi4 occurred. Use '>> 11' instead of '/ 2048' to avoid the division. Signed-off-by: Heinrich Schuchardt --- disk/part.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/disk/part.c b/disk/part.c index 98cc54db20..862078f3e7 100644 --- a/disk/part.c +++ b/disk/part.c @@ -103,17 +103,17 @@ typedef lbaint_t lba512_t; #endif /* - * Overflowless variant of (block_count * mul_by / div_by) + * Overflowless variant of (block_count * mul_by / 2**div_by) * when div_by > mul_by */ -static lba512_t lba512_muldiv(lba512_t block_count, lba512_t mul_by, lba512_t div_by) +static lba512_t lba512_muldiv(lba512_t block_count, lba512_t mul_by, int div_by) { lba512_t bc_quot, bc_rem; /* x * m / d == x / d * m + (x % d) * m / d */ - bc_quot = block_count / div_by; - bc_rem = block_count - div_by * bc_quot; - return bc_quot * mul_by + (bc_rem * mul_by) / div_by; + bc_quot = block_count >> div_by; + bc_rem = block_count - (bc_quot << div_by); + return bc_quot * mul_by + ((bc_rem * mul_by) >> div_by); } void dev_print (struct blk_desc *dev_desc) @@ -193,7 +193,7 @@ void dev_print (struct blk_desc *dev_desc) lba512 = (lba * (dev_desc->blksz/512)); /* round to 1 digit */ /* 2048 = (1024 * 1024) / 512 MB */ - mb = lba512_muldiv(lba512, 10, 2048); + mb = lba512_muldiv(lba512, 10, 11); mb_quot = mb / 10; mb_rem = mb - (10 * mb_quot); -- 2.25.1