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[Qemu-block] [PATCH 2/2] vhdx: Simplify vhdx_set_shift_bits()
From: |
Max Reitz |
Subject: |
[Qemu-block] [PATCH 2/2] vhdx: Simplify vhdx_set_shift_bits() |
Date: |
Fri, 18 Dec 2015 16:04:26 +0100 |
For values which are powers of two (and we do assume all of these to
be), sizeof(x) * 8 - 1 - clz(x) == ctz(x). Therefore, use ctz().
Signed-off-by: Max Reitz <address@hidden>
---
block/vhdx.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/block/vhdx.c b/block/vhdx.c
index 3955f7f..475f602 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -263,10 +263,10 @@ static void vhdx_region_unregister_all(BDRVVHDXState *s)
static void vhdx_set_shift_bits(BDRVVHDXState *s)
{
- s->logical_sector_size_bits = 31 - clz32(s->logical_sector_size);
- s->sectors_per_block_bits = 31 - clz32(s->sectors_per_block);
- s->chunk_ratio_bits = 63 - clz64(s->chunk_ratio);
- s->block_size_bits = 31 - clz32(s->block_size);
+ s->logical_sector_size_bits = ctz32(s->logical_sector_size);
+ s->sectors_per_block_bits = ctz32(s->sectors_per_block);
+ s->chunk_ratio_bits = ctz64(s->chunk_ratio);
+ s->block_size_bits = ctz32(s->block_size);
}
/*
--
2.6.4