From aa380d4323bcc4dae0f8bafdd074466f8bc5bcf5 Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Sat, 5 Jan 2013 17:36:04 +0100
Subject: [PATCH 086/364] * grub-core/fs/ntfs.c: Eliminate useless
divisions in favor of shifts. * grub-core/fs/ntfscomp.c: Likewise. *
include/grub/ntfs.h (grub_ntfs_data): Replace spc with log_spc.
(grub_ntfs_comp): Likewise.
---
ChangeLog | 7 +++++++
grub-core/fs/ntfs.c | 47 ++++++++++++++++++++++++-----------------------
grub-core/fs/ntfscomp.c | 39 ++++++++++++++++++++-------------------
include/grub/ntfs.h | 6 ++++--
4 files changed, 55 insertions(+), 44 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index ea191b3..88fd763 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
2013-01-05 Vladimir Serbinenko <phcoder@gmail.com>
+ * grub-core/fs/ntfs.c: Eliminate useless divisions in favor of shifts.
+ * grub-core/fs/ntfscomp.c: Likewise.
+ * include/grub/ntfs.h (grub_ntfs_data): Replace spc with log_spc.
+ (grub_ntfs_comp): Likewise.
+
+2013-01-05 Vladimir Serbinenko <phcoder@gmail.com>
+
* grub-core/fs/nilfs2.c (-grub_nilfs2_palloc_groups_per_desc_block):
Rename to ...
(grub_nilfs2_palloc_log_groups_per_desc_block): ... this. Return log
diff --git a/grub-core/fs/ntfs.c b/grub-core/fs/ntfs.c
index b9762b6..6004e1f 100644
--- a/grub-core/fs/ntfs.c
+++ b/grub-core/fs/ntfs.c
@@ -391,7 +391,7 @@ read_data (struct grub_ntfs_attr *at, char *pa, char *dest,
grub_memset (&cc, 0, sizeof (cc));
ctx = &cc;
ctx->attr = at;
- ctx->comp.spc = at->mft->data->spc;
+ ctx->comp.log_spc = at->mft->data->log_spc;
ctx->comp.disk = at->mft->data->disk;
if (pa[8] == 0)
@@ -440,11 +440,11 @@ read_data (struct grub_ntfs_attr *at, char *pa, char *dest,
at->save_pos = 1;
}
- vcn = ctx->target_vcn = (ofs >> GRUB_NTFS_COM_LOG_LEN) * (GRUB_NTFS_COM_SEC / ctx->comp.spc);
+ vcn = ctx->target_vcn = (ofs >> GRUB_NTFS_COM_LOG_LEN) * (GRUB_NTFS_COM_SEC >> ctx->comp.log_spc);
ctx->target_vcn &= ~0xFULL;
}
else
- vcn = ctx->target_vcn = grub_divmod64 (ofs >> GRUB_NTFS_BLK_SHR, ctx->comp.spc, 0);
+ vcn = ctx->target_vcn = ofs >> (GRUB_NTFS_BLK_SHR + ctx->comp.log_spc);
ctx->next_vcn = u32at (pa, 0x10);
ctx->curr_lcn = 0;
@@ -459,17 +459,17 @@ read_data (struct grub_ntfs_attr *at, char *pa, char *dest,
grub_disk_addr_t st0, st1;
grub_uint64_t m;
- grub_divmod64 (ofs >> GRUB_NTFS_BLK_SHR, ctx->comp.spc, &m);
+ m = (ofs >> GRUB_NTFS_BLK_SHR) & ((1 << ctx->comp.log_spc) - 1);
st0 =
- (ctx->target_vcn - ctx->curr_vcn + ctx->curr_lcn) * ctx->comp.spc + m;
+ ((ctx->target_vcn - ctx->curr_vcn + ctx->curr_lcn) << ctx->comp.log_spc) + m;
st1 = st0 + 1;
if (st1 ==
- (ctx->next_vcn - ctx->curr_vcn + ctx->curr_lcn) * ctx->comp.spc)
+ (ctx->next_vcn - ctx->curr_vcn + ctx->curr_lcn) << ctx->comp.log_spc)
{
if (grub_ntfs_read_run_list (ctx))
return grub_errno;
- st1 = ctx->curr_lcn * ctx->comp.spc;
+ st1 = ctx->curr_lcn << ctx->comp.log_spc;
}
grub_set_unaligned32 (dest, grub_cpu_to_le32 (st0));
grub_set_unaligned32 (dest + 4, grub_cpu_to_le32 (st1));
@@ -478,12 +478,10 @@ read_data (struct grub_ntfs_attr *at, char *pa, char *dest,
if (!(ctx->flags & GRUB_NTFS_RF_COMP))
{
- unsigned int pow;
-
- if (!grub_fshelp_log2blksize (ctx->comp.spc, &pow))
- grub_fshelp_read_file (ctx->comp.disk, (grub_fshelp_node_t) ctx,
- read_hook, ofs, len, dest,
- grub_ntfs_read_block, ofs + len, pow, 0);
+ grub_fshelp_read_file (ctx->comp.disk, (grub_fshelp_node_t) ctx,
+ read_hook, ofs, len, dest,
+ grub_ntfs_read_block, ofs + len,
+ ctx->comp.log_spc, 0);
return grub_errno;
}
@@ -515,11 +513,11 @@ read_attr (struct grub_ntfs_attr *at, char *dest, grub_disk_addr_t ofs,
/* If compression is possible make sure that we include possible
compressed block size. */
- if (GRUB_NTFS_COM_SEC >= at->mft->data->spc)
+ if (GRUB_NTFS_LOG_COM_SEC >= at->mft->data->log_spc)
vcn = ((ofs >> GRUB_NTFS_COM_LOG_LEN)
- * (GRUB_NTFS_COM_SEC / at->mft->data->spc)) & ~0xFULL;
+ << (GRUB_NTFS_LOG_COM_SEC - at->mft->data->log_spc)) & ~0xFULL;
else
- vcn = grub_divmod64 (ofs, at->mft->data->spc << GRUB_NTFS_BLK_SHR, 0);
+ vcn = ofs >> (at->mft->data->log_spc + GRUB_NTFS_BLK_SHR);
pa = at->attr_nxt + u16at (at->attr_nxt, 4);
while (pa < at->attr_end)
{
@@ -934,6 +932,7 @@ grub_ntfs_mount (grub_disk_t disk)
{
struct grub_ntfs_bpb bpb;
struct grub_ntfs_data *data = 0;
+ grub_uint32_t spc;
if (!disk)
goto fail;
@@ -955,23 +954,25 @@ grub_ntfs_mount (grub_disk_t disk)
|| (bpb.bytes_per_sector & (bpb.bytes_per_sector - 1)) != 0)
goto fail;
- data->spc = (((grub_uint32_t) bpb.sectors_per_cluster
- * (grub_uint32_t) grub_le_to_cpu16 (bpb.bytes_per_sector))
- >> GRUB_NTFS_BLK_SHR);
- if (!data->spc)
+ spc = (((grub_uint32_t) bpb.sectors_per_cluster
+ * (grub_uint32_t) grub_le_to_cpu16 (bpb.bytes_per_sector))
+ >> GRUB_NTFS_BLK_SHR);
+ if (spc == 0 || (spc & (spc - 1)))
goto fail;
+ for (data->log_spc = 0; (1U << data->log_spc) < spc; data->log_spc++);
+
if (bpb.clusters_per_mft > 0)
- data->mft_size = data->spc * bpb.clusters_per_mft;
+ data->mft_size = bpb.clusters_per_mft << data->log_spc;
else
data->mft_size = 1 << (-bpb.clusters_per_mft - GRUB_NTFS_BLK_SHR);
if (bpb.clusters_per_index > 0)
- data->idx_size = data->spc * bpb.clusters_per_index;
+ data->idx_size = bpb.clusters_per_index << data->log_spc;
else
data->idx_size = 1 << (-bpb.clusters_per_index - GRUB_NTFS_BLK_SHR);
- data->mft_start = grub_le_to_cpu64 (bpb.mft_lcn) * data->spc;
+ data->mft_start = grub_le_to_cpu64 (bpb.mft_lcn) << data->log_spc;
if ((data->mft_size > GRUB_NTFS_MAX_MFT) || (data->idx_size > GRUB_NTFS_MAX_IDX))
goto fail;
diff --git a/grub-core/fs/ntfscomp.c b/grub-core/fs/ntfscomp.c
index ec359fa..9b3b75d 100644
--- a/grub-core/fs/ntfscomp.c
+++ b/grub-core/fs/ntfscomp.c
@@ -33,8 +33,9 @@ decomp_nextvcn (struct grub_ntfs_comp *cc)
if (grub_disk_read
(cc->disk,
(cc->comp_table[cc->comp_head].next_lcn -
- (cc->comp_table[cc->comp_head].next_vcn - cc->cbuf_vcn)) * cc->spc, 0,
- cc->spc << GRUB_NTFS_BLK_SHR, cc->cbuf))
+ (cc->comp_table[cc->comp_head].next_vcn - cc->cbuf_vcn)) << cc->log_spc,
+ 0,
+ 1 << (cc->log_spc + GRUB_NTFS_BLK_SHR), cc->cbuf))
return grub_errno;
cc->cbuf_vcn++;
if ((cc->cbuf_vcn >= cc->comp_table[cc->comp_head].next_vcn))
@@ -46,7 +47,7 @@ decomp_nextvcn (struct grub_ntfs_comp *cc)
static grub_err_t
decomp_getch (struct grub_ntfs_comp *cc, unsigned char *res)
{
- if (cc->cbuf_ofs >= (cc->spc << GRUB_NTFS_BLK_SHR))
+ if (cc->cbuf_ofs >= (1U << (cc->log_spc + GRUB_NTFS_BLK_SHR)))
{
if (decomp_nextvcn (cc))
return grub_errno;
@@ -159,7 +160,7 @@ decomp_block (struct grub_ntfs_comp *cc, char *dest)
{
int n;
- n = (cc->spc << GRUB_NTFS_BLK_SHR) - cc->cbuf_ofs;
+ n = (1 << (cc->log_spc + GRUB_NTFS_BLK_SHR)) - cc->cbuf_ofs;
if (n > cnt)
n = cnt;
if ((dest) && (n))
@@ -178,7 +179,7 @@ decomp_block (struct grub_ntfs_comp *cc, char *dest)
static grub_err_t
read_block (struct grub_ntfs_rlst *ctx, char *buf, grub_size_t num)
{
- int cpb = GRUB_NTFS_COM_SEC / ctx->comp.spc;
+ int log_cpb = GRUB_NTFS_LOG_COM_SEC - ctx->comp.log_spc;
while (num)
{
@@ -192,7 +193,7 @@ read_block (struct grub_ntfs_rlst *ctx, char *buf, grub_size_t num)
return grub_error (GRUB_ERR_BAD_FS, "invalid compression block");
ctx->comp.comp_head = ctx->comp.comp_tail = 0;
ctx->comp.cbuf_vcn = ctx->target_vcn;
- ctx->comp.cbuf_ofs = (ctx->comp.spc << GRUB_NTFS_BLK_SHR);
+ ctx->comp.cbuf_ofs = (1 << (ctx->comp.log_spc + GRUB_NTFS_BLK_SHR));
if (ctx->target_vcn >= ctx->next_vcn)
{
if (grub_ntfs_read_run_list (ctx))
@@ -211,14 +212,14 @@ read_block (struct grub_ntfs_rlst *ctx, char *buf, grub_size_t num)
}
}
- nn = (16 - (unsigned) (ctx->target_vcn & 0xF)) / cpb;
+ nn = (16 - (unsigned) (ctx->target_vcn & 0xF)) >> log_cpb;
if (nn > num)
nn = num;
num -= nn;
if (ctx->flags & GRUB_NTFS_RF_BLNK)
{
- ctx->target_vcn += nn * cpb;
+ ctx->target_vcn += nn << log_cpb;
if (ctx->comp.comp_tail == 0)
{
if (buf)
@@ -241,7 +242,7 @@ read_block (struct grub_ntfs_rlst *ctx, char *buf, grub_size_t num)
}
else
{
- nn *= cpb;
+ nn <<= log_cpb;
while ((ctx->comp.comp_head < ctx->comp.comp_tail) && (nn))
{
grub_disk_addr_t tt;
@@ -258,10 +259,10 @@ read_block (struct grub_ntfs_rlst *ctx, char *buf, grub_size_t num)
(ctx->comp.disk,
(ctx->comp.comp_table[ctx->comp.comp_head].next_lcn -
(ctx->comp.comp_table[ctx->comp.comp_head].next_vcn -
- ctx->target_vcn)) * ctx->comp.spc, 0,
- tt * (ctx->comp.spc << GRUB_NTFS_BLK_SHR), buf))
+ ctx->target_vcn)) << ctx->comp.log_spc, 0,
+ tt << (ctx->comp.log_spc + GRUB_NTFS_BLK_SHR), buf))
return grub_errno;
- buf += tt * (ctx->comp.spc << GRUB_NTFS_BLK_SHR);
+ buf += tt << (ctx->comp.log_spc + GRUB_NTFS_BLK_SHR);
}
nn -= tt;
if (ctx->target_vcn >=
@@ -275,10 +276,10 @@ read_block (struct grub_ntfs_rlst *ctx, char *buf, grub_size_t num)
if (grub_disk_read
(ctx->comp.disk,
(ctx->target_vcn - ctx->curr_vcn +
- ctx->curr_lcn) * ctx->comp.spc, 0,
- nn * (ctx->comp.spc << GRUB_NTFS_BLK_SHR), buf))
+ ctx->curr_lcn) << ctx->comp.log_spc, 0,
+ nn << (ctx->comp.log_spc + GRUB_NTFS_BLK_SHR), buf))
return grub_errno;
- buf += nn * (ctx->comp.spc << GRUB_NTFS_BLK_SHR);
+ buf += nn << (ctx->comp.log_spc + GRUB_NTFS_BLK_SHR);
}
ctx->target_vcn += nn;
}
@@ -294,7 +295,7 @@ ntfscomp (struct grub_ntfs_attr *at, char *dest, grub_disk_addr_t ofs,
grub_err_t ret;
ctx->comp.comp_head = ctx->comp.comp_tail = 0;
- ctx->comp.cbuf = grub_malloc ((ctx->comp.spc) << GRUB_NTFS_BLK_SHR);
+ ctx->comp.cbuf = grub_malloc (1 << (ctx->comp.log_spc + GRUB_NTFS_BLK_SHR));
if (!ctx->comp.cbuf)
return 0;
@@ -304,7 +305,7 @@ ntfscomp (struct grub_ntfs_attr *at, char *dest, grub_disk_addr_t ofs,
if ((vcn > ctx->target_vcn) &&
(read_block
- (ctx, NULL, ((vcn - ctx->target_vcn) * ctx->comp.spc) / GRUB_NTFS_COM_SEC)))
+ (ctx, NULL, (vcn - ctx->target_vcn) >> (GRUB_NTFS_LOG_COM_SEC - ctx->comp.log_spc))))
{
ret = grub_errno;
goto quit;
@@ -314,7 +315,7 @@ ntfscomp (struct grub_ntfs_attr *at, char *dest, grub_disk_addr_t ofs,
{
grub_uint32_t t, n, o;
- t = ctx->target_vcn * (ctx->comp.spc << GRUB_NTFS_BLK_SHR);
+ t = ctx->target_vcn << (ctx->comp.log_spc + GRUB_NTFS_BLK_SHR);
if (read_block (ctx, at->sbuf, 1))
{
ret = grub_errno;
@@ -346,7 +347,7 @@ ntfscomp (struct grub_ntfs_attr *at, char *dest, grub_disk_addr_t ofs,
{
grub_uint32_t t;
- t = ctx->target_vcn * (ctx->comp.spc << GRUB_NTFS_BLK_SHR);
+ t = ctx->target_vcn << (ctx->comp.log_spc + GRUB_NTFS_BLK_SHR);
if (read_block (ctx, at->sbuf, 1))
{
ret = grub_errno;
diff --git a/include/grub/ntfs.h b/include/grub/ntfs.h
index 0935342..cc28a01 100644
--- a/include/grub/ntfs.h
+++ b/include/grub/ntfs.h
@@ -87,6 +87,7 @@ enum
#define GRUB_NTFS_COM_LEN 4096
#define GRUB_NTFS_COM_LOG_LEN 12
#define GRUB_NTFS_COM_SEC (GRUB_NTFS_COM_LEN >> GRUB_NTFS_BLK_SHR)
+#define GRUB_NTFS_LOG_COM_SEC (GRUB_NTFS_COM_LOG_LEN - GRUB_NTFS_BLK_SHR)
enum
{
@@ -156,7 +157,7 @@ struct grub_ntfs_data
grub_disk_t disk;
grub_uint32_t mft_size;
grub_uint32_t idx_size;
- grub_uint32_t spc;
+ int log_spc;
grub_uint32_t mft_start;
grub_uint64_t uuid;
};
@@ -172,7 +173,8 @@ struct grub_ntfs_comp
grub_disk_t disk;
int comp_head, comp_tail;
struct grub_ntfs_comp_table_element comp_table[16];
- grub_uint32_t cbuf_ofs, cbuf_vcn, spc;
+ grub_uint32_t cbuf_ofs, cbuf_vcn;
+ int log_spc;
char *cbuf;
};
--
1.8.1.4