Libgomp's usage of struct gomp_coalesce_buf is a little confusing. The
member chunks is an array where the even elements represent the starting
address of the chunk cache line and the odd elements represent the
corresponding ending addresses. This patch clarifies the usage of the
chunks member by introducing a new gomp_coalesce_chunk structure with
explicit start and end members. Beyond that, there's no functional
changes to this patch.
Is it OK for trunk? I tested it against x86_64-linux with nvptx
acceleration.
Thanks,
Cesar
2018-05-02 Cesar Philippidis <ce...@codesourcery.com>
libgomp/
* target.c (struct gomp_coalesce_chunk): New structure.
(struct gomp_coalesce_buf): Update the chunks member to use that
type.
(gomp_coalesce_buf_add): Update usage of chunks member.
(gomp_copy_host2dev): Likewise.
(gomp_map_vars): Likewise.
>From e67d2ca0abed0f5f9f1ec6ceda8200cf385ba7fd Mon Sep 17 00:00:00 2001
From: Cesar Philippidis <ce...@codesourcery.com>
Date: Tue, 1 May 2018 09:29:39 -0700
Subject: [PATCH] cleanup struct gomp_coalesce_buf
---
libgomp/target.c | 54 +++++++++++++++++++++++++++++++-----------------------
1 file changed, 31 insertions(+), 23 deletions(-)
diff --git a/libgomp/target.c b/libgomp/target.c
index 509776d17a8..4e774a89688 100644
--- a/libgomp/target.c
+++ b/libgomp/target.c
@@ -177,8 +177,14 @@ gomp_device_copy (struct gomp_device_descr *devicep,
}
}
-/* Infrastructure for coalescing adjacent or nearly adjacent (in device addresses)
- host to device memory transfers. */
+/* Infrastructure for coalescing adjacent or nearly adjacent (in
+ device addresses) host to device memory transfers. */
+
+struct gomp_coalesce_chunk
+{
+ /* The starting and ending point of a coalesced chunk of memory. */
+ size_t start, end;
+};
struct gomp_coalesce_buf
{
@@ -186,10 +192,10 @@ struct gomp_coalesce_buf
it will be copied to the device. */
void *buf;
struct target_mem_desc *tgt;
- /* Array with offsets, chunks[2 * i] is the starting offset and
- chunks[2 * i + 1] ending offset relative to tgt->tgt_start device address
+ /* Array with offsets, chunks[i].start is the starting offset and
+ chunks[i].end ending offset relative to tgt->tgt_start device address
of chunks which are to be copied to buf and later copied to device. */
- size_t *chunks;
+ struct gomp_coalesce_chunk *chunks;
/* Number of chunks in chunks array, or -1 if coalesce buffering should not
be performed. */
long chunk_cnt;
@@ -222,14 +228,14 @@ gomp_coalesce_buf_add (struct gomp_coalesce_buf *cbuf, size_t start, size_t len)
{
if (cbuf->chunk_cnt < 0)
return;
- if (start < cbuf->chunks[2 * cbuf->chunk_cnt - 1])
+ if (start < cbuf->chunks[cbuf->chunk_cnt-1].end)
{
cbuf->chunk_cnt = -1;
return;
}
- if (start < cbuf->chunks[2 * cbuf->chunk_cnt - 1] + MAX_COALESCE_BUF_GAP)
+ if (start < cbuf->chunks[cbuf->chunk_cnt-1].end + MAX_COALESCE_BUF_GAP)
{
- cbuf->chunks[2 * cbuf->chunk_cnt - 1] = start + len;
+ cbuf->chunks[cbuf->chunk_cnt-1].end = start + len;
cbuf->use_cnt++;
return;
}
@@ -239,8 +245,8 @@ gomp_coalesce_buf_add (struct gomp_coalesce_buf *cbuf, size_t start, size_t len)
if (cbuf->use_cnt == 1)
cbuf->chunk_cnt--;
}
- cbuf->chunks[2 * cbuf->chunk_cnt] = start;
- cbuf->chunks[2 * cbuf->chunk_cnt + 1] = start + len;
+ cbuf->chunks[cbuf->chunk_cnt].start = start;
+ cbuf->chunks[cbuf->chunk_cnt].end = start + len;
cbuf->chunk_cnt++;
cbuf->use_cnt = 1;
}
@@ -271,20 +277,20 @@ gomp_copy_host2dev (struct gomp_device_descr *devicep,
if (cbuf)
{
uintptr_t doff = (uintptr_t) d - cbuf->tgt->tgt_start;
- if (doff < cbuf->chunks[2 * cbuf->chunk_cnt - 1])
+ if (doff < cbuf->chunks[cbuf->chunk_cnt-1].end)
{
long first = 0;
long last = cbuf->chunk_cnt - 1;
while (first <= last)
{
long middle = (first + last) >> 1;
- if (cbuf->chunks[2 * middle + 1] <= doff)
+ if (cbuf->chunks[middle].end <= doff)
first = middle + 1;
- else if (cbuf->chunks[2 * middle] <= doff)
+ else if (cbuf->chunks[middle].start <= doff)
{
- if (doff + sz > cbuf->chunks[2 * middle + 1])
+ if (doff + sz > cbuf->chunks[middle].end)
gomp_fatal ("internal libgomp cbuf error");
- memcpy ((char *) cbuf->buf + (doff - cbuf->chunks[0]),
+ memcpy ((char *) cbuf->buf + (doff - cbuf->chunks[0].start),
h, sz);
return;
}
@@ -510,8 +516,8 @@ gomp_map_vars (struct gomp_device_descr *devicep, size_t mapnum,
cbuf.buf = NULL;
if (mapnum > 1 || pragma_kind == GOMP_MAP_VARS_TARGET)
{
- cbuf.chunks
- = (size_t *) gomp_alloca ((2 * mapnum + 2) * sizeof (size_t));
+ size_t chunk_size = (mapnum + 1) * sizeof (struct gomp_coalesce_chunk);
+ cbuf.chunks = (struct gomp_coalesce_chunk *) gomp_alloca (chunk_size);
cbuf.chunk_cnt = 0;
}
if (pragma_kind == GOMP_MAP_VARS_TARGET)
@@ -521,8 +527,8 @@ gomp_map_vars (struct gomp_device_descr *devicep, size_t mapnum,
tgt_size = mapnum * sizeof (void *);
cbuf.chunk_cnt = 1;
cbuf.use_cnt = 1 + (mapnum > 1);
- cbuf.chunks[0] = 0;
- cbuf.chunks[1] = tgt_size;
+ cbuf.chunks[0].start = 0;
+ cbuf.chunks[0].end = tgt_size;
}
gomp_mutex_lock (&devicep->lock);
@@ -707,7 +713,7 @@ gomp_map_vars (struct gomp_device_descr *devicep, size_t mapnum,
if (cbuf.chunk_cnt > 0)
{
cbuf.buf
- = malloc (cbuf.chunks[2 * cbuf.chunk_cnt - 1] - cbuf.chunks[0]);
+ = malloc (cbuf.chunks[cbuf.chunk_cnt-1].end - cbuf.chunks[0].start);
if (cbuf.buf)
{
cbuf.tgt = tgt;
@@ -981,9 +987,11 @@ gomp_map_vars (struct gomp_device_descr *devicep, size_t mapnum,
{
long c = 0;
for (c = 0; c < cbuf.chunk_cnt; ++c)
- gomp_copy_host2dev (devicep, (void *) (tgt->tgt_start + cbuf.chunks[2 * c]),
- (char *) cbuf.buf + (cbuf.chunks[2 * c] - cbuf.chunks[0]),
- cbuf.chunks[2 * c + 1] - cbuf.chunks[2 * c], NULL);
+ gomp_copy_host2dev (devicep,
+ (void *) (tgt->tgt_start + cbuf.chunks[c].start),
+ (char *) cbuf.buf + (cbuf.chunks[c].start
+ - cbuf.chunks[0].start),
+ cbuf.chunks[c].end - cbuf.chunks[c].start, NULL);
free (cbuf.buf);
}
--
2.14.3
