[hsa-branch] Make section::add return pointer to data

[hsa-branch] Make section::add return pointer to data

[Martin Jambor]

Hi,

when emitting a BRIG function definition, we need to fixup the leading
directive after all of the instructions and everything has been added to
the section (well, we could pre-compute the value but it is not worth
it).  At the moment the function emitting code calculates the pointer in
an ugly way, when it is much better to just add that ability to the
interface, like this patch does.

I'll commit it to the HSA branch for now but will commit it to trunk
after a while too.

Martin

2016-08-04  Martin Jambor  <mjambor@suse.cz>

	* hsa-brig.c (hsa_brig_section): Make allocate_new_chunk, chunks
	and cur_chunk provate, add a default NULL parameter to add method.
	(hsa_brig_section::add): Added a new parameter, store pointer to
	output data there if it is non-NULL.
	(emit_function_directives): Use this new parameter instead of
	calculating the pointer itself, fix function comment.
	(hsa_brig_emit_function): Add forgotten endian conversion.
---
 gcc/hsa-brig.c | 54 +++++++++++++++++++++++++++---------------------------
 1 file changed, 27 insertions(+), 27 deletions(-)

diff --git a/gcc/hsa-brig.c b/gcc/hsa-brig.c
index 1edd126..34231d7 100644
--- a/gcc/hsa-brig.c
+++ b/gcc/hsa-brig.c
@@ -160,19 +160,21 @@ public:
   /* The size of the header of the section without any padding.  */
   unsigned header_byte_delta;
 
-  /* Buffers of binary data, each containing BRIG_CHUNK_MAX_SIZE bytes.  */
-  vec <struct hsa_brig_data_chunk> chunks;
-
-  /* More convenient access to the last chunk from the vector above.  */
-  struct hsa_brig_data_chunk *cur_chunk;
-
-  void allocate_new_chunk ();
   void init (const char *name);
   void release ();
   void output ();
-  unsigned add (const void *data, unsigned len);
+  unsigned add (const void *data, unsigned len, void **output = NULL);
   void round_size_up (int factor);
   void *get_ptr_by_offset (unsigned int offset);
+
+private:
+  void allocate_new_chunk ();
+
+  /* Buffers of binary data, each containing BRIG_CHUNK_MAX_SIZE bytes.  */
+  vec <struct hsa_brig_data_chunk> chunks;
+
+  /* More convenient access to the last chunk from the vector above.  */
+  struct hsa_brig_data_chunk *cur_chunk;
 };
 
 static struct hsa_brig_section brig_data, brig_code, brig_operand;
@@ -270,10 +272,11 @@ hsa_brig_section::output ()
 }
 
 /* Add to the stream LEN bytes of opaque binary DATA.  Return the offset at
-   which it was stored.  */
+   which it was stored.  If OUTPUT is not NULL, store into it the pointer to
+   the place where DATA was actually stored.  */
 
 unsigned
-hsa_brig_section::add (const void *data, unsigned len)
+hsa_brig_section::add (const void *data, unsigned len, void **output)
 {
   unsigned offset = total_size;
 
@@ -281,7 +284,10 @@ hsa_brig_section::add (const void *data, unsigned len)
   if (cur_chunk->size > (BRIG_CHUNK_MAX_SIZE - len))
     allocate_new_chunk ();
 
-  memcpy (cur_chunk->data + cur_chunk->size, data, len);
+  char *dst = cur_chunk->data + cur_chunk->size;
+  memcpy (dst, data, len);
+  if (output)
+    *output = dst;
   cur_chunk->size += len;
   total_size += len;
 
@@ -625,8 +631,12 @@ emit_directive_variable (struct hsa_symbol *symbol)
   return symbol->m_directive_offset;
 }
 
-/* Emit directives describing either a function declaration or
-   definition F.  */
+/* Emit directives describing either a function declaration or definition F and
+   return the produced BrigDirectiveExecutable structure.  The function does
+   not take into account any instructions when calculating nextModuleEntry
+   field of the produced BrigDirectiveExecutable structure so when emitting
+   actual definitions, this field needs to be updated after all of the function
+   is actually added to the code section.  */
 
 static BrigDirectiveExecutable *
 emit_function_directives (hsa_function_representation *f, bool is_declaration)
@@ -634,7 +644,7 @@ emit_function_directives (hsa_function_representation *f, bool is_declaration)
   struct BrigDirectiveExecutable fndir;
   unsigned name_offset, inarg_off, scoped_off, next_toplev_off;
   int count = 0;
-  BrigDirectiveExecutable *ptr_to_fndir;
+  void *ptr_to_fndir;
   hsa_symbol *sym;
 
   if (!f->m_declaration_p)
@@ -692,17 +702,7 @@ emit_function_directives (hsa_function_representation *f, bool is_declaration)
       *slot = int_fn;
     }
 
-  brig_code.add (&fndir, sizeof (fndir));
-  /* terrible hack: we need to set instCount after we emit all
-     insns, but we need to emit directive in order, and we emit directives
-     during insn emitting.  So we need to emit the FUNCTION directive
-     early, then the insns, and then we need to set instCount, so remember
-     a pointer to it, in some horrible way.  cur_chunk.data+size points
-     directly to after fndir here.  */
-  ptr_to_fndir
-      = (BrigDirectiveExecutable *)(brig_code.cur_chunk->data
-				    + brig_code.cur_chunk->size
-				    - sizeof (fndir));
+  brig_code.add (&fndir, sizeof (fndir), &ptr_to_fndir);
 
   if (f->m_output_arg)
     emit_directive_variable (f->m_output_arg);
@@ -723,7 +723,7 @@ emit_function_directives (hsa_function_representation *f, bool is_declaration)
 	}
     }
 
-  return ptr_to_fndir;
+  return (BrigDirectiveExecutable *) ptr_to_fndir;
 }
 
 /* Emit a label directive for the given HBB.  We assume it is about to start on
@@ -2013,7 +2013,7 @@ hsa_brig_emit_function (void)
       prev_bb = bb;
     }
   perhaps_emit_branch (prev_bb, NULL);
-  ptr_to_fndir->nextModuleEntry = brig_code.total_size;
+  ptr_to_fndir->nextModuleEntry = lendian32 (brig_code.total_size);
 
   /* Fill up label references for all sbr instructions.  */
   if (switch_instructions)
-- 
2.9.2