Simplify newNode() by removing special cases

- Remove MemoryContextAllocZeroAligned(). It was supposed to be a
  faster version of MemoryContextAllocZero(), but modern compilers turn
  the MemSetLoop() into a call to memset() anyway, making it more or
  less identical to MemoryContextAllocZero(). That was the only user of
  MemSetTest, MemSetLoop, so remove those too, as well as palloc0fast().

- Convert newNode() to a static inline function. When this was
  originally originally written, it was written as a macro because
  testing showed that gcc didn't inline the size check as we
  intended. Modern compiler versions do, and now that it just calls
  palloc0() there is no size-check to inline anyway.

One nice effect is that the palloc0() takes one less argument than
MemoryContextAllocZeroAligned(), which saves a few instructions in the
callers of newNode().

Reviewed-by: Peter Eisentraut, Tom Lane, John Naylor, Thomas Munro
Discussion: https://www.postgresql.org/message-id/b51f1fa7-7e6a-4ecc-936d-90a8a1659e7c@iki.fi

4 files changed, 0 insertions, 71 deletions

diff --git a/src/backend/nodes/Makefile b/src/backend/nodes/Makefile
index ebbe9052cb7..66bbad8e6e0 100644
--- a/src/backend/nodes/Makefile
+++ b/src/backend/nodes/Makefile
@@ -23,7 +23,6 @@ OBJS = \
 	makefuncs.o \
 	multibitmapset.o \
 	nodeFuncs.o \
-	nodes.o \
 	outfuncs.o \
 	params.o \
 	print.o \
diff --git a/src/backend/nodes/meson.build b/src/backend/nodes/meson.build
index 31467a12d3b..1efbf2c11ca 100644
--- a/src/backend/nodes/meson.build
+++ b/src/backend/nodes/meson.build
@@ -7,7 +7,6 @@ backend_sources += files(
   'makefuncs.c',
   'multibitmapset.c',
   'nodeFuncs.c',
-  'nodes.c',
   'params.c',
   'print.c',
   'read.c',
diff --git a/src/backend/nodes/nodes.c b/src/backend/nodes/nodes.c
deleted file mode 100644
index 1913a4bdf7d..00000000000
--- a/src/backend/nodes/nodes.c
+++ /dev/null
@@ -1,31 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * nodes.c
- *	  support code for nodes (now that we have removed the home-brew
- *	  inheritance system, our support code for nodes is much simpler)
- *
- * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- *
- * IDENTIFICATION
- *	  src/backend/nodes/nodes.c
- *
- * HISTORY
- *	  Andrew Yu			Oct 20, 1994	file creation
- *
- *-------------------------------------------------------------------------
- */
-#include "postgres.h"
-
-#include "nodes/nodes.h"
-
-/*
- * Support for newNode() macro
- *
- * In a GCC build there is no need for the global variable newNodeMacroHolder.
- * However, we create it anyway, to support the case of a non-GCC-built
- * loadable module being loaded into a GCC-built backend.
- */
-
-Node	   *newNodeMacroHolder;
diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
index 9fc83f11f6f..4b30fcaebd0 100644
--- a/src/backend/utils/mmgr/mcxt.c
+++ b/src/backend/utils/mmgr/mcxt.c
@@ -1092,44 +1092,6 @@ MemoryContextAllocZero(MemoryContext context, Size size)
 }
 
 /*
- * MemoryContextAllocZeroAligned
- *		MemoryContextAllocZero where length is suitable for MemSetLoop
- *
- *	This might seem overly specialized, but it's not because newNode()
- *	is so often called with compile-time-constant sizes.
- */
-void *
-MemoryContextAllocZeroAligned(MemoryContext context, Size size)
-{
-	void	   *ret;
-
-	Assert(MemoryContextIsValid(context));
-	AssertNotInCriticalSection(context);
-
-	if (!AllocSizeIsValid(size))
-		elog(ERROR, "invalid memory alloc request size %zu", size);
-
-	context->isReset = false;
-
-	ret = context->methods->alloc(context, size);
-	if (unlikely(ret == NULL))
-	{
-		MemoryContextStats(TopMemoryContext);
-		ereport(ERROR,
-				(errcode(ERRCODE_OUT_OF_MEMORY),
-				 errmsg("out of memory"),
-				 errdetail("Failed on request of size %zu in memory context \"%s\".",
-						   size, context->name)));
-	}
-
-	VALGRIND_MEMPOOL_ALLOC(context, ret, size);
-
-	MemSetLoop(ret, 0, size);
-
-	return ret;
-}
-
-/*
  * MemoryContextAllocExtended
  *		Allocate space within the specified context using the given flags.
  */