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

1 files changed, 0 insertions, 14 deletions

diff --git a/src/include/utils/palloc.h b/src/include/utils/palloc.h
index d1146c12351..cf98ddc0ec9 100644
--- a/src/include/utils/palloc.h
+++ b/src/include/utils/palloc.h
@@ -70,7 +70,6 @@ extern PGDLLIMPORT MemoryContext CurrentMemoryContext;
  */
 extern void *MemoryContextAlloc(MemoryContext context, Size size);
 extern void *MemoryContextAllocZero(MemoryContext context, Size size);
-extern void *MemoryContextAllocZeroAligned(MemoryContext context, Size size);
 extern void *MemoryContextAllocExtended(MemoryContext context,
 										Size size, int flags);
 extern void *MemoryContextAllocAligned(MemoryContext context,
@@ -109,19 +108,6 @@ extern void pfree(void *pointer);
 #define repalloc_array(pointer, type, count) ((type *) repalloc(pointer, sizeof(type) * (count)))
 #define repalloc0_array(pointer, type, oldcount, count) ((type *) repalloc0(pointer, sizeof(type) * (oldcount), sizeof(type) * (count)))
 
-/*
- * The result of palloc() is always word-aligned, so we can skip testing
- * alignment of the pointer when deciding which MemSet variant to use.
- * Note that this variant does not offer any advantage, and should not be
- * used, unless its "sz" argument is a compile-time constant; therefore, the
- * issue that it evaluates the argument multiple times isn't a problem in
- * practice.
- */
-#define palloc0fast(sz) \
-	( MemSetTest(0, sz) ? \
-		MemoryContextAllocZeroAligned(CurrentMemoryContext, sz) : \
-		MemoryContextAllocZero(CurrentMemoryContext, sz) )
-
 /* Higher-limit allocators. */
 extern void *MemoryContextAllocHuge(MemoryContext context, Size size);
 extern pg_nodiscard void *repalloc_huge(void *pointer, Size size);