From 709170b790c11b4012004a6baf11a0fc6ec950de Mon Sep 17 00:00:00 2001
From: Noah Misch <noah@leadboat.com>
Date: Sun, 20 Oct 2013 21:04:52 -0400
Subject: [PATCH] Consistently use unsigned arithmetic for alignment
calculations.
This avoids an assumption about the signed number representation. It is
anticipated to have no functional changes on supported configurations;
many two's complement assumptions remain elsewhere.
Per a suggestion from Andres Freund.
---
src/backend/access/hash/hashfunc.c | 2 +-
src/include/access/tupmacs.h | 8 ++++----
src/include/c.h | 10 +++++-----
3 files changed, 10 insertions(+), 10 deletions(-)
diff --git a/src/backend/access/hash/hashfunc.c b/src/backend/access/hash/hashfunc.c
index d5992821933..cb3b7e92783 100644
--- a/src/backend/access/hash/hashfunc.c
+++ b/src/backend/access/hash/hashfunc.c
@@ -314,7 +314,7 @@ hash_any(register const unsigned char *k, register int keylen)
a = b = c = 0x9e3779b9 + len + 3923095;
/* If the source pointer is word-aligned, we use word-wide fetches */
- if (((intptr_t) k & UINT32_ALIGN_MASK) == 0)
+ if (((uintptr_t) k & UINT32_ALIGN_MASK) == 0)
{
/* Code path for aligned source data */
register const uint32 *ka = (const uint32 *) k;
diff --git a/src/include/access/tupmacs.h b/src/include/access/tupmacs.h
index 2886cedc1c8..42a50e4604f 100644
--- a/src/include/access/tupmacs.h
+++ b/src/include/access/tupmacs.h
@@ -101,7 +101,7 @@
#define att_align_datum(cur_offset, attalign, attlen, attdatum) \
( \
((attlen) == -1 && VARATT_IS_SHORT(DatumGetPointer(attdatum))) ? \
- (intptr_t) (cur_offset) : \
+ (uintptr_t) (cur_offset) : \
att_align_nominal(cur_offset, attalign) \
)
@@ -116,13 +116,13 @@
* aligned 4-byte length word; in either case we need not align.)
*
* Note: some callers pass a "char *" pointer for cur_offset. This is
- * a bit of a hack but should work all right as long as intptr_t is the
+ * a bit of a hack but should work all right as long as uintptr_t is the
* correct width.
*/
#define att_align_pointer(cur_offset, attalign, attlen, attptr) \
( \
((attlen) == -1 && VARATT_NOT_PAD_BYTE(attptr)) ? \
- (intptr_t) (cur_offset) : \
+ (uintptr_t) (cur_offset) : \
att_align_nominal(cur_offset, attalign) \
)
@@ -144,7 +144,7 @@
#define att_align_nominal(cur_offset, attalign) \
( \
((attalign) == 'i') ? INTALIGN(cur_offset) : \
- (((attalign) == 'c') ? (intptr_t) (cur_offset) : \
+ (((attalign) == 'c') ? (uintptr_t) (cur_offset) : \
(((attalign) == 'd') ? DOUBLEALIGN(cur_offset) : \
( \
AssertMacro((attalign) == 's'), \
diff --git a/src/include/c.h b/src/include/c.h
index 8916310b5bf..6e19c6df878 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -486,7 +486,7 @@ typedef NameData *Name;
* True iff pointer is properly aligned to point to the given type.
*/
#define PointerIsAligned(pointer, type) \
- (((intptr_t)(pointer) % (sizeof (type))) == 0)
+ (((uintptr_t)(pointer) % (sizeof (type))) == 0)
#define OidIsValid(objectId) ((bool) ((objectId) != InvalidOid))
@@ -532,7 +532,7 @@ typedef NameData *Name;
*/
#define TYPEALIGN(ALIGNVAL,LEN) \
- (((intptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((intptr_t) ((ALIGNVAL) - 1)))
+ (((uintptr_t) (LEN) + ((ALIGNVAL) - 1)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
#define SHORTALIGN(LEN) TYPEALIGN(ALIGNOF_SHORT, (LEN))
#define INTALIGN(LEN) TYPEALIGN(ALIGNOF_INT, (LEN))
@@ -543,7 +543,7 @@ typedef NameData *Name;
#define BUFFERALIGN(LEN) TYPEALIGN(ALIGNOF_BUFFER, (LEN))
#define TYPEALIGN_DOWN(ALIGNVAL,LEN) \
- (((intptr_t) (LEN)) & ~((intptr_t) ((ALIGNVAL) - 1)))
+ (((uintptr_t) (LEN)) & ~((uintptr_t) ((ALIGNVAL) - 1)))
#define SHORTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_SHORT, (LEN))
#define INTALIGN_DOWN(LEN) TYPEALIGN_DOWN(ALIGNOF_INT, (LEN))
@@ -552,7 +552,7 @@ typedef NameData *Name;
#define MAXALIGN_DOWN(LEN) TYPEALIGN_DOWN(MAXIMUM_ALIGNOF, (LEN))
/*
- * The above macros will not work with types wider than intptr_t, like with
+ * The above macros will not work with types wider than uintptr_t, like with
* uint64 on 32-bit platforms. That's not problem for the usual use where a
* pointer or a length is aligned, but for the odd case that you need to
* align something (potentially) wider, use TYPEALIGN64.
@@ -763,7 +763,7 @@ typedef NameData *Name;
int _val = (val); \
Size _len = (len); \
\
- if ((((intptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \
+ if ((((uintptr_t) _vstart) & LONG_ALIGN_MASK) == 0 && \
(_len & LONG_ALIGN_MASK) == 0 && \
_val == 0 && \
_len <= MEMSET_LOOP_LIMIT && \
--
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