From b87df9e1c6326b4983a821d3035f8bafba221805 Mon Sep 17 00:00:00 2001
From: Colin Leroy-Mira <colin@colino.net>
Date: Fri, 12 Jan 2024 23:04:14 +0100
Subject: [PATCH] Optimize -36 bytes out of posix_memalign

And add a unit test
---
 libsrc/common/pmemalign.c       | 22 ++++++++++++++--------
 test/val/lib_common_pmemalign.c | 31 +++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 8 deletions(-)
 create mode 100644 test/val/lib_common_pmemalign.c

diff --git a/libsrc/common/pmemalign.c b/libsrc/common/pmemalign.c
index 52adb240d..4499084d1 100644
--- a/libsrc/common/pmemalign.c
+++ b/libsrc/common/pmemalign.c
@@ -50,7 +50,6 @@
 */
 
 
-
 int __fastcall__ posix_memalign (void** memptr, size_t alignment, size_t size)
 /* Allocate a block of memory with the given "size", which is aligned to a
 ** memory address that is a multiple of "alignment".  "alignment" MUST NOT be
@@ -64,20 +63,27 @@ int __fastcall__ posix_memalign (void** memptr, size_t alignment, size_t size)
     size_t rawsize;
     size_t uppersize;
     size_t lowersize;
+    char err;
     register struct usedblock* b;       /* points to raw Block */
     register struct usedblock* u;       /* points to User block */
     register struct usedblock* p;       /* Points to upper block */
 
     /* Handle requests for zero-sized blocks */
     if (size == 0) {
+err_einval:
+        err = EINVAL;
+err_out:
         *memptr = NULL;
-        return EINVAL;
+        return err;
     }
 
-    /* Test alignment: is it a power of two? There must be only one bit set. */
-    if (alignment == 0 || (alignment & (alignment - 1)) != 0) {
-        *memptr = NULL;
-        return EINVAL;
+    /* Test alignment: is it a power of two? There must be one and only one bit set. */
+    if (alignment == 0) {
+        goto err_einval;
+    }
+
+    if (alignment & (alignment - 1)) {
+        goto err_einval;
     }
 
     /* Augment the block size up to the alignment, and allocate memory.
@@ -90,8 +96,8 @@ int __fastcall__ posix_memalign (void** memptr, size_t alignment, size_t size)
 
     /* Handle out-of-memory */
     if (b == NULL) {
-        *memptr = NULL;
-        return ENOMEM;
+        err = ENOMEM;
+        goto err_out;
     }
 
     /* Create (and return) a new pointer that points to the user-visible
diff --git a/test/val/lib_common_pmemalign.c b/test/val/lib_common_pmemalign.c
new file mode 100644
index 000000000..0e9e5f52f
--- /dev/null
+++ b/test/val/lib_common_pmemalign.c
@@ -0,0 +1,31 @@
+#include <errno.h>
+#include <stdlib.h>
+#include "unittest.h"
+
+TEST
+{
+    void *buf;
+    int r;
+
+    r = posix_memalign(&buf, 123, 1024);
+    ASSERT_IsTrue(r == EINVAL, "posix_memalign did not return EINVAL with wrong alignment");
+    ASSERT_IsTrue(buf == NULL, "posix_memalign did not set buf to NULL with wrong alignment");
+
+    r = posix_memalign(&buf, 0, 1024);
+    ASSERT_IsTrue(r == EINVAL, "posix_memalign did not return EINVAL with 0 alignment");
+    ASSERT_IsTrue(buf == NULL, "posix_memalign did not set buf to NULL with 0 alignment");
+
+    r = posix_memalign(&buf, 256, 0);
+    ASSERT_IsTrue(r == EINVAL, "posix_memalign did not return EINVAL with 0 size");
+    ASSERT_IsTrue(buf == NULL, "posix_memalign did not set buf to NULL with 0 size");
+
+    r = posix_memalign(&buf, 256, 32768U);
+    ASSERT_IsTrue(r == 0, "posix_memalign did not return 0 on correct call");
+    ASSERT_IsTrue(buf != NULL, "posix_memalign left buf set to NULL on correct call");
+    ASSERT_IsTrue(((unsigned int)buf & 0x00FF) == 0x00, "posix_memalign did not align memory");
+
+    r = posix_memalign(&buf, 256, 32768U);
+    ASSERT_IsTrue(r == ENOMEM, "posix_memalign did not return ENOMEM when no memory is available");
+    ASSERT_IsTrue(buf == NULL, "posix_memalign did not set buf to NULL when no memory is available");
+}
+ENDTEST