* lib/rawmemchr.c (rawmemchr): Use unsigned char for longword,
since CHERI doesn’t allow the aligned-word trick to speed up
performance.
---
ChangeLog | 7 +++++++
lib/rawmemchr.c | 13 +++++++++----
2 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index aae72a1987..83c1b520b9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2023-11-11 Paul Eggert <egg...@cs.ucla.edu>
+
+ rawmemchr: port better to CHERI
+ * lib/rawmemchr.c (rawmemchr): Use unsigned char for longword,
+ since CHERI doesn’t allow the aligned-word trick to speed up
+ performance.
+
2023-11-10 Paul Eggert <egg...@cs.ucla.edu>
di-set: port better to CHERI-64
diff --git a/lib/rawmemchr.c b/lib/rawmemchr.c
index 6f2809071b..137d7282a6 100644
--- a/lib/rawmemchr.c
+++ b/lib/rawmemchr.c
@@ -30,11 +30,16 @@
void *
rawmemchr (const void *s, int c_in)
{
+#ifdef __CHERI__
+ /* Most architectures let you read an aligned word, even if the unsigned char
+ array at S ends in the middle of the word. However, CHERI does not. */
+ typedef unsigned char longword;
+#else
/* Change this typedef to experiment with performance. */
- typedef unsigned long longword;
- /* If you change the "unsigned long", you should change ULONG_WIDTH to match.
- This verifies that the type does not have padding bits. */
- static_assert (ULONG_WIDTH == UCHAR_WIDTH * sizeof (longword));
+ typedef uintptr_t longword;
+ /* Verify that the longword type lacks padding bits. */
+ static_assert (UINTPTR_WIDTH == UCHAR_WIDTH * sizeof (uintptr_t));
+#endif
const unsigned char *char_ptr;
unsigned char c = c_in;
--
2.40.1
