cmpstrnsi expander may pass the actual string length directly to cmpstrnqi
patterns. For cmpstrnsi, one of the strings must be a constant and
expand_builtin_strncmp rewrites the length argument to be the minimum of
the const string length and the actual string length. But it is not the
case for cmpmemsi. Pass a copy of the string length to cmpstrnqi patterns
to avoid changing the actual string length by cmpstrnqi patterns.
gcc/
PR target/95443
* config/i386/i386.md (cmpstrnsi): Pass a copy of the string
length to cmpstrnqi patterns.
gcc/testsuite/
PR target/95443
* gcc.target/i386/pr95443-1.c: New test.
* gcc.target/i386/pr95443-2.c: Likewise.
---
gcc/config/i386/i386.md | 6 +-
gcc/testsuite/gcc.target/i386/pr95443-1.c | 130 ++
gcc/testsuite/gcc.target/i386/pr95443-2.c | 79 +
3 files changed, 214 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr95443-1.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr95443-2.c
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 459cf62b0de..c2de1bdaf42 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -17816,7 +17816,11 @@ (define_expand "cmpstrnsi"
if (addr2 != XEXP (operands[2], 0))
operands[2] = replace_equiv_address_nv (operands[2], addr2);
- countreg = ix86_zero_extend_to_Pmode (operands[3]);
+ /* NB: Make a copy of the data length to avoid changing the original
+ data length by cmpstrnqi patterns. */
+ rtx count = ix86_zero_extend_to_Pmode (operands[3]);
+ countreg = gen_reg_rtx (Pmode);
+ emit_move_insn (countreg, count);
/* %%% Iff we are testing strict equality, we can use known alignment
to good advantage. This may be possible with combine, particularly
diff --git a/gcc/testsuite/gcc.target/i386/pr95443-1.c
b/gcc/testsuite/gcc.target/i386/pr95443-1.c
new file mode 100644
index 000..292ff16afdd
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr95443-1.c
@@ -0,0 +1,130 @@
+/* { dg-do run { target mmap } } */
+/* { dg-options "-O2 -minline-all-stringops" } */
+
+#include
+#include
+#include
+#include
+#include
+#ifndef MAP_ANON
+#define MAP_ANON 0
+#endif
+#ifndef MAP_FAILED
+#define MAP_FAILED ((void *)-1)
+#endif
+
+uint8_t shift[256];
+
+static size_t
+__attribute__ ((noclone, noinline))
+hash2(const unsigned char *p)
+{
+ return (((size_t)(p)[0] - ((size_t)(p)[-1] << 3)) % sizeof (shift));
+}
+
+char *
+simple_strstr (const char *haystack, const char *needle)
+{
+ const unsigned char *hs = (const unsigned char *) haystack;
+ const unsigned char *ne = (const unsigned char *) needle;
+ size_t ne_len = strlen ((const char*)ne);
+ size_t hs_len = strnlen ((const char*)hs, ne_len | 512);
+
+ if (hs_len < ne_len)
+return NULL;
+
+ if (memcmp (hs, ne, ne_len) == 0)
+return (char *) hs;
+
+ const unsigned char *end = hs + hs_len - ne_len;
+ size_t tmp, shift1;
+ size_t m1 = ne_len - 1;
+ size_t offset = 0;
+
+ memset (shift, 0, sizeof (shift));
+ for (int i = 1; i < m1; i++)
+shift[hash2 (ne + i)] = i;
+ shift1 = m1 - shift[hash2 (ne + m1)];
+ shift[hash2 (ne + m1)] = m1;
+
+ while (1)
+{
+ if (__glibc_unlikely (hs > end))
+ {
+ end += strnlen ((const char*)end + m1 + 1, 2048);
+ if (hs > end)
+ return NULL;
+ }
+
+ do
+ {
+ hs += m1;
+ tmp = shift[hash2 (hs)];
+ }
+ while (tmp == 0 && hs <= end);
+
+ hs -= tmp;
+ if (tmp < m1)
+ continue;
+
+ if (m1 < 15 || memcmp (hs + offset, ne + offset, 8) == 0)
+ {
+ if (memcmp (hs, ne, m1) == 0)
+ return (void *) hs;
+
+ offset = (offset >= 8 ? offset : m1) - 8;
+ }
+
+ hs += shift1;
+}
+}
+
+static int
+check_result (const char *s1, const char *s2,
+ char *exp_result)
+{
+ char *result = simple_strstr (s1, s2);
+ if (result != exp_result)
+return -1;
+
+ return 0;
+}
+
+void
+__attribute__ ((noclone, noinline))
+check1 (void)
+{
+ const char s1[] =
+
"F_BD_CE_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_C3_88_20_EF_BF_BD_EF_BF_BD_EF_BF_BD_C3_A7_20_EF_BF_BD";
+ const char s2[] = "_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD_EF_BF_BD";
+ char *exp_result;
+
+ exp_result = simple_strstr (s1, s2);
+ if (check_result (s1, s2, exp_result) != 0)
+abort ();
+}
+
+int
+main (void)
+{
+ unsigned char *buf1, *buf2;
+ size_t page_size = 2 * sysconf(_SC_PAGESIZE);
+ buf1 = mmap (0, (1 + 1) * page_size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANON, -1, 0);
+ if (buf1 == MAP_FAILED)
+return -1;
+ if (mprotect (buf1 + 1 * page_size, page_size, PROT_NONE))
+return -1;
+ buf2 = mmap (0, 2 * page_size, PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANON, -1, 0);
+ if (buf2 == MAP_FAILED)
+return -1;
+ if (mprotect (buf2 + page_size, page_size, PROT_NONE))
+return -1;
+
+
