[PATCH] tree-optimization/107554 - fix ICE in stlen optimization

[Richard Biener via Gcc-patches]

The following fixes a wrongly typed variable causing an ICE.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

        PR tree-optimization/107554
        * tree-ssa-strlen.cc (strlen_pass::count_nonzero_bytes):
        Use unsigned HOST_WIDE_INT type for the strlen.

        * gcc.dg/pr107554.c: New testcase.

Co-Authored-By: Nikita Voronov <nik_1...@mail.ru>
---
 gcc/testsuite/gcc.dg/pr107554.c | 12 ++++++++++++
 gcc/tree-ssa-strlen.cc          |  2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr107554.c

diff --git a/gcc/testsuite/gcc.dg/pr107554.c b/gcc/testsuite/gcc.dg/pr107554.c
new file mode 100644
index 00000000000..8bbe6b07ae9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr107554.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O -foptimize-strlen" } */
+
+#define ELEMS 0x40000000
+
+int a[ELEMS];
+int b[ELEMS];
+
+int main()
+{
+  __builtin_memcpy(a, b, ELEMS*sizeof(int));
+}
diff --git a/gcc/tree-ssa-strlen.cc b/gcc/tree-ssa-strlen.cc
index b87c7c7ce1f..abec225566d 100644
--- a/gcc/tree-ssa-strlen.cc
+++ b/gcc/tree-ssa-strlen.cc
@@ -4735,7 +4735,7 @@ strlen_pass::count_nonzero_bytes (tree exp, gimple *stmt,
 
   /* Compute the number of leading nonzero bytes in the representation
      and update the minimum and maximum.  */
-  unsigned n = prep ? strnlen (prep, nbytes) : nbytes;
+  unsigned HOST_WIDE_INT n = prep ? strnlen (prep, nbytes) : nbytes;
 
   if (n < lenrange[0])
     lenrange[0] = n;
-- 
2.35.3