3 files changed, 66 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd
index 17613ec..391c60b 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -2873,6 +2873,8 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 (match with_possible_nonzero_bits
  INTEGER_CST@0)
 (match with_possible_nonzero_bits
+ POLY_INT_CST@0)
+(match with_possible_nonzero_bits
  SSA_NAME@0
  (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))))
 /* Slightly extended version, do not make it recursive to keep it cheap.  */
diff --git a/gcc/testsuite/gcc.target/aarch64/sve/cnt_fold_4.c b/gcc/testsuite/gcc.target/aarch64/sve/cnt_fold_4.c
new file mode 100644
index 0000000..b7a5370
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/sve/cnt_fold_4.c
@@ -0,0 +1,61 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+/* { dg-final { check-function-bodies "**" "" } } */
+
+#include <arm_sve.h>
+
+/*
+** f1:
+**	cnth	x0
+**	ret
+*/
+uint64_t
+f1 ()
+{
+  uint64_t x = svcntw ();
+  x >>= 2;
+  return x << 3;
+}
+
+/*
+** f2:
+**	[^\n]+
+**	[^\n]+
+**	...
+**	ret
+*/
+uint64_t
+f2 ()
+{
+  uint64_t x = svcntd ();
+  x >>= 2;
+  return x << 3;
+}
+
+/*
+** f3:
+**	cntb	x0, all, mul #4
+**	ret
+*/
+uint64_t
+f3 ()
+{
+  uint64_t x = svcntd ();
+  x >>= 1;
+  return x << 6;
+}
+
+/*
+** f4:
+**	[^\n]+
+**	[^\n]+
+**	...
+**	ret
+*/
+uint64_t
+f4 ()
+{
+  uint64_t x = svcntd ();
+  x >>= 2;
+  return x << 2;
+}
diff --git a/gcc/tree-ssanames.cc b/gcc/tree-ssanames.cc
index 4f83fcb..ae6a0cd 100644
--- a/gcc/tree-ssanames.cc
+++ b/gcc/tree-ssanames.cc
@@ -502,6 +502,9 @@ get_nonzero_bits (const_tree name)
   if (TREE_CODE (name) == INTEGER_CST)
     return wi::to_wide (name);
 
+  if (POLY_INT_CST_P (name))
+    return -known_alignment (wi::to_poly_wide (name));
+
   /* Use element_precision instead of TYPE_PRECISION so complex and
      vector types get a non-zero precision.  */
   unsigned int precision = element_precision (TREE_TYPE (name));