vect-patterns: Fix up vect_recog_rotate_pattern [PR108064]

Since vect_recog_rotate_pattern has been extended to work also
on signed types in r13-1100 we miscompile the testcase below.
vect_recog_rotate_pattern actually emits correct scalar code into
the pattern def sequence (in particular cast to utype, doing the
2 shifts in utype so that the right shift is logical and not arithmetic,
or and then cast back to the signed type), but it didn't supply vectype
for most of those pattern statements, which means that the generic handling
fills it up later with the vectype provided by vect_recog_rotate_pattern.
The problem is that it is vectype of the result of the whole pattern,
i.e. vector of signed values in this case, while the conversion to utype,
2 shifts and or (everything with utype lhs in scalar code) should have
uvectype as STMT_VINFO_VECTYPE.

2022-12-13  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/108064
	* tree-vect-patterns.cc (vect_recog_rotate_pattern): Pass uvectype
	as 4th argument to append_pattern_def_seq for statements with lhs
	with utype type.

	* gcc.c-torture/execute/pr108064.c: New test.

diff --git a/gcc/testsuite/gcc.c-torture/execute/pr108064.c b/gcc/testsuite/gcc.c-torture/execute/pr108064.c
new file mode 100644 (file)
index 0000000..a7170bc
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr108064.c
@@ -0,0 +1,28 @@
+/* PR tree-optimization/108064 */
+
+static inline short
+foo (short value)
+{
+  return ((value >> 8) & 0xff) | ((value & 0xff) << 8);
+}
+
+__attribute__((noipa))
+void
+bar (short *d, const short *s)
+{
+  for (unsigned long i = 0; i < 4; i++)
+    d[i] = foo (s[i]);
+}
+
+int
+main ()
+{
+  short a[4] __attribute__((aligned (16))) = { 0xff, 0, 0, 0 };
+  short b[4] __attribute__((aligned (16)));
+  short c[4] __attribute__((aligned (16)));
+
+  bar (b, a);
+  bar (c, b);
+  if (a[0] != c[0])
+    __builtin_abort ();
+}

diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index d9fdb24..32f95a7 100644 (file)
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -3113,7 +3113,7 @@ vect_recog_rotate_pattern (vec_info *vinfo,
     {
       def = vect_recog_temp_ssa_var (utype, NULL);
       def_stmt = gimple_build_assign (def, NOP_EXPR, oprnd0);
-      append_pattern_def_seq (vinfo, stmt_vinfo, def_stmt);
+      append_pattern_def_seq (vinfo, stmt_vinfo, def_stmt, uvectype);
       oprnd0 = def;
     }
 
@@ -3137,7 +3137,7 @@ vect_recog_rotate_pattern (vec_info *vinfo,
     {
       def = vect_recog_temp_ssa_var (utype, NULL);
       def_stmt = gimple_build_assign (def, NOP_EXPR, oprnd1);
-      append_pattern_def_seq (vinfo, stmt_vinfo, def_stmt);
+      append_pattern_def_seq (vinfo, stmt_vinfo, def_stmt, uvectype);
     }
   stype = TREE_TYPE (def);
 
@@ -3185,13 +3185,13 @@ vect_recog_rotate_pattern (vec_info *vinfo,
   def_stmt = gimple_build_assign (var1, rhs_code == LROTATE_EXPR
                                        ? LSHIFT_EXPR : RSHIFT_EXPR,
                                  oprnd0, def);
-  append_pattern_def_seq (vinfo, stmt_vinfo, def_stmt);
+  append_pattern_def_seq (vinfo, stmt_vinfo, def_stmt, uvectype);
 
   var2 = vect_recog_temp_ssa_var (utype, NULL);
   def_stmt = gimple_build_assign (var2, rhs_code == LROTATE_EXPR
                                        ? RSHIFT_EXPR : LSHIFT_EXPR,
                                  oprnd0, def2);
-  append_pattern_def_seq (vinfo, stmt_vinfo, def_stmt);
+  append_pattern_def_seq (vinfo, stmt_vinfo, def_stmt, uvectype);
 
   /* Pattern detected.  */
   vect_pattern_detected ("vect_recog_rotate_pattern", last_stmt);
@@ -3202,7 +3202,7 @@ vect_recog_rotate_pattern (vec_info *vinfo,
 
   if (!useless_type_conversion_p (type, utype))
     {
-      append_pattern_def_seq (vinfo, stmt_vinfo, pattern_stmt);
+      append_pattern_def_seq (vinfo, stmt_vinfo, pattern_stmt, uvectype);
       tree result = vect_recog_temp_ssa_var (type, NULL);
       pattern_stmt = gimple_build_assign (result, NOP_EXPR, var);
     }