sccvn: Don't use SCALAR_INT_TYPE_MODE on BLKmode BITINT_TYPEs [PR113459]

sccvn uses GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (type)) for INTEGER_TYPEs,
most likely because that is what native_{interpret,encode}_int used.
This obviously doesn't work for larger BITINT_TYPEs which have BLKmode
and the above ICEs on those.  native_{interpret,encode}_int checks whether
the BITINT_TYPE is medium/large/huge (i.e. an array of 2+ ABI limbs)
and uses TYPE_SIZE_UNIT for that case, otherwise SCALAR_INT_TYPE_MODE like
for the INTEGER_TYPE case.

The following patch instead just uses SCALAR_INT_TYPE_MODE for non-BLKmode
TYPE_MODE and TYPE_SIZE_UNIT otherwise.

2024-01-19  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/113459
	* tree-ssa-sccvn.cc (vn_walk_cb_data::push_partial_def): Use
	TREE_INT_CST_LOW of TYPE_SIZE_UNIT rather than GET_MODE_SIZE
	of SCALAR_INT_TYPE_MODE if type has BLKmode.
	(vn_reference_lookup_3): Likewise.  Formatting fix.

	* gcc.dg/bitint-73.c: New test.

diff --git a/gcc/testsuite/gcc.dg/bitint-73.c b/gcc/testsuite/gcc.dg/bitint-73.c
new file mode 100644 (file)
index 0000000..d796134
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/bitint-73.c
@@ -0,0 +1,18 @@
+/* PR tree-optimization/113459 */
+/* { dg-do compile { target bitint } } */
+/* { dg-options "-std=c23 -O2" } */
+
+#if __BITINT_MAXWIDTH__ >= 129
+# define N 129
+#else
+# define N 63
+#endif
+
+_BitInt(N) a;
+
+_BitInt(N)
+foo (void)
+{
+  __builtin_memset (&a, 6, sizeof a);
+  return a;
+}

diff --git a/gcc/tree-ssa-sccvn.cc b/gcc/tree-ssa-sccvn.cc
index 97f5c7923dbd7d07b5f23723b1751a3239980e2c..f0fa718a723db09720848fe3fe84409e33f0515e 100644 (file)
--- a/gcc/tree-ssa-sccvn.cc
+++ b/gcc/tree-ssa-sccvn.cc
@@ -2287,7 +2287,12 @@ vn_walk_cb_data::push_partial_def (pd_data pd,
                                    BITS_PER_UNIT
                                    - (maxsizei % BITS_PER_UNIT));
       if (INTEGRAL_TYPE_P (type))
-       sz = GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (type));
+       {
+         if (TYPE_MODE (type) != BLKmode)
+           sz = GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (type));
+         else
+           sz = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (type));
+       }
       if (sz > needed_len)
        {
          memcpy (this_buffer + (sz - needed_len), buffer, needed_len);
@@ -2967,8 +2972,10 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
            }
          else
            {
-             unsigned buflen = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (vr->type)) + 1;
-             if (INTEGRAL_TYPE_P (vr->type))
+             unsigned buflen
+               = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (vr->type)) + 1;
+             if (INTEGRAL_TYPE_P (vr->type)
+                 && TYPE_MODE (vr->type) != BLKmode)
                buflen = GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (vr->type)) + 1;
              unsigned char *buf = XALLOCAVEC (unsigned char, buflen);
              memset (buf, TREE_INT_CST_LOW (gimple_call_arg (def_stmt, 1)),
@@ -3165,7 +3172,12 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
                         offset + maxsize - 1.  */
                      HOST_WIDE_INT sz = maxsizei / BITS_PER_UNIT;
                      if (INTEGRAL_TYPE_P (type))
-                       sz = GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (type));
+                       {
+                         if (TYPE_MODE (type) != BLKmode)
+                           sz = GET_MODE_SIZE (SCALAR_INT_TYPE_MODE (type));
+                         else
+                           sz = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (type));
+                       }
                      amnt = ((unsigned HOST_WIDE_INT) offset2i + size2i
                              - offseti - maxsizei) % BITS_PER_UNIT;
                      if (amnt)