forwprop: Handle RAW_DATA_CST in check_ctz_array

In order to stress test RAW_DATA_CST handling, I've tested trunk gcc with
r15-6339 reapplied and a hack where I've changed
  const unsigned int raw_data_min_len = 128;
to
  const unsigned int raw_data_min_len = 2;
in cp_lexer_new_main and 64 to 4 several times in c_parser_initval
and c_maybe_optimize_large_byte_initializer, so that RAW_DATA_CST doesn't
trigger just on very large initializers, but even quite small ones.

One of the regressions (will work on the others next) was that pr90838.c
testcase regressed, check_ctz_array needs to handle RAW_DATA_CST, otherwise
on larger initializers or if those come from #embed just won't trigger.
The new testcase shows when it doesn't trigger anymore (regression from 14).

The patch just handles RAW_DATA_CST in the CONSTRUCTOR_ELTS the same as is
it was a series of INTEGER_CSTs.

2025-01-02  Jakub Jelinek  <jakub@redhat.com>

	* tree-ssa-forwprop.cc (check_ctz_array): Handle also RAW_DATA_CST
	in the CONSTRUCTOR_ELTS.

	* gcc.dg/pr90838-2.c: New test.

diff --git a/gcc/testsuite/gcc.dg/pr90838-2.c b/gcc/testsuite/gcc.dg/pr90838-2.c
new file mode 100644 (file)
index 0000000..7ecbf1e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr90838-2.c
@@ -0,0 +1,39 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-forwprop2-details" } */
+/* { dg-additional-options "-mbmi" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } } */
+/* { dg-additional-options "-march=rv64gc_zbb" { target { rv64 } } } */
+/* { dg-additional-options "-march=rv32gc_zbb" { target { rv32 } } } */
+/* { dg-require-effective-target int32plus } */
+
+static const unsigned long long magic = 0x03f08c5392f756cdULL;
+
+static const char table[128] = {
+     0,  1, 12,  2, 13, 22, 17,  3,
+    14, 33, 23, 36, 18, 58, 28,  4,
+    62, 15, 34, 26, 24, 48, 50, 37,
+    19, 55, 59, 52, 29, 44, 39,  5,
+    63, 11, 21, 16, 32, 35, 57, 27,
+    61, 25, 47, 49, 54, 51, 43, 38,
+    10, 20, 31, 56, 60, 46, 53, 42,
+     9, 30, 45, 41,  8, 40,  7,  6,
+     1,  2,  3,  4,  5,  6,  7,  8,
+     9, 10, 11, 12, 13, 14, 15, 16,
+    17, 18, 19, 20, 21, 22, 23, 24,
+    25, 26, 27, 28, 29, 30, 31, 32,
+    33, 34, 35, 36, 37, 38, 39, 40,
+    41, 42, 43, 44, 45, 46, 47, 48,
+    49, 50, 51, 52, 53, 54, 55, 56,
+    57, 58, 59, 60, 61, 62, 63, 64
+};
+
+int ctz4 (unsigned long x)
+{
+  unsigned long lsb = x & -x;
+  return table[(lsb * magic) >> 58];
+}
+
+/* { dg-final { scan-tree-dump {= \.CTZ} "forwprop2" { target { { i?86-*-* x86_64-*-* } && { ! { ia32 } } } } } } */
+/* { dg-final { scan-tree-dump {= \.CTZ} "forwprop2" { target aarch64*-*-* } } } */
+/* { dg-final { scan-tree-dump {= \.CTZ} "forwprop2" { target { rv64 } } } } */
+/* { dg-final { scan-tree-dump {= \.CTZ} "forwprop2" { target { rv32 } } } } */
+/* { dg-final { scan-tree-dump {= \.CTZ} "forwprop2" { target { loongarch64*-*-* } } } } */

diff --git a/gcc/tree-ssa-forwprop.cc b/gcc/tree-ssa-forwprop.cc
index 7f5872dae9608a31361790e029935eab37c3ef4b..b35f845a42a0fca82ee9930bc7f2480568e08bdd 100644 (file)
--- a/gcc/tree-ssa-forwprop.cc
+++ b/gcc/tree-ssa-forwprop.cc
@@ -2269,7 +2269,7 @@ check_ctz_array (tree ctor, unsigned HOST_WIDE_INT mulc,
                 HOST_WIDE_INT &zero_val, unsigned shift, unsigned bits)
 {
   tree elt, idx;
-  unsigned HOST_WIDE_INT i, mask;
+  unsigned HOST_WIDE_INT i, mask, raw_idx = 0;
   unsigned matched = 0;
 
   mask = ((HOST_WIDE_INT_1U << (bits - shift)) - 1) << shift;
@@ -2278,13 +2278,34 @@ check_ctz_array (tree ctor, unsigned HOST_WIDE_INT mulc,
 
   FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), i, idx, elt)
     {
-      if (TREE_CODE (idx) != INTEGER_CST || TREE_CODE (elt) != INTEGER_CST)
+      if (TREE_CODE (idx) != INTEGER_CST)
        return false;
-      if (i > bits * 2)
+      if (TREE_CODE (elt) != INTEGER_CST && TREE_CODE (elt) != RAW_DATA_CST)
        return false;
 
       unsigned HOST_WIDE_INT index = tree_to_shwi (idx);
-      HOST_WIDE_INT val = tree_to_shwi (elt);
+      HOST_WIDE_INT val;
+
+      if (TREE_CODE (elt) == INTEGER_CST)
+       val = tree_to_shwi (elt);
+      else
+       {
+         if (raw_idx == (unsigned) RAW_DATA_LENGTH (elt))
+           {
+             raw_idx = 0;
+             continue;
+           }
+         if (TYPE_UNSIGNED (TREE_TYPE (elt)))
+           val = RAW_DATA_UCHAR_ELT (elt, raw_idx);
+         else
+           val = RAW_DATA_SCHAR_ELT (elt, raw_idx);
+         index += raw_idx;
+         raw_idx++;
+         i--;
+       }
+
+      if (index > bits * 2)
+       return false;
 
       if (index == 0)
        {