https://gcc.gnu.org/g:cb403df46fc9275530669925faac5c256fdd2596
commit r15-6502-gcb403df46fc9275530669925faac5c256fdd2596
Author: Jakub Jelinek <ja...@redhat.com>
Date: Thu Jan 2 12:29:31 2025 +0100
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 <ja...@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:
---
gcc/testsuite/gcc.dg/pr90838-2.c | 39 +++++++++++++++++++++++++++++++++++++++
gcc/tree-ssa-forwprop.cc | 29 +++++++++++++++++++++++++----
2 files changed, 64 insertions(+), 4 deletions(-)
diff --git a/gcc/testsuite/gcc.dg/pr90838-2.c b/gcc/testsuite/gcc.dg/pr90838-2.c
new file mode 100644
index 000000000000..7ecbf1e4418a
--- /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 7f5872dae960..b35f845a42a0 100644
--- 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)
{
