On 3/4/26 15:14, Richard Biener wrote:
> CAUTION: This email originated from outside of the organization. Do not click
> links or open attachments unless you recognize the sender and know the
> content is safe.
>
>
> On Wed, Mar 4, 2026 at 2:49 PM Radosav Krunic
> <[email protected]> wrote:
>> This patch addresses a regression introduced in r8-568-gf9f69dd651b2f1
>> (i.e., refactoring ivopts pass) for target mips-r6-linux-gnu. It
>> corrects the complexity calculation in ivopts. The fix involves
>> complexity computation reordering and proper invariant variables
>> handling in address expressions. These changes align with the approach
>> used before r8-568-gf9f69dd651b2f1 (e.g., in parent commit c2b64ce). The
>> improved complexity calculations ensure better candidate selection and
>> reduced code size, particularly for RISC CPUs.
>>
>> Signed-off-by: Radosav Krunic <[email protected]>
>> Signed-off-by: Aleksandar Rakic <[email protected]>
>> Signed-off-by: Jovan Dmitrovic <[email protected]>
> Please state how you tested this patch.
It was tested on an x86_64-pc-linux-gnu host. A cross-compiler toolchain
was built and installed for the target mips64-r6-linux-gnu, and the GCC
regression tests were run under QEMU. The command used was:
make -k -j$(nproc) check-gcc \
RUNTESTFLAGS="--target_board=mips-sim-mti64_64/-march=mips64r6/-mabi=64 \
SIM='$EMUPATH -L $SYSROOT'"
Here, $EMUPATH is the path to QEMU, and $SYSROOT is the path to the
sysroot directory, which is a subdirectory of the installation prefix
directory. Testing was performed with GCC at commit a4954130d43
("c++: define __cpp_pack_indexing [PR113798]").
The tests completed successfully with no new regressions.
>
>> gcc/ChangeLog:
>>
>> * tree-ssa-loop-ivopts.cc (get_address_cost): Fixed
>> complexity calculation.
>>
>> gcc/testsuite/ChangeLog:
>>
>> * gcc.target/mips/bug_tree-optimization_109429.c: New test.
>> ---
>> .../mips/bug_tree-optimization_109429.c | 24 +++++++++
>> gcc/tree-ssa-loop-ivopts.cc | 54 +++++++++----------
>> 2 files changed, 50 insertions(+), 28 deletions(-)
>> create mode 100644
>> gcc/testsuite/gcc.target/mips/bug_tree-optimization_109429.c
>>
>> diff --git a/gcc/testsuite/gcc.target/mips/bug_tree-optimization_109429.c
>> b/gcc/testsuite/gcc.target/mips/bug_tree-optimization_109429.c
>> new file mode 100644
>> index 00000000000..96a62278fcd
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/mips/bug_tree-optimization_109429.c
>> @@ -0,0 +1,24 @@
>> +/* { dg-do compile} */
>> +/* { dg-skip-if "" { *-*-* } { "*" } { "-O2" } } */
>> +/* { dg-options "-march=mips64r6 -mabi=64" } */
>> +
>> +static void daxpy (float *vector1, float *vector2, int n, float fp_const)
>> +{
>> + for (int i = 0; i < n; ++i)
>> + vector1[i] += fp_const * vector2[i];
>> +}
>> +
>> +void dgefa (float *vector, int m, int n, int l)
>> +{
>> + for (int i = 0; i < n - 1; ++i)
>> + {
>> + for (int j = i + 1; j < n; ++j)
>> + {
>> + float t = vector[m * j + l];
>> + daxpy (&vector[m * i + i + 1],
>> + &vector[m * j + i + 1], n - (i + 1), t);
>> + }
>> + }
>> +}
>> +
>> +/* { dg-final { scan-assembler
>> "\\.L6:\\n\\tlwc1\t\\\$f1,0\\\(\\\$7\\\)\\n\tdaddiu\t\\\$2,\\\$2,4\\n\tlwc1\t\\\$f0,-4\\\(\\\$2\\\)"
>> } } */
>> diff --git a/gcc/tree-ssa-loop-ivopts.cc b/gcc/tree-ssa-loop-ivopts.cc
>> index 6ecf5bef7b4..0df365671ef 100644
>> --- a/gcc/tree-ssa-loop-ivopts.cc
>> +++ b/gcc/tree-ssa-loop-ivopts.cc
>> @@ -4695,38 +4695,35 @@ get_address_cost (struct ivopts_data *data, struct
>> iv_use *use,
>> if (!ok_with_ratio_p)
>> parts.step = NULL_TREE;
>> }
>> - if (ok_with_ratio_p || ok_without_ratio_p)
>> + if (!(ok_with_ratio_p || ok_without_ratio_p))
>> + parts.index = NULL_TREE;
>> + if (maybe_ne (aff_inv->offset, 0))
>> {
>> - if (maybe_ne (aff_inv->offset, 0))
>> - {
>> - parts.offset = wide_int_to_tree (sizetype, aff_inv->offset);
>> - /* Addressing mode "base + index [<< scale] + offset". */
>> - if (!valid_mem_ref_p (mem_mode, as, &parts, code))
>> - parts.offset = NULL_TREE;
>> - else
>> - aff_inv->offset = 0;
>> - }
>> + parts.offset = wide_int_to_tree (sizetype, aff_inv->offset);
>> + /* Addressing mode "base[+ index[<< scale]] + offset". */
>> + if (!valid_mem_ref_p (mem_mode, as, &parts, code))
>> + parts.offset = NULL_TREE;
>> + else
>> + aff_inv->offset = 0;
>> + }
>>
>> - move_fixed_address_to_symbol (&parts, aff_inv);
>> - /* Base is fixed address and is moved to symbol part. */
>> - if (parts.symbol != NULL_TREE && aff_combination_zero_p (aff_inv))
>> - parts.base = NULL_TREE;
>> + move_fixed_address_to_symbol (&parts, aff_inv);
>> + /* Base is fixed address and is moved to symbol part. */
>> + if (parts.symbol != NULL_TREE && aff_combination_zero_p (aff_inv))
>> + parts.base = NULL_TREE;
>>
>> - /* Addressing mode "symbol + base + index [<< scale] [+ offset]".
>> */
>> - if (parts.symbol != NULL_TREE
>> - && !valid_mem_ref_p (mem_mode, as, &parts, code))
>> - {
>> - aff_combination_add_elt (aff_inv, parts.symbol, 1);
>> - parts.symbol = NULL_TREE;
>> - /* Reset SIMPLE_INV since symbol address needs to be computed
>> - outside of address expression in this case. */
>> - simple_inv = false;
>> - /* Symbol part is moved back to base part, it can't be NULL.
>> */
>> - parts.base = integer_one_node;
>> - }
>> + /* Addressing mode "symbol + base[+ index[<< scale]] [+ offset]". */
>> + if (parts.symbol != NULL_TREE
>> + && !valid_mem_ref_p (mem_mode, as, &parts, code))
>> + {
>> + aff_combination_add_elt (aff_inv, parts.symbol, 1);
>> + parts.symbol = NULL_TREE;
>> + /* Reset SIMPLE_INV since symbol address needs to be computed
>> + outside of address expression in this case. */
>> + simple_inv = false;
>> + /* Symbol part is moved back to base part, it can't be NULL. */
>> + parts.base = integer_one_node;
>> }
>> - else
>> - parts.index = NULL_TREE;
>> }
>> else
>> {
>> @@ -4787,6 +4784,7 @@ get_address_cost (struct ivopts_data *data, struct
>> iv_use *use,
>> neutralize such effects. */
>> cost.cost = adjust_setup_cost (data, cost.cost, true);
>> cost.scratch = cost.cost;
>> + cost.complexity += 1;
>> }
>>
>> cost += var_cost;
>> --
>> 2.43.0
