On Wed, Mar 13, 2024 at 2:56 PM Ajit Agarwal <aagar...@linux.ibm.com> wrote:
>
> Hello Richard:
>
> Currently, code sinking will sink code at the use points with loop having same
> nesting depth. The following patch improves code sinking by placing the sunk
> code in begining of the block after the labels.
>
> For example :
>
> void bar();
> int j;
> void foo(int a, int b, int c, int d, int e, int f)
> {
> int l;
> l = a + b + c + d +e + f;
> if (a != 5)
> {
> bar();
> j = l;
> }
> }
>
> Code Sinking does the following:
>
> void bar();
> int j;
> void foo(int a, int b, int c, int d, int e, int f)
> {
> int l;
>
> if (a != 5)
> {
> l = a + b + c + d +e + f;
> bar();
> j = l;
> }
> }
>
> Bootstrapped regtested on powerpc64-linux-gnu.
>
> Thanks & Regards
>
> tree-ssa-sink: Improve code sinking pass
>
> Currently, code sinking will sink code at the use points with loop having same
> nesting depth. The following patch improves code sinking by placing the sunk
> code in begining of the block after the labels.
>
> 2024-03-13 Ajit Kumar Agarwal <aagar...@linux.ibm.com>
>
> gcc/ChangeLog:
>
> PR tree-optimization/81953
> * tree-ssa-sink.cc (statement_sink_location):Sink statements at
> the begining of the basic block after labels.
>
> gcc/testsuite/ChangeLog:
>
> PR tree-optimization/81953
> * gcc.dg/tree-ssa/ssa-sink-21.c: New test.
> ---
> gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-21.c | 15 +++++++++++++++
> gcc/tree-ssa-sink.cc | 7 ++-----
> 2 files changed, 17 insertions(+), 5 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-21.c
>
> diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-21.c
> b/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-21.c
> new file mode 100644
> index 00000000000..d3b79ca5803
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-sink-21.c
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-sink-stats" } */
> +void bar();
> +int j;
> +void foo(int a, int b, int c, int d, int e, int f)
> +{
> + int l;
> + l = a + b + c + d +e + f;
> + if (a != 5)
> + {
> + bar();
> + j = l;
> + }
> +}
> +/* { dg-final { scan-tree-dump
> {l_12\s+=\s+_4\s+\+\s+f_11\(D\);\n\s+bar\s+\(\)} sink1 } } */
> diff --git a/gcc/tree-ssa-sink.cc b/gcc/tree-ssa-sink.cc
> index 880d6f70a80..1ec5c048fe7 100644
> --- a/gcc/tree-ssa-sink.cc
> +++ b/gcc/tree-ssa-sink.cc
> @@ -208,7 +208,6 @@ select_best_block (basic_block early_bb,
> loop nest. */
> temp_bb = get_immediate_dominator (CDI_DOMINATORS, temp_bb);
> }
> -
> /* Placing a statement before a setjmp-like function would be invalid
> (it cannot be reevaluated when execution follows an abnormal edge).
> If we selected a block with abnormal predecessors, just punt. */
> @@ -430,6 +429,7 @@ statement_sink_location (gimple *stmt, basic_block frombb,
> continue;
> break;
> }
> +
> use = USE_STMT (one_use);
>
> if (gimple_code (use) != GIMPLE_PHI)
OK if you avoid the stray whitespace changes above.
Richard.
> @@ -439,10 +439,7 @@ statement_sink_location (gimple *stmt, basic_block
> frombb,
> if (sinkbb == frombb)
> return false;
>
> - if (sinkbb == gimple_bb (use))
> - *togsi = gsi_for_stmt (use);
> - else
> - *togsi = gsi_after_labels (sinkbb);
> + *togsi = gsi_after_labels (sinkbb);
>
> return true;
> }
> --
> 2.39.3
>
