| Message ID | 20240726043600.47858-3-quic_apinski@quicinc.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/3] isel: Move duplicate comparisons to its own function | expand |
On Fri, Jul 26, 2024 at 6:37 AM Andrew Pinski <quic_apinski@quicinc.com> wrote: > > While doing cleanups on this code I noticed that we do the duplicate > of comparisons at -O0. For C and C++ code this makes no difference as > the gimplifier never produces COND_EXPR. But it could make a difference > for other front-ends. > Oh and for -fno-tree-ter, duplicating the comparison is just a waste > as it is never used for expand. > > I also decided to add a few testcases so this is checked in the future. > Even added one for the duplication itself. > > Bootstrapped and tested on x86_64-linux-gnu with no regressions. OK > PR tree-optimization/116101 > > gcc/ChangeLog: > > * gimple-isel.cc (maybe_duplicate_comparison): Don't > do anything for -O0 or -fno-tree-ter. > > gcc/testsuite/ChangeLog: > > * gcc.dg/tree-ssa/dup_compare_cond-1.c: New test. > * gcc.dg/tree-ssa/dup_compare_cond-2.c: New test. > * gcc.dg/tree-ssa/dup_compare_cond-3.c: New test. > > Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com> > --- > gcc/gimple-isel.cc | 5 +++++ > .../gcc.dg/tree-ssa/dup_compare_cond-1.c | 19 +++++++++++++++++++ > .../gcc.dg/tree-ssa/dup_compare_cond-2.c | 19 +++++++++++++++++++ > .../gcc.dg/tree-ssa/dup_compare_cond-3.c | 19 +++++++++++++++++++ > 4 files changed, 62 insertions(+) > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-1.c > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-2.c > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-3.c > > diff --git a/gcc/gimple-isel.cc b/gcc/gimple-isel.cc > index 99bfc937bd5..2817ab659af 100644 > --- a/gcc/gimple-isel.cc > +++ b/gcc/gimple-isel.cc > @@ -407,6 +407,11 @@ maybe_duplicate_comparison (gassign *stmt, basic_block bb) > tree lhs = gimple_assign_lhs (stmt); > unsigned cnt = 0; > > + /* This is should not be used for -O0 nor it is not useful > + when ter is turned off. */ > + if (!optimize || !flag_tree_ter) > + return; > + > FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs) > { > if (is_gimple_debug (USE_STMT (use_p))) > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-1.c b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-1.c > new file mode 100644 > index 00000000000..0321a60b34f > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-1.c > @@ -0,0 +1,19 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fgimple -O0 -fdump-tree-optimized " } */ > +/* PR tree-optimization/116101 */ > + > +int __GIMPLE() f(int a, int b, int c, int d, int e) > +{ > + _Bool t; > + int ff; > + int gg; > + int res; > + t = a == b; > + ff = t ? a : e; > + gg = t ? d : b; > + res = ff+gg; > + return res; > +} > + > +/* At -O0 we should not duplicate the comparison. */ > +/* { dg-final { scan-tree-dump-times " == " 1 "optimized" } } */ > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-2.c b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-2.c > new file mode 100644 > index 00000000000..07e2175c612 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-2.c > @@ -0,0 +1,19 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fgimple -O2 -fdump-tree-optimized " } */ > +/* PR middle-end/105715 */ > + > +int __GIMPLE() f(int a, int b, int c, int d, int e) > +{ > + _Bool t; > + int ff; > + int gg; > + int res; > + t = a == b; > + ff = t ? a : e; > + gg = t ? d : b; > + res = ff+gg; > + return res; > +} > + > +/* At -O2 we should have duplicate the comparison. */ > +/* { dg-final { scan-tree-dump-times " == " 2 "optimized" } } */ > diff --git a/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-3.c b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-3.c > new file mode 100644 > index 00000000000..88bf19795e0 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-3.c > @@ -0,0 +1,19 @@ > +/* { dg-do compile } */ > +/* { dg-options "-fgimple -O2 -fno-tree-ter -fdump-tree-optimized " } */ > +/* PR tree-optimization/116101 */ > + > +int __GIMPLE() f(int a, int b, int c, int d, int e) > +{ > + _Bool t; > + int ff; > + int gg; > + int res; > + t = a == b; > + ff = t ? a : e; > + gg = t ? d : b; > + res = ff+gg; > + return res; > +} > + > +/* With -fno-tree-ter it is not useful to duplicate the comparison. */ > +/* { dg-final { scan-tree-dump-times " == " 1 "optimized" } } */ > -- > 2.43.0 >
diff --git a/gcc/gimple-isel.cc b/gcc/gimple-isel.cc index 99bfc937bd5..2817ab659af 100644 --- a/gcc/gimple-isel.cc +++ b/gcc/gimple-isel.cc @@ -407,6 +407,11 @@ maybe_duplicate_comparison (gassign *stmt, basic_block bb) tree lhs = gimple_assign_lhs (stmt); unsigned cnt = 0; + /* This is should not be used for -O0 nor it is not useful + when ter is turned off. */ + if (!optimize || !flag_tree_ter) + return; + FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs) { if (is_gimple_debug (USE_STMT (use_p))) diff --git a/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-1.c b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-1.c new file mode 100644 index 00000000000..0321a60b34f --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-1.c @@ -0,0 +1,19 @@ +/* { dg-do compile } */ +/* { dg-options "-fgimple -O0 -fdump-tree-optimized " } */ +/* PR tree-optimization/116101 */ + +int __GIMPLE() f(int a, int b, int c, int d, int e) +{ + _Bool t; + int ff; + int gg; + int res; + t = a == b; + ff = t ? a : e; + gg = t ? d : b; + res = ff+gg; + return res; +} + +/* At -O0 we should not duplicate the comparison. */ +/* { dg-final { scan-tree-dump-times " == " 1 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-2.c b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-2.c new file mode 100644 index 00000000000..07e2175c612 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-2.c @@ -0,0 +1,19 @@ +/* { dg-do compile } */ +/* { dg-options "-fgimple -O2 -fdump-tree-optimized " } */ +/* PR middle-end/105715 */ + +int __GIMPLE() f(int a, int b, int c, int d, int e) +{ + _Bool t; + int ff; + int gg; + int res; + t = a == b; + ff = t ? a : e; + gg = t ? d : b; + res = ff+gg; + return res; +} + +/* At -O2 we should have duplicate the comparison. */ +/* { dg-final { scan-tree-dump-times " == " 2 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-3.c b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-3.c new file mode 100644 index 00000000000..88bf19795e0 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-3.c @@ -0,0 +1,19 @@ +/* { dg-do compile } */ +/* { dg-options "-fgimple -O2 -fno-tree-ter -fdump-tree-optimized " } */ +/* PR tree-optimization/116101 */ + +int __GIMPLE() f(int a, int b, int c, int d, int e) +{ + _Bool t; + int ff; + int gg; + int res; + t = a == b; + ff = t ? a : e; + gg = t ? d : b; + res = ff+gg; + return res; +} + +/* With -fno-tree-ter it is not useful to duplicate the comparison. */ +/* { dg-final { scan-tree-dump-times " == " 1 "optimized" } } */
While doing cleanups on this code I noticed that we do the duplicate of comparisons at -O0. For C and C++ code this makes no difference as the gimplifier never produces COND_EXPR. But it could make a difference for other front-ends. Oh and for -fno-tree-ter, duplicating the comparison is just a waste as it is never used for expand. I also decided to add a few testcases so this is checked in the future. Even added one for the duplication itself. Bootstrapped and tested on x86_64-linux-gnu with no regressions. PR tree-optimization/116101 gcc/ChangeLog: * gimple-isel.cc (maybe_duplicate_comparison): Don't do anything for -O0 or -fno-tree-ter. gcc/testsuite/ChangeLog: * gcc.dg/tree-ssa/dup_compare_cond-1.c: New test. * gcc.dg/tree-ssa/dup_compare_cond-2.c: New test. * gcc.dg/tree-ssa/dup_compare_cond-3.c: New test. Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com> --- gcc/gimple-isel.cc | 5 +++++ .../gcc.dg/tree-ssa/dup_compare_cond-1.c | 19 +++++++++++++++++++ .../gcc.dg/tree-ssa/dup_compare_cond-2.c | 19 +++++++++++++++++++ .../gcc.dg/tree-ssa/dup_compare_cond-3.c | 19 +++++++++++++++++++ 4 files changed, 62 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-1.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-2.c create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/dup_compare_cond-3.c