| Message ID | 20240814151804.217324-1-konstantinos.eleftheriou@vrull.eu |
|---|---|
| State | New |
| Headers | show |
| Series | match: Fix A || B not optimized to true when !B implies A [PR114326] | expand |
Konstantinos Eleftheriou <konstantinos.eleftheriou@vrull.eu> writes: > From: kelefth <konstantinos.eleftheriou@vrull.eu> > > In expressions like (a != b || ((a ^ b) & CST0) == CST1) and > (a != b || (a ^ b) == CST), (a ^ b) is folded to false. > In the equivalent expressions (((a ^ b) & CST0) == CST1 || a != b) and > ((a ^ b) == CST, (a ^ b) || a != b) this is not happening. > > This patch adds the following simplifications in match.pd: > ((a ^ b) & CST0) == CST1 || a != b --> 0 == (CST1 || a != b) > (a ^ b) == CST || a != b --> 0 == CST || (a != b) > > PR tree-optimization/114326 > > gcc/ChangeLog: > > * match.pd: Add two patterns to fold a ^ b to 0, when a == b. > > gcc/testsuite/ChangeLog: > > * gcc.dg/tree-ssa/fold-xor-and-or-1.c: New test. > * gcc.dg/tree-ssa/fold-xor-and-or-2.c: New test. > * gcc.dg/tree-ssa/fold-xor-or-1.c: New test. > * gcc.dg/tree-ssa/fold-xor-or-2.c: New test. > > Reviewed-by: Christoph Müllner <christoph.muellner@vrull.eu> > Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu> > Signed-off-by: Konstantinos Eleftheriou <konstantinos.eleftheriou@vrull.eu> > --- > gcc/match.pd | 30 +++++++++++++++++++ > .../gcc.dg/tree-ssa/fold-xor-and-or-1.c | 17 +++++++++++ > .../gcc.dg/tree-ssa/fold-xor-and-or-2.c | 19 ++++++++++++ > gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-1.c | 17 +++++++++++ > gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-2.c | 19 ++++++++++++ > 5 files changed, 102 insertions(+) > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-1.c > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-2.c > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-1.c > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-2.c > > [...] > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-2.c > @@ -0,0 +1,19 @@ > +/* { dg-do-compile } */ /* { dg-do compile } */ Please fix each instance of that. Thanks! > [...] sam
Thanks, fixed ( https://gcc.gnu.org/pipermail/gcc-patches/2024-August/660631.html). On Thu, Aug 15, 2024 at 3:57 PM Sam James <sam@gentoo.org> wrote: > Konstantinos Eleftheriou <konstantinos.eleftheriou@vrull.eu> writes: > > > From: kelefth <konstantinos.eleftheriou@vrull.eu> > > > > In expressions like (a != b || ((a ^ b) & CST0) == CST1) and > > (a != b || (a ^ b) == CST), (a ^ b) is folded to false. > > In the equivalent expressions (((a ^ b) & CST0) == CST1 || a != b) and > > ((a ^ b) == CST, (a ^ b) || a != b) this is not happening. > > > > This patch adds the following simplifications in match.pd: > > ((a ^ b) & CST0) == CST1 || a != b --> 0 == (CST1 || a != b) > > (a ^ b) == CST || a != b --> 0 == CST || (a != b) > > > > PR tree-optimization/114326 > > > > gcc/ChangeLog: > > > > * match.pd: Add two patterns to fold a ^ b to 0, when a == b. > > > > gcc/testsuite/ChangeLog: > > > > * gcc.dg/tree-ssa/fold-xor-and-or-1.c: New test. > > * gcc.dg/tree-ssa/fold-xor-and-or-2.c: New test. > > * gcc.dg/tree-ssa/fold-xor-or-1.c: New test. > > * gcc.dg/tree-ssa/fold-xor-or-2.c: New test. > > > > Reviewed-by: Christoph Müllner <christoph.muellner@vrull.eu> > > Signed-off-by: Philipp Tomsich <philipp.tomsich@vrull.eu> > > Signed-off-by: Konstantinos Eleftheriou < > konstantinos.eleftheriou@vrull.eu> > > --- > > gcc/match.pd | 30 +++++++++++++++++++ > > .../gcc.dg/tree-ssa/fold-xor-and-or-1.c | 17 +++++++++++ > > .../gcc.dg/tree-ssa/fold-xor-and-or-2.c | 19 ++++++++++++ > > gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-1.c | 17 +++++++++++ > > gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-2.c | 19 ++++++++++++ > > 5 files changed, 102 insertions(+) > > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-1.c > > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-2.c > > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-1.c > > create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-2.c > > > > [...] > > --- /dev/null > > +++ b/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-2.c > > @@ -0,0 +1,19 @@ > > +/* { dg-do-compile } */ > > /* { dg-do compile } */ > > Please fix each instance of that. Thanks! > > > [...] > > sam >
diff --git a/gcc/match.pd b/gcc/match.pd index c9c8478d286..1c55bd72f09 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -10680,3 +10680,33 @@ and, } (if (full_perm_p) (vec_perm (op@3 @0 @1) @3 @2)))))) + +/* ((a ^ b) & CST0) == CST1 || a != b --> 0 == (CST1 || a != b). */ +(for cmp (simple_comparison) + (simplify + (bit_ior + (cmp + (bit_and + (bit_xor @0 @1) + INTEGER_CST) + @3) + (ne@4 @0 @1)) + (bit_ior + (cmp + { build_zero_cst (TREE_TYPE (@0)); } + @3) + @4))) + +/* (a ^ b) == CST || a != b --> 0 == CST || (a != b). */ +(for cmp (simple_comparison) + (simplify + (bit_ior + (cmp + (bit_xor @0 @1) + @2) + (ne@3 @0 @1)) + (bit_ior + (cmp + {build_zero_cst (TREE_TYPE (@0)); } + @2) + @3))) \ No newline at end of file diff --git a/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-1.c b/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-1.c new file mode 100644 index 00000000000..2bcf98d93c3 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-1.c @@ -0,0 +1,17 @@ +/* { dg-do-compile } */ +/* { dg-options "-O3 -fdump-tree-optimized" } */ + +int cmp1(int d1, int d2) { + if (((d1 ^ d2) & 0xabcd) == 0 || d1 != d2) + return 0; + return 1; +} + +int cmp2(int d1, int d2) { + if (d1 != d2 || ((d1 ^ d2) & 0xabcd) == 0) + return 0; + return 1; +} + +/* The if should be removed, so the condition should not exist */ +/* { dg-final { scan-tree-dump-not "d1_\[0-9\]+.D. \\^ d2_\[0-9\]+.D." "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-2.c b/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-2.c new file mode 100644 index 00000000000..8771897181a --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-and-or-2.c @@ -0,0 +1,19 @@ +/* { dg-do-compile } */ +/* { dg-options "-O3 -fdump-tree-optimized" } */ + +typedef unsigned long int uint64_t; + +int cmp1(uint64_t d1, uint64_t d2) { + if (((d1 ^ d2) & 0xabcd) == 0 || d1 != d2) + return 0; + return 1; +} + +int cmp2(uint64_t d1, uint64_t d2) { + if (d1 != d2 || ((d1 ^ d2) & 0xabcd) == 0) + return 0; + return 1; +} + +/* The if should be removed, so the condition should not exist */ +/* { dg-final { scan-tree-dump-not "d1_\[0-9\]+.D. \\^ d2_\[0-9\]+.D." "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-1.c b/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-1.c new file mode 100644 index 00000000000..eb08e086014 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-1.c @@ -0,0 +1,17 @@ +/* { dg-do-compile } */ +/* { dg-options "-O3 -fdump-tree-optimized" } */ + +int cmp1(int d1, int d2) { + if ((d1 ^ d2) == 0xabcd || d1 != d2) + return 0; + return 1; +} + +int cmp2(int d1, int d2) { + if (d1 != d2 || (d1 ^ d2) == 0xabcd) + return 0; + return 1; +} + +/* The if should be removed, so the condition should not exist */ +/* { dg-final { scan-tree-dump-not "d1_\[0-9\]+.D. \\^ d2_\[0-9\]+.D." "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-2.c b/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-2.c new file mode 100644 index 00000000000..b621651e636 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/fold-xor-or-2.c @@ -0,0 +1,19 @@ +/* { dg-do-compile } */ +/* { dg-options "-O3 -fdump-tree-optimized" } */ + +typedef unsigned long int uint64_t; + +int cmp1(uint64_t d1, uint64_t d2) { + if ((d1 ^ d2) == 0xabcd || d1 != d2) + return 0; + return 1; +} + +int cmp2(uint64_t d1, uint64_t d2) { + if (d1 != d2 || (d1 ^ d2) == 0xabcd) + return 0; + return 1; +} + +/* The if should be removed, so the condition should not exist */ +/* { dg-final { scan-tree-dump-not "d1_\[0-9\]+.D. \\^ d2_\[0-9\]+.D." "optimized" } } */