On December 5, 2020 10:14:49 AM GMT+01:00, Jakub Jelinek <ja...@redhat.com>
wrote:
>Hi!
>
>The following patch improves code generation on the included testcase
>by
>enabling two_value_replacement on booleans. It does that only for
>arg0/arg1
>values that conditional_replacement doesn't handle, and only does it if
>not
>in the early phiopt pass, because conditional_replacement isn't done
>early
>either.
>I must say I'm not sure about that, in PR87105 / PR87608 you've added
>the
>early phiopt pass and specifically excluded conditional_replacement and
>a
>few others from being optimized early, but then 3 months later I've
>added
>two_value_replacement and didn't restrict it to !early_p. Shall we
>instead
>do two_value_replacement only in late phiopt?
Yeah, I guess that would make sense. I don't remember exactly but I saw
regressions with early doing if conversion besides min/max/abs detection.
>Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
Richard.
>2020-12-05 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/96232
> * tree-ssa-phiopt.c (two_value_replacement): Add early_p argument.
> If false, optimize even boolean lhs cases as long as arg0 has wider
> precision and conditional_replacement doesn't handle that case.
>
> * gcc.dg/tree-ssa/pr96232-2.c: New test.
>
>--- gcc/tree-ssa-phiopt.c.jj 2020-12-04 17:27:53.472837921 +0100
>+++ gcc/tree-ssa-phiopt.c 2020-12-04 17:54:56.070689584 +0100
>@@ -51,7 +51,7 @@ along with GCC; see the file COPYING3.
>
> static unsigned int tree_ssa_phiopt_worker (bool, bool, bool);
>static bool two_value_replacement (basic_block, basic_block, edge, gphi
>*,
>- tree, tree);
>+ tree, tree, bool);
> static bool conditional_replacement (basic_block, basic_block,
> edge, edge, gphi *, tree, tree);
>static gphi *factor_out_conditional_conversion (edge, edge, gphi *,
>tree, tree,
>@@ -337,7 +337,7 @@ tree_ssa_phiopt_worker (bool do_store_el
> }
>
> /* Do the replacement of conditional if it can be done. */
>- if (two_value_replacement (bb, bb1, e2, phi, arg0, arg1))
>+ if (two_value_replacement (bb, bb1, e2, phi, arg0, arg1, early_p))
> cfgchanged = true;
> else if (!early_p
> && conditional_replacement (bb, bb1, e1, e2, phi,
>@@ -614,7 +614,7 @@ factor_out_conditional_conversion (edge
>
> static bool
> two_value_replacement (basic_block cond_bb, basic_block middle_bb,
>- edge e1, gphi *phi, tree arg0, tree arg1)
>+ edge e1, gphi *phi, tree arg0, tree arg1, bool early_p)
> {
> /* Only look for adjacent integer constants. */
> if (!INTEGRAL_TYPE_P (TREE_TYPE (arg0))
>@@ -635,7 +635,7 @@ two_value_replacement (basic_block cond_
>
> if (TREE_CODE (lhs) != SSA_NAME
> || !INTEGRAL_TYPE_P (TREE_TYPE (lhs))
>- || TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE
>+ || (early_p && TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE)
> || TREE_CODE (rhs) != INTEGER_CST)
> return false;
>
>@@ -648,9 +648,25 @@ two_value_replacement (basic_block cond_
> return false;
> }
>
>+ /* Defer boolean x ? 0 : {1,-1} or x ? {1,-1} : 0 to
>+ conditional_replacement. */
>+ if (TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE
>+ && (integer_zerop (arg0)
>+ || integer_zerop (arg1)
>+ || TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE
>+ || (TYPE_PRECISION (TREE_TYPE (arg0))
>+ <= TYPE_PRECISION (TREE_TYPE (lhs)))))
>+ return false;
>+
> wide_int min, max;
>- if (get_range_info (lhs, &min, &max) != VR_RANGE
>- || min + 1 != max
>+ if (TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE)
>+ {
>+ min = wi::to_wide (boolean_false_node);
>+ max = wi::to_wide (boolean_true_node);
>+ }
>+ else if (get_range_info (lhs, &min, &max) != VR_RANGE)
>+ return false;
>+ if (min + 1 != max
> || (wi::to_wide (rhs) != min
> && wi::to_wide (rhs) != max))
> return false;
>--- gcc/testsuite/gcc.dg/tree-ssa/pr96232-2.c.jj 2020-12-04
>17:56:22.180730234 +0100
>+++ gcc/testsuite/gcc.dg/tree-ssa/pr96232-2.c 2020-12-04
>17:57:27.973997239 +0100
>@@ -0,0 +1,18 @@
>+/* PR tree-optimization/96232 */
>+/* { dg-do compile } */
>+/* { dg-options "-O2 -fdump-tree-optimized" } */
>+/* { dg-final { scan-tree-dump " 38 - " "optimized" } } */
>+/* { dg-final { scan-tree-dump " \\+ 97;" "optimized" } } */
>+/* { dg-final { scan-tree-dump-not "PHI <" "optimized" } } */
>+
>+int
>+foo (_Bool x)
>+{
>+ return x ? 37 : 38;
>+}
>+
>+int
>+bar (_Bool x)
>+{
>+ return x ? 98 : 97;
>+}
>
> Jakub
