[PATCH] phiopt: Handle bool in two_value_replacement [PR796232]

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.  Additionally
it limits two_value_replacement optimization to the late phiopt like
conditional_replacement.

2020-12-06  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/96232
	* tree-ssa-phiopt.c (two_value_replacement): Optimize even boolean lhs
	cases as long as arg0 has wider precision and conditional_replacement
	doesn't handle that case.
	(tree_ssa_phiopt_worker): Don't call two_value_replacement during
	early phiopt.

	* gcc.dg/tree-ssa/pr96232-2.c: New test.
	* gcc.dg/tree-ssa/pr88676-2.c: Check phiopt2 dump rather than phiopt1.
This commit is contained in:
Jakub Jelinek 2020-12-06 10:58:10 +01:00
parent 9e12b8b181
commit 8c23434fda
3 changed files with 39 additions and 6 deletions

View File

@ -1,7 +1,7 @@
/* PR tree-optimization/88676 */
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-phiopt1" } */
/* { dg-final { scan-tree-dump-not " = PHI <" "phiopt1" { target le } } } */
/* { dg-options "-O2 -fdump-tree-phiopt2" } */
/* { dg-final { scan-tree-dump-not " = PHI <" "phiopt2" { target le } } } */
struct foo1 {
int i:1;

View File

@ -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;
}

View File

@ -337,7 +337,7 @@ tree_ssa_phiopt_worker (bool do_store_elim, bool do_hoist_loads, bool early_p)
}
/* Do the replacement of conditional if it can be done. */
if (two_value_replacement (bb, bb1, e2, phi, arg0, arg1))
if (!early_p && two_value_replacement (bb, bb1, e2, phi, arg0, arg1))
cfgchanged = true;
else if (!early_p
&& conditional_replacement (bb, bb1, e1, e2, phi,
@ -635,7 +635,6 @@ two_value_replacement (basic_block cond_bb, basic_block middle_bb,
if (TREE_CODE (lhs) != SSA_NAME
|| !INTEGRAL_TYPE_P (TREE_TYPE (lhs))
|| TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE
|| TREE_CODE (rhs) != INTEGER_CST)
return false;
@ -648,9 +647,25 @@ two_value_replacement (basic_block cond_bb, basic_block middle_bb,
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;