aboutsummaryrefslogtreecommitdiff
path: root/gcc/tree-ssa-phiopt.c
diff options
context:
space:
mode:
Diffstat (limited to 'gcc/tree-ssa-phiopt.c')
-rw-r--r--gcc/tree-ssa-phiopt.c102
1 files changed, 87 insertions, 15 deletions
diff --git a/gcc/tree-ssa-phiopt.c b/gcc/tree-ssa-phiopt.c
index 8da7a5c..a752fe0 100644
--- a/gcc/tree-ssa-phiopt.c
+++ b/gcc/tree-ssa-phiopt.c
@@ -1045,7 +1045,7 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
gassign *new_stmt;
edge true_edge, false_edge;
enum tree_code cmp, minmax, ass_code;
- tree smaller, larger, arg_true, arg_false;
+ tree smaller, alt_smaller, larger, alt_larger, arg_true, arg_false;
gimple_stmt_iterator gsi, gsi_from;
type = TREE_TYPE (PHI_RESULT (phi));
@@ -1059,15 +1059,59 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
/* This transformation is only valid for order comparisons. Record which
operand is smaller/larger if the result of the comparison is true. */
+ alt_smaller = NULL_TREE;
+ alt_larger = NULL_TREE;
if (cmp == LT_EXPR || cmp == LE_EXPR)
{
smaller = gimple_cond_lhs (cond);
larger = gimple_cond_rhs (cond);
+ /* If we have smaller < CST it is equivalent to smaller <= CST-1.
+ Likewise smaller <= CST is equivalent to smaller < CST+1. */
+ if (TREE_CODE (larger) == INTEGER_CST)
+ {
+ if (cmp == LT_EXPR)
+ {
+ bool overflow;
+ wide_int alt = wi::sub (larger, 1, TYPE_SIGN (TREE_TYPE (larger)),
+ &overflow);
+ if (! overflow)
+ alt_larger = wide_int_to_tree (TREE_TYPE (larger), alt);
+ }
+ else
+ {
+ bool overflow;
+ wide_int alt = wi::add (larger, 1, TYPE_SIGN (TREE_TYPE (larger)),
+ &overflow);
+ if (! overflow)
+ alt_larger = wide_int_to_tree (TREE_TYPE (larger), alt);
+ }
+ }
}
else if (cmp == GT_EXPR || cmp == GE_EXPR)
{
smaller = gimple_cond_rhs (cond);
larger = gimple_cond_lhs (cond);
+ /* If we have larger > CST it is equivalent to larger >= CST+1.
+ Likewise larger >= CST is equivalent to larger > CST-1. */
+ if (TREE_CODE (smaller) == INTEGER_CST)
+ {
+ if (cmp == GT_EXPR)
+ {
+ bool overflow;
+ wide_int alt = wi::add (smaller, 1, TYPE_SIGN (TREE_TYPE (smaller)),
+ &overflow);
+ if (! overflow)
+ alt_smaller = wide_int_to_tree (TREE_TYPE (smaller), alt);
+ }
+ else
+ {
+ bool overflow;
+ wide_int alt = wi::sub (smaller, 1, TYPE_SIGN (TREE_TYPE (smaller)),
+ &overflow);
+ if (! overflow)
+ alt_smaller = wide_int_to_tree (TREE_TYPE (smaller), alt);
+ }
+ }
}
else
return false;
@@ -1098,8 +1142,12 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
if (empty_block_p (middle_bb))
{
- if (operand_equal_for_phi_arg_p (arg_true, smaller)
- && operand_equal_for_phi_arg_p (arg_false, larger))
+ if ((operand_equal_for_phi_arg_p (arg_true, smaller)
+ || (alt_smaller
+ && operand_equal_for_phi_arg_p (arg_true, alt_smaller)))
+ && (operand_equal_for_phi_arg_p (arg_false, larger)
+ || (alt_larger
+ && operand_equal_for_phi_arg_p (arg_true, alt_larger))))
{
/* Case
@@ -1109,8 +1157,12 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
rslt = larger; */
minmax = MIN_EXPR;
}
- else if (operand_equal_for_phi_arg_p (arg_false, smaller)
- && operand_equal_for_phi_arg_p (arg_true, larger))
+ else if ((operand_equal_for_phi_arg_p (arg_false, smaller)
+ || (alt_smaller
+ && operand_equal_for_phi_arg_p (arg_false, alt_smaller)))
+ && (operand_equal_for_phi_arg_p (arg_true, larger)
+ || (alt_larger
+ && operand_equal_for_phi_arg_p (arg_true, alt_larger))))
minmax = MAX_EXPR;
else
return false;
@@ -1148,7 +1200,9 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
if (!operand_equal_for_phi_arg_p (lhs, arg_true))
return false;
- if (operand_equal_for_phi_arg_p (arg_false, larger))
+ if (operand_equal_for_phi_arg_p (arg_false, larger)
+ || (alt_larger
+ && operand_equal_for_phi_arg_p (arg_false, alt_larger)))
{
/* Case
@@ -1161,9 +1215,13 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
return false;
minmax = MIN_EXPR;
- if (operand_equal_for_phi_arg_p (op0, smaller))
+ if (operand_equal_for_phi_arg_p (op0, smaller)
+ || (alt_smaller
+ && operand_equal_for_phi_arg_p (op0, alt_smaller)))
bound = op1;
- else if (operand_equal_for_phi_arg_p (op1, smaller))
+ else if (operand_equal_for_phi_arg_p (op1, smaller)
+ || (alt_smaller
+ && operand_equal_for_phi_arg_p (op1, alt_smaller)))
bound = op0;
else
return false;
@@ -1173,7 +1231,9 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
bound, larger)))
return false;
}
- else if (operand_equal_for_phi_arg_p (arg_false, smaller))
+ else if (operand_equal_for_phi_arg_p (arg_false, smaller)
+ || (alt_smaller
+ && operand_equal_for_phi_arg_p (arg_false, alt_smaller)))
{
/* Case
@@ -1186,9 +1246,13 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
return false;
minmax = MAX_EXPR;
- if (operand_equal_for_phi_arg_p (op0, larger))
+ if (operand_equal_for_phi_arg_p (op0, larger)
+ || (alt_larger
+ && operand_equal_for_phi_arg_p (op0, alt_larger)))
bound = op1;
- else if (operand_equal_for_phi_arg_p (op1, larger))
+ else if (operand_equal_for_phi_arg_p (op1, larger)
+ || (alt_larger
+ && operand_equal_for_phi_arg_p (op1, alt_larger)))
bound = op0;
else
return false;
@@ -1207,7 +1271,9 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
if (!operand_equal_for_phi_arg_p (lhs, arg_false))
return false;
- if (operand_equal_for_phi_arg_p (arg_true, larger))
+ if (operand_equal_for_phi_arg_p (arg_true, larger)
+ || (alt_larger
+ && operand_equal_for_phi_arg_p (arg_true, alt_larger)))
{
/* Case
@@ -1220,9 +1286,13 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
return false;
minmax = MAX_EXPR;
- if (operand_equal_for_phi_arg_p (op0, smaller))
+ if (operand_equal_for_phi_arg_p (op0, smaller)
+ || (alt_smaller
+ && operand_equal_for_phi_arg_p (op0, alt_smaller)))
bound = op1;
- else if (operand_equal_for_phi_arg_p (op1, smaller))
+ else if (operand_equal_for_phi_arg_p (op1, smaller)
+ || (alt_smaller
+ && operand_equal_for_phi_arg_p (op1, alt_smaller)))
bound = op0;
else
return false;
@@ -1232,7 +1302,9 @@ minmax_replacement (basic_block cond_bb, basic_block middle_bb,
bound, larger)))
return false;
}
- else if (operand_equal_for_phi_arg_p (arg_true, smaller))
+ else if (operand_equal_for_phi_arg_p (arg_true, smaller)
+ || (alt_smaller
+ && operand_equal_for_phi_arg_p (arg_true, alt_smaller)))
{
/* Case
generated by cgit v1.1 at 2025-06-02 09:33:49 +0000