https://gcc.gnu.org/g:d339dbee2c1429fee8792a03f571fa75d036566b
commit r15-4279-gd339dbee2c1429fee8792a03f571fa75d036566b
Author: Pan Li <pan2...@intel.com>
Date: Fri Oct 11 11:58:30 2024 +0800
Vect: Try the pattern of vector signed integer SAT_SUB
Almost the same as vector unsigned integer SAT_SUB, try to match
the signed version during the vector pattern matching.
The below test suites are passed for this patch.
* The rv64gcv fully regression test.
* The x86 bootstrap test.
* The x86 fully regression test.
gcc/ChangeLog:
* tree-vect-patterns.cc (gimple_signed_integer_sat_sub): Add new
func decl for signed SAT_SUB.
(vect_recog_sat_sub_pattern_transform): Update comments.
(vect_recog_sat_sub_pattern): Try the vector signed SAT_SUB
pattern.
Signed-off-by: Pan Li <pan2...@intel.com>
Diff:
---
gcc/tree-vect-patterns.cc | 26 +++++++++++++++++++++++++-
1 file changed, 25 insertions(+), 1 deletion(-)
diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc
index 9bf8526ac995..746f100a0842 100644
--- a/gcc/tree-vect-patterns.cc
+++ b/gcc/tree-vect-patterns.cc
@@ -4538,6 +4538,7 @@ extern bool gimple_unsigned_integer_sat_sub (tree, tree*,
tree (*)(tree));
extern bool gimple_unsigned_integer_sat_trunc (tree, tree*, tree (*)(tree));
extern bool gimple_signed_integer_sat_add (tree, tree*, tree (*)(tree));
+extern bool gimple_signed_integer_sat_sub (tree, tree*, tree (*)(tree));
static gimple *
vect_recog_build_binary_gimple_stmt (vec_info *vinfo, stmt_vec_info stmt_info,
@@ -4684,6 +4685,7 @@ vect_recog_sat_sub_pattern_transform (vec_info *vinfo,
/*
* Try to detect saturation sub pattern (SAT_ADD), aka below gimple:
+ * Unsigned:
* _7 = _1 >= _2;
* _8 = _1 - _2;
* _10 = (long unsigned int) _7;
@@ -4691,6 +4693,27 @@ vect_recog_sat_sub_pattern_transform (vec_info *vinfo,
*
* And then simplied to
* _9 = .SAT_SUB (_1, _2);
+ *
+ * Signed:
+ * x.0_4 = (unsigned char) x_16;
+ * y.1_5 = (unsigned char) y_18;
+ * _6 = x.0_4 - y.1_5;
+ * minus_19 = (int8_t) _6;
+ * _7 = x_16 ^ y_18;
+ * _8 = x_16 ^ minus_19;
+ * _44 = _7 < 0;
+ * _23 = x_16 < 0;
+ * _24 = (signed char) _23;
+ * _58 = (unsigned char) _24;
+ * _59 = -_58;
+ * _25 = (signed char) _59;
+ * _26 = _25 ^ 127;
+ * _42 = _8 < 0;
+ * _41 = _42 & _44;
+ * iftmp.2_11 = _41 ? _26 : minus_19;
+ *
+ * And then simplied to
+ * iftmp.2_11 = .SAT_SUB (x_16, y_18);
*/
static gimple *
@@ -4705,7 +4728,8 @@ vect_recog_sat_sub_pattern (vec_info *vinfo,
stmt_vec_info stmt_vinfo,
tree ops[2];
tree lhs = gimple_assign_lhs (last_stmt);
- if (gimple_unsigned_integer_sat_sub (lhs, ops, NULL))
+ if (gimple_unsigned_integer_sat_sub (lhs, ops, NULL)
+ || gimple_signed_integer_sat_sub (lhs, ops, NULL))
{
vect_recog_sat_sub_pattern_transform (vinfo, stmt_vinfo, lhs, ops);
gimple *stmt = vect_recog_build_binary_gimple_stmt (vinfo, stmt_vinfo,
