@@ -325,6 +325,22 @@ chrec_fold_plus_1 (enum tree_code code, tree type,
: build_int_cst_type (type, -1)));
CASE_CONVERT:
+ {
+ /* We can strip sign-conversions to signed by performing the
+ operation in unsigned. */
+ tree optype = TREE_TYPE (TREE_OPERAND (op1, 0));
+ if (INTEGRAL_TYPE_P (type)
+ && INTEGRAL_TYPE_P (optype)
+ && tree_nop_conversion_p (type, optype)
+ && TYPE_UNSIGNED (optype))
+ return chrec_convert (type,
+ chrec_fold_plus_1 (code, optype,
+ chrec_convert (optype,
+ op0, NULL),
+ TREE_OPERAND (op1, 0)),
+ NULL);
+ }
+
if (tree_contains_chrecs (op1, NULL))
return chrec_dont_know;
/* FALLTHRU */
@@ -424,6 +440,22 @@ chrec_fold_multiply (tree type,
return chrec_fold_multiply_poly_poly (type, op0, op1);
CASE_CONVERT:
+ {
+ /* We can strip sign-conversions to signed by performing the
+ operation in unsigned. */
+ tree optype = TREE_TYPE (TREE_OPERAND (op1, 0));
+ if (INTEGRAL_TYPE_P (type)
+ && INTEGRAL_TYPE_P (optype)
+ && tree_nop_conversion_p (type, optype)
+ && TYPE_UNSIGNED (optype))
+ return chrec_convert (type,
+ chrec_fold_multiply (optype,
+ chrec_convert (optype,
+ op0, NULL),
+ TREE_OPERAND (op1, 0)),
+ NULL);
+ }
+
if (tree_contains_chrecs (op1, NULL))
return chrec_dont_know;
/* FALLTHRU */
@@ -474,6 +506,22 @@ chrec_fold_multiply (tree type,
}
CASE_CONVERT:
+ {
+ /* We can strip sign-conversions to signed by performing the
+ operation in unsigned. */
+ tree optype = TREE_TYPE (TREE_OPERAND (op0, 0));
+ if (INTEGRAL_TYPE_P (type)
+ && INTEGRAL_TYPE_P (optype)
+ && tree_nop_conversion_p (type, optype)
+ && TYPE_UNSIGNED (optype))
+ return chrec_convert (type,
+ chrec_fold_multiply (optype,
+ TREE_OPERAND (op0, 0),
+ chrec_convert (optype,
+ op1, NULL)),
+ NULL);
+ }
+
if (tree_contains_chrecs (op0, NULL))
return chrec_dont_know;
/* FALLTHRU */
The following addresses a performance regression caused by the recent SCEV analysis fix with regard to folding multiplications and undefined behavior on overflow. We do not handle (T) { a, +, b } * c but can treat sign-conversions from unsigned by performing the multiplication in the unsigned type. That's what we already do for additions (but that misses one case that turns out important). This fixes the 434.zeusmp regression for me. Bootstrap and regtest running on x86_64-unknown-linux-gnu. PR tree-optimization/114269 * tree-chrec.cc (chrec_fold_plus_1): Handle sign-conversions in the third CASE_CONVERT case as well. (chrec_fold_multiply): Handle sign-conversions from unsigned by performing the operation in the unsigned type. --- gcc/tree-chrec.cc | 48 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+)