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author | Pan Li <pan2.li@intel.com> | 2024-05-15 10:14:05 +0800 |
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committer | Pan Li <pan2.li@intel.com> | 2024-05-16 20:08:16 +0800 |
commit | 52b0536710ff3f3ace72ab00ce9ef6c630cd1183 (patch) | |
tree | 0e33ea915143143205a0c52ebd4c5e89b1726b7f /gcc/match.pd | |
parent | da73261ce7731be7f2b164f1db796878cdc23365 (diff) | |
download | gcc-52b0536710ff3f3ace72ab00ce9ef6c630cd1183.zip gcc-52b0536710ff3f3ace72ab00ce9ef6c630cd1183.tar.gz gcc-52b0536710ff3f3ace72ab00ce9ef6c630cd1183.tar.bz2 |
Internal-fn: Support new IFN SAT_ADD for unsigned scalar int
This patch would like to add the middle-end presentation for the
saturation add. Aka set the result of add to the max when overflow.
It will take the pattern similar as below.
SAT_ADD (x, y) => (x + y) | (-(TYPE)((TYPE)(x + y) < x))
Take uint8_t as example, we will have:
* SAT_ADD (1, 254) => 255.
* SAT_ADD (1, 255) => 255.
* SAT_ADD (2, 255) => 255.
* SAT_ADD (255, 255) => 255.
Given below example for the unsigned scalar integer uint64_t:
uint64_t sat_add_u64 (uint64_t x, uint64_t y)
{
return (x + y) | (- (uint64_t)((uint64_t)(x + y) < x));
}
Before this patch:
uint64_t sat_add_uint64_t (uint64_t x, uint64_t y)
{
long unsigned int _1;
_Bool _2;
long unsigned int _3;
long unsigned int _4;
uint64_t _7;
long unsigned int _10;
__complex__ long unsigned int _11;
;; basic block 2, loop depth 0
;; pred: ENTRY
_11 = .ADD_OVERFLOW (x_5(D), y_6(D));
_1 = REALPART_EXPR <_11>;
_10 = IMAGPART_EXPR <_11>;
_2 = _10 != 0;
_3 = (long unsigned int) _2;
_4 = -_3;
_7 = _1 | _4;
return _7;
;; succ: EXIT
}
After this patch:
uint64_t sat_add_uint64_t (uint64_t x, uint64_t y)
{
uint64_t _7;
;; basic block 2, loop depth 0
;; pred: ENTRY
_7 = .SAT_ADD (x_5(D), y_6(D)); [tail call]
return _7;
;; succ: EXIT
}
The below tests are passed for this patch:
1. The riscv fully regression tests.
3. The x86 bootstrap tests.
4. The x86 fully regression tests.
PR target/51492
PR target/112600
gcc/ChangeLog:
* internal-fn.cc (commutative_binary_fn_p): Add type IFN_SAT_ADD
to the return true switch case(s).
* internal-fn.def (SAT_ADD): Add new signed optab SAT_ADD.
* match.pd: Add unsigned SAT_ADD match(es).
* optabs.def (OPTAB_NL): Remove fixed-point limitation for
us/ssadd.
* tree-ssa-math-opts.cc (gimple_unsigned_integer_sat_add): New
extern func decl generated in match.pd match.
(match_saturation_arith): New func impl to match the saturation arith.
(math_opts_dom_walker::after_dom_children): Try match saturation
arith when IOR expr.
Signed-off-by: Pan Li <pan2.li@intel.com>
Diffstat (limited to 'gcc/match.pd')
-rw-r--r-- | gcc/match.pd | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 07e743a..0f9c34f 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -3043,6 +3043,57 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) || POINTER_TYPE_P (itype)) && wi::eq_p (wi::to_wide (int_cst), wi::max_value (itype)))))) +/* Unsigned Saturation Add */ +(match (usadd_left_part_1 @0 @1) + (plus:c @0 @1) + (if (INTEGRAL_TYPE_P (type) + && TYPE_UNSIGNED (TREE_TYPE (@0)) + && types_match (type, TREE_TYPE (@0)) + && types_match (type, TREE_TYPE (@1))))) + +(match (usadd_left_part_2 @0 @1) + (realpart (IFN_ADD_OVERFLOW:c @0 @1)) + (if (INTEGRAL_TYPE_P (type) + && TYPE_UNSIGNED (TREE_TYPE (@0)) + && types_match (type, TREE_TYPE (@0)) + && types_match (type, TREE_TYPE (@1))))) + +(match (usadd_right_part_1 @0 @1) + (negate (convert (lt (plus:c @0 @1) @0))) + (if (INTEGRAL_TYPE_P (type) + && TYPE_UNSIGNED (TREE_TYPE (@0)) + && types_match (type, TREE_TYPE (@0)) + && types_match (type, TREE_TYPE (@1))))) + +(match (usadd_right_part_1 @0 @1) + (negate (convert (gt @0 (plus:c @0 @1)))) + (if (INTEGRAL_TYPE_P (type) + && TYPE_UNSIGNED (TREE_TYPE (@0)) + && types_match (type, TREE_TYPE (@0)) + && types_match (type, TREE_TYPE (@1))))) + +(match (usadd_right_part_2 @0 @1) + (negate (convert (ne (imagpart (IFN_ADD_OVERFLOW:c @0 @1)) integer_zerop))) + (if (INTEGRAL_TYPE_P (type) + && TYPE_UNSIGNED (TREE_TYPE (@0)) + && types_match (type, TREE_TYPE (@0)) + && types_match (type, TREE_TYPE (@1))))) + +/* We cannot merge or overload usadd_left_part_1 and usadd_left_part_2 + because the sub part of left_part_2 cannot work with right_part_1. + For example, left_part_2 pattern focus one .ADD_OVERFLOW but the + right_part_1 has nothing to do with .ADD_OVERFLOW. */ + +/* Unsigned saturation add, case 1 (branchless): + SAT_U_ADD = (X + Y) | - ((X + Y) < X) or + SAT_U_ADD = (X + Y) | - (X > (X + Y)). */ +(match (unsigned_integer_sat_add @0 @1) + (bit_ior:c (usadd_left_part_1 @0 @1) (usadd_right_part_1 @0 @1))) + +/* Unsigned saturation add, case 2 (branchless with .ADD_OVERFLOW). */ +(match (unsigned_integer_sat_add @0 @1) + (bit_ior:c (usadd_left_part_2 @0 @1) (usadd_right_part_2 @0 @1))) + /* x > y && x != XXX_MIN --> x > y x > y && x == XXX_MIN --> false . */ (for eqne (eq ne) |