From: Pan Li <pan2...@intel.com>
This patch would like to add form 2 support for the .SAT_TRUNC. Aka:
Form 2:
#define DEF_SAT_U_TRUC_FMT_2(NT, WT) \
NT __attribute__((noinline)) \
sat_u_truc_##WT##_to_##NT##_fmt_2 (WT x) \
{ \
bool overflow = x > (WT)(NT)(-1); \
return overflow ? (NT)-1 : (NT)x; \
}
DEF_SAT_U_TRUC_FMT_2(uint32, uint64)
Before this patch:
3 │
4 │ __attribute__((noinline))
5 │ uint32_t sat_u_truc_uint64_t_to_uint32_t_fmt_2 (uint64_t x)
6 │ {
7 │ uint32_t _1;
8 │ long unsigned int _3;
9 │
10 │ ;; basic block 2, loop depth 0
11 │ ;; pred: ENTRY
12 │ _3 = MIN_EXPR <x_2(D), 4294967295>;
13 │ _1 = (uint32_t) _3;
14 │ return _1;
15 │ ;; succ: EXIT
16 │
17 │ }
After this patch:
3 │
4 │ __attribute__((noinline))
5 │ uint32_t sat_u_truc_uint64_t_to_uint32_t_fmt_2 (uint64_t x)
6 │ {
7 │ uint32_t _1;
8 │
9 │ ;; basic block 2, loop depth 0
10 │ ;; pred: ENTRY
11 │ _1 = .SAT_TRUNC (x_2(D)); [tail call]
12 │ return _1;
13 │ ;; succ: EXIT
14 │
15 │ }
The below test suites are passed for this patch:
1. The x86 bootstrap test.
2. The x86 fully regression test.
3. The rv64gcv fully regresssion test.
gcc/ChangeLog:
* match.pd: Add form 2 for .SAT_TRUNC.
* tree-ssa-math-opts.cc (math_opts_dom_walker::after_dom_children):
Add new case NOP_EXPR, and try to match SAT_TRUNC.
Signed-off-by: Pan Li <pan2...@intel.com>
---
gcc/match.pd | 17 ++++++++++++++++-
gcc/tree-ssa-math-opts.cc | 4 ++++
2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/gcc/match.pd b/gcc/match.pd
index 4edfa2ae2c9..3759c64d461 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3234,7 +3234,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
&& types_match (type, @0, @1))))
-/* Unsigned saturation truncate, case 1 (), sizeof (WT) > sizeof (NT).
+/* Unsigned saturation truncate, case 1, sizeof (WT) > sizeof (NT).
SAT_U_TRUNC = (NT)x | (NT)(-(X > (WT)(NT)(-1))). */
(match (unsigned_integer_sat_trunc @0)
(bit_ior:c (negate (convert (gt @0 INTEGER_CST@1)))
@@ -3250,6 +3250,21 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
}
(if (otype_precision < itype_precision && wi::eq_p (trunc_max, int_cst))))))
+/* Unsigned saturation truncate, case 2, sizeof (WT) > sizeof (NT).
+ SAT_U_TRUNC = (NT)(MIN_EXPR (X, 255)). */
+(match (unsigned_integer_sat_trunc @0)
+ (convert (min @0 INTEGER_CST@1))
+ (if (INTEGRAL_TYPE_P (type) && TYPE_UNSIGNED (type)
+ && TYPE_UNSIGNED (TREE_TYPE (@0)))
+ (with
+ {
+ unsigned itype_precision = TYPE_PRECISION (TREE_TYPE (@0));
+ unsigned otype_precision = TYPE_PRECISION (type);
+ wide_int trunc_max = wi::mask (otype_precision, false, itype_precision);
+ wide_int int_cst = wi::to_wide (@1, itype_precision);
+ }
+ (if (otype_precision < itype_precision && wi::eq_p (trunc_max, int_cst))))))
+
/* x > y && x != XXX_MIN --> x > y
x > y && x == XXX_MIN --> false . */
(for eqne (eq ne)
diff --git a/gcc/tree-ssa-math-opts.cc b/gcc/tree-ssa-math-opts.cc
index a35caf5f058..ac86be8eb94 100644
--- a/gcc/tree-ssa-math-opts.cc
+++ b/gcc/tree-ssa-math-opts.cc
@@ -6170,6 +6170,10 @@ math_opts_dom_walker::after_dom_children (basic_block bb)
match_unsigned_saturation_sub (&gsi, as_a<gassign *> (stmt));
break;
+ case NOP_EXPR:
+ match_unsigned_saturation_trunc (&gsi, as_a<gassign *> (stmt));
+ break;
+
default:;
}
}
--
2.34.1
