Hi!
The following patch adds sqrt support (but similarly to sincos, only
dumb basic ranges only).
Ok for trunk if it passes bootstrap/regtest?
Will improve this incrementally and sin/cos as well.
2023-04-27 Jakub Jelinek <ja...@redhat.com>
* gimple-range-op.cc (class cfn_sqrt): New type.
(op_cfn_sqrt): New variable.
(gimple_range_op_handler::maybe_builtin_call): Handle
CASE_CFN_SQRT{,_FN}.
* gcc.dg/tree-ssa/range-sqrt.c: New test.
--- gcc/gimple-range-op.cc.jj 2023-04-27 11:57:09.865879982 +0200
+++ gcc/gimple-range-op.cc 2023-04-27 15:15:05.089787859 +0200
@@ -400,6 +400,83 @@ public:
}
} op_cfn_copysign;
+class cfn_sqrt : public range_operator_float
+{
+public:
+ using range_operator_float::fold_range;
+ using range_operator_float::op1_range;
+ virtual bool fold_range (frange &r, tree type,
+ const frange &lh, const frange &,
+ relation_trio) const final override
+ {
+ if (lh.undefined_p ())
+ return false;
+ if (lh.known_isnan () || real_less (&lh.upper_bound (), &dconstm0))
+ {
+ r.set_nan (type);
+ return true;
+ }
+ unsigned bulps
+ = targetm.libm_function_max_error (CFN_SQRT, TYPE_MODE (type), true);
+ if (bulps == ~0U)
+ r.set_varying (type);
+ else if (bulps == 0)
+ r.set (type, dconstm0, dconstinf);
+ else
+ {
+ REAL_VALUE_TYPE boundmin = dconstm0;
+ while (bulps--)
+ frange_nextafter (TYPE_MODE (type), boundmin, dconstninf);
+ r.set (type, boundmin, dconstinf);
+ }
+ if (!lh.maybe_isnan () && !real_less (&lh.lower_bound (), &dconst0))
+ r.clear_nan ();
+ return true;
+ }
+ virtual bool op1_range (frange &r, tree type,
+ const frange &lhs, const frange &,
+ relation_trio) const final override
+ {
+ if (lhs.undefined_p ())
+ return false;
+
+ // A known NAN means the input is [-INF,-0.) U +-NAN.
+ if (lhs.known_isnan ())
+ {
+ known_nan:
+ REAL_VALUE_TYPE ub = dconstm0;
+ frange_nextafter (TYPE_MODE (type), ub, dconstninf);
+ r.set (type, dconstninf, ub);
+ // No r.flush_denormals_to_zero (); here - it is a reverse op.
+ return true;
+ }
+
+ // Results outside of [-0.0, +Inf] are impossible.
+ const REAL_VALUE_TYPE &ub = lhs.upper_bound ();
+ if (real_less (&ub, &dconstm0))
+ {
+ if (!lhs.maybe_isnan ())
+ r.set_undefined ();
+ else
+ // If lhs could be NAN and finite result is impossible,
+ // the range is like lhs.known_isnan () above.
+ goto known_nan;
+ return true;
+ }
+
+ if (!lhs.maybe_isnan ())
+ {
+ // If NAN is not valid result, the input cannot include either
+ // a NAN nor values smaller than -0.
+ r.set (type, dconstm0, dconstinf, nan_state (false, false));
+ return true;
+ }
+
+ r.set_varying (type);
+ return true;
+ }
+} op_cfn_sqrt;
+
class cfn_sincos : public range_operator_float
{
public:
@@ -961,6 +1038,13 @@ gimple_range_op_handler::maybe_builtin_c
m_valid = true;
break;
+ CASE_CFN_SQRT:
+ CASE_CFN_SQRT_FN:
+ m_op1 = gimple_call_arg (call, 0);
+ m_float = &op_cfn_sqrt;
+ m_valid = true;
+ break;
+
CASE_CFN_SIN:
CASE_CFN_SIN_FN:
m_op1 = gimple_call_arg (call, 0);
--- gcc/testsuite/gcc.dg/tree-ssa/range-sqrt.c.jj 2023-04-27
15:10:09.285102144 +0200
+++ gcc/testsuite/gcc.dg/tree-ssa/range-sqrt.c 2023-04-27 15:12:01.478465821
+0200
@@ -0,0 +1,41 @@
+// { dg-do compile }
+// { dg-options "-O2 -fdump-tree-evrp -fno-thread-jumps" }
+
+#include <math.h>
+
+void use (double);
+void link_error ();
+
+void
+foo (double x)
+{
+ if (__builtin_isnan (x))
+ __builtin_unreachable ();
+ x = sqrt (x);
+ if (x < -0.0)
+ link_error ();
+ use (x);
+}
+
+void
+bar (double x)
+{
+ if (!__builtin_isnan (sqrt (x)))
+ {
+ if (__builtin_isnan (x))
+ link_error ();
+ if (x < -0.0)
+ link_error ();
+ }
+}
+
+void
+stool (double x)
+{
+ double res1 = sqrt (x);
+ double res2 = __builtin_sqrt (x);
+ if (res1 < -0.0 || res2 < -0.0)
+ link_error ();
+}
+
+// { dg-final { scan-tree-dump-not "link_error" "evrp" { target { { *-*-linux*
} && { glibc } } } } }
Jakub
