Hi! On Tue, Apr 18, 2023 at 03:12:50PM +0200, Aldy Hernandez wrote: > [I don't know why I keep poking at floats. I must really like the pain. > Jakub, are you OK with this patch for trunk?] > > This is the range-op entry for sin/cos. It is meant to serve as an > example of what we can do for glibc math functions. It is by no means > exhaustive, just a stub to restrict the return range from sin/cos to > [-1.0, 1.0] with appropriate smarts of NANs. > > As can be seen in the testcase, we see sin() as well as > __builtin_sin() in the IL, and can resolve the resulting range > accordingly. > > gcc/ChangeLog: > > * gimple-range-op.cc (class cfn_sincos): New. > (gimple_range_op_handler::maybe_builtin_call): Add case for sin/cos. > > gcc/testsuite/ChangeLog: > > * gcc.dg/tree-ssa/range-sincos.c: New test.
Here is an updated version of the patch on top of the v2: Add targetm.libm_function_max_error patch with all my comments incorporated into your patch (but still no handling of sin/cos ranges shorter than 2*M_PI). So far tested on the new testcase with RUNTESTFLAGS='--target_board=unix\{,-frounding-math} tree-ssa.exp=range-sincos.c' where expectedly without -frounding-math it PASSes and with it fails (as the hooks return 4ulps in that case for the boundaries). Ok for trunk if it passes bootstrap/regtest? I'll defer tweaks to frange_nextafter for ulps or whatever you want to do with it. 2023-04-27 Aldy Hernandez <al...@redhat.com> Jakub Jelinek <ja...@redhat.com> * value-range.h (frange_nextafter): Declare. * gimple-range-op.cc (class cfn_sincos): New. (op_cfn_sin, op_cfn_cos): New variables. (gimple_range_op_handler::maybe_builtin_call): Handle CASE_CFN_{SIN,COS}{,_FN}. * gcc.dg/tree-ssa/range-sincos.c: New test. --- gcc/value-range.h.jj 2023-04-27 10:17:46.504485376 +0200 +++ gcc/value-range.h 2023-04-27 12:07:09.891147869 +0200 @@ -1388,4 +1388,7 @@ frange::nan_signbit_p (bool &signbit) co return true; } +void frange_nextafter (enum machine_mode, REAL_VALUE_TYPE &, + const REAL_VALUE_TYPE &); + #endif // GCC_VALUE_RANGE_H --- gcc/gimple-range-op.cc.jj 2023-04-22 10:23:26.942812958 +0200 +++ gcc/gimple-range-op.cc 2023-04-27 11:57:09.865879982 +0200 @@ -400,6 +400,89 @@ public: } } op_cfn_copysign; +class cfn_sincos : public range_operator_float +{ +public: + using range_operator_float::fold_range; + using range_operator_float::op1_range; + cfn_sincos (combined_fn cfn) { m_cfn = cfn; } + 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 () || lh.known_isinf ()) + { + r.set_nan (type); + return true; + } + unsigned bulps = targetm.libm_function_max_error (m_cfn, TYPE_MODE (type), + true); + if (bulps == ~0U) + r.set_varying (type); + else if (bulps == 0) + r.set (type, dconstm1, dconst1); + else + { + REAL_VALUE_TYPE boundmin, boundmax; + boundmax = dconst1; + while (bulps--) + frange_nextafter (TYPE_MODE (type), boundmax, dconstinf); + real_arithmetic (&boundmin, NEGATE_EXPR, &boundmax, NULL); + r.set (type, boundmin, boundmax); + } + if (!lh.maybe_isnan () && !lh.maybe_isinf ()) + 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,-INF][+INF,+INF] U +-NAN, + // which we can't currently represent. + if (lhs.known_isnan ()) + { + r.set_varying (type); + return true; + } + + // Results outside of [-1.0, +1.0] are impossible. + REAL_VALUE_TYPE lb = lhs.lower_bound (); + REAL_VALUE_TYPE ub = lhs.upper_bound (); + if (real_less (&ub, &dconstm1) || real_less (&dconst1, &lb)) + { + 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, + [-INF,-INF][+INF,+INF] U +-NAN. */ + r.set_varying (type); + return true; + } + + if (!lhs.maybe_isnan ()) + { + // If NAN is not valid result, the input cannot include either + // a NAN nor a +-INF. + lb = real_min_representable (type); + ub = real_max_representable (type); + r.set (type, lb, ub, nan_state (false, false)); + return true; + } + + r.set_varying (type); + return true; + } +private: + combined_fn m_cfn; +} op_cfn_sin (CFN_SIN), op_cfn_cos (CFN_COS); + // Implement range operator for CFN_BUILT_IN_TOUPPER and CFN_BUILT_IN_TOLOWER. class cfn_toupper_tolower : public range_operator { @@ -878,6 +961,20 @@ gimple_range_op_handler::maybe_builtin_c m_valid = true; break; + CASE_CFN_SIN: + CASE_CFN_SIN_FN: + m_op1 = gimple_call_arg (call, 0); + m_float = &op_cfn_sin; + m_valid = true; + break; + + CASE_CFN_COS: + CASE_CFN_COS_FN: + m_op1 = gimple_call_arg (call, 0); + m_float = &op_cfn_cos; + m_valid = true; + break; + case CFN_BUILT_IN_TOUPPER: case CFN_BUILT_IN_TOLOWER: // Only proceed If the argument is compatible with the LHS. --- gcc/testsuite/gcc.dg/tree-ssa/range-sincos.c.jj 2023-04-27 10:27:08.135348612 +0200 +++ gcc/testsuite/gcc.dg/tree-ssa/range-sincos.c 2023-04-27 12:14:50.788437504 +0200 @@ -0,0 +1,43 @@ +// { 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 = sin (x); + if (x < -1.0 || x > 1.0) + link_error (); + use (x); +} + +void +bar (double x) +{ + if (!__builtin_isnan (sin (x))) + { + if (__builtin_isnan (x)) + link_error (); + if (__builtin_isinf (x)) + link_error (); + } +} + +void +stool (double x) +{ + double res1 = sin (x); + double res2 = __builtin_sin (x); + if (res1 < -1.0 || res2 < -1.0) + link_error (); + if (res1 > 1.0 || res2 > 1.0) + link_error (); +} + +// { dg-final { scan-tree-dump-not "link_error" "evrp" { target { { *-*-linux* } && { glibc } } } } } Jakub