From 55738d8d96bb4f39a72cf5e3739d35b39fc2146a Mon Sep 17 00:00:00 2001 From: Andrew MacLeod Date: Tue, 20 Sep 2022 18:19:30 -0400 Subject: [PATCH 12/17] Convert CFN_CTZ builtins to range-ops. * gimple-range-fold.cc (range_of_builtin_int_call): Remove case for CFN_CTZ. * gimple-range-op.cc (class cfn_ctz): New. (gimple_range_op_handler::maybe_builtin_call): Set arguments. --- gcc/gimple-range-fold.cc | 61 +------------------------------ gcc/gimple-range-op.cc | 79 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 80 insertions(+), 60 deletions(-) diff --git a/gcc/gimple-range-fold.cc b/gcc/gimple-range-fold.cc index 63eaa90be96..96a138a7a02 100644 --- a/gcc/gimple-range-fold.cc +++ b/gcc/gimple-range-fold.cc @@ -917,7 +917,7 @@ fold_using_range::range_of_builtin_int_call (irange &r, gcall *call, tree type = gimple_range_type (call); tree arg; - int mini, maxi, zerov = 0, prec; + int prec; scalar_int_mode mode; switch (func) @@ -926,65 +926,6 @@ fold_using_range::range_of_builtin_int_call (irange &r, gcall *call, r.set (build_zero_cst (type), build_one_cst (type)); return true; - CASE_CFN_CTZ: - // __builtin_ctz* return [0, prec-1], except for when the - // argument is 0, but that is undefined behavior. - // - // For __builtin_ctz* consider argument of 0 always undefined - // behavior, for internal fns depending on CTZ_DEFINED_VALUE_AT_ZERO. - arg = gimple_call_arg (call, 0); - prec = TYPE_PRECISION (TREE_TYPE (arg)); - mini = 0; - maxi = prec - 1; - mode = SCALAR_INT_TYPE_MODE (TREE_TYPE (arg)); - if (gimple_call_internal_p (call)) - { - if (optab_handler (ctz_optab, mode) != CODE_FOR_nothing - && CTZ_DEFINED_VALUE_AT_ZERO (mode, zerov) == 2) - { - // Handle only the two common values. - if (zerov == -1) - mini = -1; - else if (zerov == prec) - maxi = prec; - else - // Magic value to give up, unless we can prove arg is non-zero. - mini = -2; - } - } - src.get_operand (r, arg); - if (!r.undefined_p ()) - { - // If arg is non-zero, then use [0, prec - 1]. - if (!range_includes_zero_p (&r)) - { - mini = 0; - maxi = prec - 1; - } - // If some high bits are known to be zero, we can decrease - // the maximum. - wide_int max = r.upper_bound (); - if (max == 0) - { - // Argument is [0, 0]. If CTZ_DEFINED_VALUE_AT_ZERO - // is 2 with value -1 or prec, return [-1, -1] or [prec, prec]. - // Otherwise ignore the range. - if (mini == -1) - maxi = -1; - else if (maxi == prec) - mini = prec; - } - // If value at zero is prec and 0 is in the range, we can't lower - // the upper bound. We could create two separate ranges though, - // [0,floor_log2(max)][prec,prec] though. - else if (maxi != prec) - maxi = wi::floor_log2 (max); - } - if (mini == -2) - break; - r.set (build_int_cst (type, mini), build_int_cst (type, maxi)); - return true; - CASE_CFN_CLRSB: arg = gimple_call_arg (call, 0); prec = TYPE_PRECISION (TREE_TYPE (arg)); diff --git a/gcc/gimple-range-op.cc b/gcc/gimple-range-op.cc index caba49309f9..801c2bb235e 100644 --- a/gcc/gimple-range-op.cc +++ b/gcc/gimple-range-op.cc @@ -489,6 +489,76 @@ cfn_clz::fold_range (irange &r, tree type, const irange &lh, return true; } +// Implement range operator for CFN_BUILT_IN_CTZ +class cfn_ctz : public range_operator +{ +public: + cfn_ctz (bool internal) { m_gimple_call_internal_p = internal; } + using range_operator::fold_range; + virtual bool fold_range (irange &r, tree type, const irange &lh, + const irange &, relation_kind) const; +private: + bool m_gimple_call_internal_p; +} op_cfn_ctz (false), op_cfn_ctz_internal (true); + +bool +cfn_ctz::fold_range (irange &r, tree type, const irange &lh, + const irange &, relation_kind) const +{ + if (lh.undefined_p ()) + return false; + int prec = TYPE_PRECISION (lh.type ()); + int mini = 0; + int maxi = prec - 1; + int zerov = 0; + scalar_int_mode mode = SCALAR_INT_TYPE_MODE (lh.type ()); + + if (m_gimple_call_internal_p) + { + if (optab_handler (ctz_optab, mode) != CODE_FOR_nothing + && CTZ_DEFINED_VALUE_AT_ZERO (mode, zerov) == 2) + { + // Handle only the two common values. + if (zerov == -1) + mini = -1; + else if (zerov == prec) + maxi = prec; + else + // Magic value to give up, unless we can prove arg is non-zero. + mini = -2; + } + } + // If arg is non-zero, then use [0, prec - 1]. + if (!range_includes_zero_p (&lh)) + { + mini = 0; + maxi = prec - 1; + } + // If some high bits are known to be zero, we can decrease + // the maximum. + wide_int max = lh.upper_bound (); + if (max == 0) + { + // Argument is [0, 0]. If CTZ_DEFINED_VALUE_AT_ZERO + // is 2 with value -1 or prec, return [-1, -1] or [prec, prec]. + // Otherwise ignore the range. + if (mini == -1) + maxi = -1; + else if (maxi == prec) + mini = prec; + } + // If value at zero is prec and 0 is in the range, we can't lower + // the upper bound. We could create two separate ranges though, + // [0,floor_log2(max)][prec,prec] though. + else if (maxi != prec) + maxi = wi::floor_log2 (max); + + if (mini == -2) + return false; + r.set (build_int_cst (type, mini), build_int_cst (type, maxi)); + return true; +} + // Set up a gimple_range_op_handler for any built in function which can be // supported via range-ops. @@ -553,6 +623,15 @@ gimple_range_op_handler::maybe_builtin_call () m_int = &op_cfn_clz; break; + CASE_CFN_CTZ: + m_op1 = gimple_call_arg (call, 0); + m_valid = true; + if (gimple_call_internal_p (call)) + m_int = &op_cfn_ctz_internal; + else + m_int = &op_cfn_ctz; + break; + default: break; } -- 2.37.3