--- /dev/null
+/* { dg-do run { target { ! "*-*-darwin" } } } */
+/* { dg-options "-O2 -fmath-errno -fdump-tree-cdce-details -lm" } */
+/* { dg-final { scan-tree-dump "cdce3.C:68: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:69: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:70: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:71: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:72: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:73: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:74: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:75: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:76: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:77: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:78: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:79: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:80: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:81: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:82: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { scan-tree-dump "cdce3.C:83: note: function call is shrink-wrapped into error conditions\." "cdce" } }*/
+/* { dg-final { cleanup-tree-dump "cdce" } } */
+#include <stdlib.h>
+#include <math.h>
+#ifdef DEBUG
+#include <stdio.h>
+#endif
+#include <errno.h>
+typedef long double ldouble;
+typedef void (*FP) (int xp);
+#define NI __attribute__((noinline))
+ldouble result;
+
+#define DEF_MATH_FUNC(prefix, name) NI void prefix##name##f (int x) \
+{ \
+ float yy = name##f ((float) x); \
+ STORE_RESULT; \
+} \
+NI void prefix##name (int x) \
+{ \
+ double yy = name ((double)x); \
+ STORE_RESULT; \
+} \
+NI void prefix##name##l (int x) \
+{ \
+ ldouble yy = name##l ((ldouble)x); \
+ STORE_RESULT; \
+}
+
+#undef STORE_RESULT
+#define STORE_RESULT result = yy
+DEF_MATH_FUNC (m,pow10)
+DEF_MATH_FUNC (m,exp10)
+DEF_MATH_FUNC (m,exp2)
+DEF_MATH_FUNC (m,exp)
+DEF_MATH_FUNC (m,expm1)
+DEF_MATH_FUNC (m,cosh)
+DEF_MATH_FUNC (m,sinh)
+DEF_MATH_FUNC (m,acos)
+DEF_MATH_FUNC (m,asin)
+DEF_MATH_FUNC (m,acosh)
+DEF_MATH_FUNC (m,atanh)
+DEF_MATH_FUNC (m,log)
+DEF_MATH_FUNC (m,log2)
+DEF_MATH_FUNC (m,log10)
+DEF_MATH_FUNC (m,log1p)
+DEF_MATH_FUNC (m,sqrt)
+
+#undef STORE_RESULT
+#define STORE_RESULT
+DEF_MATH_FUNC (o,pow10)
+DEF_MATH_FUNC (o,exp10)
+DEF_MATH_FUNC (o,exp2)
+DEF_MATH_FUNC (o,exp)
+DEF_MATH_FUNC (o,expm1)
+DEF_MATH_FUNC (o,cosh)
+DEF_MATH_FUNC (o,sinh)
+DEF_MATH_FUNC (o,acos)
+DEF_MATH_FUNC (o,asin)
+DEF_MATH_FUNC (o,acosh)
+DEF_MATH_FUNC (o,atanh)
+DEF_MATH_FUNC (o,log)
+DEF_MATH_FUNC (o,log2)
+DEF_MATH_FUNC (o,log10)
+DEF_MATH_FUNC (o,log1p)
+DEF_MATH_FUNC (o,sqrt)
+
+#define INIT_MATH_FUNC(prefix, name, lb, ub) { prefix##name##f, #name "f", 0, 0, lb, ub }, \
+{ prefix##name, #name, 0, 0, lb, ub }, \
+{ prefix##name##l, #name "l" , 0, 0, lb, ub },
+
+struct MathFuncInfo
+{
+ FP math_func;
+ const char* name;
+ int lb;
+ int ub;
+ bool has_lb;
+ bool has_ub;
+} math_func_arr[] = {
+ INIT_MATH_FUNC (m,pow10, false, true)
+ INIT_MATH_FUNC (m,exp10, false, true)
+ INIT_MATH_FUNC (m,exp2, false, true)
+ INIT_MATH_FUNC (m,expm1, false, true)
+ INIT_MATH_FUNC (m,exp, false, true)
+ INIT_MATH_FUNC (m,cosh, true, true)
+ INIT_MATH_FUNC (m,sinh, true, true)
+ INIT_MATH_FUNC (m,acos, true, true)
+ INIT_MATH_FUNC (m,asin, true, true)
+ INIT_MATH_FUNC (m,acosh, true, false)
+ INIT_MATH_FUNC (m,atanh, true, true)
+ INIT_MATH_FUNC (m,log10, true, false)
+ INIT_MATH_FUNC (m,log, true, false)
+ INIT_MATH_FUNC (m,log2, true, false)
+ INIT_MATH_FUNC (m,log1p, true, false)
+ INIT_MATH_FUNC (m,sqrt, true, false)
+ { 0, 0, 0, 0, 0, 0} };
+
+MathFuncInfo opt_math_func_arr[] =
+{ INIT_MATH_FUNC (o,pow10, false, true)
+ INIT_MATH_FUNC (o,exp10, false, true)
+ INIT_MATH_FUNC (o,exp2, false, true)
+ INIT_MATH_FUNC (o,expm1, false, true)
+ INIT_MATH_FUNC (o,exp, false, true)
+ INIT_MATH_FUNC (o,cosh, true, true)
+ INIT_MATH_FUNC (o,sinh, true, true)
+ INIT_MATH_FUNC (o,acos, true, true)
+ INIT_MATH_FUNC (o,asin, true, true)
+ INIT_MATH_FUNC (o,acosh, true, false)
+ INIT_MATH_FUNC (o,atanh, true, true)
+ INIT_MATH_FUNC (o,log10, true, false)
+ INIT_MATH_FUNC (o,log, true, false)
+ INIT_MATH_FUNC (o,log2, true, false)
+ INIT_MATH_FUNC (o,log1p, true, false)
+ INIT_MATH_FUNC (o,sqrt, true, false)
+ { 0, 0, 0, 0, 0, 0} };
+
+int test (MathFuncInfo* math_func_infos)
+{
+ int i = 0;
+ int te = 0;
+
+ for (i = 0; math_func_infos[i].math_func; i++)
+ {
+ MathFuncInfo& info = math_func_infos[i];
+ int j;
+ if (info.has_lb)
+ {
+ for (j = 0; j > -500000; j--)
+ {
+
+ errno = 0;
+ info.math_func (j);
+ if (errno != 0)
+ {
+ te++;
+ info.lb = j ;
+ break;
+ }
+ }
+ }
+ if (info.has_ub)
+ {
+ for (j = 0; j < 500000; j++)
+ {
+ errno = 0;
+ info.math_func (j);
+ if (errno != 0)
+ {
+ te++;
+ info.ub = j ;
+ break;
+ }
+ }
+ }
+ }
+ return te;
+}
+
+int main()
+{
+ int te1, te2;
+
+ te1 = test (&math_func_arr[0]);
+ te2 = test (&opt_math_func_arr[0]);
+
+ // Now examine the result
+ int i = 0;
+ int errcnt = 0;
+ for (i = 0; math_func_arr[i].math_func; i++)
+ {
+ MathFuncInfo& info = math_func_arr[i];
+ MathFuncInfo& opt_info = opt_math_func_arr[i];
+#ifdef DEBUG
+ fprintf (stderr," %s: lb = %d, ub = %d: lb_opt = %d, ub_opt = %d\n",
+ info.name, info.lb, info.ub, opt_info.lb, opt_info.ub);
+#endif
+ if (info.lb != opt_info.lb) errcnt ++;
+ if (info.ub != opt_info.ub) errcnt ++;
+ }
+ if (errcnt) abort();
+ return 0;
+}
--- /dev/null
+/* Conditional Dead Call Elimination pass for the GNU compiler.
+ Copyright (C) 2008
+ Free Software Foundation, Inc.
+ Contributed by Xinliang David Li <davidxl@google.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 3, or (at your option) any
+later version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "ggc.h"
+
+/* These RTL headers are needed for basic-block.h. */
+#include "rtl.h"
+#include "tm_p.h"
+#include "hard-reg-set.h"
+#include "obstack.h"
+#include "basic-block.h"
+
+#include "tree.h"
+#include "diagnostic.h"
+#include "tree-flow.h"
+#include "tree-gimple.h"
+#include "tree-dump.h"
+#include "tree-pass.h"
+#include "timevar.h"
+#include "flags.h"
+\f
+
+/* Conditional dead call elimination
+
+ Some builtin functions can set errno on error conditions, but they
+ are otherwise pure. If the result of a call to such a function is
+ not used, the compiler can still not eliminate the call without
+ powerful interprocedural analysis to prove that the errno is not
+ checked. However, if the conditions under which the error occurs
+ are known, the compiler can conditionally dead code eliminate the
+ calls by shrink-wrapping the semi-dead calls into the error condition:
+
+ built_in_call (args)
+ ==>
+ if (error_cond (args))
+ built_in_call (args)
+
+ An actual simple example is :
+ log (x); // Mostly dead call
+ ==>
+ if (x < 0)
+ log (x);
+ With this change, call to log (x) is effectively eliminated, as
+ in majority of the cases, log won't be called with x out of
+ range. The branch is totally predictable, so the branch cost
+ is low.
+
+ Note that library functions are not supposed to clear errno to zero without
+ error. See IEEE Std 1003.1, section 2.3 Error Numbers, and section 7.5:3 of
+ ISO/IEC 9899 (C99).
+
+ The condition wrapping the builtin call is conservatively set to avoid too
+ aggressive (wrong) shrink wrapping. The optimization is called conditional
+ dead call elimination because the call is eliminated under the condition
+ that the input arguments would not lead to domain or range error (for
+ instance when x <= 0 for a log (x) call), however the chances that the error
+ condition is hit is very low (those builtin calls which are conditionally
+ dead are usually part of the C++ abstraction penalty exposed after
+ inlining). */
+
+
+/* A structure for representing input domain of
+ a function argument in integer. If the lower
+ bound is -inf, has_lb is set to false. If the
+ upper bound is +inf, has_ub is false.
+ is_lb_inclusive and is_ub_inclusive are flags
+ to indicate if lb and ub value are inclusive
+ respectively. */
+
+typedef struct input_domain
+{
+ int lb;
+ int ub;
+ bool has_lb;
+ bool has_ub;
+ bool is_lb_inclusive;
+ bool is_ub_inclusive;
+} inp_domain;
+
+static VEC (tree, heap) *cond_dead_built_in_calls;
+
+/* A helper function to construct and return an input
+ domain object. LB is the lower bound, HAS_LB is
+ a boolean flag indicating if the lower bound exists,
+ and LB_INCLUSIVE is a boolean flag indicating if the
+ lower bound is inclusive or not. UB, HAS_UB, and
+ UB_INCLUSIVE have the same meaning, but for upper
+ bound of the domain. */
+
+static inp_domain
+get_domain (int lb, bool has_lb, bool lb_inclusive,
+ int ub, bool has_ub, bool ub_inclusive)
+{
+ inp_domain domain;
+ domain.lb = lb;
+ domain.has_lb = has_lb;
+ domain.is_lb_inclusive = lb_inclusive;
+ domain.ub = ub;
+ domain.has_ub = has_ub;
+ domain.is_ub_inclusive = ub_inclusive;
+ return domain;
+}
+
+/* A helper function to check the target format for the
+ argument type. In this implementation, only IEEE formats
+ are supported. ARG is the call argument to be checked.
+ Returns true if the format is supported. To support other
+ target formats, function get_no_error_domain needs to be
+ enhanced to have range bounds properly computed. Since
+ the check is cheap (very small number of candidates
+ to be checked), the result is not cached for each float type. */
+
+static bool
+check_target_format (tree arg)
+{
+ tree type;
+ enum machine_mode mode;
+ const struct real_format *rfmt;
+
+ type = TREE_TYPE (arg);
+ mode = TYPE_MODE (type);
+ rfmt = REAL_MODE_FORMAT (mode);
+ if ((mode == SFmode && rfmt == &ieee_single_format)
+ || (mode == DFmode && rfmt == &ieee_double_format)
+ /* For long double, we can not really check XFmode
+ which is only defined on intel platforms.
+ Candidate pre-selection using builtin function
+ code guarantees that we are checking formats
+ for long double modes: double, quad, and extended. */
+ || (mode != SFmode && mode != DFmode
+ && (rfmt == &ieee_quad_format
+ || rfmt == &ieee_extended_intel_96_format
+ || rfmt == &ieee_extended_intel_128_format
+ || rfmt == &ieee_extended_intel_96_round_53_format)))
+ return true;
+
+ return false;
+}
+
+\f
+/* A helper function to help select calls to pow that are suitable for
+ conditional DCE transformation. It looks for pow calls that can be
+ guided with simple conditions. Such calls either have constant base
+ values or base values converted from integers. Returns true if
+ the pow call POW_CALL is a candidate. */
+
+/* The maximum integer bit size for base argument of a pow call
+ that is suitable for shrink-wrapping transformation. */
+#define MAX_BASE_INT_BIT_SIZE 32
+
+static bool
+check_pow (tree pow_call)
+{
+ tree base, expn;
+ enum tree_code bc, ec;
+
+ if (call_expr_nargs (pow_call) != 2)
+ return false;
+
+ base = CALL_EXPR_ARG (pow_call, 0);
+ expn = CALL_EXPR_ARG (pow_call, 1);
+
+ if (!check_target_format (expn))
+ return false;
+
+ bc = TREE_CODE (base);
+ ec = TREE_CODE (expn);
+
+ /* Folding candidates are not interesting.
+ Can actually assert that it is already folded. */
+ if (ec == REAL_CST && bc == REAL_CST)
+ return false;
+
+ if (bc == REAL_CST)
+ {
+ /* Only handle a fixed range of constant. */
+ REAL_VALUE_TYPE mv;
+ REAL_VALUE_TYPE bcv = TREE_REAL_CST (base);
+ if (REAL_VALUES_EQUAL (bcv, dconst1))
+ return false;
+ if (REAL_VALUES_LESS (bcv, dconst1))
+ return false;
+ real_from_integer (&mv, TYPE_MODE (TREE_TYPE (base)), 256, 0, 1);
+ if (REAL_VALUES_LESS (mv, bcv))
+ return false;
+ return true;
+ }
+ else if (bc == SSA_NAME)
+ {
+ tree base_def, base_val, base_val0, base_var, type;
+ int bit_sz;
+
+ /* Only handles cases where base value is converted
+ from integer values. */
+ base_def = SSA_NAME_DEF_STMT (base);
+ if (TREE_CODE (base_def) != GIMPLE_MODIFY_STMT)
+ return false;
+
+ base_val = GIMPLE_STMT_OPERAND (base_def, 1);
+
+ if (TREE_CODE (base_val) != FLOAT_EXPR)
+ return false;
+ base_val0 = TREE_OPERAND (base_val, 0);
+
+ base_var = SSA_NAME_VAR (base_val0);
+ if (!DECL_P (base_var))
+ return false;
+
+ type = TREE_TYPE (base_var);
+ if (TREE_CODE (type) != INTEGER_TYPE)
+ return false;
+ bit_sz = TYPE_PRECISION (type);
+ /* If the type of the base is too wide,
+ the resulting shrink wrapping condition
+ will be too conservative. */
+ if (bit_sz > MAX_BASE_INT_BIT_SIZE)
+ return false;
+
+ return true;
+ }
+ else
+ return false;
+}
+
+/* A helper function to help select candidate function calls that are
+ suitable for conditional DCE. Candidate functions must have single
+ valid input domain in this implementation except for pow (see check_pow).
+ Returns true if the function call is a candidate. */
+
+static bool
+check_builtin_call (tree bcall)
+{
+ tree arg;
+
+ arg = CALL_EXPR_ARG (bcall, 0);
+ return check_target_format (arg);
+}
+
+/* A helper function to determine if a builtin function call is a
+ candidate for conditional DCE. Returns true if the builtin call
+ is a candidate. */
+
+static bool
+is_call_dce_candidate (tree call)
+{
+ tree fn;
+ enum built_in_function fnc;
+
+ if (!flag_tree_builtin_call_dce)
+ return false;
+
+ gcc_assert (call && TREE_CODE (call) == CALL_EXPR);
+
+ fn = get_callee_fndecl (call);
+ if (!fn || !DECL_BUILT_IN (fn)
+ || (DECL_BUILT_IN_CLASS (fn) != BUILT_IN_NORMAL))
+ return false;
+
+ fnc = DECL_FUNCTION_CODE (fn);
+ switch (fnc)
+ {
+ /* Trig functions. */
+ CASE_FLT_FN (BUILT_IN_ACOS):
+ CASE_FLT_FN (BUILT_IN_ASIN):
+ /* Hyperbolic functions. */
+ CASE_FLT_FN (BUILT_IN_ACOSH):
+ CASE_FLT_FN (BUILT_IN_ATANH):
+ CASE_FLT_FN (BUILT_IN_COSH):
+ CASE_FLT_FN (BUILT_IN_SINH):
+ /* Log functions. */
+ CASE_FLT_FN (BUILT_IN_LOG):
+ CASE_FLT_FN (BUILT_IN_LOG2):
+ CASE_FLT_FN (BUILT_IN_LOG10):
+ CASE_FLT_FN (BUILT_IN_LOG1P):
+ /* Exp functions. */
+ CASE_FLT_FN (BUILT_IN_EXP):
+ CASE_FLT_FN (BUILT_IN_EXP2):
+ CASE_FLT_FN (BUILT_IN_EXP10):
+ CASE_FLT_FN (BUILT_IN_EXPM1):
+ CASE_FLT_FN (BUILT_IN_POW10):
+ /* Sqrt. */
+ CASE_FLT_FN (BUILT_IN_SQRT):
+ return check_builtin_call (call);
+ /* Special one: two argument pow. */
+ case BUILT_IN_POW:
+ return check_pow (call);
+ default:
+ break;
+ }
+
+ return false;
+}
+
+\f
+/* A helper function to generate gimple statements for
+ one bound comparison. ARG is the call argument to
+ be compared with the bound, LBUB is the bound value
+ in integer, TCODE is the tree_code of the comparison,
+ TEMP_NAME1/TEMP_NAME2 are names of the temporaries,
+ CONDS is a vector holding the produced GIMPLE statements,
+ and NCONDS points to the variable holding the number
+ of logical comparisons. CONDS is either empty or
+ a list ended with a null tree. */
+
+static void
+gen_one_condition (tree arg, int lbub,
+ enum tree_code tcode,
+ const char *temp_name1,
+ const char *temp_name2,
+ VEC (tree, heap) *conds,
+ unsigned *nconds)
+{
+ tree lbub_real_cst, lbub_cst, float_type;
+ tree temp, tempn, tempc, tempcn;
+ tree stmt1, stmt2, stmt3;
+
+ float_type = TREE_TYPE (arg);
+ lbub_cst = build_int_cst (integer_type_node, lbub);
+ lbub_real_cst = build_real_from_int_cst (float_type, lbub_cst);
+
+ temp = create_tmp_var (float_type, temp_name1);
+ stmt1 = build_gimple_modify_stmt (temp, arg);
+ tempn = make_ssa_name (temp, stmt1);
+ GIMPLE_STMT_OPERAND (stmt1, 0) = tempn;
+
+ tempc = create_tmp_var (boolean_type_node, temp_name2);
+ stmt2 = build_gimple_modify_stmt (tempc,
+ fold_build2 (tcode,
+ boolean_type_node,
+ tempn, lbub_real_cst));
+ tempcn = make_ssa_name (tempc, stmt2);
+ GIMPLE_STMT_OPERAND (stmt2, 0) = tempcn;
+
+ /* fold_built3 not used for gimple statement here,
+ as it will hit assertion. */
+ stmt3 = build3 (COND_EXPR, void_type_node,
+ tempcn, NULL_TREE, NULL_TREE);
+ VEC_quick_push (tree, conds, stmt1);
+ VEC_quick_push (tree, conds, stmt2);
+ VEC_quick_push (tree, conds, stmt3);
+ (*nconds)++;
+}
+
+/* A helper function to generate GIMPLE statements for
+ out of input domain check. ARG is the call argument
+ to be runtime checked, DOMAIN holds the valid domain
+ for the given function, CONDS points to the vector
+ holding the result GIMPLE statements. *NCONDS is
+ the number of logical comparisons. This function
+ produces no more than two logical comparisons, one
+ for lower bound check, one for upper bound check. */
+
+static void
+gen_conditions_for_domain (tree arg, inp_domain domain,
+ VEC (tree, heap) *conds,
+ unsigned *nconds)
+{
+ if (domain.has_lb)
+ gen_one_condition (arg, domain.lb,
+ (domain.is_lb_inclusive
+ ? LT_EXPR : LE_EXPR),
+ "DCE_COND_LB", "DCE_COND_LB_TEST",
+ conds, nconds);
+
+ if (domain.has_ub)
+ {
+ /* Now push a separator. */
+ if (domain.has_lb)
+ VEC_quick_push (tree, conds, NULL);
+
+ gen_one_condition (arg, domain.ub,
+ (domain.is_ub_inclusive
+ ? GT_EXPR : GE_EXPR),
+ "DCE_COND_UB", "DCE_COND_UB_TEST",
+ conds, nconds);
+ }
+}
+
+
+/* A helper function to generate condition
+ code for the y argument in call pow (some_const, y).
+ See candidate selection in check_pow. Since the
+ candidates' base values have a limited range,
+ the guarded code generated for y are simple:
+ if (y > max_y)
+ pow (const, y);
+ Note max_y can be computed separately for each
+ const base, but in this implementation, we
+ choose to compute it using the max base
+ in the allowed range for the purpose of
+ simplicity. BASE is the constant base value,
+ EXPN is the expression for the exponent argument,
+ *CONDS is the vector to hold resulting statements,
+ and *NCONDS is the number of logical conditions. */
+
+static void
+gen_conditions_for_pow_cst_base (tree base, tree expn,
+ VEC (tree, heap) *conds,
+ unsigned *nconds)
+{
+ inp_domain exp_domain;
+ /* Validate the range of the base constant to make
+ sure it is consistent with check_pow. */
+ REAL_VALUE_TYPE mv;
+ REAL_VALUE_TYPE bcv = TREE_REAL_CST (base);
+ gcc_assert (!REAL_VALUES_EQUAL (bcv, dconst1)
+ && !REAL_VALUES_LESS (bcv, dconst1));
+ real_from_integer (&mv, TYPE_MODE (TREE_TYPE (base)), 256, 0, 1);
+ gcc_assert (!REAL_VALUES_LESS (mv, bcv));
+
+ exp_domain = get_domain (0, false, false,
+ 127, true, false);
+
+ gen_conditions_for_domain (expn, exp_domain,
+ conds, nconds);
+}
+
+/* Generate error condition code for pow calls with
+ non constant base values. The candidates selected
+ have their base argument value converted from
+ integer (see check_pow) value (1, 2, 4 bytes), and
+ the max exp value is computed based on the size
+ of the integer type (i.e. max possible base value).
+ The resulting input domain for exp argument is thus
+ conservative (smaller than the max value allowed by
+ the runtime value of the base). BASE is the integer
+ base value, EXPN is the expression for the exponent
+ argument, *CONDS is the vector to hold resulting
+ statements, and *NCONDS is the number of logical
+ conditions. */
+
+static void
+gen_conditions_for_pow_int_base (tree base, tree expn,
+ VEC (tree, heap) *conds,
+ unsigned *nconds)
+{
+ tree base_def, base_nm, base_val, base_val0;
+ tree base_var, int_type;
+ tree temp, tempn;
+ tree cst0, stmt1, stmt2;
+ int bit_sz, max_exp;
+ inp_domain exp_domain;
+
+ base_def = SSA_NAME_DEF_STMT (base);
+ base_nm = GIMPLE_STMT_OPERAND (base_def, 0);
+ base_val = GIMPLE_STMT_OPERAND (base_def, 1);
+ base_val0 = TREE_OPERAND (base_val, 0);
+ base_var = SSA_NAME_VAR (base_val0);
+ int_type = TREE_TYPE (base_var);
+ bit_sz = TYPE_PRECISION (int_type);
+ gcc_assert (bit_sz > 0
+ && bit_sz <= MAX_BASE_INT_BIT_SIZE);
+
+ /* Determine the max exp argument value according to
+ the size of the base integer. The max exp value
+ is conservatively estimated assuming IEEE754 double
+ precision format. */
+ if (bit_sz == 8)
+ max_exp = 128;
+ else if (bit_sz == 16)
+ max_exp = 64;
+ else
+ {
+ gcc_assert (bit_sz == MAX_BASE_INT_BIT_SIZE);
+ max_exp = 32;
+ }
+
+ /* For pow ((double)x, y), generate the following conditions:
+ cond 1:
+ temp1 = x;
+ if (temp1 <= 0)
+
+ cond 2:
+ temp2 = y;
+ if (temp2 > max_exp_real_cst) */
+
+ /* Generate condition in reverse order -- first
+ the condition for the exp argument. */
+
+ exp_domain = get_domain (0, false, false,
+ max_exp, true, true);
+
+ gen_conditions_for_domain (expn, exp_domain,
+ conds, nconds);
+
+ /* Now generate condition for the base argument.
+ Note it does not use the helper function
+ gen_conditions_for_domain because the base
+ type is integer. */
+
+ /* Push a separator. */
+ VEC_quick_push (tree, conds, NULL);
+
+ temp = create_tmp_var (int_type, "DCE_COND1");
+ cst0 = build_int_cst (int_type, 0);
+ stmt1 = build_gimple_modify_stmt (temp, base_val0);
+ tempn = make_ssa_name (temp, stmt1);
+ GIMPLE_STMT_OPERAND (stmt1, 0) = tempn;
+ stmt2 = build3 (COND_EXPR, void_type_node,
+ fold_build2 (LE_EXPR, boolean_type_node, tempn, cst0),
+ NULL_TREE, NULL_TREE);
+
+ VEC_quick_push (tree, conds, stmt1);
+ VEC_quick_push (tree, conds, stmt2);
+ (*nconds)++;
+}
+
+/* Method to generate conditional statements for guarding conditionally
+ dead calls to pow. One or more statements can be generated for
+ each logical condition. Statement groups of different conditions
+ are separated by a NULL tree and they are stored in the VEC
+ conds. The number of logical conditions are stored in *nconds.
+
+ See C99 standard, 7.12.7.4:2, for description of pow (x, y).
+ The precise condition for domain errors are complex. In this
+ implementation, a simplified (but conservative) valid domain
+ for x and y are used: x is positive to avoid dom errors, while
+ y is smaller than a upper bound (depending on x) to avoid range
+ errors. Runtime code is generated to check x (if not constant)
+ and y against the valid domain. If it is out, jump to the call,
+ otherwise the call is bypassed. POW_CALL is the call statement,
+ *CONDS is a vector holding the resulting condition statements,
+ and *NCONDS is the number of logical conditions. */
+
+static void
+gen_conditions_for_pow (tree pow_call, VEC (tree, heap) *conds,
+ unsigned *nconds)
+{
+ tree base, expn;
+ enum tree_code bc, ec;
+
+#ifdef ENABLE_CHECKING
+ gcc_assert (check_pow (pow_call));
+#endif
+
+ *nconds = 0;
+
+ base = CALL_EXPR_ARG (pow_call, 0);
+ expn = CALL_EXPR_ARG (pow_call, 1);
+
+ bc = TREE_CODE (base);
+ ec = TREE_CODE (expn);
+
+ if (bc == REAL_CST)
+ gen_conditions_for_pow_cst_base (base, expn,
+ conds, nconds);
+ else if (bc == SSA_NAME)
+ gen_conditions_for_pow_int_base (base, expn,
+ conds, nconds);
+ else
+ gcc_unreachable ();
+}
+
+/* A helper routine to help computing the valid input domain
+ for a builtin function. See C99 7.12.7 for details. In this
+ implementation, we only handle single region domain. The
+ resulting region can be conservative (smaller) than the actual
+ one and rounded to integers. Some of the bounds are documented
+ in the standard, while other limit constants are computed
+ assuming IEEE floating point format (for SF and DF modes).
+ Since IEEE only sets minimum requirements for long double format,
+ different long double formats exist under different implementations
+ (e.g, 64 bit double precision (DF), 80 bit double-extended
+ precision (XF), and 128 bit quad precision (QF) ). For simplicity,
+ in this implementation, the computed bounds for long double assume
+ 64 bit format (DF), and are therefore conservative. Another
+ assumption is that single precision float type is always SF mode,
+ and double type is DF mode. This function is quite
+ implementation specific, so it may not be suitable to be part of
+ builtins.c. This needs to be revisited later to see if it can
+ be leveraged in x87 assembly expansion. */
+
+static inp_domain
+get_no_error_domain (enum built_in_function fnc)
+{
+ switch (fnc)
+ {
+ /* Trig functions: return [-1, +1] */
+ CASE_FLT_FN (BUILT_IN_ACOS):
+ CASE_FLT_FN (BUILT_IN_ASIN):
+ return get_domain (-1, true, true,
+ 1, true, true);
+ /* Hyperbolic functions. */
+ CASE_FLT_FN (BUILT_IN_ACOSH):
+ /* acosh: [1, +inf) */
+ return get_domain (1, true, true,
+ 1, false, false);
+ CASE_FLT_FN (BUILT_IN_ATANH):
+ /* atanh: (-1, +1) */
+ return get_domain (-1, true, false,
+ 1, true, false);
+ case BUILT_IN_COSHF:
+ case BUILT_IN_SINHF:
+ /* coshf: (-89, +89) */
+ return get_domain (-89, true, false,
+ 89, true, false);
+ case BUILT_IN_COSH:
+ case BUILT_IN_SINH:
+ case BUILT_IN_COSHL:
+ case BUILT_IN_SINHL:
+ /* cosh: (-710, +710) */
+ return get_domain (-710, true, false,
+ 710, true, false);
+ /* Log functions: (0, +inf) */
+ CASE_FLT_FN (BUILT_IN_LOG):
+ CASE_FLT_FN (BUILT_IN_LOG2):
+ CASE_FLT_FN (BUILT_IN_LOG10):
+ return get_domain (0, true, false,
+ 0, false, false);
+ CASE_FLT_FN (BUILT_IN_LOG1P):
+ return get_domain (-1, true, false,
+ 0, false, false);
+ /* Exp functions. */
+ case BUILT_IN_EXPF:
+ case BUILT_IN_EXPM1F:
+ /* expf: (-inf, 88) */
+ return get_domain (-1, false, false,
+ 88, true, false);
+ case BUILT_IN_EXP:
+ case BUILT_IN_EXPM1:
+ case BUILT_IN_EXPL:
+ case BUILT_IN_EXPM1L:
+ /* exp: (-inf, 709) */
+ return get_domain (-1, false, false,
+ 709, true, false);
+ case BUILT_IN_EXP2F:
+ /* exp2f: (-inf, 128) */
+ return get_domain (-1, false, false,
+ 128, true, false);
+ case BUILT_IN_EXP2:
+ case BUILT_IN_EXP2L:
+ /* exp2: (-inf, 1024) */
+ return get_domain (-1, false, false,
+ 1024, true, false);
+ case BUILT_IN_EXP10F:
+ case BUILT_IN_POW10F:
+ /* exp10f: (-inf, 38) */
+ return get_domain (-1, false, false,
+ 38, true, false);
+ case BUILT_IN_EXP10:
+ case BUILT_IN_POW10:
+ case BUILT_IN_EXP10L:
+ case BUILT_IN_POW10L:
+ /* exp10: (-inf, 308) */
+ return get_domain (-1, false, false,
+ 308, true, false);
+ /* sqrt: [0, +inf) */
+ CASE_FLT_FN (BUILT_IN_SQRT):
+ return get_domain (0, true, true,
+ 0, false, false);
+ default:
+ gcc_unreachable ();
+ }
+
+ gcc_unreachable ();
+}
+
+/* The function to generate shrink wrap conditions for a partially
+ dead builtin call whose return value is not used anywhere,
+ but has to be kept live due to potential error condition.
+ BI_CALL is the builtin call, CONDS is the vector of statements
+ for condition code, NCODES is the pointer to the number of
+ logical conditions. Statements belonging to different logical
+ condition are separated by NULL tree in the vector. */
+
+static void
+gen_shrink_wrap_conditions (tree bi_call, VEC (tree, heap) *conds,
+ unsigned int *nconds)
+{
+ tree call, fn;
+ enum built_in_function fnc;
+
+ gcc_assert (nconds && conds);
+ gcc_assert (VEC_length (tree, conds) == 0);
+ gcc_assert (TREE_CODE (bi_call) == GIMPLE_MODIFY_STMT
+ || TREE_CODE (bi_call) == CALL_EXPR);
+
+ call = bi_call;
+ if (TREE_CODE (call) == GIMPLE_MODIFY_STMT)
+ call = get_call_expr_in (bi_call);
+
+ fn = get_callee_fndecl (call);
+ gcc_assert (fn && DECL_BUILT_IN (fn));
+ fnc = DECL_FUNCTION_CODE (fn);
+ *nconds = 0;
+
+ if (fnc == BUILT_IN_POW)
+ gen_conditions_for_pow (call, conds, nconds);
+ else
+ {
+ tree arg;
+ inp_domain domain = get_no_error_domain (fnc);
+ *nconds = 0;
+ arg = CALL_EXPR_ARG (bi_call, 0);
+ gen_conditions_for_domain (arg, domain, conds, nconds);
+ }
+
+ return;
+}
+
+
+/* Probability of the branch (to the call) is taken. */
+#define ERR_PROB 0.01
+
+/* The function to shrink wrap a partially dead builtin call
+ whose return value is not used anywhere, but has to be kept
+ live due to potential error condition. Returns true if the
+ transformation actually happens. */
+
+static bool
+shrink_wrap_one_built_in_call (tree bi_call)
+{
+ block_stmt_iterator bi_call_bsi;
+ basic_block bi_call_bb, join_tgt_bb, guard_bb, guard_bb0;
+ edge join_tgt_in_edge_from_call, join_tgt_in_edge_fall_thru;
+ edge bi_call_in_edge0, guard_bb_in_edge;
+ VEC (tree, heap) *conds;
+ unsigned tn_cond_stmts, nconds;
+ unsigned ci;
+ tree cond_expr = NULL;
+ tree cond_expr_start;
+ tree bi_call_label_decl;
+ tree bi_call_label;
+
+ conds = VEC_alloc (tree, heap, 12);
+ gen_shrink_wrap_conditions (bi_call, conds, &nconds);
+
+ /* This can happen if the condition generator decides
+ it is not beneficial to do the transformation. Just
+ return false and do not do any transformation for
+ the call. */
+ if (nconds == 0)
+ return false;
+
+ bi_call_bb = bb_for_stmt (bi_call);
+
+ /* Now find the join target bb -- split
+ bi_call_bb if needed. */
+ bi_call_bsi = bsi_for_stmt (bi_call);
+
+ join_tgt_in_edge_from_call = split_block (bi_call_bb, bi_call);
+ bi_call_bsi = bsi_for_stmt (bi_call);
+
+ join_tgt_bb = join_tgt_in_edge_from_call->dest;
+
+ /* Now it is time to insert the first conditional expression
+ into bi_call_bb and split this bb so that bi_call is
+ shrink-wrapped. */
+ tn_cond_stmts = VEC_length (tree, conds);
+ cond_expr = NULL;
+ cond_expr_start = VEC_index (tree, conds, 0);
+ for (ci = 0; ci < tn_cond_stmts; ci++)
+ {
+ tree c = VEC_index (tree, conds, ci);
+ gcc_assert (c || ci != 0);
+ if (!c)
+ break;
+ bsi_insert_before (&bi_call_bsi, c, BSI_SAME_STMT);
+ cond_expr = c;
+ }
+ nconds--;
+ ci++;
+ gcc_assert (cond_expr && TREE_CODE (cond_expr) == COND_EXPR);
+
+ /* Now the label. */
+ bi_call_label_decl = create_artificial_label ();
+ bi_call_label = build1 (LABEL_EXPR, void_type_node, bi_call_label_decl);
+ bsi_insert_before (&bi_call_bsi, bi_call_label, BSI_SAME_STMT);
+
+ bi_call_in_edge0 = split_block (bi_call_bb, cond_expr);
+ bi_call_in_edge0->flags &= ~EDGE_FALLTHRU;
+ bi_call_in_edge0->flags |= EDGE_TRUE_VALUE;
+ guard_bb0 = bi_call_bb;
+ bi_call_bb = bi_call_in_edge0->dest;
+ join_tgt_in_edge_fall_thru = make_edge (guard_bb0, join_tgt_bb,
+ EDGE_FALSE_VALUE);
+
+ bi_call_in_edge0->probability = REG_BR_PROB_BASE * ERR_PROB;
+ join_tgt_in_edge_fall_thru->probability =
+ REG_BR_PROB_BASE - bi_call_in_edge0->probability;
+
+ /* Code generation for the rest of the conditions */
+ guard_bb = guard_bb0;
+ while (nconds > 0)
+ {
+ unsigned ci0;
+ edge bi_call_in_edge;
+ block_stmt_iterator guard_bsi = bsi_for_stmt (cond_expr_start);
+ ci0 = ci;
+ cond_expr_start = VEC_index (tree, conds, ci0);
+ for (; ci < tn_cond_stmts; ci++)
+ {
+ tree c = VEC_index (tree, conds, ci);
+ gcc_assert (c || ci != ci0);
+ if (!c)
+ break;
+ bsi_insert_before (&guard_bsi, c, BSI_SAME_STMT);
+ cond_expr = c;
+ }
+ nconds--;
+ ci++;
+ gcc_assert (cond_expr && TREE_CODE (cond_expr) == COND_EXPR);
+ guard_bb_in_edge = split_block (guard_bb, cond_expr);
+ guard_bb_in_edge->flags &= ~EDGE_FALLTHRU;
+ guard_bb_in_edge->flags |= EDGE_FALSE_VALUE;
+
+ bi_call_in_edge = make_edge (guard_bb, bi_call_bb, EDGE_TRUE_VALUE);
+
+ bi_call_in_edge->probability = REG_BR_PROB_BASE * ERR_PROB;
+ guard_bb_in_edge->probability =
+ REG_BR_PROB_BASE - bi_call_in_edge->probability;
+ }
+
+ VEC_free (tree, heap, conds);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ location_t loc;
+ loc = EXPR_LOCATION (bi_call);
+ fprintf (dump_file,
+ "%s:%d: note: function call is shrink-wrapped"
+ " into error conditions.\n",
+ LOCATION_FILE (loc), LOCATION_LINE (loc));
+ }
+
+ return true;
+}
+
+/* The top level function for conditional dead code shrink
+ wrapping transformation. */
+
+static bool
+shrink_wrap_conditional_dead_built_in_calls (void)
+{
+ bool changed = false;
+ unsigned i = 0;
+
+ unsigned n = VEC_length (tree, cond_dead_built_in_calls);
+ if (n == 0)
+ return false;
+
+ for (; i < n ; i++)
+ {
+ tree bi_call = VEC_index (tree, cond_dead_built_in_calls, i);
+ changed |= shrink_wrap_one_built_in_call (bi_call);
+ }
+
+ return changed;
+}
+
+/* Pass entry points. */
+
+static unsigned int
+tree_call_cdce (void)
+{
+ basic_block bb;
+ block_stmt_iterator i;
+ bool something_changed = false;
+ cond_dead_built_in_calls = VEC_alloc (tree, heap, 64);
+
+ FOR_EACH_BB (bb)
+ {
+ /* Collect dead call candidates. */
+ for (i = bsi_start (bb); ! bsi_end_p (i); bsi_next (&i))
+ {
+ tree stmt = bsi_stmt (i);
+ if (TREE_CODE (stmt) == CALL_EXPR
+ && is_call_dce_candidate (stmt))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Found conditional dead call: ");
+ print_generic_stmt (dump_file, stmt, TDF_SLIM);
+ fprintf (dump_file, "\n");
+ }
+ VEC_quick_push (tree, cond_dead_built_in_calls, stmt);
+ }
+ }
+ }
+
+ something_changed =
+ shrink_wrap_conditional_dead_built_in_calls ();
+
+ VEC_free (tree, heap, cond_dead_built_in_calls);
+
+ if (something_changed)
+ {
+ free_dominance_info (CDI_DOMINATORS);
+ free_dominance_info (CDI_POST_DOMINATORS);
+ return (TODO_update_ssa | TODO_cleanup_cfg | TODO_ggc_collect
+ | TODO_remove_unused_locals);
+ }
+ else
+ return 0;
+}
+
+static bool
+gate_call_cdce (void)
+{
+ /* The limit constants used in the implementation
+ assume IEEE floating point format. Other formats
+ can be supported in the future if needed. */
+ return flag_tree_builtin_call_dce != 0;
+}
+
+struct gimple_opt_pass pass_call_cdce =
+{
+ {
+ GIMPLE_PASS,
+ "cdce", /* name */
+ gate_call_cdce, /* gate */
+ tree_call_cdce, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_TREE_CALL_CDCE, /* tv_id */
+ PROP_cfg | PROP_ssa, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_dump_func | TODO_verify_ssa /* todo_flags_finish */
+ }
+};
projects / gcc.git / commitdiff