Mercurial > hg > CbC > CbC_gcc
annotate gcc/tree-call-cdce.c @ 111:04ced10e8804
gcc 7
| author | kono |
|---|---|
| date | Fri, 27 Oct 2017 22:46:09 +0900 |
| parents | f6334be47118 |
| children | 84e7813d76e9 |
| rev | line source |
|---|---|
| 0 | 1 /* Conditional Dead Call Elimination pass for the GNU compiler. |
| 111 | 2 Copyright (C) 2008-2017 Free Software Foundation, Inc. |
| 0 | 3 Contributed by Xinliang David Li <davidxl@google.com> |
| 4 | |
| 5 This file is part of GCC. | |
|
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6 |
| 0 | 7 GCC is free software; you can redistribute it and/or modify it |
| 8 under the terms of the GNU General Public License as published by the | |
| 9 Free Software Foundation; either version 3, or (at your option) any | |
| 10 later version. | |
|
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11 |
| 0 | 12 GCC is distributed in the hope that it will be useful, but WITHOUT |
| 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 15 for more details. | |
|
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16 |
| 0 | 17 You should have received a copy of the GNU General Public License |
| 18 along with GCC; see the file COPYING3. If not see | |
| 19 <http://www.gnu.org/licenses/>. */ | |
| 20 | |
| 21 #include "config.h" | |
| 22 #include "system.h" | |
| 23 #include "coretypes.h" | |
| 111 | 24 #include "backend.h" |
| 0 | 25 #include "tree.h" |
| 111 | 26 #include "gimple.h" |
| 27 #include "cfghooks.h" | |
| 28 #include "tree-pass.h" | |
| 29 #include "ssa.h" | |
|
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30 #include "gimple-pretty-print.h" |
| 111 | 31 #include "fold-const.h" |
| 32 #include "stor-layout.h" | |
| 33 #include "gimple-iterator.h" | |
| 34 #include "tree-cfg.h" | |
| 35 #include "tree-into-ssa.h" | |
| 36 #include "builtins.h" | |
| 37 #include "internal-fn.h" | |
| 38 #include "tree-dfa.h" | |
| 0 | 39 |
| 40 | |
| 111 | 41 /* This pass serves two closely-related purposes: |
| 42 | |
| 43 1. It conditionally executes calls that set errno if (a) the result of | |
| 44 the call is unused and (b) a simple range check on the arguments can | |
| 45 detect most cases where errno does not need to be set. | |
| 46 | |
| 47 This is the "conditional dead-code elimination" that gave the pass | |
| 48 its original name, since the call is dead for most argument values. | |
| 49 The calls for which it helps are usually part of the C++ abstraction | |
| 50 penalty exposed after inlining. | |
| 0 | 51 |
| 111 | 52 2. It looks for calls to built-in functions that set errno and whose |
| 53 result is used. It checks whether there is an associated internal | |
| 54 function that doesn't set errno and whether the target supports | |
| 55 that internal function. If so, the pass uses the internal function | |
| 56 to compute the result of the built-in function but still arranges | |
| 57 for errno to be set when necessary. There are two ways of setting | |
| 58 errno: | |
| 59 | |
| 60 a. by protecting the original call with the same argument checks as (1) | |
| 61 | |
| 62 b. by protecting the original call with a check that the result | |
| 63 of the internal function is not equal to itself (i.e. is NaN). | |
| 0 | 64 |
| 111 | 65 (b) requires that NaNs are the only erroneous results. It is not |
| 66 appropriate for functions like log, which returns ERANGE for zero | |
| 67 arguments. (b) is also likely to perform worse than (a) because it | |
| 68 requires the result to be calculated first. The pass therefore uses | |
| 69 (a) when it can and uses (b) as a fallback. | |
| 70 | |
| 71 For (b) the pass can replace the original call with a call to | |
| 72 IFN_SET_EDOM, if the target supports direct assignments to errno. | |
| 0 | 73 |
| 111 | 74 In both cases, arguments that require errno to be set should occur |
| 75 rarely in practice. Checks of the errno result should also be rare, | |
| 76 but the compiler would need powerful interprocedural analysis to | |
| 77 prove that errno is not checked. It's much easier to add argument | |
| 78 checks or result checks instead. | |
| 79 | |
| 80 An example of (1) is: | |
| 81 | |
| 82 log (x); // Mostly dead call | |
| 0 | 83 ==> |
| 111 | 84 if (__builtin_islessequal (x, 0)) |
| 85 log (x); | |
| 86 | |
| 0 | 87 With this change, call to log (x) is effectively eliminated, as |
| 111 | 88 in the majority of the cases, log won't be called with x out of |
| 0 | 89 range. The branch is totally predictable, so the branch cost |
|
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90 is low. |
| 0 | 91 |
| 111 | 92 An example of (2) is: |
| 93 | |
| 94 y = sqrt (x); | |
| 95 ==> | |
| 96 y = IFN_SQRT (x); | |
| 97 if (__builtin_isless (x, 0)) | |
| 98 sqrt (x); | |
| 99 | |
| 100 In the vast majority of cases we should then never need to call sqrt. | |
| 101 | |
| 0 | 102 Note that library functions are not supposed to clear errno to zero without |
| 103 error. See IEEE Std 1003.1, section 2.3 Error Numbers, and section 7.5:3 of | |
| 104 ISO/IEC 9899 (C99). | |
| 105 | |
| 106 The condition wrapping the builtin call is conservatively set to avoid too | |
| 111 | 107 aggressive (wrong) shrink wrapping. */ |
| 0 | 108 |
| 109 | |
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110 /* A structure for representing input domain of |
| 0 | 111 a function argument in integer. If the lower |
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112 bound is -inf, has_lb is set to false. If the |
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113 upper bound is +inf, has_ub is false. |
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114 is_lb_inclusive and is_ub_inclusive are flags |
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115 to indicate if lb and ub value are inclusive |
| 0 | 116 respectively. */ |
| 117 | |
| 111 | 118 struct inp_domain |
| 0 | 119 { |
| 120 int lb; | |
| 121 int ub; | |
| 122 bool has_lb; | |
| 123 bool has_ub; | |
| 124 bool is_lb_inclusive; | |
| 125 bool is_ub_inclusive; | |
| 111 | 126 }; |
| 0 | 127 |
| 128 /* A helper function to construct and return an input | |
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129 domain object. LB is the lower bound, HAS_LB is |
| 0 | 130 a boolean flag indicating if the lower bound exists, |
| 131 and LB_INCLUSIVE is a boolean flag indicating if the | |
| 132 lower bound is inclusive or not. UB, HAS_UB, and | |
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133 UB_INCLUSIVE have the same meaning, but for upper |
| 0 | 134 bound of the domain. */ |
| 135 | |
| 136 static inp_domain | |
| 137 get_domain (int lb, bool has_lb, bool lb_inclusive, | |
| 138 int ub, bool has_ub, bool ub_inclusive) | |
| 139 { | |
| 140 inp_domain domain; | |
| 141 domain.lb = lb; | |
| 142 domain.has_lb = has_lb; | |
| 143 domain.is_lb_inclusive = lb_inclusive; | |
| 144 domain.ub = ub; | |
| 145 domain.has_ub = has_ub; | |
| 146 domain.is_ub_inclusive = ub_inclusive; | |
| 147 return domain; | |
| 148 } | |
| 149 | |
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150 /* A helper function to check the target format for the |
| 0 | 151 argument type. In this implementation, only IEEE formats |
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152 are supported. ARG is the call argument to be checked. |
| 0 | 153 Returns true if the format is supported. To support other |
| 154 target formats, function get_no_error_domain needs to be | |
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155 enhanced to have range bounds properly computed. Since |
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156 the check is cheap (very small number of candidates |
| 0 | 157 to be checked), the result is not cached for each float type. */ |
| 158 | |
| 159 static bool | |
| 160 check_target_format (tree arg) | |
| 161 { | |
| 162 tree type; | |
| 111 | 163 machine_mode mode; |
| 0 | 164 const struct real_format *rfmt; |
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165 |
| 0 | 166 type = TREE_TYPE (arg); |
| 167 mode = TYPE_MODE (type); | |
| 168 rfmt = REAL_MODE_FORMAT (mode); | |
| 169 if ((mode == SFmode | |
| 170 && (rfmt == &ieee_single_format || rfmt == &mips_single_format | |
| 171 || rfmt == &motorola_single_format)) | |
| 172 || (mode == DFmode | |
| 173 && (rfmt == &ieee_double_format || rfmt == &mips_double_format | |
| 174 || rfmt == &motorola_double_format)) | |
| 175 /* For long double, we can not really check XFmode | |
|
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176 which is only defined on intel platforms. |
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177 Candidate pre-selection using builtin function |
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178 code guarantees that we are checking formats |
| 0 | 179 for long double modes: double, quad, and extended. */ |
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180 || (mode != SFmode && mode != DFmode |
| 0 | 181 && (rfmt == &ieee_quad_format |
| 182 || rfmt == &mips_quad_format | |
| 183 || rfmt == &ieee_extended_motorola_format | |
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184 || rfmt == &ieee_extended_intel_96_format |
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185 || rfmt == &ieee_extended_intel_128_format |
| 0 | 186 || rfmt == &ieee_extended_intel_96_round_53_format))) |
| 187 return true; | |
| 188 | |
| 189 return false; | |
| 190 } | |
| 191 | |
| 192 | |
| 193 /* A helper function to help select calls to pow that are suitable for | |
| 194 conditional DCE transformation. It looks for pow calls that can be | |
| 195 guided with simple conditions. Such calls either have constant base | |
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196 values or base values converted from integers. Returns true if |
| 0 | 197 the pow call POW_CALL is a candidate. */ |
| 198 | |
| 199 /* The maximum integer bit size for base argument of a pow call | |
| 200 that is suitable for shrink-wrapping transformation. */ | |
| 201 #define MAX_BASE_INT_BIT_SIZE 32 | |
| 202 | |
| 203 static bool | |
| 111 | 204 check_pow (gcall *pow_call) |
| 0 | 205 { |
| 206 tree base, expn; | |
| 207 enum tree_code bc, ec; | |
| 208 | |
| 209 if (gimple_call_num_args (pow_call) != 2) | |
| 210 return false; | |
| 211 | |
| 212 base = gimple_call_arg (pow_call, 0); | |
| 213 expn = gimple_call_arg (pow_call, 1); | |
| 214 | |
| 215 if (!check_target_format (expn)) | |
| 216 return false; | |
| 217 | |
| 218 bc = TREE_CODE (base); | |
| 219 ec = TREE_CODE (expn); | |
| 220 | |
| 221 /* Folding candidates are not interesting. | |
| 222 Can actually assert that it is already folded. */ | |
| 223 if (ec == REAL_CST && bc == REAL_CST) | |
| 224 return false; | |
| 225 | |
| 226 if (bc == REAL_CST) | |
| 227 { | |
| 228 /* Only handle a fixed range of constant. */ | |
| 229 REAL_VALUE_TYPE mv; | |
| 230 REAL_VALUE_TYPE bcv = TREE_REAL_CST (base); | |
| 111 | 231 if (real_equal (&bcv, &dconst1)) |
| 0 | 232 return false; |
| 111 | 233 if (real_less (&bcv, &dconst1)) |
| 0 | 234 return false; |
| 111 | 235 real_from_integer (&mv, TYPE_MODE (TREE_TYPE (base)), 256, UNSIGNED); |
| 236 if (real_less (&mv, &bcv)) | |
| 0 | 237 return false; |
| 238 return true; | |
| 239 } | |
| 240 else if (bc == SSA_NAME) | |
| 241 { | |
| 111 | 242 tree base_val0, type; |
| 243 gimple *base_def; | |
| 0 | 244 int bit_sz; |
| 245 | |
| 246 /* Only handles cases where base value is converted | |
|
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247 from integer values. */ |
| 0 | 248 base_def = SSA_NAME_DEF_STMT (base); |
| 249 if (gimple_code (base_def) != GIMPLE_ASSIGN) | |
| 250 return false; | |
| 251 | |
| 252 if (gimple_assign_rhs_code (base_def) != FLOAT_EXPR) | |
| 253 return false; | |
| 254 base_val0 = gimple_assign_rhs1 (base_def); | |
| 255 | |
| 111 | 256 type = TREE_TYPE (base_val0); |
| 0 | 257 if (TREE_CODE (type) != INTEGER_TYPE) |
| 258 return false; | |
| 259 bit_sz = TYPE_PRECISION (type); | |
| 260 /* If the type of the base is too wide, | |
| 261 the resulting shrink wrapping condition | |
| 262 will be too conservative. */ | |
| 263 if (bit_sz > MAX_BASE_INT_BIT_SIZE) | |
| 264 return false; | |
| 265 | |
| 266 return true; | |
| 267 } | |
| 268 else | |
| 269 return false; | |
| 270 } | |
| 271 | |
| 272 /* A helper function to help select candidate function calls that are | |
| 273 suitable for conditional DCE. Candidate functions must have single | |
| 274 valid input domain in this implementation except for pow (see check_pow). | |
| 275 Returns true if the function call is a candidate. */ | |
| 276 | |
| 277 static bool | |
| 111 | 278 check_builtin_call (gcall *bcall) |
| 0 | 279 { |
| 280 tree arg; | |
| 281 | |
| 282 arg = gimple_call_arg (bcall, 0); | |
| 283 return check_target_format (arg); | |
| 284 } | |
| 285 | |
| 111 | 286 /* Return true if built-in function call CALL calls a math function |
| 287 and if we know how to test the range of its arguments to detect _most_ | |
| 288 situations in which errno is not set. The test must err on the side | |
| 289 of treating non-erroneous values as potentially erroneous. */ | |
| 0 | 290 |
| 291 static bool | |
| 111 | 292 can_test_argument_range (gcall *call) |
| 0 | 293 { |
| 111 | 294 switch (DECL_FUNCTION_CODE (gimple_call_fndecl (call))) |
| 0 | 295 { |
| 296 /* Trig functions. */ | |
| 297 CASE_FLT_FN (BUILT_IN_ACOS): | |
| 298 CASE_FLT_FN (BUILT_IN_ASIN): | |
| 299 /* Hyperbolic functions. */ | |
| 300 CASE_FLT_FN (BUILT_IN_ACOSH): | |
| 301 CASE_FLT_FN (BUILT_IN_ATANH): | |
| 302 CASE_FLT_FN (BUILT_IN_COSH): | |
| 303 CASE_FLT_FN (BUILT_IN_SINH): | |
| 304 /* Log functions. */ | |
| 305 CASE_FLT_FN (BUILT_IN_LOG): | |
| 306 CASE_FLT_FN (BUILT_IN_LOG2): | |
| 307 CASE_FLT_FN (BUILT_IN_LOG10): | |
| 308 CASE_FLT_FN (BUILT_IN_LOG1P): | |
| 309 /* Exp functions. */ | |
| 310 CASE_FLT_FN (BUILT_IN_EXP): | |
| 311 CASE_FLT_FN (BUILT_IN_EXP2): | |
| 312 CASE_FLT_FN (BUILT_IN_EXP10): | |
| 313 CASE_FLT_FN (BUILT_IN_EXPM1): | |
| 314 CASE_FLT_FN (BUILT_IN_POW10): | |
| 315 /* Sqrt. */ | |
| 316 CASE_FLT_FN (BUILT_IN_SQRT): | |
| 317 return check_builtin_call (call); | |
| 318 /* Special one: two argument pow. */ | |
| 319 case BUILT_IN_POW: | |
| 320 return check_pow (call); | |
| 321 default: | |
| 322 break; | |
| 323 } | |
| 324 | |
| 325 return false; | |
| 326 } | |
| 327 | |
| 111 | 328 /* Return true if CALL can produce a domain error (EDOM) but can never |
| 329 produce a pole, range overflow or range underflow error (all ERANGE). | |
| 330 This means that we can tell whether a function would have set errno | |
| 331 by testing whether the result is a NaN. */ | |
| 332 | |
| 333 static bool | |
| 334 edom_only_function (gcall *call) | |
| 335 { | |
| 336 switch (DECL_FUNCTION_CODE (gimple_call_fndecl (call))) | |
| 337 { | |
| 338 CASE_FLT_FN (BUILT_IN_ACOS): | |
| 339 CASE_FLT_FN (BUILT_IN_ASIN): | |
| 340 CASE_FLT_FN (BUILT_IN_ATAN): | |
| 341 CASE_FLT_FN (BUILT_IN_COS): | |
| 342 CASE_FLT_FN (BUILT_IN_SIGNIFICAND): | |
| 343 CASE_FLT_FN (BUILT_IN_SIN): | |
| 344 CASE_FLT_FN (BUILT_IN_SQRT): | |
| 345 CASE_FLT_FN (BUILT_IN_FMOD): | |
| 346 CASE_FLT_FN (BUILT_IN_REMAINDER): | |
| 347 return true; | |
| 348 | |
| 349 default: | |
| 350 return false; | |
| 351 } | |
| 352 } | |
| 353 | |
| 354 /* Return true if it is structurally possible to guard CALL. */ | |
| 355 | |
| 356 static bool | |
| 357 can_guard_call_p (gimple *call) | |
| 358 { | |
| 359 return (!stmt_ends_bb_p (call) | |
| 360 || find_fallthru_edge (gimple_bb (call)->succs)); | |
| 361 } | |
| 0 | 362 |
| 111 | 363 /* A helper function to generate gimple statements for one bound |
| 364 comparison, so that the built-in function is called whenever | |
| 365 TCODE <ARG, LBUB> is *false*. TEMP_NAME1/TEMP_NAME2 are names | |
| 366 of the temporaries, CONDS is a vector holding the produced GIMPLE | |
| 367 statements, and NCONDS points to the variable holding the number of | |
| 368 logical comparisons. CONDS is either empty or a list ended with a | |
| 369 null tree. */ | |
| 0 | 370 |
| 371 static void | |
|
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372 gen_one_condition (tree arg, int lbub, |
| 0 | 373 enum tree_code tcode, |
| 374 const char *temp_name1, | |
| 375 const char *temp_name2, | |
| 111 | 376 vec<gimple *> conds, |
| 0 | 377 unsigned *nconds) |
| 378 { | |
| 379 tree lbub_real_cst, lbub_cst, float_type; | |
| 380 tree temp, tempn, tempc, tempcn; | |
| 111 | 381 gassign *stmt1; |
| 382 gassign *stmt2; | |
| 383 gcond *stmt3; | |
| 0 | 384 |
| 385 float_type = TREE_TYPE (arg); | |
| 386 lbub_cst = build_int_cst (integer_type_node, lbub); | |
| 387 lbub_real_cst = build_real_from_int_cst (float_type, lbub_cst); | |
| 388 | |
| 389 temp = create_tmp_var (float_type, temp_name1); | |
| 390 stmt1 = gimple_build_assign (temp, arg); | |
| 391 tempn = make_ssa_name (temp, stmt1); | |
| 392 gimple_assign_set_lhs (stmt1, tempn); | |
| 393 | |
| 394 tempc = create_tmp_var (boolean_type_node, temp_name2); | |
| 395 stmt2 = gimple_build_assign (tempc, | |
| 396 fold_build2 (tcode, | |
| 397 boolean_type_node, | |
| 398 tempn, lbub_real_cst)); | |
| 399 tempcn = make_ssa_name (tempc, stmt2); | |
| 400 gimple_assign_set_lhs (stmt2, tempcn); | |
| 401 | |
| 402 stmt3 = gimple_build_cond_from_tree (tempcn, NULL_TREE, NULL_TREE); | |
| 111 | 403 conds.quick_push (stmt1); |
| 404 conds.quick_push (stmt2); | |
| 405 conds.quick_push (stmt3); | |
| 0 | 406 (*nconds)++; |
| 407 } | |
| 408 | |
| 409 /* A helper function to generate GIMPLE statements for | |
| 410 out of input domain check. ARG is the call argument | |
| 411 to be runtime checked, DOMAIN holds the valid domain | |
| 412 for the given function, CONDS points to the vector | |
|
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413 holding the result GIMPLE statements. *NCONDS is |
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414 the number of logical comparisons. This function |
| 0 | 415 produces no more than two logical comparisons, one |
| 416 for lower bound check, one for upper bound check. */ | |
| 417 | |
| 418 static void | |
| 419 gen_conditions_for_domain (tree arg, inp_domain domain, | |
| 111 | 420 vec<gimple *> conds, |
| 0 | 421 unsigned *nconds) |
| 422 { | |
| 423 if (domain.has_lb) | |
| 424 gen_one_condition (arg, domain.lb, | |
| 425 (domain.is_lb_inclusive | |
| 111 | 426 ? UNGE_EXPR : UNGT_EXPR), |
| 0 | 427 "DCE_COND_LB", "DCE_COND_LB_TEST", |
| 428 conds, nconds); | |
| 429 | |
| 430 if (domain.has_ub) | |
| 431 { | |
| 432 /* Now push a separator. */ | |
| 433 if (domain.has_lb) | |
| 111 | 434 conds.quick_push (NULL); |
| 0 | 435 |
| 436 gen_one_condition (arg, domain.ub, | |
| 437 (domain.is_ub_inclusive | |
| 111 | 438 ? UNLE_EXPR : UNLT_EXPR), |
| 0 | 439 "DCE_COND_UB", "DCE_COND_UB_TEST", |
| 440 conds, nconds); | |
| 441 } | |
| 442 } | |
| 443 | |
| 444 | |
| 445 /* A helper function to generate condition | |
| 446 code for the y argument in call pow (some_const, y). | |
|
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447 See candidate selection in check_pow. Since the |
| 0 | 448 candidates' base values have a limited range, |
| 449 the guarded code generated for y are simple: | |
| 111 | 450 if (__builtin_isgreater (y, max_y)) |
| 0 | 451 pow (const, y); |
| 452 Note max_y can be computed separately for each | |
| 453 const base, but in this implementation, we | |
| 454 choose to compute it using the max base | |
| 455 in the allowed range for the purpose of | |
| 456 simplicity. BASE is the constant base value, | |
| 457 EXPN is the expression for the exponent argument, | |
| 458 *CONDS is the vector to hold resulting statements, | |
| 459 and *NCONDS is the number of logical conditions. */ | |
| 460 | |
| 461 static void | |
| 462 gen_conditions_for_pow_cst_base (tree base, tree expn, | |
| 111 | 463 vec<gimple *> conds, |
| 0 | 464 unsigned *nconds) |
| 465 { | |
|
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466 inp_domain exp_domain; |
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467 /* Validate the range of the base constant to make |
| 0 | 468 sure it is consistent with check_pow. */ |
| 469 REAL_VALUE_TYPE mv; | |
| 470 REAL_VALUE_TYPE bcv = TREE_REAL_CST (base); | |
| 111 | 471 gcc_assert (!real_equal (&bcv, &dconst1) |
| 472 && !real_less (&bcv, &dconst1)); | |
| 473 real_from_integer (&mv, TYPE_MODE (TREE_TYPE (base)), 256, UNSIGNED); | |
| 474 gcc_assert (!real_less (&mv, &bcv)); | |
| 0 | 475 |
| 476 exp_domain = get_domain (0, false, false, | |
| 477 127, true, false); | |
| 478 | |
| 479 gen_conditions_for_domain (expn, exp_domain, | |
| 480 conds, nconds); | |
| 481 } | |
| 482 | |
| 483 /* Generate error condition code for pow calls with | |
| 484 non constant base values. The candidates selected | |
| 485 have their base argument value converted from | |
| 486 integer (see check_pow) value (1, 2, 4 bytes), and | |
| 487 the max exp value is computed based on the size | |
| 488 of the integer type (i.e. max possible base value). | |
| 489 The resulting input domain for exp argument is thus | |
|
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490 conservative (smaller than the max value allowed by |
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491 the runtime value of the base). BASE is the integer |
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492 base value, EXPN is the expression for the exponent |
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493 argument, *CONDS is the vector to hold resulting |
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494 statements, and *NCONDS is the number of logical |
| 0 | 495 conditions. */ |
| 496 | |
| 497 static void | |
| 498 gen_conditions_for_pow_int_base (tree base, tree expn, | |
| 111 | 499 vec<gimple *> conds, |
| 0 | 500 unsigned *nconds) |
| 501 { | |
| 111 | 502 gimple *base_def; |
|
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503 tree base_val0; |
| 111 | 504 tree int_type; |
| 0 | 505 tree temp, tempn; |
| 506 tree cst0; | |
| 111 | 507 gimple *stmt1, *stmt2; |
| 0 | 508 int bit_sz, max_exp; |
| 509 inp_domain exp_domain; | |
| 510 | |
| 511 base_def = SSA_NAME_DEF_STMT (base); | |
| 512 base_val0 = gimple_assign_rhs1 (base_def); | |
| 111 | 513 int_type = TREE_TYPE (base_val0); |
| 0 | 514 bit_sz = TYPE_PRECISION (int_type); |
|
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515 gcc_assert (bit_sz > 0 |
| 0 | 516 && bit_sz <= MAX_BASE_INT_BIT_SIZE); |
| 517 | |
| 518 /* Determine the max exp argument value according to | |
| 519 the size of the base integer. The max exp value | |
| 520 is conservatively estimated assuming IEEE754 double | |
| 521 precision format. */ | |
| 522 if (bit_sz == 8) | |
| 523 max_exp = 128; | |
| 524 else if (bit_sz == 16) | |
| 525 max_exp = 64; | |
| 526 else | |
|
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527 { |
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528 gcc_assert (bit_sz == MAX_BASE_INT_BIT_SIZE); |
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529 max_exp = 32; |
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530 } |
| 0 | 531 |
| 532 /* For pow ((double)x, y), generate the following conditions: | |
| 533 cond 1: | |
| 534 temp1 = x; | |
| 111 | 535 if (__builtin_islessequal (temp1, 0)) |
| 0 | 536 |
| 537 cond 2: | |
| 538 temp2 = y; | |
| 111 | 539 if (__builtin_isgreater (temp2, max_exp_real_cst)) */ |
| 0 | 540 |
| 541 /* Generate condition in reverse order -- first | |
| 542 the condition for the exp argument. */ | |
| 543 | |
| 544 exp_domain = get_domain (0, false, false, | |
| 545 max_exp, true, true); | |
| 546 | |
| 547 gen_conditions_for_domain (expn, exp_domain, | |
| 548 conds, nconds); | |
| 549 | |
| 550 /* Now generate condition for the base argument. | |
| 551 Note it does not use the helper function | |
| 552 gen_conditions_for_domain because the base | |
| 553 type is integer. */ | |
| 554 | |
| 555 /* Push a separator. */ | |
| 111 | 556 conds.quick_push (NULL); |
| 0 | 557 |
| 558 temp = create_tmp_var (int_type, "DCE_COND1"); | |
| 559 cst0 = build_int_cst (int_type, 0); | |
| 560 stmt1 = gimple_build_assign (temp, base_val0); | |
| 561 tempn = make_ssa_name (temp, stmt1); | |
| 562 gimple_assign_set_lhs (stmt1, tempn); | |
| 111 | 563 stmt2 = gimple_build_cond (GT_EXPR, tempn, cst0, NULL_TREE, NULL_TREE); |
| 0 | 564 |
| 111 | 565 conds.quick_push (stmt1); |
| 566 conds.quick_push (stmt2); | |
| 0 | 567 (*nconds)++; |
| 568 } | |
| 569 | |
| 570 /* Method to generate conditional statements for guarding conditionally | |
| 571 dead calls to pow. One or more statements can be generated for | |
| 572 each logical condition. Statement groups of different conditions | |
| 111 | 573 are separated by a NULL tree and they are stored in the vec |
| 0 | 574 conds. The number of logical conditions are stored in *nconds. |
| 575 | |
| 576 See C99 standard, 7.12.7.4:2, for description of pow (x, y). | |
| 577 The precise condition for domain errors are complex. In this | |
| 578 implementation, a simplified (but conservative) valid domain | |
| 579 for x and y are used: x is positive to avoid dom errors, while | |
| 580 y is smaller than a upper bound (depending on x) to avoid range | |
| 581 errors. Runtime code is generated to check x (if not constant) | |
| 582 and y against the valid domain. If it is out, jump to the call, | |
| 583 otherwise the call is bypassed. POW_CALL is the call statement, | |
| 584 *CONDS is a vector holding the resulting condition statements, | |
| 585 and *NCONDS is the number of logical conditions. */ | |
| 586 | |
| 587 static void | |
| 111 | 588 gen_conditions_for_pow (gcall *pow_call, vec<gimple *> conds, |
| 0 | 589 unsigned *nconds) |
| 590 { | |
| 591 tree base, expn; | |
|
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592 enum tree_code bc; |
| 0 | 593 |
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594 gcc_checking_assert (check_pow (pow_call)); |
| 0 | 595 |
| 596 *nconds = 0; | |
| 597 | |
| 598 base = gimple_call_arg (pow_call, 0); | |
| 599 expn = gimple_call_arg (pow_call, 1); | |
| 600 | |
| 601 bc = TREE_CODE (base); | |
| 602 | |
| 603 if (bc == REAL_CST) | |
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604 gen_conditions_for_pow_cst_base (base, expn, conds, nconds); |
| 0 | 605 else if (bc == SSA_NAME) |
|
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606 gen_conditions_for_pow_int_base (base, expn, conds, nconds); |
| 0 | 607 else |
| 608 gcc_unreachable (); | |
| 609 } | |
| 610 | |
| 611 /* A helper routine to help computing the valid input domain | |
| 612 for a builtin function. See C99 7.12.7 for details. In this | |
| 613 implementation, we only handle single region domain. The | |
| 614 resulting region can be conservative (smaller) than the actual | |
| 615 one and rounded to integers. Some of the bounds are documented | |
| 616 in the standard, while other limit constants are computed | |
|
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617 assuming IEEE floating point format (for SF and DF modes). |
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618 Since IEEE only sets minimum requirements for long double format, |
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619 different long double formats exist under different implementations |
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620 (e.g, 64 bit double precision (DF), 80 bit double-extended |
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621 precision (XF), and 128 bit quad precision (QF) ). For simplicity, |
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622 in this implementation, the computed bounds for long double assume |
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623 64 bit format (DF), and are therefore conservative. Another |
| 0 | 624 assumption is that single precision float type is always SF mode, |
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625 and double type is DF mode. This function is quite |
| 0 | 626 implementation specific, so it may not be suitable to be part of |
| 627 builtins.c. This needs to be revisited later to see if it can | |
| 628 be leveraged in x87 assembly expansion. */ | |
| 629 | |
| 630 static inp_domain | |
| 631 get_no_error_domain (enum built_in_function fnc) | |
| 632 { | |
| 633 switch (fnc) | |
| 634 { | |
| 635 /* Trig functions: return [-1, +1] */ | |
| 636 CASE_FLT_FN (BUILT_IN_ACOS): | |
| 637 CASE_FLT_FN (BUILT_IN_ASIN): | |
| 638 return get_domain (-1, true, true, | |
| 639 1, true, true); | |
| 640 /* Hyperbolic functions. */ | |
| 641 CASE_FLT_FN (BUILT_IN_ACOSH): | |
| 642 /* acosh: [1, +inf) */ | |
| 643 return get_domain (1, true, true, | |
| 644 1, false, false); | |
| 645 CASE_FLT_FN (BUILT_IN_ATANH): | |
| 646 /* atanh: (-1, +1) */ | |
| 647 return get_domain (-1, true, false, | |
| 648 1, true, false); | |
| 649 case BUILT_IN_COSHF: | |
| 650 case BUILT_IN_SINHF: | |
| 651 /* coshf: (-89, +89) */ | |
| 652 return get_domain (-89, true, false, | |
| 653 89, true, false); | |
| 654 case BUILT_IN_COSH: | |
| 655 case BUILT_IN_SINH: | |
| 656 case BUILT_IN_COSHL: | |
| 657 case BUILT_IN_SINHL: | |
| 658 /* cosh: (-710, +710) */ | |
| 659 return get_domain (-710, true, false, | |
| 660 710, true, false); | |
| 661 /* Log functions: (0, +inf) */ | |
| 662 CASE_FLT_FN (BUILT_IN_LOG): | |
| 663 CASE_FLT_FN (BUILT_IN_LOG2): | |
| 664 CASE_FLT_FN (BUILT_IN_LOG10): | |
| 665 return get_domain (0, true, false, | |
| 666 0, false, false); | |
| 667 CASE_FLT_FN (BUILT_IN_LOG1P): | |
| 668 return get_domain (-1, true, false, | |
| 669 0, false, false); | |
| 670 /* Exp functions. */ | |
| 671 case BUILT_IN_EXPF: | |
| 672 case BUILT_IN_EXPM1F: | |
| 673 /* expf: (-inf, 88) */ | |
| 674 return get_domain (-1, false, false, | |
| 675 88, true, false); | |
| 676 case BUILT_IN_EXP: | |
| 677 case BUILT_IN_EXPM1: | |
| 678 case BUILT_IN_EXPL: | |
| 679 case BUILT_IN_EXPM1L: | |
| 680 /* exp: (-inf, 709) */ | |
| 681 return get_domain (-1, false, false, | |
| 682 709, true, false); | |
| 683 case BUILT_IN_EXP2F: | |
| 684 /* exp2f: (-inf, 128) */ | |
| 685 return get_domain (-1, false, false, | |
| 686 128, true, false); | |
| 687 case BUILT_IN_EXP2: | |
| 688 case BUILT_IN_EXP2L: | |
| 689 /* exp2: (-inf, 1024) */ | |
| 690 return get_domain (-1, false, false, | |
| 691 1024, true, false); | |
| 692 case BUILT_IN_EXP10F: | |
| 693 case BUILT_IN_POW10F: | |
| 694 /* exp10f: (-inf, 38) */ | |
| 695 return get_domain (-1, false, false, | |
| 696 38, true, false); | |
| 697 case BUILT_IN_EXP10: | |
| 698 case BUILT_IN_POW10: | |
| 699 case BUILT_IN_EXP10L: | |
| 700 case BUILT_IN_POW10L: | |
| 701 /* exp10: (-inf, 308) */ | |
| 702 return get_domain (-1, false, false, | |
| 703 308, true, false); | |
| 704 /* sqrt: [0, +inf) */ | |
| 705 CASE_FLT_FN (BUILT_IN_SQRT): | |
| 706 return get_domain (0, true, true, | |
| 707 0, false, false); | |
| 708 default: | |
|
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709 gcc_unreachable (); |
| 0 | 710 } |
| 711 | |
|
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712 gcc_unreachable (); |
| 0 | 713 } |
| 714 | |
| 715 /* The function to generate shrink wrap conditions for a partially | |
| 716 dead builtin call whose return value is not used anywhere, | |
| 717 but has to be kept live due to potential error condition. | |
|
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718 BI_CALL is the builtin call, CONDS is the vector of statements |
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719 for condition code, NCODES is the pointer to the number of |
| 0 | 720 logical conditions. Statements belonging to different logical |
| 721 condition are separated by NULL tree in the vector. */ | |
| 722 | |
| 723 static void | |
| 111 | 724 gen_shrink_wrap_conditions (gcall *bi_call, vec<gimple *> conds, |
| 0 | 725 unsigned int *nconds) |
| 726 { | |
| 111 | 727 gcall *call; |
| 0 | 728 tree fn; |
| 729 enum built_in_function fnc; | |
| 730 | |
| 111 | 731 gcc_assert (nconds && conds.exists ()); |
| 732 gcc_assert (conds.length () == 0); | |
| 0 | 733 gcc_assert (is_gimple_call (bi_call)); |
| 734 | |
| 735 call = bi_call; | |
| 736 fn = gimple_call_fndecl (call); | |
| 737 gcc_assert (fn && DECL_BUILT_IN (fn)); | |
| 738 fnc = DECL_FUNCTION_CODE (fn); | |
| 739 *nconds = 0; | |
| 740 | |
| 741 if (fnc == BUILT_IN_POW) | |
| 742 gen_conditions_for_pow (call, conds, nconds); | |
| 743 else | |
| 744 { | |
| 745 tree arg; | |
| 746 inp_domain domain = get_no_error_domain (fnc); | |
| 747 *nconds = 0; | |
| 748 arg = gimple_call_arg (bi_call, 0); | |
| 749 gen_conditions_for_domain (arg, domain, conds, nconds); | |
| 750 } | |
| 751 | |
| 752 return; | |
| 753 } | |
| 754 | |
| 111 | 755 /* Shrink-wrap BI_CALL so that it is only called when one of the NCONDS |
| 756 conditions in CONDS is false. */ | |
| 0 | 757 |
| 111 | 758 static void |
| 759 shrink_wrap_one_built_in_call_with_conds (gcall *bi_call, vec <gimple *> conds, | |
| 760 unsigned int nconds) | |
| 0 | 761 { |
| 762 gimple_stmt_iterator bi_call_bsi; | |
| 111 | 763 basic_block bi_call_bb, join_tgt_bb, guard_bb; |
| 0 | 764 edge join_tgt_in_edge_from_call, join_tgt_in_edge_fall_thru; |
| 765 edge bi_call_in_edge0, guard_bb_in_edge; | |
| 111 | 766 unsigned tn_cond_stmts; |
| 0 | 767 unsigned ci; |
| 111 | 768 gimple *cond_expr = NULL; |
| 769 gimple *cond_expr_start; | |
| 770 | |
| 771 /* The cfg we want to create looks like this: | |
| 0 | 772 |
| 111 | 773 [guard n-1] <- guard_bb (old block) |
| 774 | \ | |
| 775 | [guard n-2] } | |
| 776 | / \ } | |
| 777 | / ... } new blocks | |
| 778 | / [guard 0] } | |
| 779 | / / | } | |
| 780 [ call ] | <- bi_call_bb } | |
| 781 | \ | | |
| 782 | \ | | |
| 783 | [ join ] <- join_tgt_bb (old iff call must end bb) | |
| 784 | | |
| 785 possible EH edges (only if [join] is old) | |
| 0 | 786 |
| 111 | 787 When [join] is new, the immediate dominators for these blocks are: |
| 0 | 788 |
| 111 | 789 1. [guard n-1]: unchanged |
| 790 2. [call]: [guard n-1] | |
| 791 3. [guard m]: [guard m+1] for 0 <= m <= n-2 | |
| 792 4. [join]: [guard n-1] | |
| 793 | |
| 794 We punt for the more complex case case of [join] being old and | |
| 795 simply free the dominance info. We also punt on postdominators, | |
| 796 which aren't expected to be available at this point anyway. */ | |
| 0 | 797 bi_call_bb = gimple_bb (bi_call); |
| 798 | |
| 111 | 799 /* Now find the join target bb -- split bi_call_bb if needed. */ |
| 800 if (stmt_ends_bb_p (bi_call)) | |
| 801 { | |
| 802 /* We checked that there was a fallthrough edge in | |
| 803 can_guard_call_p. */ | |
| 804 join_tgt_in_edge_from_call = find_fallthru_edge (bi_call_bb->succs); | |
| 805 gcc_assert (join_tgt_in_edge_from_call); | |
| 806 /* We don't want to handle PHIs. */ | |
| 807 if (EDGE_COUNT (join_tgt_in_edge_from_call->dest->preds) > 1) | |
| 808 join_tgt_bb = split_edge (join_tgt_in_edge_from_call); | |
| 809 else | |
| 810 { | |
| 811 join_tgt_bb = join_tgt_in_edge_from_call->dest; | |
| 812 /* We may have degenerate PHIs in the destination. Propagate | |
| 813 those out. */ | |
| 814 for (gphi_iterator i = gsi_start_phis (join_tgt_bb); !gsi_end_p (i);) | |
| 815 { | |
| 816 gphi *phi = i.phi (); | |
| 817 replace_uses_by (gimple_phi_result (phi), | |
| 818 gimple_phi_arg_def (phi, 0)); | |
| 819 remove_phi_node (&i, true); | |
| 820 } | |
| 821 } | |
| 822 } | |
| 823 else | |
| 824 { | |
| 825 join_tgt_in_edge_from_call = split_block (bi_call_bb, bi_call); | |
| 826 join_tgt_bb = join_tgt_in_edge_from_call->dest; | |
| 827 } | |
| 0 | 828 |
| 829 bi_call_bsi = gsi_for_stmt (bi_call); | |
| 830 | |
| 831 /* Now it is time to insert the first conditional expression | |
| 832 into bi_call_bb and split this bb so that bi_call is | |
| 833 shrink-wrapped. */ | |
| 111 | 834 tn_cond_stmts = conds.length (); |
| 0 | 835 cond_expr = NULL; |
| 111 | 836 cond_expr_start = conds[0]; |
| 0 | 837 for (ci = 0; ci < tn_cond_stmts; ci++) |
| 838 { | |
| 111 | 839 gimple *c = conds[ci]; |
| 0 | 840 gcc_assert (c || ci != 0); |
| 841 if (!c) | |
| 842 break; | |
| 843 gsi_insert_before (&bi_call_bsi, c, GSI_SAME_STMT); | |
| 844 cond_expr = c; | |
| 845 } | |
| 846 ci++; | |
| 847 gcc_assert (cond_expr && gimple_code (cond_expr) == GIMPLE_COND); | |
| 848 | |
| 111 | 849 typedef std::pair<edge, edge> edge_pair; |
| 850 auto_vec<edge_pair, 8> edges; | |
| 0 | 851 |
| 852 bi_call_in_edge0 = split_block (bi_call_bb, cond_expr); | |
| 853 bi_call_in_edge0->flags &= ~EDGE_FALLTHRU; | |
| 111 | 854 bi_call_in_edge0->flags |= EDGE_FALSE_VALUE; |
| 855 guard_bb = bi_call_bb; | |
| 0 | 856 bi_call_bb = bi_call_in_edge0->dest; |
| 111 | 857 join_tgt_in_edge_fall_thru = make_edge (guard_bb, join_tgt_bb, |
| 858 EDGE_TRUE_VALUE); | |
| 0 | 859 |
| 111 | 860 edges.reserve (nconds); |
| 861 edges.quick_push (edge_pair (bi_call_in_edge0, join_tgt_in_edge_fall_thru)); | |
| 0 | 862 |
| 863 /* Code generation for the rest of the conditions */ | |
| 111 | 864 for (unsigned int i = 1; i < nconds; ++i) |
| 0 | 865 { |
| 866 unsigned ci0; | |
| 867 edge bi_call_in_edge; | |
| 868 gimple_stmt_iterator guard_bsi = gsi_for_stmt (cond_expr_start); | |
| 869 ci0 = ci; | |
| 111 | 870 cond_expr_start = conds[ci0]; |
| 0 | 871 for (; ci < tn_cond_stmts; ci++) |
| 872 { | |
| 111 | 873 gimple *c = conds[ci]; |
| 0 | 874 gcc_assert (c || ci != ci0); |
| 875 if (!c) | |
| 876 break; | |
| 877 gsi_insert_before (&guard_bsi, c, GSI_SAME_STMT); | |
| 878 cond_expr = c; | |
| 879 } | |
| 880 ci++; | |
| 881 gcc_assert (cond_expr && gimple_code (cond_expr) == GIMPLE_COND); | |
| 882 guard_bb_in_edge = split_block (guard_bb, cond_expr); | |
| 883 guard_bb_in_edge->flags &= ~EDGE_FALLTHRU; | |
| 111 | 884 guard_bb_in_edge->flags |= EDGE_TRUE_VALUE; |
| 0 | 885 |
| 111 | 886 bi_call_in_edge = make_edge (guard_bb, bi_call_bb, EDGE_FALSE_VALUE); |
| 887 edges.quick_push (edge_pair (bi_call_in_edge, guard_bb_in_edge)); | |
| 0 | 888 } |
| 889 | |
| 111 | 890 /* Now update the probability and profile information, processing the |
| 891 guards in order of execution. | |
| 892 | |
| 893 There are two approaches we could take here. On the one hand we | |
| 894 could assign a probability of X to the call block and distribute | |
| 895 that probability among its incoming edges. On the other hand we | |
| 896 could assign a probability of X to each individual call edge. | |
| 897 | |
| 898 The choice only affects calls that have more than one condition. | |
| 899 In those cases, the second approach would give the call block | |
| 900 a greater probability than the first. However, the difference | |
| 901 is only small, and our chosen X is a pure guess anyway. | |
| 902 | |
| 903 Here we take the second approach because it's slightly simpler | |
| 904 and because it's easy to see that it doesn't lose profile counts. */ | |
| 905 bi_call_bb->count = profile_count::zero (); | |
| 906 bi_call_bb->frequency = 0; | |
| 907 while (!edges.is_empty ()) | |
| 908 { | |
| 909 edge_pair e = edges.pop (); | |
| 910 edge call_edge = e.first; | |
| 911 edge nocall_edge = e.second; | |
| 912 basic_block src_bb = call_edge->src; | |
| 913 gcc_assert (src_bb == nocall_edge->src); | |
| 914 | |
| 915 call_edge->probability = profile_probability::very_unlikely (); | |
| 916 nocall_edge->probability = profile_probability::always () | |
| 917 - call_edge->probability; | |
| 918 | |
| 919 unsigned int call_frequency | |
| 920 = call_edge->probability.apply (src_bb->frequency); | |
| 921 | |
| 922 bi_call_bb->count += call_edge->count (); | |
| 923 bi_call_bb->frequency += call_frequency; | |
| 924 | |
| 925 if (nocall_edge->dest != join_tgt_bb) | |
| 926 { | |
| 927 nocall_edge->dest->frequency = src_bb->frequency - call_frequency; | |
| 928 } | |
| 929 } | |
| 930 | |
| 931 if (dom_info_available_p (CDI_DOMINATORS)) | |
| 932 { | |
| 933 /* The split_blocks leave [guard 0] as the immediate dominator | |
| 934 of [call] and [call] as the immediate dominator of [join]. | |
| 935 Fix them up. */ | |
| 936 set_immediate_dominator (CDI_DOMINATORS, bi_call_bb, guard_bb); | |
| 937 set_immediate_dominator (CDI_DOMINATORS, join_tgt_bb, guard_bb); | |
| 938 } | |
| 939 | |
| 0 | 940 if (dump_file && (dump_flags & TDF_DETAILS)) |
| 941 { | |
| 942 location_t loc; | |
| 943 loc = gimple_location (bi_call); | |
| 944 fprintf (dump_file, | |
| 945 "%s:%d: note: function call is shrink-wrapped" | |
| 946 " into error conditions.\n", | |
| 947 LOCATION_FILE (loc), LOCATION_LINE (loc)); | |
| 948 } | |
| 111 | 949 } |
| 950 | |
| 951 /* Shrink-wrap BI_CALL so that it is only called when it might set errno | |
| 952 (but is always called if it would set errno). */ | |
| 953 | |
| 954 static void | |
| 955 shrink_wrap_one_built_in_call (gcall *bi_call) | |
| 956 { | |
| 957 unsigned nconds = 0; | |
| 958 auto_vec<gimple *, 12> conds; | |
| 959 gen_shrink_wrap_conditions (bi_call, conds, &nconds); | |
| 960 gcc_assert (nconds != 0); | |
| 961 shrink_wrap_one_built_in_call_with_conds (bi_call, conds, nconds); | |
| 962 } | |
| 963 | |
| 964 /* Return true if built-in function call CALL could be implemented using | |
| 965 a combination of an internal function to compute the result and a | |
| 966 separate call to set errno. */ | |
| 967 | |
| 968 static bool | |
| 969 can_use_internal_fn (gcall *call) | |
| 970 { | |
| 971 /* Only replace calls that set errno. */ | |
| 972 if (!gimple_vdef (call)) | |
| 973 return false; | |
| 974 | |
| 975 /* See whether there is an internal function for this built-in. */ | |
| 976 if (replacement_internal_fn (call) == IFN_LAST) | |
| 977 return false; | |
| 978 | |
| 979 /* See whether we can catch all cases where errno would be set, | |
| 980 while still avoiding the call in most cases. */ | |
| 981 if (!can_test_argument_range (call) | |
| 982 && !edom_only_function (call)) | |
| 983 return false; | |
| 0 | 984 |
| 985 return true; | |
| 986 } | |
| 987 | |
| 111 | 988 /* Implement built-in function call CALL using an internal function. */ |
| 989 | |
| 990 static void | |
| 991 use_internal_fn (gcall *call) | |
| 992 { | |
| 993 /* We'll be inserting another call with the same arguments after the | |
| 994 lhs has been set, so prevent any possible coalescing failure from | |
| 995 having both values live at once. See PR 71020. */ | |
| 996 replace_abnormal_ssa_names (call); | |
| 997 | |
| 998 unsigned nconds = 0; | |
| 999 auto_vec<gimple *, 12> conds; | |
| 1000 if (can_test_argument_range (call)) | |
| 1001 { | |
| 1002 gen_shrink_wrap_conditions (call, conds, &nconds); | |
| 1003 gcc_assert (nconds != 0); | |
| 1004 } | |
| 1005 else | |
| 1006 gcc_assert (edom_only_function (call)); | |
| 1007 | |
| 1008 internal_fn ifn = replacement_internal_fn (call); | |
| 1009 gcc_assert (ifn != IFN_LAST); | |
| 1010 | |
| 1011 /* Construct the new call, with the same arguments as the original one. */ | |
| 1012 auto_vec <tree, 16> args; | |
| 1013 unsigned int nargs = gimple_call_num_args (call); | |
| 1014 for (unsigned int i = 0; i < nargs; ++i) | |
| 1015 args.safe_push (gimple_call_arg (call, i)); | |
| 1016 gcall *new_call = gimple_build_call_internal_vec (ifn, args); | |
| 1017 gimple_set_location (new_call, gimple_location (call)); | |
| 1018 gimple_call_set_nothrow (new_call, gimple_call_nothrow_p (call)); | |
| 1019 | |
| 1020 /* Transfer the LHS to the new call. */ | |
| 1021 tree lhs = gimple_call_lhs (call); | |
| 1022 gimple_call_set_lhs (new_call, lhs); | |
| 1023 gimple_call_set_lhs (call, NULL_TREE); | |
| 1024 SSA_NAME_DEF_STMT (lhs) = new_call; | |
| 1025 | |
| 1026 /* Insert the new call. */ | |
| 1027 gimple_stmt_iterator gsi = gsi_for_stmt (call); | |
| 1028 gsi_insert_before (&gsi, new_call, GSI_SAME_STMT); | |
| 1029 | |
| 1030 if (nconds == 0) | |
| 1031 { | |
| 1032 /* Skip the call if LHS == LHS. If we reach here, EDOM is the only | |
| 1033 valid errno value and it is used iff the result is NaN. */ | |
| 1034 conds.quick_push (gimple_build_cond (EQ_EXPR, lhs, lhs, | |
| 1035 NULL_TREE, NULL_TREE)); | |
| 1036 nconds++; | |
| 1037 | |
| 1038 /* Try replacing the original call with a direct assignment to | |
| 1039 errno, via an internal function. */ | |
| 1040 if (set_edom_supported_p () && !stmt_ends_bb_p (call)) | |
| 1041 { | |
| 1042 gimple_stmt_iterator gsi = gsi_for_stmt (call); | |
| 1043 gcall *new_call = gimple_build_call_internal (IFN_SET_EDOM, 0); | |
| 1044 gimple_set_vuse (new_call, gimple_vuse (call)); | |
| 1045 gimple_set_vdef (new_call, gimple_vdef (call)); | |
| 1046 SSA_NAME_DEF_STMT (gimple_vdef (new_call)) = new_call; | |
| 1047 gimple_set_location (new_call, gimple_location (call)); | |
| 1048 gsi_replace (&gsi, new_call, false); | |
| 1049 call = new_call; | |
| 1050 } | |
| 1051 } | |
| 1052 | |
| 1053 shrink_wrap_one_built_in_call_with_conds (call, conds, nconds); | |
| 1054 } | |
| 1055 | |
| 0 | 1056 /* The top level function for conditional dead code shrink |
| 1057 wrapping transformation. */ | |
| 1058 | |
| 111 | 1059 static void |
| 1060 shrink_wrap_conditional_dead_built_in_calls (vec<gcall *> calls) | |
| 0 | 1061 { |
| 1062 unsigned i = 0; | |
| 1063 | |
| 111 | 1064 unsigned n = calls.length (); |
| 0 | 1065 for (; i < n ; i++) |
| 1066 { | |
| 111 | 1067 gcall *bi_call = calls[i]; |
| 1068 if (gimple_call_lhs (bi_call)) | |
| 1069 use_internal_fn (bi_call); | |
| 1070 else | |
| 1071 shrink_wrap_one_built_in_call (bi_call); | |
| 1072 } | |
| 1073 } | |
| 1074 | |
| 1075 namespace { | |
| 1076 | |
| 1077 const pass_data pass_data_call_cdce = | |
| 1078 { | |
| 1079 GIMPLE_PASS, /* type */ | |
| 1080 "cdce", /* name */ | |
| 1081 OPTGROUP_NONE, /* optinfo_flags */ | |
| 1082 TV_TREE_CALL_CDCE, /* tv_id */ | |
| 1083 ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
| 1084 0, /* properties_provided */ | |
| 1085 0, /* properties_destroyed */ | |
| 1086 0, /* todo_flags_start */ | |
| 1087 0, /* todo_flags_finish */ | |
| 1088 }; | |
| 1089 | |
| 1090 class pass_call_cdce : public gimple_opt_pass | |
| 1091 { | |
| 1092 public: | |
| 1093 pass_call_cdce (gcc::context *ctxt) | |
| 1094 : gimple_opt_pass (pass_data_call_cdce, ctxt) | |
| 1095 {} | |
| 1096 | |
| 1097 /* opt_pass methods: */ | |
| 1098 virtual bool gate (function *) | |
| 1099 { | |
| 1100 /* The limit constants used in the implementation | |
| 1101 assume IEEE floating point format. Other formats | |
| 1102 can be supported in the future if needed. */ | |
| 1103 return flag_tree_builtin_call_dce != 0; | |
| 0 | 1104 } |
| 1105 | |
| 111 | 1106 virtual unsigned int execute (function *); |
| 0 | 1107 |
| 111 | 1108 }; // class pass_call_cdce |
| 0 | 1109 |
| 111 | 1110 unsigned int |
| 1111 pass_call_cdce::execute (function *fun) | |
| 0 | 1112 { |
| 1113 basic_block bb; | |
| 1114 gimple_stmt_iterator i; | |
| 111 | 1115 auto_vec<gcall *> cond_dead_built_in_calls; |
| 1116 FOR_EACH_BB_FN (bb, fun) | |
| 0 | 1117 { |
| 111 | 1118 /* Skip blocks that are being optimized for size, since our |
| 1119 transformation always increases code size. */ | |
| 1120 if (optimize_bb_for_size_p (bb)) | |
| 1121 continue; | |
| 1122 | |
| 0 | 1123 /* Collect dead call candidates. */ |
| 1124 for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) | |
| 1125 { | |
| 111 | 1126 gcall *stmt = dyn_cast <gcall *> (gsi_stmt (i)); |
| 1127 if (stmt | |
| 1128 && gimple_call_builtin_p (stmt, BUILT_IN_NORMAL) | |
| 1129 && (gimple_call_lhs (stmt) | |
| 1130 ? can_use_internal_fn (stmt) | |
| 1131 : can_test_argument_range (stmt)) | |
| 1132 && can_guard_call_p (stmt)) | |
| 0 | 1133 { |
| 1134 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 1135 { | |
| 1136 fprintf (dump_file, "Found conditional dead call: "); | |
| 1137 print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
| 1138 fprintf (dump_file, "\n"); | |
| 1139 } | |
| 111 | 1140 if (!cond_dead_built_in_calls.exists ()) |
| 1141 cond_dead_built_in_calls.create (64); | |
| 1142 cond_dead_built_in_calls.safe_push (stmt); | |
| 0 | 1143 } |
| 1144 } | |
| 1145 } | |
| 1146 | |
| 111 | 1147 if (!cond_dead_built_in_calls.exists ()) |
| 0 | 1148 return 0; |
| 1149 | |
| 111 | 1150 shrink_wrap_conditional_dead_built_in_calls (cond_dead_built_in_calls); |
| 1151 free_dominance_info (CDI_POST_DOMINATORS); | |
| 1152 /* As we introduced new control-flow we need to insert PHI-nodes | |
| 1153 for the call-clobbers of the remaining call. */ | |
| 1154 mark_virtual_operands_for_renaming (fun); | |
| 1155 return TODO_update_ssa; | |
| 0 | 1156 } |
| 1157 | |
| 111 | 1158 } // anon namespace |
| 0 | 1159 |
| 111 | 1160 gimple_opt_pass * |
| 1161 make_pass_call_cdce (gcc::context *ctxt) | |
| 0 | 1162 { |
| 111 | 1163 return new pass_call_cdce (ctxt); |
| 1164 } |