Mercurial > hg > CbC > CbC_gcc
annotate gcc/tree-call-cdce.c @ 141:ce508c72660f
copy cbc flang in cfgexpand
author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
---|---|
date | Thu, 22 Nov 2018 19:44:39 +0900 |
parents | 84e7813d76e9 |
children | 1830386684a0 |
rev | line source |
---|---|
0 | 1 /* Conditional Dead Call Elimination pass for the GNU compiler. |
131 | 2 Copyright (C) 2008-2018 Free Software Foundation, Inc. |
0 | 3 Contributed by Xinliang David Li <davidxl@google.com> |
4 | |
5 This file is part of GCC. | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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. | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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. | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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" | |
63
b7f97abdc517
update gcc from gcc-4.5.0 to gcc-4.6
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
55
diff
changeset
|
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 |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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 | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
110 /* A structure for representing input domain of |
0 | 111 a function argument in integer. If the lower |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
112 bound is -inf, has_lb is set to false. If the |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
113 upper bound is +inf, has_ub is false. |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
114 is_lb_inclusive and is_ub_inclusive are flags |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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 | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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 | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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 | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
150 /* A helper function to check the target format for the |
0 | 151 argument type. In this implementation, only IEEE formats |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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 | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
155 enhanced to have range bounds properly computed. Since |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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; |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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 | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
176 which is only defined on intel platforms. |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
177 Candidate pre-selection using builtin function |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
178 code guarantees that we are checking formats |
0 | 179 for long double modes: double, quad, and extended. */ |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
180 || (mode != SFmode && mode != DFmode |
0 | 181 && (rfmt == &ieee_quad_format |
182 || rfmt == &mips_quad_format | |
183 || rfmt == &ieee_extended_motorola_format | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
184 || rfmt == &ieee_extended_intel_96_format |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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 | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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 | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
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): | |
131 | 317 CASE_FLT_FN_FLOATN_NX (BUILT_IN_SQRT): |
0 | 318 return check_builtin_call (call); |
319 /* Special one: two argument pow. */ | |
320 case BUILT_IN_POW: | |
321 return check_pow (call); | |
322 default: | |
323 break; | |
324 } | |
325 | |
326 return false; | |
327 } | |
328 | |
111 | 329 /* Return true if CALL can produce a domain error (EDOM) but can never |
330 produce a pole, range overflow or range underflow error (all ERANGE). | |
331 This means that we can tell whether a function would have set errno | |
332 by testing whether the result is a NaN. */ | |
333 | |
334 static bool | |
335 edom_only_function (gcall *call) | |
336 { | |
337 switch (DECL_FUNCTION_CODE (gimple_call_fndecl (call))) | |
338 { | |
339 CASE_FLT_FN (BUILT_IN_ACOS): | |
340 CASE_FLT_FN (BUILT_IN_ASIN): | |
341 CASE_FLT_FN (BUILT_IN_ATAN): | |
342 CASE_FLT_FN (BUILT_IN_COS): | |
343 CASE_FLT_FN (BUILT_IN_SIGNIFICAND): | |
344 CASE_FLT_FN (BUILT_IN_SIN): | |
345 CASE_FLT_FN (BUILT_IN_SQRT): | |
131 | 346 CASE_FLT_FN_FLOATN_NX (BUILT_IN_SQRT): |
111 | 347 CASE_FLT_FN (BUILT_IN_FMOD): |
348 CASE_FLT_FN (BUILT_IN_REMAINDER): | |
349 return true; | |
350 | |
351 default: | |
352 return false; | |
353 } | |
354 } | |
355 | |
356 /* Return true if it is structurally possible to guard CALL. */ | |
357 | |
358 static bool | |
359 can_guard_call_p (gimple *call) | |
360 { | |
361 return (!stmt_ends_bb_p (call) | |
362 || find_fallthru_edge (gimple_bb (call)->succs)); | |
363 } | |
0 | 364 |
111 | 365 /* A helper function to generate gimple statements for one bound |
366 comparison, so that the built-in function is called whenever | |
367 TCODE <ARG, LBUB> is *false*. TEMP_NAME1/TEMP_NAME2 are names | |
368 of the temporaries, CONDS is a vector holding the produced GIMPLE | |
369 statements, and NCONDS points to the variable holding the number of | |
370 logical comparisons. CONDS is either empty or a list ended with a | |
371 null tree. */ | |
0 | 372 |
373 static void | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
374 gen_one_condition (tree arg, int lbub, |
0 | 375 enum tree_code tcode, |
376 const char *temp_name1, | |
377 const char *temp_name2, | |
111 | 378 vec<gimple *> conds, |
0 | 379 unsigned *nconds) |
380 { | |
381 tree lbub_real_cst, lbub_cst, float_type; | |
382 tree temp, tempn, tempc, tempcn; | |
111 | 383 gassign *stmt1; |
384 gassign *stmt2; | |
385 gcond *stmt3; | |
0 | 386 |
387 float_type = TREE_TYPE (arg); | |
388 lbub_cst = build_int_cst (integer_type_node, lbub); | |
389 lbub_real_cst = build_real_from_int_cst (float_type, lbub_cst); | |
390 | |
391 temp = create_tmp_var (float_type, temp_name1); | |
392 stmt1 = gimple_build_assign (temp, arg); | |
393 tempn = make_ssa_name (temp, stmt1); | |
394 gimple_assign_set_lhs (stmt1, tempn); | |
395 | |
396 tempc = create_tmp_var (boolean_type_node, temp_name2); | |
397 stmt2 = gimple_build_assign (tempc, | |
398 fold_build2 (tcode, | |
399 boolean_type_node, | |
400 tempn, lbub_real_cst)); | |
401 tempcn = make_ssa_name (tempc, stmt2); | |
402 gimple_assign_set_lhs (stmt2, tempcn); | |
403 | |
404 stmt3 = gimple_build_cond_from_tree (tempcn, NULL_TREE, NULL_TREE); | |
111 | 405 conds.quick_push (stmt1); |
406 conds.quick_push (stmt2); | |
407 conds.quick_push (stmt3); | |
0 | 408 (*nconds)++; |
409 } | |
410 | |
411 /* A helper function to generate GIMPLE statements for | |
412 out of input domain check. ARG is the call argument | |
413 to be runtime checked, DOMAIN holds the valid domain | |
414 for the given function, CONDS points to the vector | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
415 holding the result GIMPLE statements. *NCONDS is |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
416 the number of logical comparisons. This function |
0 | 417 produces no more than two logical comparisons, one |
418 for lower bound check, one for upper bound check. */ | |
419 | |
420 static void | |
421 gen_conditions_for_domain (tree arg, inp_domain domain, | |
111 | 422 vec<gimple *> conds, |
0 | 423 unsigned *nconds) |
424 { | |
425 if (domain.has_lb) | |
426 gen_one_condition (arg, domain.lb, | |
427 (domain.is_lb_inclusive | |
111 | 428 ? UNGE_EXPR : UNGT_EXPR), |
0 | 429 "DCE_COND_LB", "DCE_COND_LB_TEST", |
430 conds, nconds); | |
431 | |
432 if (domain.has_ub) | |
433 { | |
434 /* Now push a separator. */ | |
435 if (domain.has_lb) | |
111 | 436 conds.quick_push (NULL); |
0 | 437 |
438 gen_one_condition (arg, domain.ub, | |
439 (domain.is_ub_inclusive | |
111 | 440 ? UNLE_EXPR : UNLT_EXPR), |
0 | 441 "DCE_COND_UB", "DCE_COND_UB_TEST", |
442 conds, nconds); | |
443 } | |
444 } | |
445 | |
446 | |
447 /* A helper function to generate condition | |
448 code for the y argument in call pow (some_const, y). | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
449 See candidate selection in check_pow. Since the |
0 | 450 candidates' base values have a limited range, |
451 the guarded code generated for y are simple: | |
111 | 452 if (__builtin_isgreater (y, max_y)) |
0 | 453 pow (const, y); |
454 Note max_y can be computed separately for each | |
455 const base, but in this implementation, we | |
456 choose to compute it using the max base | |
457 in the allowed range for the purpose of | |
458 simplicity. BASE is the constant base value, | |
459 EXPN is the expression for the exponent argument, | |
460 *CONDS is the vector to hold resulting statements, | |
461 and *NCONDS is the number of logical conditions. */ | |
462 | |
463 static void | |
464 gen_conditions_for_pow_cst_base (tree base, tree expn, | |
111 | 465 vec<gimple *> conds, |
0 | 466 unsigned *nconds) |
467 { | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
468 inp_domain exp_domain; |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
469 /* Validate the range of the base constant to make |
0 | 470 sure it is consistent with check_pow. */ |
471 REAL_VALUE_TYPE mv; | |
472 REAL_VALUE_TYPE bcv = TREE_REAL_CST (base); | |
111 | 473 gcc_assert (!real_equal (&bcv, &dconst1) |
474 && !real_less (&bcv, &dconst1)); | |
475 real_from_integer (&mv, TYPE_MODE (TREE_TYPE (base)), 256, UNSIGNED); | |
476 gcc_assert (!real_less (&mv, &bcv)); | |
0 | 477 |
478 exp_domain = get_domain (0, false, false, | |
479 127, true, false); | |
480 | |
481 gen_conditions_for_domain (expn, exp_domain, | |
482 conds, nconds); | |
483 } | |
484 | |
485 /* Generate error condition code for pow calls with | |
486 non constant base values. The candidates selected | |
487 have their base argument value converted from | |
488 integer (see check_pow) value (1, 2, 4 bytes), and | |
489 the max exp value is computed based on the size | |
490 of the integer type (i.e. max possible base value). | |
491 The resulting input domain for exp argument is thus | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
492 conservative (smaller than the max value allowed by |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
493 the runtime value of the base). BASE is the integer |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
494 base value, EXPN is the expression for the exponent |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
495 argument, *CONDS is the vector to hold resulting |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
496 statements, and *NCONDS is the number of logical |
0 | 497 conditions. */ |
498 | |
499 static void | |
500 gen_conditions_for_pow_int_base (tree base, tree expn, | |
111 | 501 vec<gimple *> conds, |
0 | 502 unsigned *nconds) |
503 { | |
111 | 504 gimple *base_def; |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
505 tree base_val0; |
111 | 506 tree int_type; |
0 | 507 tree temp, tempn; |
508 tree cst0; | |
111 | 509 gimple *stmt1, *stmt2; |
0 | 510 int bit_sz, max_exp; |
511 inp_domain exp_domain; | |
512 | |
513 base_def = SSA_NAME_DEF_STMT (base); | |
514 base_val0 = gimple_assign_rhs1 (base_def); | |
111 | 515 int_type = TREE_TYPE (base_val0); |
0 | 516 bit_sz = TYPE_PRECISION (int_type); |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
517 gcc_assert (bit_sz > 0 |
0 | 518 && bit_sz <= MAX_BASE_INT_BIT_SIZE); |
519 | |
520 /* Determine the max exp argument value according to | |
521 the size of the base integer. The max exp value | |
522 is conservatively estimated assuming IEEE754 double | |
523 precision format. */ | |
524 if (bit_sz == 8) | |
525 max_exp = 128; | |
526 else if (bit_sz == 16) | |
527 max_exp = 64; | |
528 else | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
529 { |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
530 gcc_assert (bit_sz == MAX_BASE_INT_BIT_SIZE); |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
531 max_exp = 32; |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
532 } |
0 | 533 |
534 /* For pow ((double)x, y), generate the following conditions: | |
535 cond 1: | |
536 temp1 = x; | |
111 | 537 if (__builtin_islessequal (temp1, 0)) |
0 | 538 |
539 cond 2: | |
540 temp2 = y; | |
111 | 541 if (__builtin_isgreater (temp2, max_exp_real_cst)) */ |
0 | 542 |
543 /* Generate condition in reverse order -- first | |
544 the condition for the exp argument. */ | |
545 | |
546 exp_domain = get_domain (0, false, false, | |
547 max_exp, true, true); | |
548 | |
549 gen_conditions_for_domain (expn, exp_domain, | |
550 conds, nconds); | |
551 | |
552 /* Now generate condition for the base argument. | |
553 Note it does not use the helper function | |
554 gen_conditions_for_domain because the base | |
555 type is integer. */ | |
556 | |
557 /* Push a separator. */ | |
111 | 558 conds.quick_push (NULL); |
0 | 559 |
560 temp = create_tmp_var (int_type, "DCE_COND1"); | |
561 cst0 = build_int_cst (int_type, 0); | |
562 stmt1 = gimple_build_assign (temp, base_val0); | |
563 tempn = make_ssa_name (temp, stmt1); | |
564 gimple_assign_set_lhs (stmt1, tempn); | |
111 | 565 stmt2 = gimple_build_cond (GT_EXPR, tempn, cst0, NULL_TREE, NULL_TREE); |
0 | 566 |
111 | 567 conds.quick_push (stmt1); |
568 conds.quick_push (stmt2); | |
0 | 569 (*nconds)++; |
570 } | |
571 | |
572 /* Method to generate conditional statements for guarding conditionally | |
573 dead calls to pow. One or more statements can be generated for | |
574 each logical condition. Statement groups of different conditions | |
111 | 575 are separated by a NULL tree and they are stored in the vec |
0 | 576 conds. The number of logical conditions are stored in *nconds. |
577 | |
578 See C99 standard, 7.12.7.4:2, for description of pow (x, y). | |
579 The precise condition for domain errors are complex. In this | |
580 implementation, a simplified (but conservative) valid domain | |
581 for x and y are used: x is positive to avoid dom errors, while | |
582 y is smaller than a upper bound (depending on x) to avoid range | |
583 errors. Runtime code is generated to check x (if not constant) | |
584 and y against the valid domain. If it is out, jump to the call, | |
585 otherwise the call is bypassed. POW_CALL is the call statement, | |
586 *CONDS is a vector holding the resulting condition statements, | |
587 and *NCONDS is the number of logical conditions. */ | |
588 | |
589 static void | |
111 | 590 gen_conditions_for_pow (gcall *pow_call, vec<gimple *> conds, |
0 | 591 unsigned *nconds) |
592 { | |
593 tree base, expn; | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
594 enum tree_code bc; |
0 | 595 |
67
f6334be47118
update gcc from gcc-4.6-20100522 to gcc-4.6-20110318
nobuyasu <dimolto@cr.ie.u-ryukyu.ac.jp>
parents:
63
diff
changeset
|
596 gcc_checking_assert (check_pow (pow_call)); |
0 | 597 |
598 *nconds = 0; | |
599 | |
600 base = gimple_call_arg (pow_call, 0); | |
601 expn = gimple_call_arg (pow_call, 1); | |
602 | |
603 bc = TREE_CODE (base); | |
604 | |
605 if (bc == REAL_CST) | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
606 gen_conditions_for_pow_cst_base (base, expn, conds, nconds); |
0 | 607 else if (bc == SSA_NAME) |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
608 gen_conditions_for_pow_int_base (base, expn, conds, nconds); |
0 | 609 else |
610 gcc_unreachable (); | |
611 } | |
612 | |
613 /* A helper routine to help computing the valid input domain | |
614 for a builtin function. See C99 7.12.7 for details. In this | |
615 implementation, we only handle single region domain. The | |
616 resulting region can be conservative (smaller) than the actual | |
617 one and rounded to integers. Some of the bounds are documented | |
618 in the standard, while other limit constants are computed | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
619 assuming IEEE floating point format (for SF and DF modes). |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
620 Since IEEE only sets minimum requirements for long double format, |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
621 different long double formats exist under different implementations |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
622 (e.g, 64 bit double precision (DF), 80 bit double-extended |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
623 precision (XF), and 128 bit quad precision (QF) ). For simplicity, |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
624 in this implementation, the computed bounds for long double assume |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
625 64 bit format (DF), and are therefore conservative. Another |
0 | 626 assumption is that single precision float type is always SF mode, |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
627 and double type is DF mode. This function is quite |
0 | 628 implementation specific, so it may not be suitable to be part of |
629 builtins.c. This needs to be revisited later to see if it can | |
630 be leveraged in x87 assembly expansion. */ | |
631 | |
632 static inp_domain | |
633 get_no_error_domain (enum built_in_function fnc) | |
634 { | |
635 switch (fnc) | |
636 { | |
637 /* Trig functions: return [-1, +1] */ | |
638 CASE_FLT_FN (BUILT_IN_ACOS): | |
639 CASE_FLT_FN (BUILT_IN_ASIN): | |
640 return get_domain (-1, true, true, | |
641 1, true, true); | |
642 /* Hyperbolic functions. */ | |
643 CASE_FLT_FN (BUILT_IN_ACOSH): | |
644 /* acosh: [1, +inf) */ | |
645 return get_domain (1, true, true, | |
646 1, false, false); | |
647 CASE_FLT_FN (BUILT_IN_ATANH): | |
648 /* atanh: (-1, +1) */ | |
649 return get_domain (-1, true, false, | |
650 1, true, false); | |
651 case BUILT_IN_COSHF: | |
652 case BUILT_IN_SINHF: | |
653 /* coshf: (-89, +89) */ | |
654 return get_domain (-89, true, false, | |
655 89, true, false); | |
656 case BUILT_IN_COSH: | |
657 case BUILT_IN_SINH: | |
658 case BUILT_IN_COSHL: | |
659 case BUILT_IN_SINHL: | |
660 /* cosh: (-710, +710) */ | |
661 return get_domain (-710, true, false, | |
662 710, true, false); | |
663 /* Log functions: (0, +inf) */ | |
664 CASE_FLT_FN (BUILT_IN_LOG): | |
665 CASE_FLT_FN (BUILT_IN_LOG2): | |
666 CASE_FLT_FN (BUILT_IN_LOG10): | |
667 return get_domain (0, true, false, | |
668 0, false, false); | |
669 CASE_FLT_FN (BUILT_IN_LOG1P): | |
670 return get_domain (-1, true, false, | |
671 0, false, false); | |
672 /* Exp functions. */ | |
673 case BUILT_IN_EXPF: | |
674 case BUILT_IN_EXPM1F: | |
675 /* expf: (-inf, 88) */ | |
676 return get_domain (-1, false, false, | |
677 88, true, false); | |
678 case BUILT_IN_EXP: | |
679 case BUILT_IN_EXPM1: | |
680 case BUILT_IN_EXPL: | |
681 case BUILT_IN_EXPM1L: | |
682 /* exp: (-inf, 709) */ | |
683 return get_domain (-1, false, false, | |
684 709, true, false); | |
685 case BUILT_IN_EXP2F: | |
686 /* exp2f: (-inf, 128) */ | |
687 return get_domain (-1, false, false, | |
688 128, true, false); | |
689 case BUILT_IN_EXP2: | |
690 case BUILT_IN_EXP2L: | |
691 /* exp2: (-inf, 1024) */ | |
692 return get_domain (-1, false, false, | |
693 1024, true, false); | |
694 case BUILT_IN_EXP10F: | |
695 case BUILT_IN_POW10F: | |
696 /* exp10f: (-inf, 38) */ | |
697 return get_domain (-1, false, false, | |
698 38, true, false); | |
699 case BUILT_IN_EXP10: | |
700 case BUILT_IN_POW10: | |
701 case BUILT_IN_EXP10L: | |
702 case BUILT_IN_POW10L: | |
703 /* exp10: (-inf, 308) */ | |
704 return get_domain (-1, false, false, | |
705 308, true, false); | |
706 /* sqrt: [0, +inf) */ | |
707 CASE_FLT_FN (BUILT_IN_SQRT): | |
131 | 708 CASE_FLT_FN_FLOATN_NX (BUILT_IN_SQRT): |
0 | 709 return get_domain (0, true, true, |
710 0, false, false); | |
711 default: | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
712 gcc_unreachable (); |
0 | 713 } |
714 | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
715 gcc_unreachable (); |
0 | 716 } |
717 | |
718 /* The function to generate shrink wrap conditions for a partially | |
719 dead builtin call whose return value is not used anywhere, | |
720 but has to be kept live due to potential error condition. | |
55
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
721 BI_CALL is the builtin call, CONDS is the vector of statements |
77e2b8dfacca
update it from 4.4.3 to 4.5.0
ryoma <e075725@ie.u-ryukyu.ac.jp>
parents:
0
diff
changeset
|
722 for condition code, NCODES is the pointer to the number of |
0 | 723 logical conditions. Statements belonging to different logical |
724 condition are separated by NULL tree in the vector. */ | |
725 | |
726 static void | |
111 | 727 gen_shrink_wrap_conditions (gcall *bi_call, vec<gimple *> conds, |
0 | 728 unsigned int *nconds) |
729 { | |
111 | 730 gcall *call; |
0 | 731 tree fn; |
732 enum built_in_function fnc; | |
733 | |
111 | 734 gcc_assert (nconds && conds.exists ()); |
735 gcc_assert (conds.length () == 0); | |
0 | 736 gcc_assert (is_gimple_call (bi_call)); |
737 | |
738 call = bi_call; | |
739 fn = gimple_call_fndecl (call); | |
131 | 740 gcc_assert (fn && fndecl_built_in_p (fn)); |
0 | 741 fnc = DECL_FUNCTION_CODE (fn); |
742 *nconds = 0; | |
743 | |
744 if (fnc == BUILT_IN_POW) | |
745 gen_conditions_for_pow (call, conds, nconds); | |
746 else | |
747 { | |
748 tree arg; | |
749 inp_domain domain = get_no_error_domain (fnc); | |
750 *nconds = 0; | |
751 arg = gimple_call_arg (bi_call, 0); | |
752 gen_conditions_for_domain (arg, domain, conds, nconds); | |
753 } | |
754 | |
755 return; | |
756 } | |
757 | |
111 | 758 /* Shrink-wrap BI_CALL so that it is only called when one of the NCONDS |
759 conditions in CONDS is false. */ | |
0 | 760 |
111 | 761 static void |
762 shrink_wrap_one_built_in_call_with_conds (gcall *bi_call, vec <gimple *> conds, | |
763 unsigned int nconds) | |
0 | 764 { |
765 gimple_stmt_iterator bi_call_bsi; | |
111 | 766 basic_block bi_call_bb, join_tgt_bb, guard_bb; |
0 | 767 edge join_tgt_in_edge_from_call, join_tgt_in_edge_fall_thru; |
768 edge bi_call_in_edge0, guard_bb_in_edge; | |
111 | 769 unsigned tn_cond_stmts; |
0 | 770 unsigned ci; |
111 | 771 gimple *cond_expr = NULL; |
772 gimple *cond_expr_start; | |
773 | |
774 /* The cfg we want to create looks like this: | |
0 | 775 |
111 | 776 [guard n-1] <- guard_bb (old block) |
777 | \ | |
778 | [guard n-2] } | |
779 | / \ } | |
780 | / ... } new blocks | |
781 | / [guard 0] } | |
782 | / / | } | |
783 [ call ] | <- bi_call_bb } | |
784 | \ | | |
785 | \ | | |
786 | [ join ] <- join_tgt_bb (old iff call must end bb) | |
787 | | |
788 possible EH edges (only if [join] is old) | |
0 | 789 |
111 | 790 When [join] is new, the immediate dominators for these blocks are: |
0 | 791 |
111 | 792 1. [guard n-1]: unchanged |
793 2. [call]: [guard n-1] | |
794 3. [guard m]: [guard m+1] for 0 <= m <= n-2 | |
795 4. [join]: [guard n-1] | |
796 | |
797 We punt for the more complex case case of [join] being old and | |
798 simply free the dominance info. We also punt on postdominators, | |
799 which aren't expected to be available at this point anyway. */ | |
0 | 800 bi_call_bb = gimple_bb (bi_call); |
801 | |
111 | 802 /* Now find the join target bb -- split bi_call_bb if needed. */ |
803 if (stmt_ends_bb_p (bi_call)) | |
804 { | |
805 /* We checked that there was a fallthrough edge in | |
806 can_guard_call_p. */ | |
807 join_tgt_in_edge_from_call = find_fallthru_edge (bi_call_bb->succs); | |
808 gcc_assert (join_tgt_in_edge_from_call); | |
809 /* We don't want to handle PHIs. */ | |
810 if (EDGE_COUNT (join_tgt_in_edge_from_call->dest->preds) > 1) | |
811 join_tgt_bb = split_edge (join_tgt_in_edge_from_call); | |
812 else | |
813 { | |
814 join_tgt_bb = join_tgt_in_edge_from_call->dest; | |
815 /* We may have degenerate PHIs in the destination. Propagate | |
816 those out. */ | |
817 for (gphi_iterator i = gsi_start_phis (join_tgt_bb); !gsi_end_p (i);) | |
818 { | |
819 gphi *phi = i.phi (); | |
820 replace_uses_by (gimple_phi_result (phi), | |
821 gimple_phi_arg_def (phi, 0)); | |
822 remove_phi_node (&i, true); | |
823 } | |
824 } | |
825 } | |
826 else | |
827 { | |
828 join_tgt_in_edge_from_call = split_block (bi_call_bb, bi_call); | |
829 join_tgt_bb = join_tgt_in_edge_from_call->dest; | |
830 } | |
0 | 831 |
832 bi_call_bsi = gsi_for_stmt (bi_call); | |
833 | |
834 /* Now it is time to insert the first conditional expression | |
835 into bi_call_bb and split this bb so that bi_call is | |
836 shrink-wrapped. */ | |
111 | 837 tn_cond_stmts = conds.length (); |
0 | 838 cond_expr = NULL; |
111 | 839 cond_expr_start = conds[0]; |
0 | 840 for (ci = 0; ci < tn_cond_stmts; ci++) |
841 { | |
111 | 842 gimple *c = conds[ci]; |
0 | 843 gcc_assert (c || ci != 0); |
844 if (!c) | |
845 break; | |
846 gsi_insert_before (&bi_call_bsi, c, GSI_SAME_STMT); | |
847 cond_expr = c; | |
848 } | |
849 ci++; | |
850 gcc_assert (cond_expr && gimple_code (cond_expr) == GIMPLE_COND); | |
851 | |
111 | 852 typedef std::pair<edge, edge> edge_pair; |
853 auto_vec<edge_pair, 8> edges; | |
0 | 854 |
855 bi_call_in_edge0 = split_block (bi_call_bb, cond_expr); | |
856 bi_call_in_edge0->flags &= ~EDGE_FALLTHRU; | |
111 | 857 bi_call_in_edge0->flags |= EDGE_FALSE_VALUE; |
858 guard_bb = bi_call_bb; | |
0 | 859 bi_call_bb = bi_call_in_edge0->dest; |
111 | 860 join_tgt_in_edge_fall_thru = make_edge (guard_bb, join_tgt_bb, |
861 EDGE_TRUE_VALUE); | |
0 | 862 |
111 | 863 edges.reserve (nconds); |
864 edges.quick_push (edge_pair (bi_call_in_edge0, join_tgt_in_edge_fall_thru)); | |
0 | 865 |
866 /* Code generation for the rest of the conditions */ | |
111 | 867 for (unsigned int i = 1; i < nconds; ++i) |
0 | 868 { |
869 unsigned ci0; | |
870 edge bi_call_in_edge; | |
871 gimple_stmt_iterator guard_bsi = gsi_for_stmt (cond_expr_start); | |
872 ci0 = ci; | |
111 | 873 cond_expr_start = conds[ci0]; |
0 | 874 for (; ci < tn_cond_stmts; ci++) |
875 { | |
111 | 876 gimple *c = conds[ci]; |
0 | 877 gcc_assert (c || ci != ci0); |
878 if (!c) | |
879 break; | |
880 gsi_insert_before (&guard_bsi, c, GSI_SAME_STMT); | |
881 cond_expr = c; | |
882 } | |
883 ci++; | |
884 gcc_assert (cond_expr && gimple_code (cond_expr) == GIMPLE_COND); | |
885 guard_bb_in_edge = split_block (guard_bb, cond_expr); | |
886 guard_bb_in_edge->flags &= ~EDGE_FALLTHRU; | |
111 | 887 guard_bb_in_edge->flags |= EDGE_TRUE_VALUE; |
0 | 888 |
111 | 889 bi_call_in_edge = make_edge (guard_bb, bi_call_bb, EDGE_FALSE_VALUE); |
890 edges.quick_push (edge_pair (bi_call_in_edge, guard_bb_in_edge)); | |
0 | 891 } |
892 | |
111 | 893 /* Now update the probability and profile information, processing the |
894 guards in order of execution. | |
895 | |
896 There are two approaches we could take here. On the one hand we | |
897 could assign a probability of X to the call block and distribute | |
898 that probability among its incoming edges. On the other hand we | |
899 could assign a probability of X to each individual call edge. | |
900 | |
901 The choice only affects calls that have more than one condition. | |
902 In those cases, the second approach would give the call block | |
903 a greater probability than the first. However, the difference | |
904 is only small, and our chosen X is a pure guess anyway. | |
905 | |
906 Here we take the second approach because it's slightly simpler | |
907 and because it's easy to see that it doesn't lose profile counts. */ | |
908 bi_call_bb->count = profile_count::zero (); | |
909 while (!edges.is_empty ()) | |
910 { | |
911 edge_pair e = edges.pop (); | |
912 edge call_edge = e.first; | |
913 edge nocall_edge = e.second; | |
914 basic_block src_bb = call_edge->src; | |
915 gcc_assert (src_bb == nocall_edge->src); | |
916 | |
917 call_edge->probability = profile_probability::very_unlikely (); | |
918 nocall_edge->probability = profile_probability::always () | |
919 - call_edge->probability; | |
920 | |
921 bi_call_bb->count += call_edge->count (); | |
922 | |
923 if (nocall_edge->dest != join_tgt_bb) | |
131 | 924 nocall_edge->dest->count = src_bb->count - bi_call_bb->count; |
111 | 925 } |
926 | |
927 if (dom_info_available_p (CDI_DOMINATORS)) | |
928 { | |
929 /* The split_blocks leave [guard 0] as the immediate dominator | |
930 of [call] and [call] as the immediate dominator of [join]. | |
931 Fix them up. */ | |
932 set_immediate_dominator (CDI_DOMINATORS, bi_call_bb, guard_bb); | |
933 set_immediate_dominator (CDI_DOMINATORS, join_tgt_bb, guard_bb); | |
934 } | |
935 | |
0 | 936 if (dump_file && (dump_flags & TDF_DETAILS)) |
937 { | |
938 location_t loc; | |
939 loc = gimple_location (bi_call); | |
940 fprintf (dump_file, | |
941 "%s:%d: note: function call is shrink-wrapped" | |
942 " into error conditions.\n", | |
943 LOCATION_FILE (loc), LOCATION_LINE (loc)); | |
944 } | |
111 | 945 } |
946 | |
947 /* Shrink-wrap BI_CALL so that it is only called when it might set errno | |
948 (but is always called if it would set errno). */ | |
949 | |
950 static void | |
951 shrink_wrap_one_built_in_call (gcall *bi_call) | |
952 { | |
953 unsigned nconds = 0; | |
954 auto_vec<gimple *, 12> conds; | |
955 gen_shrink_wrap_conditions (bi_call, conds, &nconds); | |
956 gcc_assert (nconds != 0); | |
957 shrink_wrap_one_built_in_call_with_conds (bi_call, conds, nconds); | |
958 } | |
959 | |
960 /* Return true if built-in function call CALL could be implemented using | |
961 a combination of an internal function to compute the result and a | |
962 separate call to set errno. */ | |
963 | |
964 static bool | |
965 can_use_internal_fn (gcall *call) | |
966 { | |
967 /* Only replace calls that set errno. */ | |
968 if (!gimple_vdef (call)) | |
969 return false; | |
970 | |
971 /* See whether there is an internal function for this built-in. */ | |
972 if (replacement_internal_fn (call) == IFN_LAST) | |
973 return false; | |
974 | |
975 /* See whether we can catch all cases where errno would be set, | |
976 while still avoiding the call in most cases. */ | |
977 if (!can_test_argument_range (call) | |
978 && !edom_only_function (call)) | |
979 return false; | |
0 | 980 |
981 return true; | |
982 } | |
983 | |
111 | 984 /* Implement built-in function call CALL using an internal function. */ |
985 | |
986 static void | |
987 use_internal_fn (gcall *call) | |
988 { | |
989 /* We'll be inserting another call with the same arguments after the | |
990 lhs has been set, so prevent any possible coalescing failure from | |
991 having both values live at once. See PR 71020. */ | |
992 replace_abnormal_ssa_names (call); | |
993 | |
994 unsigned nconds = 0; | |
995 auto_vec<gimple *, 12> conds; | |
996 if (can_test_argument_range (call)) | |
997 { | |
998 gen_shrink_wrap_conditions (call, conds, &nconds); | |
999 gcc_assert (nconds != 0); | |
1000 } | |
1001 else | |
1002 gcc_assert (edom_only_function (call)); | |
1003 | |
1004 internal_fn ifn = replacement_internal_fn (call); | |
1005 gcc_assert (ifn != IFN_LAST); | |
1006 | |
1007 /* Construct the new call, with the same arguments as the original one. */ | |
1008 auto_vec <tree, 16> args; | |
1009 unsigned int nargs = gimple_call_num_args (call); | |
1010 for (unsigned int i = 0; i < nargs; ++i) | |
1011 args.safe_push (gimple_call_arg (call, i)); | |
1012 gcall *new_call = gimple_build_call_internal_vec (ifn, args); | |
1013 gimple_set_location (new_call, gimple_location (call)); | |
1014 gimple_call_set_nothrow (new_call, gimple_call_nothrow_p (call)); | |
1015 | |
1016 /* Transfer the LHS to the new call. */ | |
1017 tree lhs = gimple_call_lhs (call); | |
1018 gimple_call_set_lhs (new_call, lhs); | |
1019 gimple_call_set_lhs (call, NULL_TREE); | |
1020 SSA_NAME_DEF_STMT (lhs) = new_call; | |
1021 | |
1022 /* Insert the new call. */ | |
1023 gimple_stmt_iterator gsi = gsi_for_stmt (call); | |
1024 gsi_insert_before (&gsi, new_call, GSI_SAME_STMT); | |
1025 | |
1026 if (nconds == 0) | |
1027 { | |
1028 /* Skip the call if LHS == LHS. If we reach here, EDOM is the only | |
1029 valid errno value and it is used iff the result is NaN. */ | |
1030 conds.quick_push (gimple_build_cond (EQ_EXPR, lhs, lhs, | |
1031 NULL_TREE, NULL_TREE)); | |
1032 nconds++; | |
1033 | |
1034 /* Try replacing the original call with a direct assignment to | |
1035 errno, via an internal function. */ | |
1036 if (set_edom_supported_p () && !stmt_ends_bb_p (call)) | |
1037 { | |
1038 gimple_stmt_iterator gsi = gsi_for_stmt (call); | |
1039 gcall *new_call = gimple_build_call_internal (IFN_SET_EDOM, 0); | |
1040 gimple_set_vuse (new_call, gimple_vuse (call)); | |
1041 gimple_set_vdef (new_call, gimple_vdef (call)); | |
1042 SSA_NAME_DEF_STMT (gimple_vdef (new_call)) = new_call; | |
1043 gimple_set_location (new_call, gimple_location (call)); | |
1044 gsi_replace (&gsi, new_call, false); | |
1045 call = new_call; | |
1046 } | |
1047 } | |
1048 | |
1049 shrink_wrap_one_built_in_call_with_conds (call, conds, nconds); | |
1050 } | |
1051 | |
0 | 1052 /* The top level function for conditional dead code shrink |
1053 wrapping transformation. */ | |
1054 | |
111 | 1055 static void |
1056 shrink_wrap_conditional_dead_built_in_calls (vec<gcall *> calls) | |
0 | 1057 { |
1058 unsigned i = 0; | |
1059 | |
111 | 1060 unsigned n = calls.length (); |
0 | 1061 for (; i < n ; i++) |
1062 { | |
111 | 1063 gcall *bi_call = calls[i]; |
1064 if (gimple_call_lhs (bi_call)) | |
1065 use_internal_fn (bi_call); | |
1066 else | |
1067 shrink_wrap_one_built_in_call (bi_call); | |
1068 } | |
1069 } | |
1070 | |
1071 namespace { | |
1072 | |
1073 const pass_data pass_data_call_cdce = | |
1074 { | |
1075 GIMPLE_PASS, /* type */ | |
1076 "cdce", /* name */ | |
1077 OPTGROUP_NONE, /* optinfo_flags */ | |
1078 TV_TREE_CALL_CDCE, /* tv_id */ | |
1079 ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1080 0, /* properties_provided */ | |
1081 0, /* properties_destroyed */ | |
1082 0, /* todo_flags_start */ | |
1083 0, /* todo_flags_finish */ | |
1084 }; | |
1085 | |
1086 class pass_call_cdce : public gimple_opt_pass | |
1087 { | |
1088 public: | |
1089 pass_call_cdce (gcc::context *ctxt) | |
1090 : gimple_opt_pass (pass_data_call_cdce, ctxt) | |
1091 {} | |
1092 | |
1093 /* opt_pass methods: */ | |
1094 virtual bool gate (function *) | |
1095 { | |
1096 /* The limit constants used in the implementation | |
1097 assume IEEE floating point format. Other formats | |
1098 can be supported in the future if needed. */ | |
1099 return flag_tree_builtin_call_dce != 0; | |
0 | 1100 } |
1101 | |
111 | 1102 virtual unsigned int execute (function *); |
0 | 1103 |
111 | 1104 }; // class pass_call_cdce |
0 | 1105 |
111 | 1106 unsigned int |
1107 pass_call_cdce::execute (function *fun) | |
0 | 1108 { |
1109 basic_block bb; | |
1110 gimple_stmt_iterator i; | |
111 | 1111 auto_vec<gcall *> cond_dead_built_in_calls; |
1112 FOR_EACH_BB_FN (bb, fun) | |
0 | 1113 { |
111 | 1114 /* Skip blocks that are being optimized for size, since our |
1115 transformation always increases code size. */ | |
1116 if (optimize_bb_for_size_p (bb)) | |
1117 continue; | |
1118 | |
0 | 1119 /* Collect dead call candidates. */ |
1120 for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) | |
1121 { | |
111 | 1122 gcall *stmt = dyn_cast <gcall *> (gsi_stmt (i)); |
1123 if (stmt | |
1124 && gimple_call_builtin_p (stmt, BUILT_IN_NORMAL) | |
1125 && (gimple_call_lhs (stmt) | |
1126 ? can_use_internal_fn (stmt) | |
1127 : can_test_argument_range (stmt)) | |
1128 && can_guard_call_p (stmt)) | |
0 | 1129 { |
1130 if (dump_file && (dump_flags & TDF_DETAILS)) | |
1131 { | |
1132 fprintf (dump_file, "Found conditional dead call: "); | |
1133 print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1134 fprintf (dump_file, "\n"); | |
1135 } | |
111 | 1136 if (!cond_dead_built_in_calls.exists ()) |
1137 cond_dead_built_in_calls.create (64); | |
1138 cond_dead_built_in_calls.safe_push (stmt); | |
0 | 1139 } |
1140 } | |
1141 } | |
1142 | |
111 | 1143 if (!cond_dead_built_in_calls.exists ()) |
0 | 1144 return 0; |
1145 | |
111 | 1146 shrink_wrap_conditional_dead_built_in_calls (cond_dead_built_in_calls); |
1147 free_dominance_info (CDI_POST_DOMINATORS); | |
1148 /* As we introduced new control-flow we need to insert PHI-nodes | |
1149 for the call-clobbers of the remaining call. */ | |
1150 mark_virtual_operands_for_renaming (fun); | |
1151 return TODO_update_ssa; | |
0 | 1152 } |
1153 | |
111 | 1154 } // anon namespace |
0 | 1155 |
111 | 1156 gimple_opt_pass * |
1157 make_pass_call_cdce (gcc::context *ctxt) | |
0 | 1158 { |
111 | 1159 return new pass_call_cdce (ctxt); |
1160 } |