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Diffstat (limited to 'gcc/tree-ssa-operands.cc')
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diff --git a/gcc/tree-ssa-operands.cc b/gcc/tree-ssa-operands.cc new file mode 100644 index 0000000..c77759b --- /dev/null +++ b/gcc/tree-ssa-operands.cc @@ -0,0 +1,1415 @@ +/* SSA operands management for trees. + Copyright (C) 2003-2022 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "backend.h" +#include "tree.h" +#include "gimple.h" +#include "timevar.h" +#include "ssa.h" +#include "gimple-pretty-print.h" +#include "diagnostic-core.h" +#include "stmt.h" +#include "print-tree.h" +#include "dumpfile.h" + + +/* This file contains the code required to manage the operands cache of the + SSA optimizer. For every stmt, we maintain an operand cache in the stmt + annotation. This cache contains operands that will be of interest to + optimizers and other passes wishing to manipulate the IL. + + The operand type are broken up into REAL and VIRTUAL operands. The real + operands are represented as pointers into the stmt's operand tree. Thus + any manipulation of the real operands will be reflected in the actual tree. + Virtual operands are represented solely in the cache, although the base + variable for the SSA_NAME may, or may not occur in the stmt's tree. + Manipulation of the virtual operands will not be reflected in the stmt tree. + + The routines in this file are concerned with creating this operand cache + from a stmt tree. + + The operand tree is the parsed by the various get_* routines which look + through the stmt tree for the occurrence of operands which may be of + interest, and calls are made to the append_* routines whenever one is + found. There are 4 of these routines, each representing one of the + 4 types of operands. Defs, Uses, Virtual Uses, and Virtual May Defs. + + The append_* routines check for duplication, and simply keep a list of + unique objects for each operand type in the build_* extendable vectors. + + Once the stmt tree is completely parsed, the finalize_ssa_operands() + routine is called, which proceeds to perform the finalization routine + on each of the 4 operand vectors which have been built up. + + If the stmt had a previous operand cache, the finalization routines + attempt to match up the new operands with the old ones. If it's a perfect + match, the old vector is simply reused. If it isn't a perfect match, then + a new vector is created and the new operands are placed there. For + virtual operands, if the previous cache had SSA_NAME version of a + variable, and that same variable occurs in the same operands cache, then + the new cache vector will also get the same SSA_NAME. + + i.e., if a stmt had a VUSE of 'a_5', and 'a' occurs in the new + operand vector for VUSE, then the new vector will also be modified + such that it contains 'a_5' rather than 'a'. */ + + +/* Flags to describe operand properties in helpers. */ + +/* By default, operands are loaded. */ +#define opf_use 0 + +/* Operand is the target of an assignment expression or a + call-clobbered variable. */ +#define opf_def (1 << 0) + +/* No virtual operands should be created in the expression. This is used + when traversing ADDR_EXPR nodes which have different semantics than + other expressions. Inside an ADDR_EXPR node, the only operands that we + need to consider are indices into arrays. For instance, &a.b[i] should + generate a USE of 'i' but it should not generate a VUSE for 'a' nor a + VUSE for 'b'. */ +#define opf_no_vops (1 << 1) + +/* Operand is in a place where address-taken does not imply addressable. */ +#define opf_non_addressable (1 << 3) + +/* Operand is in a place where opf_non_addressable does not apply. */ +#define opf_not_non_addressable (1 << 4) + +/* Operand is having its address taken. */ +#define opf_address_taken (1 << 5) + +/* Class containing temporary per-stmt state. */ + +class operands_scanner +{ + public: + operands_scanner (struct function *fun, gimple *statement) + { + build_vuse = NULL_TREE; + build_vdef = NULL_TREE; + fn = fun; + stmt = statement; + } + + /* Create an operands cache for STMT. */ + void build_ssa_operands (); + + /* Verifies SSA statement operands. */ + DEBUG_FUNCTION bool verify_ssa_operands (); + + private: + /* Disable copy and assign of this class, as it may have problems with + build_uses vec. */ + DISABLE_COPY_AND_ASSIGN (operands_scanner); + + /* Array for building all the use operands. */ + auto_vec<tree *, 16> build_uses; + + /* The built VDEF operand. */ + tree build_vdef; + + /* The built VUSE operand. */ + tree build_vuse; + + /* Function which STMT belongs to. */ + struct function *fn; + + /* Statement to work on. */ + gimple *stmt; + + /* Takes elements from build_uses and turns them into use operands of STMT. */ + void finalize_ssa_uses (); + + /* Clear the in_list bits and empty the build array for VDEFs and + VUSEs. */ + void cleanup_build_arrays (); + + /* Finalize all the build vectors, fill the new ones into INFO. */ + void finalize_ssa_stmt_operands (); + + /* Start the process of building up operands vectors in INFO. */ + void start_ssa_stmt_operands (); + + /* Add USE_P to the list of pointers to operands. */ + void append_use (tree *use_p); + + /* Add VAR to the set of variables that require a VDEF operator. */ + void append_vdef (tree var); + + /* Add VAR to the set of variables that require a VUSE operator. */ + void append_vuse (tree var); + + /* Add virtual operands for STMT. FLAGS is as in get_expr_operands. */ + void add_virtual_operand (int flags); + + + /* Add *VAR_P to the appropriate operand array for statement STMT. + FLAGS is as in get_expr_operands. If *VAR_P is a GIMPLE register, + it will be added to the statement's real operands, otherwise it is + added to virtual operands. */ + void add_stmt_operand (tree *var_p, int flags); + + /* A subroutine of get_expr_operands to handle MEM_REF. + + STMT is the statement being processed, EXPR is the MEM_REF + that got us here. + + FLAGS is as in get_expr_operands. */ + void get_mem_ref_operands (tree expr, int flags); + + /* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */ + void get_tmr_operands (tree expr, int flags); + + + /* If STMT is a call that may clobber globals and other symbols that + escape, add them to the VDEF/VUSE lists for it. */ + void maybe_add_call_vops (gcall *stmt); + + /* Scan operands in the ASM_EXPR stmt referred to in INFO. */ + void get_asm_stmt_operands (gasm *stmt); + + + /* Recursively scan the expression pointed to by EXPR_P in statement + STMT. FLAGS is one of the OPF_* constants modifying how to + interpret the operands found. */ + void get_expr_operands (tree *expr_p, int flags); + + /* Parse STMT looking for operands. When finished, the various + build_* operand vectors will have potential operands in them. */ + void parse_ssa_operands (); + + + /* Takes elements from build_defs and turns them into def operands of STMT. + TODO -- Make build_defs vec of tree *. */ + void finalize_ssa_defs (); +}; + +/* Accessor to tree-ssa-operands.c caches. */ +static inline struct ssa_operands * +gimple_ssa_operands (const struct function *fun) +{ + return &fun->gimple_df->ssa_operands; +} + + +/* Return true if the SSA operands cache is active. */ + +bool +ssa_operands_active (struct function *fun) +{ + if (fun == NULL) + return false; + + return fun->gimple_df && gimple_ssa_operands (fun)->ops_active; +} + + +/* Create the VOP variable, an artificial global variable to act as a + representative of all of the virtual operands FUD chain. */ + +static void +create_vop_var (struct function *fn) +{ + tree global_var; + + gcc_assert (fn->gimple_df->vop == NULL_TREE); + + global_var = build_decl (BUILTINS_LOCATION, VAR_DECL, + get_identifier (".MEM"), + void_type_node); + DECL_ARTIFICIAL (global_var) = 1; + DECL_IGNORED_P (global_var) = 1; + TREE_READONLY (global_var) = 0; + DECL_EXTERNAL (global_var) = 1; + TREE_STATIC (global_var) = 1; + TREE_USED (global_var) = 1; + DECL_CONTEXT (global_var) = NULL_TREE; + TREE_THIS_VOLATILE (global_var) = 0; + TREE_ADDRESSABLE (global_var) = 0; + VAR_DECL_IS_VIRTUAL_OPERAND (global_var) = 1; + + fn->gimple_df->vop = global_var; +} + +/* These are the sizes of the operand memory buffer in bytes which gets + allocated each time more operands space is required. The final value is + the amount that is allocated every time after that. + In 1k we can fit 25 use operands (or 63 def operands) on a host with + 8 byte pointers, that would be 10 statements each with 1 def and 2 + uses. */ + +#define OP_SIZE_INIT 0 +#define OP_SIZE_1 (1024 - sizeof (void *)) +#define OP_SIZE_2 (1024 * 4 - sizeof (void *)) +#define OP_SIZE_3 (1024 * 16 - sizeof (void *)) + +/* Initialize the operand cache routines. */ + +void +init_ssa_operands (struct function *fn) +{ + gcc_assert (gimple_ssa_operands (fn)->operand_memory == NULL); + gimple_ssa_operands (fn)->operand_memory_index + = gimple_ssa_operands (fn)->ssa_operand_mem_size; + gimple_ssa_operands (fn)->ops_active = true; + gimple_ssa_operands (fn)->ssa_operand_mem_size = OP_SIZE_INIT; + create_vop_var (fn); +} + + +/* Dispose of anything required by the operand routines. */ + +void +fini_ssa_operands (struct function *fn) +{ + struct ssa_operand_memory_d *ptr; + + gimple_ssa_operands (fn)->free_uses = NULL; + + while ((ptr = gimple_ssa_operands (fn)->operand_memory) != NULL) + { + gimple_ssa_operands (fn)->operand_memory + = gimple_ssa_operands (fn)->operand_memory->next; + ggc_free (ptr); + } + + gimple_ssa_operands (fn)->ops_active = false; + + fn->gimple_df->vop = NULL_TREE; +} + + +/* Return memory for an operand of size SIZE. */ + +static inline void * +ssa_operand_alloc (struct function *fn, unsigned size) +{ + char *ptr; + + gcc_assert (size == sizeof (struct use_optype_d)); + + if (gimple_ssa_operands (fn)->operand_memory_index + size + >= gimple_ssa_operands (fn)->ssa_operand_mem_size) + { + struct ssa_operand_memory_d *ptr; + + switch (gimple_ssa_operands (fn)->ssa_operand_mem_size) + { + case OP_SIZE_INIT: + gimple_ssa_operands (fn)->ssa_operand_mem_size = OP_SIZE_1; + break; + case OP_SIZE_1: + gimple_ssa_operands (fn)->ssa_operand_mem_size = OP_SIZE_2; + break; + case OP_SIZE_2: + case OP_SIZE_3: + gimple_ssa_operands (fn)->ssa_operand_mem_size = OP_SIZE_3; + break; + default: + gcc_unreachable (); + } + + + ptr = (ssa_operand_memory_d *) ggc_internal_alloc + (sizeof (void *) + gimple_ssa_operands (fn)->ssa_operand_mem_size); + + ptr->next = gimple_ssa_operands (fn)->operand_memory; + gimple_ssa_operands (fn)->operand_memory = ptr; + gimple_ssa_operands (fn)->operand_memory_index = 0; + } + + ptr = &(gimple_ssa_operands (fn)->operand_memory + ->mem[gimple_ssa_operands (fn)->operand_memory_index]); + gimple_ssa_operands (fn)->operand_memory_index += size; + return ptr; +} + + +/* Allocate a USE operand. */ + +static inline struct use_optype_d * +alloc_use (struct function *fn) +{ + struct use_optype_d *ret; + if (gimple_ssa_operands (fn)->free_uses) + { + ret = gimple_ssa_operands (fn)->free_uses; + gimple_ssa_operands (fn)->free_uses + = gimple_ssa_operands (fn)->free_uses->next; + } + else + ret = (struct use_optype_d *) + ssa_operand_alloc (fn, sizeof (struct use_optype_d)); + return ret; +} + + +/* Adds OP to the list of uses of statement STMT after LAST. */ + +static inline use_optype_p +add_use_op (struct function *fn, gimple *stmt, tree *op, use_optype_p last) +{ + use_optype_p new_use; + + new_use = alloc_use (fn); + USE_OP_PTR (new_use)->use = op; + link_imm_use_stmt (USE_OP_PTR (new_use), *op, stmt); + last->next = new_use; + new_use->next = NULL; + return new_use; +} + + + +/* Takes elements from build_defs and turns them into def operands of STMT. + TODO -- Make build_defs vec of tree *. */ + +inline void +operands_scanner::finalize_ssa_defs () +{ + /* Pre-pend the vdef we may have built. */ + if (build_vdef != NULL_TREE) + { + tree oldvdef = gimple_vdef (stmt); + if (oldvdef + && TREE_CODE (oldvdef) == SSA_NAME) + oldvdef = SSA_NAME_VAR (oldvdef); + if (oldvdef != build_vdef) + gimple_set_vdef (stmt, build_vdef); + } + + /* Clear and unlink a no longer necessary VDEF. */ + if (build_vdef == NULL_TREE + && gimple_vdef (stmt) != NULL_TREE) + { + if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) + { + unlink_stmt_vdef (stmt); + release_ssa_name_fn (fn, gimple_vdef (stmt)); + } + gimple_set_vdef (stmt, NULL_TREE); + } + + /* If we have a non-SSA_NAME VDEF, mark it for renaming. */ + if (gimple_vdef (stmt) + && TREE_CODE (gimple_vdef (stmt)) != SSA_NAME) + { + fn->gimple_df->rename_vops = 1; + fn->gimple_df->ssa_renaming_needed = 1; + } +} + + +/* Takes elements from build_uses and turns them into use operands of STMT. */ + +inline void +operands_scanner::finalize_ssa_uses () +{ + unsigned new_i; + struct use_optype_d new_list; + use_optype_p old_ops, ptr, last; + + /* Pre-pend the VUSE we may have built. */ + if (build_vuse != NULL_TREE) + { + tree oldvuse = gimple_vuse (stmt); + if (oldvuse + && TREE_CODE (oldvuse) == SSA_NAME) + oldvuse = SSA_NAME_VAR (oldvuse); + if (oldvuse != (build_vuse != NULL_TREE + ? build_vuse : build_vdef)) + gimple_set_vuse (stmt, NULL_TREE); + build_uses.safe_insert (0, gimple_vuse_ptr (stmt)); + } + + new_list.next = NULL; + last = &new_list; + + old_ops = gimple_use_ops (stmt); + + /* Clear a no longer necessary VUSE. */ + if (build_vuse == NULL_TREE + && gimple_vuse (stmt) != NULL_TREE) + gimple_set_vuse (stmt, NULL_TREE); + + /* If there is anything in the old list, free it. */ + if (old_ops) + { + for (ptr = old_ops; ptr->next; ptr = ptr->next) + delink_imm_use (USE_OP_PTR (ptr)); + delink_imm_use (USE_OP_PTR (ptr)); + ptr->next = gimple_ssa_operands (fn)->free_uses; + gimple_ssa_operands (fn)->free_uses = old_ops; + } + + /* If we added a VUSE, make sure to set the operand if it is not already + present and mark it for renaming. */ + if (build_vuse != NULL_TREE + && gimple_vuse (stmt) == NULL_TREE) + { + gimple_set_vuse (stmt, gimple_vop (fn)); + fn->gimple_df->rename_vops = 1; + fn->gimple_df->ssa_renaming_needed = 1; + } + + /* Now create nodes for all the new nodes. */ + for (new_i = 0; new_i < build_uses.length (); new_i++) + { + tree *op = build_uses[new_i]; + last = add_use_op (fn, stmt, op, last); + } + + /* Now set the stmt's operands. */ + gimple_set_use_ops (stmt, new_list.next); +} + + +/* Clear the in_list bits and empty the build array for VDEFs and + VUSEs. */ + +inline void +operands_scanner::cleanup_build_arrays () +{ + build_vdef = NULL_TREE; + build_vuse = NULL_TREE; + build_uses.truncate (0); +} + + +/* Finalize all the build vectors, fill the new ones into INFO. */ + +inline void +operands_scanner::finalize_ssa_stmt_operands () +{ + finalize_ssa_defs (); + finalize_ssa_uses (); + cleanup_build_arrays (); +} + + +/* Start the process of building up operands vectors in INFO. */ + +inline void +operands_scanner::start_ssa_stmt_operands () +{ + gcc_assert (build_uses.length () == 0); + gcc_assert (build_vuse == NULL_TREE); + gcc_assert (build_vdef == NULL_TREE); +} + + +/* Add USE_P to the list of pointers to operands. */ + +inline void +operands_scanner::append_use (tree *use_p) +{ + build_uses.safe_push (use_p); +} + + +/* Add VAR to the set of variables that require a VDEF operator. */ + +inline void +operands_scanner::append_vdef (tree var) +{ + gcc_assert ((build_vdef == NULL_TREE + || build_vdef == var) + && (build_vuse == NULL_TREE + || build_vuse == var)); + + build_vdef = var; + build_vuse = var; +} + + +/* Add VAR to the set of variables that require a VUSE operator. */ + +inline void +operands_scanner::append_vuse (tree var) +{ + gcc_assert (build_vuse == NULL_TREE + || build_vuse == var); + + build_vuse = var; +} + +/* Add virtual operands for STMT. FLAGS is as in get_expr_operands. */ + +void +operands_scanner::add_virtual_operand (int flags) +{ + /* Add virtual operands to the stmt, unless the caller has specifically + requested not to do that (used when adding operands inside an + ADDR_EXPR expression). */ + if (flags & opf_no_vops) + return; + + gcc_assert (!is_gimple_debug (stmt)); + + if (flags & opf_def) + append_vdef (gimple_vop (fn)); + else + append_vuse (gimple_vop (fn)); +} + + +/* Add *VAR_P to the appropriate operand array for statement STMT. + FLAGS is as in get_expr_operands. If *VAR_P is a GIMPLE register, + it will be added to the statement's real operands, otherwise it is + added to virtual operands. */ + +void +operands_scanner::add_stmt_operand (tree *var_p, int flags) +{ + tree var = *var_p; + + gcc_assert (SSA_VAR_P (*var_p) + || TREE_CODE (*var_p) == STRING_CST + || TREE_CODE (*var_p) == CONST_DECL); + + if (is_gimple_reg (var)) + { + /* The variable is a GIMPLE register. Add it to real operands. */ + if (flags & opf_def) + ; + else + append_use (var_p); + if (DECL_P (*var_p)) + fn->gimple_df->ssa_renaming_needed = 1; + } + else + { + /* Mark statements with volatile operands. */ + if (!(flags & opf_no_vops) + && TREE_THIS_VOLATILE (var)) + gimple_set_has_volatile_ops (stmt, true); + + /* The variable is a memory access. Add virtual operands. */ + add_virtual_operand (flags); + } +} + +/* Mark the base address of REF as having its address taken. + REF may be a single variable whose address has been taken or any + other valid GIMPLE memory reference (structure reference, array, + etc). */ + +static void +mark_address_taken (tree ref) +{ + tree var; + + /* Note that it is *NOT OKAY* to use the target of a COMPONENT_REF + as the only thing we take the address of. If VAR is a structure, + taking the address of a field means that the whole structure may + be referenced using pointer arithmetic. See PR 21407 and the + ensuing mailing list discussion. */ + var = get_base_address (ref); + if (VAR_P (var) + || TREE_CODE (var) == RESULT_DECL + || TREE_CODE (var) == PARM_DECL) + TREE_ADDRESSABLE (var) = 1; +} + + +/* A subroutine of get_expr_operands to handle MEM_REF. + + STMT is the statement being processed, EXPR is the MEM_REF + that got us here. + + FLAGS is as in get_expr_operands. */ + +void +operands_scanner::get_mem_ref_operands (tree expr, int flags) +{ + tree *pptr = &TREE_OPERAND (expr, 0); + + if (!(flags & opf_no_vops) + && TREE_THIS_VOLATILE (expr)) + gimple_set_has_volatile_ops (stmt, true); + + /* Add the VOP. */ + add_virtual_operand (flags); + + /* If requested, add a USE operand for the base pointer. */ + get_expr_operands (pptr, + opf_non_addressable | opf_use + | (flags & (opf_no_vops|opf_not_non_addressable))); +} + + +/* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */ + +void +operands_scanner::get_tmr_operands(tree expr, int flags) +{ + if (!(flags & opf_no_vops) + && TREE_THIS_VOLATILE (expr)) + gimple_set_has_volatile_ops (stmt, true); + + /* First record the real operands. */ + get_expr_operands (&TMR_BASE (expr), + opf_non_addressable | opf_use + | (flags & (opf_no_vops|opf_not_non_addressable))); + get_expr_operands (&TMR_INDEX (expr), opf_use | (flags & opf_no_vops)); + get_expr_operands (&TMR_INDEX2 (expr), opf_use | (flags & opf_no_vops)); + + add_virtual_operand (flags); +} + + +/* If STMT is a call that may clobber globals and other symbols that + escape, add them to the VDEF/VUSE lists for it. */ + +void +operands_scanner::maybe_add_call_vops (gcall *stmt) +{ + int call_flags = gimple_call_flags (stmt); + + /* If aliases have been computed already, add VDEF or VUSE + operands for all the symbols that have been found to be + call-clobbered. */ + if (!(call_flags & ECF_NOVOPS)) + { + /* A 'pure' or a 'const' function never call-clobbers anything. */ + if (!(call_flags & (ECF_PURE | ECF_CONST))) + add_virtual_operand (opf_def); + else if (!(call_flags & ECF_CONST)) + add_virtual_operand (opf_use); + } +} + + +/* Scan operands in the ASM_EXPR stmt referred to in INFO. */ + +void +operands_scanner::get_asm_stmt_operands (gasm *stmt) +{ + size_t i, noutputs; + const char **oconstraints; + const char *constraint; + bool allows_mem, allows_reg, is_inout; + + noutputs = gimple_asm_noutputs (stmt); + oconstraints = (const char **) alloca ((noutputs) * sizeof (const char *)); + + /* Gather all output operands. */ + for (i = 0; i < gimple_asm_noutputs (stmt); i++) + { + tree link = gimple_asm_output_op (stmt, i); + constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); + oconstraints[i] = constraint; + parse_output_constraint (&constraint, i, 0, 0, &allows_mem, + &allows_reg, &is_inout); + + /* This should have been split in gimplify_asm_expr. */ + gcc_assert (!allows_reg || !is_inout); + + /* Memory operands are addressable. Note that STMT needs the + address of this operand. */ + if (!allows_reg && allows_mem) + mark_address_taken (TREE_VALUE (link)); + + get_expr_operands (&TREE_VALUE (link), opf_def | opf_not_non_addressable); + } + + /* Gather all input operands. */ + for (i = 0; i < gimple_asm_ninputs (stmt); i++) + { + tree link = gimple_asm_input_op (stmt, i); + constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); + parse_input_constraint (&constraint, 0, 0, noutputs, 0, oconstraints, + &allows_mem, &allows_reg); + + /* Memory operands are addressable. Note that STMT needs the + address of this operand. */ + if (!allows_reg && allows_mem) + mark_address_taken (TREE_VALUE (link)); + + get_expr_operands (&TREE_VALUE (link), opf_not_non_addressable); + } + + /* Clobber all memory and addressable symbols for asm ("" : : : "memory"); */ + if (gimple_asm_clobbers_memory_p (stmt)) + add_virtual_operand (opf_def); +} + + +/* Recursively scan the expression pointed to by EXPR_P in statement + STMT. FLAGS is one of the OPF_* constants modifying how to + interpret the operands found. */ + +void +operands_scanner::get_expr_operands (tree *expr_p, int flags) +{ + enum tree_code code; + enum tree_code_class codeclass; + tree expr = *expr_p; + int uflags = opf_use; + + if (expr == NULL) + return; + + if (is_gimple_debug (stmt)) + uflags |= (flags & opf_no_vops); + + code = TREE_CODE (expr); + codeclass = TREE_CODE_CLASS (code); + + switch (code) + { + case ADDR_EXPR: + /* Taking the address of a variable does not represent a + reference to it, but the fact that the statement takes its + address will be of interest to some passes (e.g. alias + resolution). */ + if ((!(flags & opf_non_addressable) + || (flags & opf_not_non_addressable)) + && !is_gimple_debug (stmt)) + mark_address_taken (TREE_OPERAND (expr, 0)); + + /* Otherwise, there may be variables referenced inside but there + should be no VUSEs created, since the referenced objects are + not really accessed. The only operands that we should find + here are ARRAY_REF indices which will always be real operands + (GIMPLE does not allow non-registers as array indices). */ + flags |= opf_no_vops; + get_expr_operands (&TREE_OPERAND (expr, 0), + flags | opf_not_non_addressable | opf_address_taken); + return; + + case SSA_NAME: + case VAR_DECL: + case PARM_DECL: + case RESULT_DECL: + case STRING_CST: + case CONST_DECL: + if (!(flags & opf_address_taken)) + add_stmt_operand (expr_p, flags); + return; + + case DEBUG_EXPR_DECL: + gcc_assert (gimple_debug_bind_p (stmt)); + return; + + case MEM_REF: + get_mem_ref_operands (expr, flags); + return; + + case TARGET_MEM_REF: + get_tmr_operands (expr, flags); + return; + + case ARRAY_REF: + case ARRAY_RANGE_REF: + case COMPONENT_REF: + case REALPART_EXPR: + case IMAGPART_EXPR: + { + if (!(flags & opf_no_vops) + && TREE_THIS_VOLATILE (expr)) + gimple_set_has_volatile_ops (stmt, true); + + get_expr_operands (&TREE_OPERAND (expr, 0), flags); + + if (code == COMPONENT_REF) + get_expr_operands (&TREE_OPERAND (expr, 2), uflags); + else if (code == ARRAY_REF || code == ARRAY_RANGE_REF) + { + get_expr_operands (&TREE_OPERAND (expr, 1), uflags); + get_expr_operands (&TREE_OPERAND (expr, 2), uflags); + get_expr_operands (&TREE_OPERAND (expr, 3), uflags); + } + + return; + } + + case WITH_SIZE_EXPR: + /* WITH_SIZE_EXPR is a pass-through reference to its first argument, + and an rvalue reference to its second argument. */ + get_expr_operands (&TREE_OPERAND (expr, 1), uflags); + get_expr_operands (&TREE_OPERAND (expr, 0), flags); + return; + + case COND_EXPR: + case VEC_COND_EXPR: + case VEC_PERM_EXPR: + get_expr_operands (&TREE_OPERAND (expr, 0), uflags); + get_expr_operands (&TREE_OPERAND (expr, 1), uflags); + get_expr_operands (&TREE_OPERAND (expr, 2), uflags); + return; + + case CONSTRUCTOR: + { + /* General aggregate CONSTRUCTORs have been decomposed, but they + are still in use as the COMPLEX_EXPR equivalent for vectors. */ + constructor_elt *ce; + unsigned HOST_WIDE_INT idx; + + /* A volatile constructor is actually TREE_CLOBBER_P, transfer + the volatility to the statement, don't use TREE_CLOBBER_P for + mirroring the other uses of THIS_VOLATILE in this file. */ + if (!(flags & opf_no_vops) + && TREE_THIS_VOLATILE (expr)) + gimple_set_has_volatile_ops (stmt, true); + + for (idx = 0; + vec_safe_iterate (CONSTRUCTOR_ELTS (expr), idx, &ce); + idx++) + get_expr_operands (&ce->value, uflags); + + return; + } + + case BIT_FIELD_REF: + if (!(flags & opf_no_vops) + && TREE_THIS_VOLATILE (expr)) + gimple_set_has_volatile_ops (stmt, true); + /* FALLTHRU */ + + case VIEW_CONVERT_EXPR: + do_unary: + get_expr_operands (&TREE_OPERAND (expr, 0), flags); + return; + + case BIT_INSERT_EXPR: + case COMPOUND_EXPR: + case OBJ_TYPE_REF: + case ASSERT_EXPR: + do_binary: + { + get_expr_operands (&TREE_OPERAND (expr, 0), flags); + get_expr_operands (&TREE_OPERAND (expr, 1), flags); + return; + } + + case DOT_PROD_EXPR: + case SAD_EXPR: + case REALIGN_LOAD_EXPR: + case WIDEN_MULT_PLUS_EXPR: + case WIDEN_MULT_MINUS_EXPR: + { + get_expr_operands (&TREE_OPERAND (expr, 0), flags); + get_expr_operands (&TREE_OPERAND (expr, 1), flags); + get_expr_operands (&TREE_OPERAND (expr, 2), flags); + return; + } + + case FUNCTION_DECL: + case LABEL_DECL: + case CASE_LABEL_EXPR: + /* Expressions that make no memory references. */ + return; + + default: + if (codeclass == tcc_unary) + goto do_unary; + if (codeclass == tcc_binary || codeclass == tcc_comparison) + goto do_binary; + if (codeclass == tcc_constant || codeclass == tcc_type) + return; + } + + /* If we get here, something has gone wrong. */ + if (flag_checking) + { + fprintf (stderr, "unhandled expression in get_expr_operands():\n"); + debug_tree (expr); + fputs ("\n", stderr); + gcc_unreachable (); + } +} + + +/* Parse STMT looking for operands. When finished, the various + build_* operand vectors will have potential operands in them. */ + +void +operands_scanner::parse_ssa_operands () +{ + enum gimple_code code = gimple_code (stmt); + size_t i, n, start = 0; + + switch (code) + { + case GIMPLE_ASM: + get_asm_stmt_operands (as_a <gasm *> (stmt)); + break; + + case GIMPLE_TRANSACTION: + /* The start of a transaction is a memory barrier. */ + add_virtual_operand (opf_def | opf_use); + break; + + case GIMPLE_DEBUG: + if (gimple_debug_bind_p (stmt) + && gimple_debug_bind_has_value_p (stmt)) + get_expr_operands (gimple_debug_bind_get_value_ptr (stmt), + opf_use | opf_no_vops); + break; + + case GIMPLE_RETURN: + append_vuse (gimple_vop (fn)); + goto do_default; + + case GIMPLE_CALL: + /* Add call-clobbered operands, if needed. */ + maybe_add_call_vops (as_a <gcall *> (stmt)); + /* FALLTHRU */ + + case GIMPLE_ASSIGN: + get_expr_operands (gimple_op_ptr (stmt, 0), opf_def); + start = 1; + /* FALLTHRU */ + + default: + do_default: + n = gimple_num_ops (stmt); + for (i = start; i < n; i++) + get_expr_operands (gimple_op_ptr (stmt, i), opf_use); + break; + } +} + + +/* Create an operands cache for STMT. */ + +void +operands_scanner::build_ssa_operands () +{ + /* Initially assume that the statement has no volatile operands. */ + gimple_set_has_volatile_ops (stmt, false); + + start_ssa_stmt_operands (); + parse_ssa_operands (); + finalize_ssa_stmt_operands (); +} + +/* Verifies SSA statement operands. */ + +DEBUG_FUNCTION bool +operands_scanner::verify_ssa_operands () +{ + use_operand_p use_p; + def_operand_p def_p; + ssa_op_iter iter; + unsigned i; + tree def; + bool volatile_p = gimple_has_volatile_ops (stmt); + + /* build_ssa_operands w/o finalizing them. */ + gimple_set_has_volatile_ops (stmt, false); + start_ssa_stmt_operands (); + parse_ssa_operands (); + + /* Now verify the built operands are the same as present in STMT. */ + def = gimple_vdef (stmt); + if (def + && TREE_CODE (def) == SSA_NAME) + def = SSA_NAME_VAR (def); + if (build_vdef != def) + { + error ("virtual definition of statement not up to date"); + return true; + } + if (gimple_vdef (stmt) + && ((def_p = gimple_vdef_op (stmt)) == NULL_DEF_OPERAND_P + || DEF_FROM_PTR (def_p) != gimple_vdef (stmt))) + { + error ("virtual def operand missing for statement"); + return true; + } + + tree use = gimple_vuse (stmt); + if (use + && TREE_CODE (use) == SSA_NAME) + use = SSA_NAME_VAR (use); + if (build_vuse != use) + { + error ("virtual use of statement not up to date"); + return true; + } + if (gimple_vuse (stmt) + && ((use_p = gimple_vuse_op (stmt)) == NULL_USE_OPERAND_P + || USE_FROM_PTR (use_p) != gimple_vuse (stmt))) + { + error ("virtual use operand missing for statement"); + return true; + } + + FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) + { + tree *op; + FOR_EACH_VEC_ELT (build_uses, i, op) + { + if (use_p->use == op) + { + build_uses[i] = NULL; + break; + } + } + if (i == build_uses.length ()) + { + error ("excess use operand for statement"); + debug_generic_expr (USE_FROM_PTR (use_p)); + return true; + } + } + + tree *op; + FOR_EACH_VEC_ELT (build_uses, i, op) + if (op != NULL) + { + error ("use operand missing for statement"); + debug_generic_expr (*op); + return true; + } + + if (gimple_has_volatile_ops (stmt) != volatile_p) + { + error ("statement volatile flag not up to date"); + return true; + } + + cleanup_build_arrays (); + return false; +} + +/* Interface for external use. */ + +DEBUG_FUNCTION bool +verify_ssa_operands (struct function *fn, gimple *stmt) +{ + return operands_scanner (fn, stmt).verify_ssa_operands (); +} + + +/* Releases the operands of STMT back to their freelists, and clears + the stmt operand lists. */ + +void +free_stmt_operands (struct function *fn, gimple *stmt) +{ + use_optype_p uses = gimple_use_ops (stmt), last_use; + + if (uses) + { + for (last_use = uses; last_use->next; last_use = last_use->next) + delink_imm_use (USE_OP_PTR (last_use)); + delink_imm_use (USE_OP_PTR (last_use)); + last_use->next = gimple_ssa_operands (fn)->free_uses; + gimple_ssa_operands (fn)->free_uses = uses; + gimple_set_use_ops (stmt, NULL); + } + + if (gimple_has_mem_ops (stmt)) + { + gimple_set_vuse (stmt, NULL_TREE); + gimple_set_vdef (stmt, NULL_TREE); + } +} + + +/* Get the operands of statement STMT. */ + +void +update_stmt_operands (struct function *fn, gimple *stmt) +{ + /* If update_stmt_operands is called before SSA is initialized, do + nothing. */ + if (!ssa_operands_active (fn)) + return; + + timevar_push (TV_TREE_OPS); + + gcc_assert (gimple_modified_p (stmt)); + operands_scanner (fn, stmt).build_ssa_operands (); + gimple_set_modified (stmt, false); + + timevar_pop (TV_TREE_OPS); +} + + +/* Swap operands EXP0 and EXP1 in statement STMT. No attempt is done + to test the validity of the swap operation. */ + +void +swap_ssa_operands (gimple *stmt, tree *exp0, tree *exp1) +{ + tree op0, op1; + op0 = *exp0; + op1 = *exp1; + + if (op0 != op1) + { + /* Attempt to preserve the relative positions of these two operands in + their * respective immediate use lists by adjusting their use pointer + to point to the new operand position. */ + use_optype_p use0, use1, ptr; + use0 = use1 = NULL; + + /* Find the 2 operands in the cache, if they are there. */ + for (ptr = gimple_use_ops (stmt); ptr; ptr = ptr->next) + if (USE_OP_PTR (ptr)->use == exp0) + { + use0 = ptr; + break; + } + + for (ptr = gimple_use_ops (stmt); ptr; ptr = ptr->next) + if (USE_OP_PTR (ptr)->use == exp1) + { + use1 = ptr; + break; + } + + /* And adjust their location to point to the new position of the + operand. */ + if (use0) + USE_OP_PTR (use0)->use = exp1; + if (use1) + USE_OP_PTR (use1)->use = exp0; + + /* Now swap the data. */ + *exp0 = op1; + *exp1 = op0; + } +} + + +/* Scan the immediate_use list for VAR making sure its linked properly. + Return TRUE if there is a problem and emit an error message to F. */ + +DEBUG_FUNCTION bool +verify_imm_links (FILE *f, tree var) +{ + use_operand_p ptr, prev, list; + unsigned int count; + + gcc_assert (TREE_CODE (var) == SSA_NAME); + + list = &(SSA_NAME_IMM_USE_NODE (var)); + gcc_assert (list->use == NULL); + + if (list->prev == NULL) + { + gcc_assert (list->next == NULL); + return false; + } + + prev = list; + count = 0; + for (ptr = list->next; ptr != list; ) + { + if (prev != ptr->prev) + { + fprintf (f, "prev != ptr->prev\n"); + goto error; + } + + if (ptr->use == NULL) + { + fprintf (f, "ptr->use == NULL\n"); + goto error; /* 2 roots, or SAFE guard node. */ + } + else if (*(ptr->use) != var) + { + fprintf (f, "*(ptr->use) != var\n"); + goto error; + } + + prev = ptr; + ptr = ptr->next; + + count++; + if (count == 0) + { + fprintf (f, "number of immediate uses doesn't fit unsigned int\n"); + goto error; + } + } + + /* Verify list in the other direction. */ + prev = list; + for (ptr = list->prev; ptr != list; ) + { + if (prev != ptr->next) + { + fprintf (f, "prev != ptr->next\n"); + goto error; + } + prev = ptr; + ptr = ptr->prev; + if (count == 0) + { + fprintf (f, "count-- < 0\n"); + goto error; + } + count--; + } + + if (count != 0) + { + fprintf (f, "count != 0\n"); + goto error; + } + + return false; + + error: + if (ptr->loc.stmt && gimple_modified_p (ptr->loc.stmt)) + { + fprintf (f, " STMT MODIFIED. - <%p> ", (void *)ptr->loc.stmt); + print_gimple_stmt (f, ptr->loc.stmt, 0, TDF_SLIM); + } + fprintf (f, " IMM ERROR : (use_p : tree - %p:%p)", (void *)ptr, + (void *)ptr->use); + print_generic_expr (f, USE_FROM_PTR (ptr), TDF_SLIM); + fprintf (f, "\n"); + return true; +} + + +/* Dump all the immediate uses to FILE. */ + +void +dump_immediate_uses_for (FILE *file, tree var) +{ + imm_use_iterator iter; + use_operand_p use_p; + + gcc_assert (var && TREE_CODE (var) == SSA_NAME); + + print_generic_expr (file, var, TDF_SLIM); + fprintf (file, " : -->"); + if (has_zero_uses (var)) + fprintf (file, " no uses.\n"); + else + if (has_single_use (var)) + fprintf (file, " single use.\n"); + else + fprintf (file, "%d uses.\n", num_imm_uses (var)); + + FOR_EACH_IMM_USE_FAST (use_p, iter, var) + { + if (use_p->loc.stmt == NULL && use_p->use == NULL) + fprintf (file, "***end of stmt iterator marker***\n"); + else + if (!is_gimple_reg (USE_FROM_PTR (use_p))) + print_gimple_stmt (file, USE_STMT (use_p), 0, TDF_VOPS|TDF_MEMSYMS); + else + print_gimple_stmt (file, USE_STMT (use_p), 0, TDF_SLIM); + } + fprintf (file, "\n"); +} + + +/* Dump all the immediate uses to FILE. */ + +void +dump_immediate_uses (FILE *file) +{ + tree var; + unsigned int x; + + fprintf (file, "Immediate_uses: \n\n"); + FOR_EACH_SSA_NAME (x, var, cfun) + { + dump_immediate_uses_for (file, var); + } +} + + +/* Dump def-use edges on stderr. */ + +DEBUG_FUNCTION void +debug_immediate_uses (void) +{ + dump_immediate_uses (stderr); +} + + +/* Dump def-use edges on stderr. */ + +DEBUG_FUNCTION void +debug_immediate_uses_for (tree var) +{ + dump_immediate_uses_for (stderr, var); +} + + +/* Unlink STMTs virtual definition from the IL by propagating its use. */ + +void +unlink_stmt_vdef (gimple *stmt) +{ + use_operand_p use_p; + imm_use_iterator iter; + gimple *use_stmt; + tree vdef = gimple_vdef (stmt); + tree vuse = gimple_vuse (stmt); + + if (!vdef + || TREE_CODE (vdef) != SSA_NAME) + return; + + FOR_EACH_IMM_USE_STMT (use_stmt, iter, vdef) + { + FOR_EACH_IMM_USE_ON_STMT (use_p, iter) + SET_USE (use_p, vuse); + } + + if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vdef)) + SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse) = 1; +} + +/* Return true if the var whose chain of uses starts at PTR has a + single nondebug use. Set USE_P and STMT to that single nondebug + use, if so, or to NULL otherwise. */ +bool +single_imm_use_1 (const ssa_use_operand_t *head, + use_operand_p *use_p, gimple **stmt) +{ + ssa_use_operand_t *ptr, *single_use = 0; + + for (ptr = head->next; ptr != head; ptr = ptr->next) + if (USE_STMT(ptr) && !is_gimple_debug (USE_STMT (ptr))) + { + if (single_use) + { + single_use = NULL; + break; + } + single_use = ptr; + } + + if (use_p) + *use_p = single_use; + + if (stmt) + *stmt = single_use ? single_use->loc.stmt : NULL; + + return single_use; +} + |