#include "params.h"
#include "tree-ssa-propagate.h"
#include "tree-ssa-sccvn.h"
+#include "gimple-fold.h"
/* This algorithm is based on the SCC algorithm presented by Keith
Cooper and L. Taylor Simpson in "SCC-Based Value numbering"
const_vn_reference_op_t const vro1 = (const_vn_reference_op_t) p1;
const_vn_reference_op_t const vro2 = (const_vn_reference_op_t) p2;
- return vro1->opcode == vro2->opcode
- && types_compatible_p (vro1->type, vro2->type)
- && expressions_equal_p (vro1->op0, vro2->op0)
- && expressions_equal_p (vro1->op1, vro2->op1)
- && expressions_equal_p (vro1->op2, vro2->op2);
+ return (vro1->opcode == vro2->opcode
+ /* We do not care for differences in type qualification. */
+ && (vro1->type == vro2->type
+ || (vro1->type && vro2->type
+ && types_compatible_p (TYPE_MAIN_VARIANT (vro1->type),
+ TYPE_MAIN_VARIANT (vro2->type))))
+ && expressions_equal_p (vro1->op0, vro2->op0)
+ && expressions_equal_p (vro1->op1, vro2->op1)
+ && expressions_equal_p (vro1->op2, vro2->op2));
}
/* Compute the hash for a reference operand VRO1. */
vn_reference_op_s temp;
memset (&temp, 0, sizeof (temp));
- /* We do not care for spurious type qualifications. */
- temp.type = TYPE_MAIN_VARIANT (TREE_TYPE (ref));
+ temp.type = TREE_TYPE (ref);
temp.opcode = TREE_CODE (ref);
temp.op0 = TMR_INDEX (ref);
temp.op1 = TMR_STEP (ref);
vn_reference_op_s temp;
memset (&temp, 0, sizeof (temp));
- /* We do not care for spurious type qualifications. */
- temp.type = TYPE_MAIN_VARIANT (TREE_TYPE (ref));
+ temp.type = TREE_TYPE (ref);
temp.opcode = TREE_CODE (ref);
temp.off = -1;
temp.off = off.low;
}
break;
+ case VAR_DECL:
+ if (DECL_HARD_REGISTER (ref))
+ {
+ temp.op0 = ref;
+ break;
+ }
+ /* Fallthru. */
+ case PARM_DECL:
+ case CONST_DECL:
+ case RESULT_DECL:
+ /* Canonicalize decls to MEM[&decl] which is what we end up with
+ when valueizing MEM[ptr] with ptr = &decl. */
+ temp.opcode = MEM_REF;
+ temp.op0 = build_int_cst (build_pointer_type (TREE_TYPE (ref)), 0);
+ temp.off = 0;
+ VEC_safe_push (vn_reference_op_s, heap, *result, &temp);
+ temp.opcode = ADDR_EXPR;
+ temp.op0 = build_fold_addr_expr (ref);
+ temp.type = TREE_TYPE (temp.op0);
+ temp.off = -1;
+ break;
case STRING_CST:
case INTEGER_CST:
case COMPLEX_CST:
case VECTOR_CST:
case REAL_CST:
+ case FIXED_CST:
case CONSTRUCTOR:
- case VAR_DECL:
- case PARM_DECL:
- case CONST_DECL:
- case RESULT_DECL:
case SSA_NAME:
temp.op0 = ref;
break;
/* Transform any SSA_NAME's in a vector of vn_reference_op_s
structures into their value numbers. This is done in-place, and
- the vector passed in is returned. */
+ the vector passed in is returned. *VALUEIZED_ANYTHING will specify
+ whether any operands were valueized. */
static VEC (vn_reference_op_s, heap) *
-valueize_refs (VEC (vn_reference_op_s, heap) *orig)
+valueize_refs_1 (VEC (vn_reference_op_s, heap) *orig, bool *valueized_anything)
{
vn_reference_op_t vro;
unsigned int i;
+ *valueized_anything = false;
+
FOR_EACH_VEC_ELT (vn_reference_op_s, orig, i, vro)
{
if (vro->opcode == SSA_NAME
|| (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME))
{
- vro->op0 = SSA_VAL (vro->op0);
+ tree tem = SSA_VAL (vro->op0);
+ if (tem != vro->op0)
+ {
+ *valueized_anything = true;
+ vro->op0 = tem;
+ }
/* If it transforms from an SSA_NAME to a constant, update
the opcode. */
if (TREE_CODE (vro->op0) != SSA_NAME && vro->opcode == SSA_NAME)
vro->opcode = TREE_CODE (vro->op0);
}
if (vro->op1 && TREE_CODE (vro->op1) == SSA_NAME)
- vro->op1 = SSA_VAL (vro->op1);
+ {
+ tree tem = SSA_VAL (vro->op1);
+ if (tem != vro->op1)
+ {
+ *valueized_anything = true;
+ vro->op1 = tem;
+ }
+ }
if (vro->op2 && TREE_CODE (vro->op2) == SSA_NAME)
- vro->op2 = SSA_VAL (vro->op2);
+ {
+ tree tem = SSA_VAL (vro->op2);
+ if (tem != vro->op2)
+ {
+ *valueized_anything = true;
+ vro->op2 = tem;
+ }
+ }
/* If it transforms from an SSA_NAME to an address, fold with
a preceding indirect reference. */
if (i > 0
return orig;
}
+static VEC (vn_reference_op_s, heap) *
+valueize_refs (VEC (vn_reference_op_s, heap) *orig)
+{
+ bool tem;
+ return valueize_refs_1 (orig, &tem);
+}
+
static VEC(vn_reference_op_s, heap) *shared_lookup_references;
/* Create a vector of vn_reference_op_s structures from REF, a
REFERENCE_CLASS_P tree. The vector is shared among all callers of
- this function. */
+ this function. *VALUEIZED_ANYTHING will specify whether any
+ operands were valueized. */
static VEC(vn_reference_op_s, heap) *
-valueize_shared_reference_ops_from_ref (tree ref)
+valueize_shared_reference_ops_from_ref (tree ref, bool *valueized_anything)
{
if (!ref)
return NULL;
VEC_truncate (vn_reference_op_s, shared_lookup_references, 0);
copy_reference_ops_from_ref (ref, &shared_lookup_references);
- shared_lookup_references = valueize_refs (shared_lookup_references);
+ shared_lookup_references = valueize_refs_1 (shared_lookup_references,
+ valueized_anything);
return shared_lookup_references;
}
{
vn_reference_t vr = (vn_reference_t)vr_;
gimple def_stmt = SSA_NAME_DEF_STMT (vuse);
- tree fndecl;
tree base;
HOST_WIDE_INT offset, maxsize;
static VEC (vn_reference_op_s, heap) *lhs_ops = NULL;
{
VEC (vn_reference_op_s, heap) *tem;
tree lhs = gimple_assign_lhs (def_stmt);
+ bool valueized_anything = false;
/* Avoid re-allocation overhead. */
VEC_truncate (vn_reference_op_s, lhs_ops, 0);
copy_reference_ops_from_ref (lhs, &lhs_ops);
tem = lhs_ops;
- lhs_ops = valueize_refs (lhs_ops);
+ lhs_ops = valueize_refs_1 (lhs_ops, &valueized_anything);
gcc_assert (lhs_ops == tem);
- lhs_ref_ok = ao_ref_init_from_vn_reference (&lhs_ref, get_alias_set (lhs),
- TREE_TYPE (lhs), lhs_ops);
- if (lhs_ref_ok
- && !refs_may_alias_p_1 (ref, &lhs_ref, true))
- return NULL;
+ if (valueized_anything)
+ {
+ lhs_ref_ok = ao_ref_init_from_vn_reference (&lhs_ref,
+ get_alias_set (lhs),
+ TREE_TYPE (lhs), lhs_ops);
+ if (lhs_ref_ok
+ && !refs_may_alias_p_1 (ref, &lhs_ref, true))
+ return NULL;
+ }
+ else
+ {
+ ao_ref_init (&lhs_ref, lhs);
+ lhs_ref_ok = true;
+ }
}
base = ao_ref_base (ref);
from that defintion.
1) Memset. */
if (is_gimple_reg_type (vr->type)
- && is_gimple_call (def_stmt)
- && (fndecl = gimple_call_fndecl (def_stmt))
- && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
- && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_MEMSET
+ && gimple_call_builtin_p (def_stmt, BUILT_IN_MEMSET)
&& integer_zerop (gimple_call_arg (def_stmt, 1))
&& host_integerp (gimple_call_arg (def_stmt, 2), 1)
&& TREE_CODE (gimple_call_arg (def_stmt, 0)) == ADDR_EXPR)
}
}
- /* For aggregate copies translate the reference through them if
+ /* 3) For aggregate copies translate the reference through them if
the copy kills ref. */
else if (vn_walk_kind == VN_WALKREWRITE
&& gimple_assign_single_p (def_stmt)
j--;
}
+ /* ??? The innermost op should always be a MEM_REF and we already
+ checked that the assignment to the lhs kills vr. Thus for
+ aggregate copies using char[] types the vn_reference_op_eq
+ may fail when comparing types for compatibility. But we really
+ don't care here - further lookups with the rewritten operands
+ will simply fail if we messed up types too badly. */
+ if (j == 0 && i >= 0
+ && VEC_index (vn_reference_op_s, lhs_ops, 0)->opcode == MEM_REF
+ && VEC_index (vn_reference_op_s, lhs_ops, 0)->off != -1
+ && (VEC_index (vn_reference_op_s, lhs_ops, 0)->off
+ == VEC_index (vn_reference_op_s, vr->operands, i)->off))
+ i--, j--;
+
/* i now points to the first additional op.
??? LHS may not be completely contained in VR, one or more
VIEW_CONVERT_EXPRs could be in its way. We could at least
return NULL;
}
+ /* 4) For memcpy copies translate the reference through them if
+ the copy kills ref. */
+ else if (vn_walk_kind == VN_WALKREWRITE
+ && is_gimple_reg_type (vr->type)
+ /* ??? Handle BCOPY as well. */
+ && (gimple_call_builtin_p (def_stmt, BUILT_IN_MEMCPY)
+ || gimple_call_builtin_p (def_stmt, BUILT_IN_MEMPCPY)
+ || gimple_call_builtin_p (def_stmt, BUILT_IN_MEMMOVE))
+ && (TREE_CODE (gimple_call_arg (def_stmt, 0)) == ADDR_EXPR
+ || TREE_CODE (gimple_call_arg (def_stmt, 0)) == SSA_NAME)
+ && (TREE_CODE (gimple_call_arg (def_stmt, 1)) == ADDR_EXPR
+ || TREE_CODE (gimple_call_arg (def_stmt, 1)) == SSA_NAME)
+ && host_integerp (gimple_call_arg (def_stmt, 2), 1))
+ {
+ tree lhs, rhs;
+ ao_ref r;
+ HOST_WIDE_INT rhs_offset, copy_size, lhs_offset;
+ vn_reference_op_s op;
+ HOST_WIDE_INT at;
+
+
+ /* Only handle non-variable, addressable refs. */
+ if (ref->size != maxsize
+ || offset % BITS_PER_UNIT != 0
+ || ref->size % BITS_PER_UNIT != 0)
+ return (void *)-1;
+
+ /* Extract a pointer base and an offset for the destination. */
+ lhs = gimple_call_arg (def_stmt, 0);
+ lhs_offset = 0;
+ if (TREE_CODE (lhs) == SSA_NAME)
+ lhs = SSA_VAL (lhs);
+ if (TREE_CODE (lhs) == ADDR_EXPR)
+ {
+ tree tem = get_addr_base_and_unit_offset (TREE_OPERAND (lhs, 0),
+ &lhs_offset);
+ if (!tem)
+ return (void *)-1;
+ if (TREE_CODE (tem) == MEM_REF
+ && host_integerp (TREE_OPERAND (tem, 1), 1))
+ {
+ lhs = TREE_OPERAND (tem, 0);
+ lhs_offset += TREE_INT_CST_LOW (TREE_OPERAND (tem, 1));
+ }
+ else if (DECL_P (tem))
+ lhs = build_fold_addr_expr (tem);
+ else
+ return (void *)-1;
+ }
+ if (TREE_CODE (lhs) != SSA_NAME
+ && TREE_CODE (lhs) != ADDR_EXPR)
+ return (void *)-1;
+
+ /* Extract a pointer base and an offset for the source. */
+ rhs = gimple_call_arg (def_stmt, 1);
+ rhs_offset = 0;
+ if (TREE_CODE (rhs) == SSA_NAME)
+ rhs = SSA_VAL (rhs);
+ if (TREE_CODE (rhs) == ADDR_EXPR)
+ {
+ tree tem = get_addr_base_and_unit_offset (TREE_OPERAND (rhs, 0),
+ &rhs_offset);
+ if (!tem)
+ return (void *)-1;
+ if (TREE_CODE (tem) == MEM_REF
+ && host_integerp (TREE_OPERAND (tem, 1), 1))
+ {
+ rhs = TREE_OPERAND (tem, 0);
+ rhs_offset += TREE_INT_CST_LOW (TREE_OPERAND (tem, 1));
+ }
+ else if (DECL_P (tem))
+ rhs = build_fold_addr_expr (tem);
+ else
+ return (void *)-1;
+ }
+ if (TREE_CODE (rhs) != SSA_NAME
+ && TREE_CODE (rhs) != ADDR_EXPR)
+ return (void *)-1;
+
+ copy_size = TREE_INT_CST_LOW (gimple_call_arg (def_stmt, 2));
+
+ /* The bases of the destination and the references have to agree. */
+ if ((TREE_CODE (base) != MEM_REF
+ && !DECL_P (base))
+ || (TREE_CODE (base) == MEM_REF
+ && (TREE_OPERAND (base, 0) != lhs
+ || !host_integerp (TREE_OPERAND (base, 1), 1)))
+ || (DECL_P (base)
+ && (TREE_CODE (lhs) != ADDR_EXPR
+ || TREE_OPERAND (lhs, 0) != base)))
+ return (void *)-1;
+
+ /* And the access has to be contained within the memcpy destination. */
+ at = offset / BITS_PER_UNIT;
+ if (TREE_CODE (base) == MEM_REF)
+ at += TREE_INT_CST_LOW (TREE_OPERAND (base, 1));
+ if (lhs_offset > at
+ || lhs_offset + copy_size < at + maxsize / BITS_PER_UNIT)
+ return (void *)-1;
+
+ /* Make room for 2 operands in the new reference. */
+ if (VEC_length (vn_reference_op_s, vr->operands) < 2)
+ {
+ VEC (vn_reference_op_s, heap) *old = vr->operands;
+ VEC_safe_grow (vn_reference_op_s, heap, vr->operands, 2);
+ if (old == shared_lookup_references
+ && vr->operands != old)
+ shared_lookup_references = NULL;
+ }
+ else
+ VEC_truncate (vn_reference_op_s, vr->operands, 2);
+
+ /* The looked-through reference is a simple MEM_REF. */
+ memset (&op, 0, sizeof (op));
+ op.type = vr->type;
+ op.opcode = MEM_REF;
+ op.op0 = build_int_cst (ptr_type_node, at - rhs_offset);
+ op.off = at - lhs_offset + rhs_offset;
+ VEC_replace (vn_reference_op_s, vr->operands, 0, &op);
+ op.type = TREE_TYPE (rhs);
+ op.opcode = TREE_CODE (rhs);
+ op.op0 = rhs;
+ op.off = -1;
+ VEC_replace (vn_reference_op_s, vr->operands, 1, &op);
+ vr->hashcode = vn_reference_compute_hash (vr);
+
+ /* Adjust *ref from the new operands. */
+ if (!ao_ref_init_from_vn_reference (&r, vr->set, vr->type, vr->operands))
+ return (void *)-1;
+ /* This can happen with bitfields. */
+ if (ref->size != r.size)
+ return (void *)-1;
+ *ref = r;
+
+ /* Do not update last seen VUSE after translating. */
+ last_vuse_ptr = NULL;
+
+ /* Keep looking for the adjusted *REF / VR pair. */
+ return NULL;
+ }
+
/* Bail out and stop walking. */
return (void *)-1;
}
VEC (vn_reference_op_s, heap) *operands;
struct vn_reference_s vr1;
tree cst;
+ bool valuezied_anything;
if (vnresult)
*vnresult = NULL;
vr1.vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
- vr1.operands = operands = valueize_shared_reference_ops_from_ref (op);
+ vr1.operands = operands
+ = valueize_shared_reference_ops_from_ref (op, &valuezied_anything);
vr1.type = TREE_TYPE (op);
vr1.set = get_alias_set (op);
vr1.hashcode = vn_reference_compute_hash (&vr1);
{
vn_reference_t wvnresult;
ao_ref r;
- ao_ref_init (&r, op);
+ /* Make sure to use a valueized reference if we valueized anything.
+ Otherwise preserve the full reference for advanced TBAA. */
+ if (!valuezied_anything
+ || !ao_ref_init_from_vn_reference (&r, vr1.set, vr1.type,
+ vr1.operands))
+ ao_ref_init (&r, op);
vn_walk_kind = kind;
wvnresult =
(vn_reference_t)walk_non_aliased_vuses (&r, vr1.vuse,
static inline bool
set_ssa_val_to (tree from, tree to)
{
- tree currval;
+ tree currval = SSA_VAL (from);
- if (from != to
- && TREE_CODE (to) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (to))
- to = from;
+ if (from != to)
+ {
+ if (currval == from)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Not changing value number of ");
+ print_generic_expr (dump_file, from, 0);
+ fprintf (dump_file, " from VARYING to ");
+ print_generic_expr (dump_file, to, 0);
+ fprintf (dump_file, "\n");
+ }
+ return false;
+ }
+ else if (TREE_CODE (to) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (to))
+ to = from;
+ }
/* The only thing we allow as value numbers are VN_TOP, ssa_names
and invariants. So assert that here. */
print_generic_expr (dump_file, to, 0);
}
- currval = SSA_VAL (from);
-
if (currval != to && !operand_equal_p (currval, to, OEP_PURE_SAME))
{
VN_INFO (from)->valnum = to;
op1 = SSA_VAL (op1);
}
+ /* Pointer plus constant can be represented as invariant address.
+ Do so to allow further propatation, see also tree forwprop. */
+ if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR
+ && host_integerp (op1, 1)
+ && TREE_CODE (op0) == ADDR_EXPR
+ && is_gimple_min_invariant (op0))
+ return build_invariant_address (TREE_TYPE (op0),
+ TREE_OPERAND (op0, 0),
+ TREE_INT_CST_LOW (op1));
+
/* Avoid folding if nothing changed. */
if (op0 == gimple_assign_rhs1 (stmt)
&& op1 == gimple_assign_rhs2 (stmt))
return NULL_TREE;
}
+/* Valueize NAME if it is an SSA name, otherwise just return it. */
+
+static inline tree
+vn_valueize (tree name)
+{
+ if (TREE_CODE (name) == SSA_NAME)
+ {
+ tree tem = SSA_VAL (name);
+ return tem == VN_TOP ? name : tem;
+ }
+ return name;
+}
+
/* Try to simplify RHS using equivalences and constant folding. */
static tree
&& TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME)
return NULL_TREE;
+ /* First try constant folding based on our current lattice. */
+ tem = gimple_fold_stmt_to_constant (stmt, vn_valueize);
+ if (tem)
+ return tem;
+
+ /* If that didn't work try combining multiple statements. */
switch (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)))
{
- case tcc_declaration:
- tem = get_symbol_constant_value (gimple_assign_rhs1 (stmt));
- if (tem)
- return tem;
- break;
-
case tcc_reference:
- /* Do not do full-blown reference lookup here, but simplify
- reads from constant aggregates. */
- tem = fold_const_aggregate_ref (gimple_assign_rhs1 (stmt));
- if (tem)
- return tem;
-
/* Fallthrough for some codes that can operate on registers. */
if (!(TREE_CODE (gimple_assign_rhs1 (stmt)) == REALPART_EXPR
|| TREE_CODE (gimple_assign_rhs1 (stmt)) == IMAGPART_EXPR
into binary ops, but it's debatable whether it is worth it. */
case tcc_unary:
return simplify_unary_expression (stmt);
- break;
+
case tcc_comparison:
case tcc_binary:
return simplify_binary_expression (stmt);
- break;
+
default:
break;
}
/* ??? We should handle stores from calls. */
else if (TREE_CODE (lhs) == SSA_NAME)
{
- if (gimple_call_flags (stmt) & (ECF_PURE | ECF_CONST))
+ if (!gimple_call_internal_p (stmt)
+ && gimple_call_flags (stmt) & (ECF_PURE | ECF_CONST))
changed = visit_reference_op_call (lhs, stmt);
else
changed = defs_to_varying (stmt);
{
changed = false;
iterations++;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Starting iteration %d\n", iterations);
/* As we are value-numbering optimistically we have to
clear the expression tables and the simplified expressions
in each iteration until we converge. */
OSDN Git Service
