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further improved early width and sign detection in ast simplifier

This commit is contained in:
Clifford Wolf 2013-11-04 06:04:42 +01:00
parent cd0fe7d786
commit 472117d532
2 changed files with 117 additions and 11 deletions
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7
frontends/ast/genrtlil.cc
View File

@ -665,9 +665,12 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint)
break;
case AST_MEMRD:
if (!is_signed)
if (!id2ast->is_signed)
sign_hint = false;
width_hint = std::max(width_hint, current_module->memories.at(str)->width);
if (!id2ast->children[0]->range_valid)
log_error("Failed to detect with of memory access `%s' at %s:%d!\n", str.c_str(), filename.c_str(), linenum);
this_width = id2ast->children[0]->range_left - id2ast->children[0]->range_right + 1;
width_hint = std::max(width_hint, this_width);
break;
// everything should have been handled above -> print error if not.

121
frontends/ast/simplify.cc
View File

@ -175,14 +175,107 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
auto backup_current_block_child = current_block_child;
auto backup_current_top_block = current_top_block;
// calculate width and sign hints
if (type == AST_RANGE) {
int backup_width_hint = width_hint;
bool backup_sign_hint = sign_hint;
bool detect_width_simple = false;
bool child_0_is_self_determined = false;
bool child_1_is_self_determined = false;
bool children_are_self_determined = false;
bool reset_width_after_children = false;
switch (type)
{
case AST_ASSIGN_EQ:
case AST_ASSIGN_LE:
case AST_ASSIGN:
while (children[0]->simplify(false, false, true, stage, -1, false) == true) { }
while (children[1]->simplify(false, false, false, stage, -1, false) == true) { }
children[0]->detectSignWidth(width_hint, backup_sign_hint);
children[1]->detectSignWidth(backup_width_hint, sign_hint);
child_0_is_self_determined = true;
break;
case AST_TO_SIGNED:
case AST_TO_UNSIGNED:
case AST_CONCAT:
case AST_REPLICATE:
case AST_REDUCE_AND:
case AST_REDUCE_OR:
case AST_REDUCE_XOR:
case AST_REDUCE_XNOR:
case AST_REDUCE_BOOL:
detect_width_simple = true;
children_are_self_determined = true;
break;
case AST_NEG:
case AST_BIT_NOT:
case AST_POS:
case AST_BIT_AND:
case AST_BIT_OR:
case AST_BIT_XOR:
case AST_BIT_XNOR:
case AST_ADD:
case AST_SUB:
case AST_MUL:
case AST_DIV:
case AST_MOD:
detect_width_simple = true;
break;
case AST_SHIFT_LEFT:
case AST_SHIFT_RIGHT:
case AST_SHIFT_SLEFT:
case AST_SHIFT_SRIGHT:
case AST_POW:
detect_width_simple = true;
child_1_is_self_determined = true;
break;
case AST_LT:
case AST_LE:
case AST_EQ:
case AST_NE:
case AST_GE:
case AST_GT:
width_hint = -1;
sign_hint = true;
for (auto child : children) {
while (child->simplify(false, false, false, stage, -1, false) == true) { }
child->detectSignWidthWorker(width_hint, sign_hint);
}
reset_width_after_children = true;
break;
case AST_LOGIC_AND:
case AST_LOGIC_OR:
case AST_LOGIC_NOT:
detect_width_simple = true;
children_are_self_determined = true;
break;
case AST_TERNARY:
detect_width_simple = true;
child_0_is_self_determined = true;
break;
case AST_MEMRD:
detect_width_simple = true;
children_are_self_determined = true;
break;
default:
width_hint = -1;
sign_hint = false;
}
if (type == AST_ASSIGN_EQ || type == AST_ASSIGN_LE || type == AST_ASSIGN) {
while (children[0]->simplify(false, at_zero, true, stage, -1, false) == true) { }
children[0]->detectSignWidth(width_hint, sign_hint);
if (detect_width_simple && width_hint < 0) {
for (auto child : children)
while (child->simplify(false, false, in_lvalue, stage, -1, false) == true) { }
if (type == AST_REPLICATE)
while (children[0]->simplify(true, false, in_lvalue, stage, -1, false) == true) { }
detectSignWidth(width_hint, sign_hint);
}
// simplify all children first
@ -211,10 +304,12 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
}
if ((type == AST_ALWAYS || type == AST_INITIAL) && children[i]->type == AST_BLOCK)
current_top_block = children[i];
if (i == 1 && (type == AST_SHIFT_LEFT || type == AST_SHIFT_RIGHT || type == AST_SHIFT_SLEFT || type == AST_SHIFT_SRIGHT)) {
while (children[i]->simplify(false, at_zero, in_lvalue_here, stage, -1, false) == true) { }
children[i]->detectSignWidth(width_hint_here, sign_hint_here);
}
if (i == 0 && child_0_is_self_determined)
width_hint_here = -1, sign_hint_here = false;
if (i == 1 && child_1_is_self_determined)
width_hint_here = -1, sign_hint_here = false;
if (children_are_self_determined)
width_hint_here = -1, sign_hint_here = false;
did_something_here = children[i]->simplify(const_fold_here, at_zero, in_lvalue_here, stage, width_hint_here, sign_hint_here);
if (did_something_here)
did_something = true;
@ -224,6 +319,13 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
while (attr.second->simplify(true, false, false, stage, -1, false)) { }
}
if (reset_width_after_children) {
width_hint = backup_width_hint;
sign_hint = backup_sign_hint;
if (width_hint < 0)
detectSignWidth(width_hint, sign_hint);
}
current_block = backup_current_block;
current_block_child = backup_current_block_child;
current_top_block = backup_current_top_block;
@ -629,6 +731,7 @@ skip_dynamic_range_lvalue_expansion:;
children[0]->type == AST_RANGE && children[0]->children.size() == 1) {
newNode = new AstNode(AST_MEMRD, children[0]->children[0]->clone());
newNode->str = str;
newNode->id2ast = id2ast;
goto apply_newNode;
}