diff options
Diffstat (limited to 'frontends/ast/simplify.cc')
| -rw-r--r-- | frontends/ast/simplify.cc | 62 |
1 files changed, 52 insertions, 10 deletions
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc index 252219094..e6200d663 100644 --- a/frontends/ast/simplify.cc +++ b/frontends/ast/simplify.cc @@ -608,6 +608,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage, case AST_TO_BITS: case AST_TO_SIGNED: case AST_TO_UNSIGNED: + case AST_SELFSZ: case AST_CONCAT: case AST_REPLICATE: case AST_REDUCE_AND: @@ -1788,7 +1789,18 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage, result_width = abs(int(left_at_zero_ast->integer - right_at_zero_ast->integer)) + 1; } - if (0) + bool use_case_method = false; + + if (children[0]->id2ast->attributes.count(ID::nowrshmsk)) { + AstNode *node = children[0]->id2ast->attributes.at(ID::nowrshmsk); + while (node->simplify(true, false, false, stage, -1, false, false)) { } + if (node->type != AST_CONSTANT) + log_file_error(filename, location.first_line, "Non-constant value for `nowrshmsk' attribute on `%s'!\n", children[0]->id2ast->str.c_str()); + if (node->asAttrConst().as_bool()) + use_case_method = true; + } + + if (use_case_method) { // big case block @@ -1796,10 +1808,10 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage, newNode = new AstNode(AST_CASE, shift_expr); for (int i = 0; i < source_width; i++) { int start_bit = children[0]->id2ast->range_right + i; + int end_bit = std::min(start_bit+result_width,source_width) - 1; AstNode *cond = new AstNode(AST_COND, mkconst_int(start_bit, true)); AstNode *lvalue = children[0]->clone(); lvalue->delete_children(); - int end_bit = std::min(start_bit+result_width,source_width) - 1; lvalue->children.push_back(new AstNode(AST_RANGE, mkconst_int(end_bit, true), mkconst_int(start_bit, true))); cond->children.push_back(new AstNode(AST_BLOCK, new AstNode(type, lvalue, children[1]->clone()))); @@ -1846,11 +1858,40 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage, AstNode *shamt = shift_expr; - newNode->children.push_back(new AstNode(AST_ASSIGN_EQ, ref_mask->clone(), - new AstNode(AST_SHIFT_LEFT, mkconst_bits(std::vector<RTLIL::State>(result_width, State::S1), false), shamt->clone()))); - newNode->children.push_back(new AstNode(AST_ASSIGN_EQ, ref_data->clone(), - new AstNode(AST_SHIFT_LEFT, new AstNode(AST_BIT_AND, mkconst_bits(std::vector<RTLIL::State>(result_width, State::S1), false), children[1]->clone()), shamt))); - newNode->children.push_back(new AstNode(type, lvalue, new AstNode(AST_BIT_OR, new AstNode(AST_BIT_AND, old_data, new AstNode(AST_BIT_NOT, ref_mask)), ref_data))); + int shamt_width_hint = 0; + bool shamt_sign_hint = true; + shamt->detectSignWidth(shamt_width_hint, shamt_sign_hint); + + int start_bit = children[0]->id2ast->range_right; + bool use_shift = shamt_sign_hint; + + if (start_bit != 0) { + shamt = new AstNode(AST_SUB, shamt, mkconst_int(start_bit, true)); + use_shift = true; + } + + AstNode *t; + + t = mkconst_bits(std::vector<RTLIL::State>(result_width, State::S1), false); + if (use_shift) + t = new AstNode(AST_SHIFT, t, new AstNode(AST_NEG, shamt->clone())); + else + t = new AstNode(AST_SHIFT_LEFT, t, shamt->clone()); + t = new AstNode(AST_ASSIGN_EQ, ref_mask->clone(), t); + newNode->children.push_back(t); + + t = new AstNode(AST_BIT_AND, mkconst_bits(std::vector<RTLIL::State>(result_width, State::S1), false), children[1]->clone()); + if (use_shift) + t = new AstNode(AST_SHIFT, t, new AstNode(AST_NEG, shamt)); + else + t = new AstNode(AST_SHIFT_LEFT, t, shamt); + t = new AstNode(AST_ASSIGN_EQ, ref_data->clone(), t); + newNode->children.push_back(t); + + t = new AstNode(AST_BIT_AND, old_data, new AstNode(AST_BIT_NOT, ref_mask)); + t = new AstNode(AST_BIT_OR, t, ref_data); + t = new AstNode(type, lvalue, t); + newNode->children.push_back(t); } goto apply_newNode; @@ -3026,6 +3067,7 @@ replace_fcall_later:; } } break; + if (0) { case AST_SELFSZ: const_func = RTLIL::const_pos; } if (0) { case AST_POS: const_func = RTLIL::const_pos; } if (0) { case AST_NEG: const_func = RTLIL::const_neg; } if (children[0]->type == AST_CONSTANT) { @@ -3034,10 +3076,10 @@ replace_fcall_later:; } else if (children[0]->isConst()) { newNode = new AstNode(AST_REALVALUE); - if (type == AST_POS) - newNode->realvalue = +children[0]->asReal(sign_hint); - else + if (type == AST_NEG) newNode->realvalue = -children[0]->asReal(sign_hint); + else + newNode->realvalue = +children[0]->asReal(sign_hint); } break; case AST_TERNARY: |