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| author | Clifford Wolf <clifford@clifford.at> | 2014-08-18 00:02:30 +0200 |
|---|---|---|
| committer | Clifford Wolf <clifford@clifford.at> | 2014-08-18 00:02:30 +0200 |
| commit | acb435b6cf583b6c18f405a9c92566c4e9fb85e5 (patch) | |
| tree | 8d301c4a63ee0e54f99e54aaa265f930ef057b3f /frontends/ast/simplify.cc | |
| parent | aa7a3ed83f0972bd6da3b272e7bbc9efb1409067 (diff) | |
| download | yosys-acb435b6cf583b6c18f405a9c92566c4e9fb85e5.tar.gz yosys-acb435b6cf583b6c18f405a9c92566c4e9fb85e5.tar.bz2 yosys-acb435b6cf583b6c18f405a9c92566c4e9fb85e5.zip | |
Added const folding of AST_CASE to AST simplifier
Diffstat (limited to 'frontends/ast/simplify.cc')
| -rw-r--r-- | frontends/ast/simplify.cc | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc index 76d1f8270..85671213d 100644 --- a/frontends/ast/simplify.cc +++ b/frontends/ast/simplify.cc @@ -1567,7 +1567,7 @@ skip_dynamic_range_lvalue_expansion:; } // perform const folding when activated - if (const_fold && newNode == NULL) + if (const_fold) { bool string_op; std::vector<RTLIL::State> tmp_bits; @@ -1746,6 +1746,37 @@ skip_dynamic_range_lvalue_expansion:; newNode->realvalue = -children[0]->asReal(sign_hint); } break; + case AST_CASE: + if (children[0]->type == AST_CONSTANT && children[0]->bits_only_01()) { + std::vector<AstNode*> new_children; + new_children.push_back(children[0]); + for (int i = 1; i < SIZE(children); i++) { + AstNode *child = children[i]; + log_assert(child->type == AST_COND); + for (auto v : child->children) { + if (v->type == AST_DEFAULT) + goto keep_const_cond; + if (v->type == AST_BLOCK) + continue; + if (v->type == AST_CONSTANT && v->bits_only_01()) { + if (v->bits == children[0]->bits) { + while (i+1 < SIZE(children)) + delete children[++i]; + goto keep_const_cond; + } + continue; + } + goto keep_const_cond; + } + if (0) + keep_const_cond: + new_children.push_back(child); + else + delete child; + } + new_children.swap(children); + } + break; case AST_TERNARY: if (children[0]->isConst()) { |