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author | Kazuki Sakamoto <sakamoto@splhack.org> | 2020-06-14 15:15:59 -0700 |
---|---|---|
committer | Kazuki Sakamoto <sakamoto@splhack.org> | 2020-06-19 17:39:20 -0700 |
commit | 185bbbe681d02874796e70a1ee147f4b8dca6cbb (patch) | |
tree | 31ad1e634e09fdd40776a8c44a407d2b6d416f69 /frontends/ast | |
parent | 338ecbe02f8bb3cc4d69de1445c7f398a814b4e4 (diff) | |
download | yosys-185bbbe681d02874796e70a1ee147f4b8dca6cbb.tar.gz yosys-185bbbe681d02874796e70a1ee147f4b8dca6cbb.tar.bz2 yosys-185bbbe681d02874796e70a1ee147f4b8dca6cbb.zip |
static cast: support changing size and signedness
Support SystemVerilog Static Cast
- size
- signedness
- (type is not supposted yet)
Fix #535
Diffstat (limited to 'frontends/ast')
-rw-r--r-- | frontends/ast/ast.cc | 1 | ||||
-rw-r--r-- | frontends/ast/ast.h | 1 | ||||
-rw-r--r-- | frontends/ast/genrtlil.cc | 24 | ||||
-rw-r--r-- | frontends/ast/simplify.cc | 1 |
4 files changed, 27 insertions, 0 deletions
diff --git a/frontends/ast/ast.cc b/frontends/ast/ast.cc index 03fd272da..9520ae32c 100644 --- a/frontends/ast/ast.cc +++ b/frontends/ast/ast.cc @@ -95,6 +95,7 @@ std::string AST::type2str(AstNodeType type) X(AST_TO_SIGNED) X(AST_TO_UNSIGNED) X(AST_SELFSZ) + X(AST_CAST_SIZE) X(AST_CONCAT) X(AST_REPLICATE) X(AST_BIT_NOT) diff --git a/frontends/ast/ast.h b/frontends/ast/ast.h index 46864a4e1..9a5aa15f9 100644 --- a/frontends/ast/ast.h +++ b/frontends/ast/ast.h @@ -76,6 +76,7 @@ namespace AST AST_TO_SIGNED, AST_TO_UNSIGNED, AST_SELFSZ, + AST_CAST_SIZE, AST_CONCAT, AST_REPLICATE, AST_BIT_NOT, diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc index 9546558aa..e878d0dd2 100644 --- a/frontends/ast/genrtlil.cc +++ b/frontends/ast/genrtlil.cc @@ -814,6 +814,16 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun children.at(0)->detectSignWidthWorker(sub_width_hint, sign_hint); break; + case AST_CAST_SIZE: + while (children.at(0)->simplify(true, false, false, 1, -1, false, false)) { } + if (children.at(0)->type != AST_CONSTANT) + log_file_error(filename, location.first_line, "Static cast with non constant expression!\n"); + children.at(1)->detectSignWidthWorker(width_hint, sign_hint); + width_hint = children.at(0)->bitsAsConst().as_int(); + if (width_hint <= 0) + log_file_error(filename, location.first_line, "Static cast with zero or negative size!\n"); + break; + case AST_CONCAT: for (auto child : children) { sub_width_hint = 0; @@ -1289,6 +1299,20 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint) return sig; } + // changing the size of signal can be done directly using RTLIL::SigSpec + case AST_CAST_SIZE: { + RTLIL::SigSpec size = children[0]->genRTLIL(); + RTLIL::SigSpec sig = children[1]->genRTLIL(); + if (!size.is_fully_const()) + log_file_error(filename, location.first_line, "Static cast with non constant expression!\n"); + int width = size.as_int(); + if (width <= 0) + log_file_error(filename, location.first_line, "Static cast with zero or negative size!\n"); + sig.extend_u0(width, sign_hint); + is_signed = sign_hint; + return sig; + } + // concatenation of signals can be done directly using RTLIL::SigSpec case AST_CONCAT: { RTLIL::SigSpec sig; diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc index 5f026dfed..1d5dd91a7 100644 --- a/frontends/ast/simplify.cc +++ b/frontends/ast/simplify.cc @@ -950,6 +950,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage, case AST_TO_SIGNED: case AST_TO_UNSIGNED: case AST_SELFSZ: + case AST_CAST_SIZE: case AST_CONCAT: case AST_REPLICATE: case AST_REDUCE_AND: |