summaryrefslogtreecommitdiff
path: root/frontends
diff options
context:
space:
mode:
authorClifford Wolf <clifford@clifford.at>2013-11-07 18:18:16 +0100
committerClifford Wolf <clifford@clifford.at>2013-11-07 18:18:16 +0100
commit02f4f89fdba402a1fa74f2f88291f7e1a37db0f2 (patch)
treecea20ab261d5561d0be88b4d18de1d86bf5f236f /frontends
parent947bd9b96bb978e204275d6fbbc9ce9ff6eda28c (diff)
Disabled const folding of ternary op when select is undef
Diffstat (limited to 'frontends')
-rw-r--r--frontends/ast/simplify.cc16
1 files changed, 14 insertions, 2 deletions
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 7712023c..7b5ae064 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -1058,8 +1058,20 @@ skip_dynamic_range_lvalue_expansion:;
break;
case AST_TERNARY:
if (children[0]->type == AST_CONSTANT) {
- AstNode *choice = children[children[0]->integer ? 1 : 2];
- if (choice->type == AST_CONSTANT) {
+ bool found_sure_true = false;
+ bool found_maybe_true = false;
+ for (auto &bit : children[0]->bits) {
+ if (bit == RTLIL::State::S1)
+ found_sure_true = true;
+ if (bit > RTLIL::State::S1)
+ found_maybe_true = true;
+ }
+ AstNode *choice = NULL;
+ if (found_sure_true)
+ choice = children[1];
+ else if (!found_maybe_true)
+ choice = children[2];
+ if (choice != NULL && choice->type == AST_CONSTANT) {
RTLIL::Const y = choice->bitsAsConst(width_hint, sign_hint);
newNode = mkconst_bits(y.bits, sign_hint);
}