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Preserve byte_extract structure in trace RHS for incremental SMT2 backend #8910

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Preserve byte_extract structure in trace RHS for incremental SMT2 backend #8910

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2 changes: 1 addition & 1 deletion regression/cbmc/trace-values/unbounded_array.desc
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Original file line number Diff line number Diff line change
@@ -1,4 +1,4 @@
CORE broken-smt-backend no-new-smt
CORE broken-smt-backend
unbounded_array.c
--trace
\{ \[0u?l?l?\]=1, \[1u?l?l?\]=2, \[\d+u?l?l?\]=42 \}
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25 changes: 22 additions & 3 deletions src/goto-symex/build_goto_trace.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -392,9 +392,28 @@ void build_goto_trace(

if(SSA_step.ssa_full_lhs.is_not_nil())
{
goto_trace_step.full_lhs_value =
decision_procedure.get(SSA_step.ssa_full_lhs);
simplify(goto_trace_step.full_lhs_value, ns);
if(
SSA_step.ssa_full_lhs.id() == ID_byte_extract_little_endian ||
SSA_step.ssa_full_lhs.id() == ID_byte_extract_big_endian)
{
// Preserve the byte_extract structure by resolving
// operands individually rather than simplifying the
// entire expression, which would evaluate away the
// byte_extract.
byte_extract_exprt be = to_byte_extract_expr(SSA_step.ssa_full_lhs);
be.op() = decision_procedure.get(be.op());
simplify(be.op(), ns);
replace_nondet_in_type(be.op(), decision_procedure);
be.offset() = decision_procedure.get(be.offset());
simplify(be.offset(), ns);
goto_trace_step.full_lhs_value = std::move(be);
}
else
{
goto_trace_step.full_lhs_value =
decision_procedure.get(SSA_step.ssa_full_lhs);
simplify(goto_trace_step.full_lhs_value, ns);
}
replace_nondet_in_type(
goto_trace_step.full_lhs_value, decision_procedure);
}
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