ast: fixes #1710; do not generate RTLIL for unreachable ternary

This commit is contained in:
Eddie Hung 2020-02-27 16:55:55 -08:00
parent 825b96fdcf
commit 5bba9c3640
2 changed files with 52 additions and 9 deletions

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@ -1338,18 +1338,31 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
detectSignWidth(width_hint, sign_hint);
RTLIL::SigSpec cond = children[0]->genRTLIL();
RTLIL::SigSpec val1 = children[1]->genRTLIL(width_hint, sign_hint);
RTLIL::SigSpec val2 = children[2]->genRTLIL(width_hint, sign_hint);
RTLIL::SigSpec sig;
if (cond.is_fully_const()) {
if (cond.as_bool()) {
sig = children[1]->genRTLIL(width_hint, sign_hint);
widthExtend(this, sig, sig.size(), children[1]->is_signed);
}
else {
sig = children[2]->genRTLIL(width_hint, sign_hint);
widthExtend(this, sig, sig.size(), children[2]->is_signed);
}
}
else {
RTLIL::SigSpec val1 = children[1]->genRTLIL(width_hint, sign_hint);
RTLIL::SigSpec val2 = children[2]->genRTLIL(width_hint, sign_hint);
if (cond.size() > 1)
cond = uniop2rtlil(this, "$reduce_bool", 1, cond, false);
if (cond.size() > 1)
cond = uniop2rtlil(this, "$reduce_bool", 1, cond, false);
int width = max(val1.size(), val2.size());
is_signed = children[1]->is_signed && children[2]->is_signed;
widthExtend(this, val1, width, is_signed);
widthExtend(this, val2, width, is_signed);
int width = max(val1.size(), val2.size());
is_signed = children[1]->is_signed && children[2]->is_signed;
widthExtend(this, val1, width, is_signed);
widthExtend(this, val2, width, is_signed);
RTLIL::SigSpec sig = mux2rtlil(this, cond, val1, val2);
sig = mux2rtlil(this, cond, val1, val2);
}
if (sig.size() < width_hint)
sig.extend_u0(width_hint, sign_hint);

30
tests/various/bug1710.ys Normal file
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@ -0,0 +1,30 @@
logger -werror "out of bounds"
read_verilog <<EOT
module Example;
parameter FLAG = 1;
wire [3:0] inp;
reg out1;
initial out1 = FLAG ? &inp[2:0] : &inp[4:0];
reg out2;
initial
if (FLAG)
out2 = &inp[2:0];
else
out2 = &inp[4:0];
wire out3;
assign out3 = FLAG ? &inp[2:0] : &inp[4:0];
wire out4;
generate
if (FLAG)
assign out4 = &inp[2:0];
else
assign out4 = &inp[4:0];
endgenerate
endmodule
EOT