Fix error on wide numbers that represent shifts, bug1088.

This commit is contained in:
Wilson Snyder 2016-09-14 20:27:20 -04:00
parent 7d8c51181d
commit 2117fe414e
5 changed files with 54 additions and 4 deletions

View File

@ -12,7 +12,7 @@ indicates the contributor was also the author of the fix; Thanks!
**** Fix SystemC compiles with VPI, bug1081. [Arthur Kahlich]
**** Fix error on wide numbers that represent msb/lsb or shifts, msg1991. [Mandy Xu]
**** Fix error on wide numbers that represent shifts, msg1991, bug1088. [Mandy Xu]
**** Improve Verilation performance on internal strings, msg1975. [Johan Bjork]

View File

@ -263,6 +263,11 @@ private:
// Shifts of > 32/64 bits in C++ will wrap-around and generate non-0s
if (!nodep->user2SetOnce()) {
UINFO(4," ShiftFix "<<nodep<<endl);
AstConst* shiftp = nodep->rhsp()->castConst();
if (shiftp && shiftp->num().mostSetBitP1() > 32) {
shiftp->v3error("Unsupported: Shifting of by over 32-bit number isn't supported."
<<" (This isn't a shift of 32 bits, but a shift of 2^32, or 4 billion!)\n");
}
if (nodep->widthMin()<=64 // Else we'll use large operators which work right
// C operator's width must be < maximum shift which is based on Verilog width
&& nodep->width() < (1LL<<nodep->rhsp()->widthMin())) {

View File

@ -2632,9 +2632,6 @@ private:
AstNode* shiftp = nodep->rhsp();
nodep->rhsp()->replaceWith(new AstConst(shiftp->fileline(), num));
shiftp->deleteTree(); VL_DANGLING(shiftp);
} else if (!m_paramsOnly) {
nodep->rhsp()->v3error("Unsupported: Shifting of by over 32-bit number isn't supported."
<<" (This isn't a shift of 32 bits, but a shift of 2^32, or 4 billion!)\n");
}
}
}

18
test_regress/t/t_param_shift.pl Executable file
View File

@ -0,0 +1,18 @@
#!/usr/bin/perl
if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
# DESCRIPTION: Verilator: Verilog Test driver/expect definition
#
# Copyright 2003 by Wilson Snyder. This program is free software; you can
# redistribute it and/or modify it under the terms of either the GNU
# Lesser General Public License Version 3 or the Perl Artistic License
# Version 2.0.
compile (
);
execute (
check_finished=>1,
);
ok(1);
1;

View File

@ -0,0 +1,30 @@
// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed into the Public Domain, for any use,
// without warranty, 2016 by Mandy Xu.
module t
#(parameter[95:0] P = 1)
(input clk);
localparam [32:0] M = 4;
function [M:0] gen_matrix;
gen_matrix[0] = 1>> M;
endfunction
reg [95: 0] lfsr = 0;
always @(posedge clk) begin
lfsr <= (1 >> P);
end
wire [95: 0] lfsr_w = 1 >> P;
localparam [95: 0] lfsr_p = 1 >> P;
initial begin
$write("*-* All Finished *-*\n");
$finish;
end
endmodule