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Diffstat (limited to 'techlibs/common/simlib.v')
| -rw-r--r-- | techlibs/common/simlib.v | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/techlibs/common/simlib.v b/techlibs/common/simlib.v index 2cdddeabb..125b8e013 100644 --- a/techlibs/common/simlib.v +++ b/techlibs/common/simlib.v @@ -997,6 +997,12 @@ endmodule // -------------------------------------------------------- +// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| +//- +//- $div (A, B, Y) +//- +//- Division with truncated result (rounded towards 0). +//- module \$div (A, B, Y); parameter A_SIGNED = 0; @@ -1021,6 +1027,14 @@ endmodule // -------------------------------------------------------- +// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| +//- +//- $mod (A, B, Y) +//- +//- Modulo/remainder of division with truncated result (rounded towards 0). +//- +//- Invariant: $div(A, B) * B + $mod(A, B) == A +//- module \$mod (A, B, Y); parameter A_SIGNED = 0; @@ -1044,6 +1058,83 @@ endgenerate endmodule // -------------------------------------------------------- + +// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| +//- +//- $divfloor (A, B, Y) +//- +//- Division with floored result (rounded towards negative infinity). +//- +module \$divfloor (A, B, Y); + +parameter A_SIGNED = 0; +parameter B_SIGNED = 0; +parameter A_WIDTH = 0; +parameter B_WIDTH = 0; +parameter Y_WIDTH = 0; + +input [A_WIDTH-1:0] A; +input [B_WIDTH-1:0] B; +output [Y_WIDTH-1:0] Y; + +generate + if (A_SIGNED && B_SIGNED) begin:BLOCK1 + localparam WIDTH = + A_WIDTH >= B_WIDTH && A_WIDTH >= Y_WIDTH ? A_WIDTH : + B_WIDTH >= A_WIDTH && B_WIDTH >= Y_WIDTH ? B_WIDTH : Y_WIDTH; + wire [WIDTH:0] A_buf, B_buf, N_buf; + assign A_buf = $signed(A); + assign B_buf = $signed(B); + assign N_buf = (A[A_WIDTH-1] == B[B_WIDTH-1]) || A == 0 ? A_buf : $signed(A_buf - (B[B_WIDTH-1] ? B_buf+1 : B_buf-1)); + assign Y = $signed(N_buf) / $signed(B_buf); + end else begin:BLOCK2 + assign Y = A / B; + end +endgenerate + +endmodule + +// -------------------------------------------------------- + +// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| +//- +//- $modfloor (A, B, Y) +//- +//- Modulo/remainder of division with floored result (rounded towards negative infinity). +//- +//- Invariant: $divfloor(A, B) * B + $modfloor(A, B) == A +//- +module \$modfloor (A, B, Y); + +parameter A_SIGNED = 0; +parameter B_SIGNED = 0; +parameter A_WIDTH = 0; +parameter B_WIDTH = 0; +parameter Y_WIDTH = 0; + +input [A_WIDTH-1:0] A; +input [B_WIDTH-1:0] B; +output [Y_WIDTH-1:0] Y; + +generate + if (A_SIGNED && B_SIGNED) begin:BLOCK1 + localparam WIDTH = B_WIDTH >= Y_WIDTH ? B_WIDTH : Y_WIDTH; + wire [WIDTH-1:0] B_buf, Y_trunc; + assign B_buf = $signed(B); + assign Y_trunc = $signed(A) % $signed(B); + // flooring mod is the same as truncating mod for positive division results (A and B have + // the same sign), as well as when there's no remainder. + // For all other cases, they behave as `floor - trunc = B` + assign Y = (A[A_WIDTH-1] == B[B_WIDTH-1]) || Y_trunc == 0 ? Y_trunc : $signed(B_buf) + $signed(Y_trunc); + end else begin:BLOCK2 + // no difference between truncating and flooring for unsigned + assign Y = A % B; + end +endgenerate + +endmodule + +// -------------------------------------------------------- `ifndef SIMLIB_NOPOW module \$pow (A, B, Y); |