diff options
Diffstat (limited to 'techlibs/common/cmp2lcu.v')
| -rw-r--r-- | techlibs/common/cmp2lcu.v | 29 |
1 files changed, 13 insertions, 16 deletions
diff --git a/techlibs/common/cmp2lcu.v b/techlibs/common/cmp2lcu.v index a221727e7..4e62039e9 100644 --- a/techlibs/common/cmp2lcu.v +++ b/techlibs/common/cmp2lcu.v @@ -41,10 +41,7 @@ generate wire [WIDTH-1:0] BB = {{(WIDTH-B_WIDTH){B_SIGNED ? B[B_WIDTH-1] : 1'b0}}, B}; // For $ge operation, start with the assumption that A and B are // equal (propagating this equality if A and B turn out to be so) - if (_TECHMAP_CELLTYPE_ == "$ge") - localparam CI = 1'b1; - else - localparam CI = 1'b0; + localparam CI = _TECHMAP_CELLTYPE_ == "$ge"; $__CMP2LCU #(.AB_WIDTH(WIDTH), .AB_SIGNED(A_SIGNED && B_SIGNED), .LCU_WIDTH(1), .BUDGET(`LUT_WIDTH), .CI(CI)) _TECHMAP_REPLACE_ (.A(AA), .B(BB), .P(1'b1), .G(1'b0), .Y(Y)); end @@ -81,12 +78,12 @@ generate assign Y = CO[LCU_WIDTH-1]; end else begin - if (_TECHMAP_CONSTMSK_A_[AB_WIDTH-1:0] && _TECHMAP_CONSTMSK_B_[AB_WIDTH-1:0]) - localparam COST = 0; - else if (_TECHMAP_CONSTMSK_A_[AB_WIDTH-1:0] || _TECHMAP_CONSTMSK_B_[AB_WIDTH-1:0]) - localparam COST = 1; - else - localparam COST = 2; + localparam COST = + _TECHMAP_CONSTMSK_A_[AB_WIDTH-1:0] && _TECHMAP_CONSTMSK_B_[AB_WIDTH-1:0] + ? 0 + : (_TECHMAP_CONSTMSK_A_[AB_WIDTH-1:0] || _TECHMAP_CONSTMSK_B_[AB_WIDTH-1:0] + ? 1 + : 2); if (BUDGET < COST) $__CMP2LCU #(.AB_WIDTH(AB_WIDTH), .AB_SIGNED(AB_SIGNED), .LCU_WIDTH(LCU_WIDTH+1), .BUDGET(`LUT_WIDTH), .CI(CI)) @@ -104,21 +101,21 @@ generate // from MSB down, deferring to less significant bits if the // MSBs are equal assign GG = P[0] & (A[AB_WIDTH-1] & ~B[AB_WIDTH-1]); + (* force_downto *) + wire [LCU_WIDTH-1:0] P_, G_; if (LCU_WIDTH == 1) begin // Propagate only if all pairs are equal // (inconclusive evidence to say A >= B) - wire P_ = P[0] & PP; + assign P_ = P[0] & PP; // Generate if any comparisons call for it - wire G_ = G[0] | GG; + assign G_ = G[0] | GG; end else begin // Propagate only if all pairs are equal // (inconclusive evidence to say A >= B) - (* force_downto *) - wire [LCU_WIDTH-1:0] P_ = {P[LCU_WIDTH-1:1], P[0] & PP}; + assign P_ = {P[LCU_WIDTH-1:1], P[0] & PP}; // Generate if any comparisons call for it - (* force_downto *) - wire [LCU_WIDTH-1:0] G_ = {G[LCU_WIDTH-1:1], G[0] | GG}; + assign G_ = {G[LCU_WIDTH-1:1], G[0] | GG}; end if (AB_WIDTH == 1) $__CMP2LCU #(.AB_WIDTH(AB_WIDTH-1), .AB_SIGNED(1'b0), .LCU_WIDTH(LCU_WIDTH), .BUDGET(BUDGET-COST), .CI(CI)) |