From f2d030a70f1754e7ee6bd1fb588c5abadac4dd08 Mon Sep 17 00:00:00 2001 From: Eddie Hung Date: Tue, 10 Sep 2019 15:14:55 -0700 Subject: [PATCH] Be sensitive to signedness --- techlibs/common/mul2dsp.v | 41 ++++++++++++++++++++------------------- 1 file changed, 21 insertions(+), 20 deletions(-) diff --git a/techlibs/common/mul2dsp.v b/techlibs/common/mul2dsp.v index 51a6c5fb9..f2b44222e 100644 --- a/techlibs/common/mul2dsp.v +++ b/techlibs/common/mul2dsp.v @@ -153,11 +153,11 @@ module _80_mul (A, B, Y); // to save on a call to 'opt_expr -fine' which would // optimise away the '<<' op and trim size of adder //assign partial_sum[i] = (partial[i] << i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)) + partial_sum[i-1]; - wire [Y_WIDTH-1:0] shifted_sum = {partial[i], {i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom){1'b0}}}; - assign partial_sum[i] = { - partial_sum[i-1][i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)-1:0], - shifted_sum[Y_WIDTH-1:i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)] + partial_sum[i-1][Y_WIDTH-1:i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)] - }; + if (A_SIGNED && B_SIGNED) + assign partial_sum[i][Y_WIDTH-1:i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)] = partial[i] + $signed(partial_sum[i-1][Y_WIDTH-1:i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)]); + else + assign partial_sum[i][Y_WIDTH-1:i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)] = partial[i] + partial_sum[i-1][Y_WIDTH-1:i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)]; + assign partial_sum[i][i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)-1:0] = partial_sum[i-1][i*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)-1:0]; end end @@ -173,11 +173,11 @@ module _80_mul (A, B, Y); .Y(last_partial) ); //assign partial_sum[n] = (last_partial << n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)) + partial_sum[n-1]; - wire [Y_WIDTH-1:0] shifted_sum = {last_partial, {n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom){1'b0}}}; - assign partial_sum[n] = { - partial_sum[n-1][n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)-1:0], - shifted_sum[Y_WIDTH-1:n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)] + partial_sum[n-1][Y_WIDTH-1:n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)] - }; + if (A_SIGNED && B_SIGNED) + assign partial_sum[n][Y_WIDTH-1:n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)] = last_partial + $signed(partial_sum[n-1][Y_WIDTH-1:n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)]); + else + assign partial_sum[n][Y_WIDTH-1:n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)] = last_partial + partial_sum[n-1][Y_WIDTH-1:n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)]; + assign partial_sum[n][n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)-1:0] = partial_sum[n-1][n*(`DSP_A_MAXWIDTH_PARTIAL-sign_headroom)-1:0]; assign Y = partial_sum[n]; end else if (B_WIDTH > `DSP_B_MAXWIDTH) begin @@ -217,11 +217,12 @@ module _80_mul (A, B, Y); // Rewrite the following statement explicitly in order // to save on a call to 'opt_expr -fine' which would // optimise away the '<<' op and trim size of adder - wire [Y_WIDTH-1:0] shifted_sum = {partial[i], {i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom){1'b0}}}; - assign partial_sum[i] = { - partial_sum[i-1][i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)-1:0], - shifted_sum[Y_WIDTH-1:i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)] + partial_sum[i-1][Y_WIDTH-1:i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)] - }; + //assign partial_sum[i] = (partial[i] << i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)) + partial_sum[i-1]; + if (A_SIGNED && B_SIGNED) + assign partial_sum[i][Y_WIDTH-1:i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)] = partial[i] + $signed(partial_sum[i-1][Y_WIDTH-1:i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)]); + else + assign partial_sum[i][Y_WIDTH-1:i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)] = partial[i] + partial_sum[i-1][Y_WIDTH-1:i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)]; + assign partial_sum[i][i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)-1:0] = partial_sum[i-1][i*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)-1:0]; end end @@ -237,11 +238,11 @@ module _80_mul (A, B, Y); .Y(last_partial) ); //assign partial_sum[n] = (last_partial << n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)) + partial_sum[n-1]; - wire [Y_WIDTH-1:0] shifted_sum = {last_partial, {n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom){1'b0}}}; - assign partial_sum[n] = { - partial_sum[n-1][n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)-1:0], - shifted_sum[Y_WIDTH-1:n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)] + partial_sum[n-1][Y_WIDTH-1:n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)] - }; + if (A_SIGNED && B_SIGNED) + assign partial_sum[n][Y_WIDTH-1:n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)] = last_partial + partial_sum[n-1][Y_WIDTH-1:n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)]; + else + assign partial_sum[n][Y_WIDTH-1:n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)] = last_partial + $signed(partial_sum[n-1][Y_WIDTH-1:n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)]); + assign partial_sum[n][n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)-1:0] = partial_sum[n-1][n*(`DSP_B_MAXWIDTH_PARTIAL-sign_headroom)-1:0]; assign Y = partial_sum[n]; end else begin -- 2.30.2