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|
`include "gfx/gfx_defs.sv"
module gfx_perspective
(
input logic clk,
input attr4 clip_attr,
input logic stall,
in_start,
out_start,
output attr4 ndc_attr,
output fp w_inv
);
fp selected_w_inv, next_w_inv, vertex_w_inv, w_inv_pipes[`FP_MUL_STAGES];
vec4 in_pipes[`FP_INV_STAGES], div_q;
assign w_inv = w_inv_pipes[`FP_MUL_STAGES - 1];
assign selected_w_inv = in_start ? next_w_inv : vertex_w_inv;
gfx_fp_inv inv
(
.a(clip_attr.w),
.q(next_w_inv),
.*
);
genvar i;
generate
for (i = 0; i < `FLOATS_PER_VEC; ++i) begin: divs
gfx_fp_mul div
(
.a(in_pipes[`FP_INV_STAGES - 1][i]),
.b(selected_w_inv),
.q(div_q[i]),
.*
);
end
for (i = 1; i < `FP_INV_STAGES; ++i) begin: in
always_ff @(posedge clk)
if (!stall)
in_pipes[i] <= in_pipes[i - 1];
end
for (i = 1; i < `FP_MUL_STAGES; ++i) begin: out
always_ff @(posedge clk)
if (!stall)
w_inv_pipes[i] <= w_inv_pipes[i - 1];
end
endgenerate
always_comb begin
ndc_attr = div_q;
if (out_start)
ndc_attr.w = `FP_UNIT;
end
always_ff @(posedge clk)
if (!stall) begin
if (in_start)
vertex_w_inv <= next_w_inv;
in_pipes[0] <= clip_attr;
w_inv_pipes[0] <= selected_w_inv;
end
endmodule
|
