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Instead of MUXCY/XORCY use CARRY4 (with timing)

This commit is contained in:
Eddie Hung 2019-05-21 16:19:45 -07:00
parent 0f094fba08
commit ee8435b820
4 changed files with 20 additions and 11 deletions
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22
techlibs/xilinx/abc.box
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@ -1,5 +1,4 @@
# Max delays from https://pastebin.com/v2hrcksd # Max delays from https://github.com/SymbiFlow/prjxray-db/blob/34ea6eb08a63d21ec16264ad37a0a7b142ff6031/artix7/timings/CLBLL_L.sdf
# from https://github.com/SymbiFlow/prjxray/pull/706#issuecomment-479380321
# F7BMUX slower than F7AMUX # F7BMUX slower than F7AMUX
# Inputs: I0 I1 S0 # Inputs: I0 I1 S0
@ -12,8 +11,17 @@ F7BMUX 1 1 3 1
MUXF8 2 1 3 1 MUXF8 2 1 3 1
104 94 273 104 94 273
MUXCY 3 1 3 1 # CARRY4 + CARRY4_[ABCD]X
1 1 1 # Inputs: CI CYINIT DI0 DI1 DI2 DI3 S0 S1 S2 S3
# Outputs: CO0 CO1 CO2 CO3 O0 O1 O2 O3
XORCY 4 1 2 1 CARRY4 3 1 10 8
1 1 271 157 228 114 222 334 239 313
536 494 592 580 482 598 584 642
379 465 540 526 - 407 556 615
- 445 520 507 - - 537 596
- - 356 398 - - - 438
- - - 385 - - - -
340 433 512 508 223 400 523 582
- 469 548 528 - 205 558 618
- - 292 376 - - 226 330
- - - 380 - - - 227

4
techlibs/xilinx/arith_map.v
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@ -180,7 +180,7 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
// First one // First one
if (i == 0) begin if (i == 0) begin
CARRY4 #(.IS_INITIALIZED(1'd1)) carry4_1st_part CARRY4 carry4_1st_part
( (
.CYINIT(CI), .CYINIT(CI),
.CI (1'd0), .CI (1'd0),
@ -207,7 +207,7 @@ module _80_xilinx_alu (A, B, CI, BI, X, Y, CO);
// First one // First one
if (i == 0) begin if (i == 0) begin
CARRY4 #(.IS_INITIALIZED(1'd1)) carry4_1st_full CARRY4 carry4_1st_full
( (
.CYINIT(CI), .CYINIT(CI),
.CI (1'd0), .CI (1'd0),

3
techlibs/xilinx/cells_sim.v
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@ -155,7 +155,6 @@ module LUT6_2(output O6, output O5, input I0, I1, I2, I3, I4, I5);
assign O5 = I0 ? s5_1[1] : s5_1[0]; assign O5 = I0 ? s5_1[1] : s5_1[0];
endmodule endmodule
(* abc_box_id = 3, lib_whitebox *)
module MUXCY(output O, input CI, DI, S); module MUXCY(output O, input CI, DI, S);
assign O = S ? CI : DI; assign O = S ? CI : DI;
endmodule endmodule
@ -170,11 +169,11 @@ module MUXF8(output O, input I0, I1, S);
assign O = S ? I1 : I0; assign O = S ? I1 : I0;
endmodule endmodule
(* abc_box_id = 4, lib_whitebox *)
module XORCY(output O, input CI, LI); module XORCY(output O, input CI, LI);
assign O = CI ^ LI; assign O = CI ^ LI;
endmodule endmodule
(* abc_box_id = 3, lib_whitebox *)
module CARRY4(output [3:0] CO, O, input CI, CYINIT, input [3:0] DI, S); module CARRY4(output [3:0] CO, O, input CI, CYINIT, input [3:0] DI, S);
assign O = S ^ {CO[2:0], CI | CYINIT}; assign O = S ^ {CO[2:0], CI | CYINIT};
assign CO[0] = S[0] ? CI | CYINIT : DI[0]; assign CO[0] = S[0] ? CI | CYINIT : DI[0];

2
techlibs/xilinx/synth_xilinx.cc
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@ -261,6 +261,8 @@ struct SynthXilinxPass : public ScriptPass
if (vpr && !nocarry && !help_mode) if (vpr && !nocarry && !help_mode)
run("techmap -map +/xilinx/arith_map.v -D _EXPLICIT_CARRY"); run("techmap -map +/xilinx/arith_map.v -D _EXPLICIT_CARRY");
else if (abc == "abc9" && !nocarry && !help_mode)
run("techmap -map +/xilinx/arith_map.v -D _CLB_CARRY", "(skip if '-nocarry')");
else if (!nocarry || help_mode) else if (!nocarry || help_mode)
run("techmap -map +/xilinx/arith_map.v", "(skip if '-nocarry')"); run("techmap -map +/xilinx/arith_map.v", "(skip if '-nocarry')");