From c1ebe51a75ef8ce47d6b1406fa87b15bd8f97760 Mon Sep 17 00:00:00 2001 From: Eddie Hung Date: Wed, 17 Apr 2019 11:10:20 -0700 Subject: [PATCH] Revert "Try using an ICE40_CARRY_LUT primitive to avoid ABC issues" This reverts commit a7632ab3326c5247b8152a53808413b259c13253. --- techlibs/ice40/arith_map.v | 37 ++++++++++++++--------------------- techlibs/ice40/cells.box | 12 ++++++++---- techlibs/ice40/cells_box.v | 24 +++++++++-------------- techlibs/ice40/cells_map.v | 24 ----------------------- techlibs/ice40/cells_sim.v | 22 --------------------- techlibs/ice40/ice40_opt.cc | 16 ++------------- techlibs/ice40/synth_ice40.cc | 2 +- 7 files changed, 35 insertions(+), 102 deletions(-) diff --git a/techlibs/ice40/arith_map.v b/techlibs/ice40/arith_map.v index eefc375dd..4449fdc1b 100644 --- a/techlibs/ice40/arith_map.v +++ b/techlibs/ice40/arith_map.v @@ -44,32 +44,25 @@ module _80_ice40_alu (A, B, CI, BI, X, Y, CO); genvar i; generate for (i = 0; i < Y_WIDTH; i = i + 1) begin:slice - ICE40_CARRY_LUT carry_lut ( + SB_CARRY carry ( + .I0(AA[i]), + .I1(BB[i]), + .CI(C[i]), + .CO(CO[i]) + ); + SB_LUT4 #( + // I0: 1010 1010 1010 1010 + // I1: 1100 1100 1100 1100 + // I2: 1111 0000 1111 0000 + // I3: 1111 1111 0000 0000 + .LUT_INIT(16'b 0110_1001_1001_0110) + ) adder ( + .I0(1'b0), .I1(AA[i]), .I2(BB[i]), - .CI(C[i]), - .CO(CO[i]), + .I3(C[i]), .O(Y[i]) ); -// SB_CARRY carry ( -// .I0(AA[i]), -// .I1(BB[i]), -// .CI(C[i]), -// .CO(CO[i]) -// ); -// SB_LUT4 #( -// // I0: 1010 1010 1010 1010 -// // I1: 1100 1100 1100 1100 -// // I2: 1111 0000 1111 0000 -// // I3: 1111 1111 0000 0000 -// .LUT_INIT(16'b 0110_1001_1001_0110) -// ) adder ( -// .I0(1'b0), -// .I1(AA[i]), -// .I2(BB[i]), -// .I3(C[i]), -// .O(Y[i]) -// ); end endgenerate assign X = AA ^ BB; diff --git a/techlibs/ice40/cells.box b/techlibs/ice40/cells.box index 34d1f372e..d775efa78 100644 --- a/techlibs/ice40/cells.box +++ b/techlibs/ice40/cells.box @@ -2,8 +2,12 @@ # NB: Inputs/Outputs must be ordered alphabetically -# Inputs: CI I1 I2 -# Outputs: CO O -ICE40_CARRY_LUT 1 1 3 2 +# Inputs: CI I0 I1 +# Outputs: CO +SB_CARRY 1 1 3 1 126 259 231 -316 400 379 + +# Inputs: I0 I1 I2 I3 +# Outputs: O +SB_LUT4 2 1 4 1 +316 379 400 449 diff --git a/techlibs/ice40/cells_box.v b/techlibs/ice40/cells_box.v index d0eb8708c..e2a54a42c 100644 --- a/techlibs/ice40/cells_box.v +++ b/techlibs/ice40/cells_box.v @@ -1,18 +1,12 @@ (* abc_box_id = 1 *) -module ICE40_CARRY_LUT (output CO, O, input CI, I1, I2); - assign CO = (I1 && I2) || ((I1 || I2) && CI); - - wire I0, I3; - assign I0 = 1'b0; - assign I3 = CI; +module SB_CARRY (output CO, input CI, I0, I1); + assign CO = (I0 && I1) || ((I0 || I1) && CI); +endmodule - // I0: 1010 1010 1010 1010 - // I1: 1100 1100 1100 1100 - // I2: 1111 0000 1111 0000 - // I3: 1111 1111 0000 0000 - localparam [15:0] LUT_INIT = 16'b 0110_1001_1001_0110; - wire [7:0] s3 = I3 ? LUT_INIT[15:8] : LUT_INIT[7:0]; - wire [3:0] s2 = I2 ? s3[ 7:4] : s3[3:0]; - wire [1:0] s1 = I1 ? s2[ 3:2] : s2[1:0]; - assign O = I0 ? s1[1] : s1[0]; +(* abc_box_id = 2 *) +module SB_LUT4 (output O, input I0, I1, I2, I3); + parameter [15:0] LUT_INIT = 0; + // Indicate this is a black-box + assign O = 1'b0; endmodule + diff --git a/techlibs/ice40/cells_map.v b/techlibs/ice40/cells_map.v index d4c611686..d0ddfd02e 100644 --- a/techlibs/ice40/cells_map.v +++ b/techlibs/ice40/cells_map.v @@ -57,27 +57,3 @@ module \$lut (A, Y); endgenerate endmodule `endif - -`ifndef NO_CARRY -module ICE40_CARRY_LUT (output CO, O, input CI, I1, I2); - SB_CARRY carry ( - .I0(I1), - .I1(I2), - .CI(CI), - .CO(CO), - ); - SB_LUT4 #( - // I0: 1010 1010 1010 1010 - // I1: 1100 1100 1100 1100 - // I2: 1111 0000 1111 0000 - // I3: 1111 1111 0000 0000 - .LUT_INIT(16'b 0110_1001_1001_0110) - ) adder ( - .I0(1'b0), - .I1(I1), - .I2(I2), - .I3(CI), - .O(O) - ); -endmodule -`endif diff --git a/techlibs/ice40/cells_sim.v b/techlibs/ice40/cells_sim.v index b5a739a63..322c1e5c7 100644 --- a/techlibs/ice40/cells_sim.v +++ b/techlibs/ice40/cells_sim.v @@ -1384,25 +1384,3 @@ module SB_MAC16 ( assign LCI = (BOTADDSUB_CARRYSELECT == 0) ? 1'b0 : (BOTADDSUB_CARRYSELECT == 1) ? 1'b1 : (BOTADDSUB_CARRYSELECT == 2) ? ACCUMCI : CI; assign O = {Oh, Ol}; endmodule - -module ICE40_CARRY_LUT (input CI, input I1, input I2, output CO, output O); - SB_CARRY carry ( - .I0(I1), - .I1(I2), - .CI(CI), - .CO(CO), - ); - SB_LUT4 #( - // I0: 1010 1010 1010 1010 - // I1: 1100 1100 1100 1100 - // I2: 1111 0000 1111 0000 - // I3: 1111 1111 0000 0000 - .LUT_INIT(16'b 0110_1001_1001_0110) - ) adder ( - .I0(1'b0), - .I1(I1), - .I2(I2), - .I3(CI), - .O(O) - ); -endmodule diff --git a/techlibs/ice40/ice40_opt.cc b/techlibs/ice40/ice40_opt.cc index edb293b93..f528607d6 100644 --- a/techlibs/ice40/ice40_opt.cc +++ b/techlibs/ice40/ice40_opt.cc @@ -47,20 +47,16 @@ static void run_ice40_opts(Module *module) continue; } - if (cell->type.in("\\SB_CARRY", "\\ICE40_CARRY_LUT")) + if (cell->type == "\\SB_CARRY") { SigSpec non_const_inputs, replacement_output; int count_zeros = 0, count_ones = 0; SigBit inbit[3] = { + get_bit_or_zero(cell->getPort("\\I0")), get_bit_or_zero(cell->getPort("\\I1")), get_bit_or_zero(cell->getPort("\\CI")) }; - if (cell->type == "\\SB_CARRY") - inbit[2] = get_bit_or_zero(cell->getPort("\\I0")); - else if (cell->type == "\\ICE40_CARRY_LUT") - inbit[2] = get_bit_or_zero(cell->getPort("\\I2")); - else log_abort(); for (int i = 0; i < 3; i++) if (inbit[i].wire == nullptr) { if (inbit[i] == State::S1) @@ -83,14 +79,6 @@ static void run_ice40_opts(Module *module) module->design->scratchpad_set_bool("opt.did_something", true); log("Optimized away SB_CARRY cell %s.%s: CO=%s\n", log_id(module), log_id(cell), log_signal(replacement_output)); - - if (cell->type == "\\ICE40_CARRY_LUT") - module->addLut(NEW_ID, - { RTLIL::S0, cell->getPort("\\I1"), cell->getPort("\\I2"), cell->getPort("\\CI") }, - cell->getPort("\\O"), - RTLIL::Const("0110_1001_1001_0110"), - cell->get_src_attribute()); - module->remove(cell); } continue; diff --git a/techlibs/ice40/synth_ice40.cc b/techlibs/ice40/synth_ice40.cc index d09a1184c..3faa10b4f 100644 --- a/techlibs/ice40/synth_ice40.cc +++ b/techlibs/ice40/synth_ice40.cc @@ -296,7 +296,7 @@ struct SynthIce40Pass : public ScriptPass run("opt_merge"); run(stringf("dff2dffe -unmap-mince %d", min_ce_use)); } - run("techmap -D NO_LUT -D NO_CARRY -map +/ice40/cells_map.v"); + run("techmap -D NO_LUT -map +/ice40/cells_map.v"); run("opt_expr -mux_undef"); run("simplemap"); run("ice40_ffinit"); -- 2.30.2