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	Merge pull request #1355 from YosysHQ/eddie/peepopt_dffmuxext
peepopt_dffmux -- bit optimisations for word level $dff + (enable/reset) $mux cells
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					 6 changed files with 291 additions and 14 deletions
				
			
		|  | @ -985,7 +985,7 @@ void AigerReader::post_process() | |||
| 	// operate (and run checks on) this one module
 | ||||
| 	RTLIL::Design *mapped_design = new RTLIL::Design; | ||||
| 	mapped_design->add(module); | ||||
| 	Pass::call(mapped_design, "clean -purge"); | ||||
| 	Pass::call(mapped_design, "clean"); | ||||
| 	mapped_design->modules_.erase(module->name); | ||||
| 	delete mapped_design; | ||||
| 
 | ||||
|  |  | |||
|  | @ -27,6 +27,7 @@ $(eval $(call add_extra_objs,passes/pmgen/peepopt_pm.h)) | |||
| 
 | ||||
| PEEPOPT_PATTERN  = passes/pmgen/peepopt_shiftmul.pmg | ||||
| PEEPOPT_PATTERN += passes/pmgen/peepopt_muldiv.pmg | ||||
| PEEPOPT_PATTERN += passes/pmgen/peepopt_dffmux.pmg | ||||
| 
 | ||||
| passes/pmgen/peepopt_pm.h: passes/pmgen/pmgen.py $(PEEPOPT_PATTERN) | ||||
| 	$(P) mkdir -p passes/pmgen && python3 $< -o $@ -p peepopt $(filter-out $<,$^) | ||||
|  |  | |||
|  | @ -60,6 +60,7 @@ struct PeepoptPass : public Pass { | |||
| 				peepopt_pm pm(module, module->selected_cells()); | ||||
| 				pm.run_shiftmul(); | ||||
| 				pm.run_muldiv(); | ||||
| 				pm.run_dffmux(); | ||||
| 			} | ||||
| 		} | ||||
| 	} | ||||
|  |  | |||
							
								
								
									
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								passes/pmgen/peepopt_dffmux.pmg
									
										
									
									
									
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								passes/pmgen/peepopt_dffmux.pmg
									
										
									
									
									
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							|  | @ -0,0 +1,113 @@ | |||
| pattern dffmux | ||||
| 
 | ||||
| state <IdString> cemuxAB rstmuxBA | ||||
| state <SigSpec> sigD | ||||
| 
 | ||||
| match dff | ||||
| 	select dff->type == $dff | ||||
| 	select GetSize(port(dff, \D)) > 1 | ||||
| endmatch | ||||
| 
 | ||||
| match rstmux | ||||
| 	select rstmux->type == $mux | ||||
| 	select GetSize(port(rstmux, \Y)) > 1 | ||||
| 	index <SigSpec> port(rstmux, \Y) === port(dff, \D) | ||||
| 	choice <IdString> BA {\B, \A} | ||||
| 	select port(rstmux, BA).is_fully_const() | ||||
| 	set rstmuxBA BA | ||||
| 	optional | ||||
| endmatch | ||||
| 
 | ||||
| code sigD | ||||
| 	if (rstmux) | ||||
| 		sigD = port(rstmux, rstmuxBA == \B ? \A : \B); | ||||
| 	else | ||||
| 		sigD = port(dff, \D); | ||||
| endcode | ||||
| 
 | ||||
| match cemux | ||||
| 	select cemux->type == $mux | ||||
| 	select GetSize(port(cemux, \Y)) > 1 | ||||
| 	index <SigSpec> port(cemux, \Y) === sigD | ||||
| 	choice <IdString> AB {\A, \B} | ||||
| 	index <SigSpec> port(cemux, AB) === port(dff, \Q) | ||||
| 	set cemuxAB AB | ||||
| endmatch | ||||
| 
 | ||||
| code | ||||
| 	SigSpec D = port(cemux, cemuxAB == \A ? \B : \A); | ||||
| 	SigSpec Q = port(dff, \Q); | ||||
| 	Const rst; | ||||
| 	if (rstmux) | ||||
| 		rst = port(rstmux, rstmuxBA).as_const(); | ||||
| 	int width = GetSize(D); | ||||
| 
 | ||||
| 	SigSpec &ceA = cemux->connections_.at(\A); | ||||
| 	SigSpec &ceB = cemux->connections_.at(\B); | ||||
| 	SigSpec &ceY = cemux->connections_.at(\Y); | ||||
| 	SigSpec &dffD = dff->connections_.at(\D); | ||||
| 	SigSpec &dffQ = dff->connections_.at(\Q); | ||||
| 
 | ||||
| 	if (D[width-1] == D[width-2]) { | ||||
| 		did_something = true; | ||||
| 
 | ||||
| 		SigBit sign = D[width-1]; | ||||
| 		bool is_signed = sign.wire; | ||||
| 		int i; | ||||
| 		for (i = width-1; i >= 2; i--) { | ||||
| 			if (!is_signed) { | ||||
| 				module->connect(Q[i], sign); | ||||
| 				if (D[i-1] != sign || (rst.size() && rst[i-1] != rst[width-1])) | ||||
| 					break; | ||||
| 			} | ||||
| 			else { | ||||
| 				module->connect(Q[i], Q[i-1]); | ||||
| 				if (D[i-2] != sign || (rst.size() && rst[i-1] != rst[width-1])) | ||||
| 					break; | ||||
| 			} | ||||
| 		} | ||||
| 
 | ||||
| 		ceA.remove(i, width-i); | ||||
| 		ceB.remove(i, width-i); | ||||
| 		ceY.remove(i, width-i); | ||||
| 		cemux->fixup_parameters(); | ||||
| 		dffD.remove(i, width-i); | ||||
| 		dffQ.remove(i, width-i); | ||||
| 		dff->fixup_parameters(); | ||||
| 
 | ||||
| 		log("dffcemux pattern in %s: dff=%s, cemux=%s; removed top %d bits.\n", log_id(module), log_id(dff), log_id(cemux), width-i); | ||||
| 		accept; | ||||
| 	} | ||||
| 	else { | ||||
| 		int count = 0; | ||||
| 		for (int i = width-1; i >= 0; i--) { | ||||
| 			if (D[i].wire) | ||||
| 				continue; | ||||
| 			Wire *w = Q[i].wire; | ||||
| 			auto it = w->attributes.find(\init); | ||||
| 			State init; | ||||
| 			if (it != w->attributes.end()) | ||||
| 				init = it->second[Q[i].offset]; | ||||
| 			else | ||||
| 				init = State::Sx; | ||||
| 
 | ||||
| 			if (init == State::Sx || init == D[i].data) { | ||||
| 				count++; | ||||
| 				module->connect(Q[i], D[i]); | ||||
| 				ceA.remove(i); | ||||
| 				ceB.remove(i); | ||||
| 				ceY.remove(i); | ||||
| 				dffD.remove(i); | ||||
| 				dffQ.remove(i); | ||||
| 			} | ||||
| 		} | ||||
| 		if (count > 0) { | ||||
| 			did_something = true; | ||||
| 			cemux->fixup_parameters(); | ||||
| 			dff->fixup_parameters(); | ||||
| 			log("dffcemux pattern in %s: dff=%s, cemux=%s; removed %d constant bits.\n", log_id(module), log_id(dff), log_id(cemux), count); | ||||
| 		} | ||||
| 
 | ||||
| 		accept; | ||||
| 	} | ||||
| endcode | ||||
|  | @ -1,13 +0,0 @@ | |||
| module peepopt_shiftmul_0 #(parameter N=3, parameter W=3) (input [N*W-1:0] i, input [$clog2(N)-1:0] s, output [W-1:0] o); | ||||
| assign o = i[s*W+:W]; | ||||
| endmodule | ||||
| 
 | ||||
| module peepopt_shiftmul_1 (output y, input [2:0] w); | ||||
| assign y = 1'b1 >> (w * (3'b110)); | ||||
| endmodule | ||||
| 
 | ||||
| module peepopt_muldiv_0(input [1:0] i, output [1:0] o); | ||||
| wire [3:0] t; | ||||
| assign t = i * 3; | ||||
| assign o = t / 3; | ||||
| endmodule | ||||
							
								
								
									
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								tests/various/peepopt.ys
									
										
									
									
									
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							|  | @ -0,0 +1,175 @@ | |||
| read_verilog <<EOT | ||||
| module peepopt_shiftmul_0 #(parameter N=3, parameter W=3) (input [N*W-1:0] i, input [$clog2(N)-1:0] s, output [W-1:0] o); | ||||
| assign o = i[s*W+:W]; | ||||
| endmodule | ||||
| EOT | ||||
| 
 | ||||
| prep -nokeepdc | ||||
| equiv_opt -assert peepopt | ||||
| design -load postopt | ||||
| clean | ||||
| select -assert-count 1 t:$shiftx | ||||
| select -assert-count 0 t:$shiftx t:* %D | ||||
| 
 | ||||
| #################### | ||||
| 
 | ||||
| design -reset | ||||
| read_verilog <<EOT | ||||
| module peepopt_shiftmul_1 (output [7:0] y, input [2:0] w); | ||||
| assign y = 1'b1 >> (w * (3'b110)); | ||||
| endmodule | ||||
| EOT | ||||
| 
 | ||||
| prep -nokeepdc | ||||
| equiv_opt -assert peepopt | ||||
| design -load postopt | ||||
| clean | ||||
| select -assert-count 1 t:$shr | ||||
| select -assert-count 1 t:$mul | ||||
| select -assert-count 0 t:$shr t:$mul %% t:* %D | ||||
| 
 | ||||
| #################### | ||||
| 
 | ||||
| design -reset | ||||
| read_verilog <<EOT | ||||
| module peepopt_shiftmul_2 (input [11:0] D, input [1:0] S, output [11:0] Y); | ||||
| 	assign Y = D >> (S*3); | ||||
| endmodule | ||||
| EOT | ||||
| 
 | ||||
| prep | ||||
| design -save gold | ||||
| peepopt | ||||
| design -stash gate | ||||
| 
 | ||||
| design -import gold -as gold peepopt_shiftmul_2 | ||||
| design -import gate -as gate peepopt_shiftmul_2 | ||||
| 
 | ||||
| miter -equiv -make_assert -make_outputs -ignore_gold_x -flatten gold gate miter | ||||
| sat -show-public -enable_undef -prove-asserts miter | ||||
| cd gate | ||||
| select -assert-count 1 t:$shr | ||||
| select -assert-count 1 t:$mul | ||||
| select -assert-count 0 t:$shr t:$mul %% t:* %D | ||||
| 
 | ||||
| #################### | ||||
| 
 | ||||
| design -reset | ||||
| read_verilog <<EOT | ||||
| module peepopt_muldiv_0(input [1:0] i, output [1:0] o); | ||||
| wire [3:0] t; | ||||
| assign t = i * 3; | ||||
| assign o = t / 3; | ||||
| endmodule | ||||
| EOT | ||||
| 
 | ||||
| prep -nokeepdc | ||||
| equiv_opt -assert peepopt | ||||
| design -load postopt | ||||
| clean | ||||
| select -assert-count 0 t:* | ||||
| 
 | ||||
| #################### | ||||
| 
 | ||||
| design -reset | ||||
| read_verilog <<EOT | ||||
| module peepopt_dffmuxext_unsigned(input clk, ce, input [1:0] i, output reg [3:0] o); | ||||
|     always @(posedge clk) if (ce) o <= i; | ||||
| endmodule | ||||
| EOT | ||||
| 
 | ||||
| proc | ||||
| equiv_opt -assert peepopt | ||||
| design -load postopt | ||||
| clean | ||||
| select -assert-count 1 t:$dff r:WIDTH=2 %i | ||||
| select -assert-count 1 t:$mux r:WIDTH=2 %i | ||||
| select -assert-count 0 t:$dff t:$mux %% t:* %D | ||||
| 
 | ||||
| #################### | ||||
| 
 | ||||
| design -reset | ||||
| read_verilog <<EOT | ||||
| module peepopt_dffmuxext_signed(input clk, ce, input signed [1:0] i, output reg signed [3:0] o); | ||||
|     always @(posedge clk) if (ce) o <= i; | ||||
| endmodule | ||||
| EOT | ||||
| 
 | ||||
| proc | ||||
| equiv_opt -assert peepopt | ||||
| design -load postopt | ||||
| clean | ||||
| select -assert-count 1 t:$dff r:WIDTH=2 %i | ||||
| select -assert-count 1 t:$mux r:WIDTH=2 %i | ||||
| select -assert-count 0 t:$dff t:$mux %% t:* %D | ||||
| 
 | ||||
| ################### | ||||
| 
 | ||||
| design -reset | ||||
| read_verilog <<EOT | ||||
| module peepopt_dffmuxext_const(input clk, ce, input [1:0] i, output reg [5:0] o); | ||||
|     always @(posedge clk) if (ce) o <= {1'b0, i[1], 2'b1x, i[0], 1'bz}; | ||||
| endmodule | ||||
| EOT | ||||
| 
 | ||||
| proc | ||||
| equiv_opt -assert peepopt | ||||
| design -load postopt | ||||
| select -assert-count 1 t:$dff r:WIDTH=2 %i | ||||
| select -assert-count 1 t:$mux r:WIDTH=2 %i | ||||
| select -assert-count 0 t:$dff t:$mux %% t:* %D | ||||
| 
 | ||||
| ################### | ||||
| 
 | ||||
| design -reset | ||||
| read_verilog <<EOT | ||||
| module peepopt_dffmuxext_const_init(input clk, ce, input [1:0] i, (* init=6'b0x00x1 *) output reg [5:0] o); | ||||
|     always @(posedge clk) if (ce) o <= {1'b0, i[1], 2'b1x, i[0], 1'bz}; | ||||
| endmodule | ||||
| EOT | ||||
| 
 | ||||
| proc | ||||
| equiv_opt -assert peepopt | ||||
| design -load postopt | ||||
| select -assert-count 1 t:$dff r:WIDTH=5 %i | ||||
| select -assert-count 1 t:$mux r:WIDTH=5 %i | ||||
| select -assert-count 0 t:$dff t:$mux %% t:* %D | ||||
| 
 | ||||
| #################### | ||||
| 
 | ||||
| design -reset | ||||
| read_verilog <<EOT | ||||
| module peepopt_dffmuxext_unsigned_rst(input clk, ce, rst, input [1:0] i, output reg [3:0] o); | ||||
|     always @(posedge clk) if (rst) o <= 0; else if (ce) o <= i; | ||||
| endmodule | ||||
| EOT | ||||
| 
 | ||||
| proc | ||||
| equiv_opt -assert peepopt | ||||
| design -load postopt | ||||
| wreduce | ||||
| select -assert-count 1 t:$dff r:WIDTH=2 %i | ||||
| select -assert-count 2 t:$mux | ||||
| select -assert-count 2 t:$mux r:WIDTH=2 %i | ||||
| select -assert-count 0 t:$dff t:$mux %% t:* %D | ||||
| 
 | ||||
| #################### | ||||
| 
 | ||||
| design -reset | ||||
| read_verilog <<EOT | ||||
| module peepopt_dffmuxext_signed_rst(input clk, ce, rstn, input signed [1:0] i, output reg signed [3:0] o); | ||||
|     always @(posedge clk) begin | ||||
|         if (ce) o <= i; | ||||
|         if (!rstn) o <= 4'b1111; | ||||
|     end | ||||
| endmodule | ||||
| EOT | ||||
| 
 | ||||
| proc | ||||
| equiv_opt -assert peepopt | ||||
| design -load postopt | ||||
| wreduce | ||||
| select -assert-count 1 t:$dff r:WIDTH=2 %i | ||||
| select -assert-count 2 t:$mux | ||||
| select -assert-count 2 t:$mux r:WIDTH=2 %i | ||||
| select -assert-count 0 t:$logic_not t:$dff t:$mux %% t:* %D | ||||
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