Added IDIV_ON_FPU flag to control whether integer division uses FPU

pipelined/config/buildroot/wally-config.vh

@@ -72,6 +72,7 @@
 // Integer Divider Configuration
 // DIV_BITSPERCYCLE must be 1, 2, or 4
 `define DIV_BITSPERCYCLE 4
+`define IDIV_ON_FPU 0
 
 // Legal number of PMP entries are 0, 16, or 64
 `define PMP_ENTRIES 16

pipelined/config/fpga/wally-config.vh

@@ -74,6 +74,7 @@
 // Integer Divider Configuration
 // DIV_BITSPERCYCLE must be 1, 2, or 4
 `define DIV_BITSPERCYCLE 4
+`define IDIV_ON_FPU 0
 
 // Legal number of PMP entries are 0, 16, or 64
 `define PMP_ENTRIES 64

pipelined/config/rv32e/wally-config.vh

@@ -73,6 +73,7 @@
 // Integer Divider Configuration
 // DIV_BITSPERCYCLE must be 1, 2, or 4
 `define DIV_BITSPERCYCLE 1
+`define IDIV_ON_FPU 0
 
 // Legal number of PMP entries are 0, 16, or 64
 `define PMP_ENTRIES 0

pipelined/config/rv32gc/wally-config.vh

@@ -72,6 +72,7 @@
 // Integer Divider Configuration
 // DIV_BITSPERCYCLE must be 1, 2, or 4
 `define DIV_BITSPERCYCLE 4
+`define IDIV_ON_FPU 0
 
 // Legal number of PMP entries are 0, 16, or 64
 `define PMP_ENTRIES 64

pipelined/config/rv32i/wally-config.vh

@@ -73,6 +73,7 @@
 // Integer Divider Configuration
 // DIV_BITSPERCYCLE must be 1, 2, or 4
 `define DIV_BITSPERCYCLE 4
+`define IDIV_ON_FPU 0
 
 // Legal number of PMP entries are 0, 16, or 64
 `define PMP_ENTRIES 64

pipelined/config/rv32ic/wally-config.vh

@@ -72,6 +72,7 @@
 // Integer Divider Configuration
 // DIV_BITSPERCYCLE must be 1, 2, or 4
 `define DIV_BITSPERCYCLE 4
+`define IDIV_ON_FPU 0
 
 // Legal number of PMP entries are 0, 16, or 64
 `define PMP_ENTRIES 0

pipelined/config/rv64BP/wally-config.vh

@@ -76,6 +76,7 @@
 // Integer Divider Configuration
 // DIV_BITSPERCYCLE must be 1, 2, or 4
 `define DIV_BITSPERCYCLE 4
+`define IDIV_ON_FPU 0
 
 // Address space
 `define RESET_VECTOR 64'h0000000000001000

pipelined/config/rv64fpquad/wally-config.vh

@@ -74,6 +74,7 @@
 // Integer Divider Configuration
 // DIV_BITSPERCYCLE must be 1, 2, or 4
 `define DIV_BITSPERCYCLE 4
+`define IDIV_ON_FPU 0
 
 // Legal number of PMP entries are 0, 16, or 64
 `define PMP_ENTRIES 64

pipelined/config/rv64gc/wally-config.vh

@@ -74,6 +74,7 @@
 // Integer Divider Configuration
 // DIV_BITSPERCYCLE must be 1, 2, or 4
 `define DIV_BITSPERCYCLE 4
+`define IDIV_ON_FPU 0
 
 // Legal number of PMP entries are 0, 16, or 64
 `define PMP_ENTRIES 64

pipelined/config/rv64i/wally-config.vh

@@ -74,6 +74,7 @@
 // Integer Divider Configuration
 // DIV_BITSPERCYCLE must be 1, 2, or 4
 `define DIV_BITSPERCYCLE 4
+`define IDIV_ON_FPU 0
 
 // Legal number of PMP entries are 0, 16, or 64
 `define PMP_ENTRIES 0

pipelined/src/ieu/datapath.sv

@@ -126,7 +126,11 @@ module datapath (
   if (`F_SUPPORTED) begin:fpmux
     mux2  #(`XLEN)  resultmuxM(IEUResultM, FIntResM, FWriteIntM, IFResultM);
     mux2  #(`XLEN)  cvtresultmuxW(IFResultW, FCvtIntResW, FCvtIntW, IFCvtResultW);
-    mux2  #(`XLEN)  divresultmuxW(MDUResultW, FPIntDivResultW, DivW, MulDivResultW);
+    if (`IDIV_ON_FPU) begin
+      mux2  #(`XLEN)  divresultmuxW(MDUResultW, FPIntDivResultW, DivW, MulDivResultW);
+    end else begin 
+      assign MulDivResultW = MDUResultW;
+    end
   end else begin:fpmux
     assign IFResultM = IEUResultM; assign IFCvtResultW = IFResultW;
     assign MulDivResultW = MDUResultW;

pipelined/src/muldiv/muldiv.sv

@@ -60,7 +60,7 @@ module muldiv (
 	// Divide
 	// Start a divide when a new division instruction is received and the divider isn't already busy or finishing
 	// When F extensions are supported, use the FPU divider instead
-	if (`F_SUPPORTED) begin  
+	if (`IDIV_ON_FPU) begin  
 	  assign QuotM = 0;
 	  assign RemM = 0;
 	  assign DivBusyE = 0;