Github_Repos/cvw
1
0
Fork 1
mirror of https://github.com/openhwgroup/cvw synced 2025-02-11 06:05:49 +00:00
Code Issues Packages Projects Releases Wiki Activity

shifter bug fix

Browse Source 
- roli not passing unless I keep the MSB (instead of inverting) of truncated offset
This commit is contained in:
Kevin Kim 2023-02-17 21:58:26 -08:00
parent 77fc40149f
commit f85c1058ff
1 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/ieu/shifter.sv
View File

@ -36,7 +36,7 @@ module shifter (
output logic [`XLEN-1:0] Y); // Shifted result output logic [`XLEN-1:0] Y); // Shifted result
logic [2*`XLEN-2:0] z, zshift; // Input to funnel shifter, shifted amount before truncated to 32 or 64 bits logic [2*`XLEN-2:0] z, zshift; // Input to funnel shifter, shifted amount before truncated to 32 or 64 bits
logic [`LOG_XLEN-1:0] amttrunc, offset; // Shift amount adjusted for RV64, right-shift amount logic [`LOG_XLEN-1:0] amttrunc, offset, CondOffsetTrunc; // Shift amount adjusted for RV64, right-shift amount
// Handle left and right shifts with a funnel shifter. // Handle left and right shifts with a funnel shifter.
// For RV32, only 32-bit shifts are needed. // For RV32, only 32-bit shifts are needed.
@ -129,9 +129,11 @@ module shifter (
// Opposite offset for right shifts // Opposite offset for right shifts
assign offset = Right ? amttrunc : ~amttrunc; assign offset = Right ? amttrunc : ~amttrunc;
if (`XLEN == 64) assign CondOffsetTrunc = (W64 & Rotate) ? {{1'b0}, offset[4:0]} : offset;
else assign CondOffsetTrunc = offset;
// Funnel operation // Funnel operation
assign zshift = z >> offset; assign zshift = z >> CondOffsetTrunc;
assign Y = zshift[`XLEN-1:0]; assign Y = zshift[`XLEN-1:0];
endmodule endmodule