Issues openhwgroup#726 and openhwgroup#729 correction.

Signed-off-by: Pascal Gouedo <[email protected]>
pascalgouedo · Aug 16, 2023 · fcaaf84 · fcaaf84
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commit fcaaf84
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/rtl/vendor/pulp_platform_fpnew/src/fpnew_fma.sv b/rtl/vendor/pulp_platform_fpnew/src/fpnew_fma.sv
@@ -613,7 +613,12 @@ module fpnew_fma #(
   );
 
   // Classification after rounding
-  assign uf_after_round = rounded_abs[EXP_BITS+MAN_BITS-1:MAN_BITS] == '0; // exponent = 0
+  assign uf_after_round = (rounded_abs[EXP_BITS+MAN_BITS-1:MAN_BITS] == '0) // denormal
+                          || ((pre_round_abs[EXP_BITS+MAN_BITS-1:MAN_BITS] == '0)
+                              && (rounded_abs[EXP_BITS+MAN_BITS-1:MAN_BITS] == 1)
+                              && ((round_sticky_bits != 2'b11)
+                                  || (!sum_sticky_bits[MAN_BITS*2 + 4]
+                                      && ((rnd_mode_i == fpnew_pkg::RNE) || (rnd_mode_i == fpnew_pkg::RMM)))));
   assign of_after_round = rounded_abs[EXP_BITS+MAN_BITS-1:MAN_BITS] == '1; // exponent all ones
 
   // -----------------

diff --git a/rtl/vendor/pulp_platform_fpnew/src/fpnew_fma_multi.sv b/rtl/vendor/pulp_platform_fpnew/src/fpnew_fma_multi.sv
@@ -746,7 +746,13 @@ module fpnew_fma_multi #(
     if (FpFmtConfig[fmt]) begin : active_format
       always_comb begin : post_process
         // detect of / uf
-        fmt_uf_after_round[fmt] = rounded_abs[EXP_BITS+MAN_BITS-1:MAN_BITS] == '0; // denormal
+        fmt_uf_after_round[fmt] = (rounded_abs[EXP_BITS+MAN_BITS-1:MAN_BITS] == '0) // denormal
+                                  || ((pre_round_abs[EXP_BITS+MAN_BITS-1:MAN_BITS] == '0)
+                                      && (rounded_abs[EXP_BITS+MAN_BITS-1:MAN_BITS] == 1)
+                                      && ((round_sticky_bits != 2'b11)
+                                          || (!sum_sticky_bits[MAN_BITS*2 + 4]
+                                              && ((rnd_mode_i == fpnew_pkg::RNE)
+                                                  || (rnd_mode_i == fpnew_pkg::RMM)))));
         fmt_of_after_round[fmt] = rounded_abs[EXP_BITS+MAN_BITS-1:MAN_BITS] == '1; // inf exp.
 
         // Assemble regular result, nan box short ones.