From 9ba35991e36517ff1ccb0818bce59ccd8ae3f9a0 Mon Sep 17 00:00:00 2001
From: David Harris <David_Harris@hmc.edu>
Date: Thu, 15 Feb 2024 20:01:28 -0800
Subject: [PATCH] Finished FPU coverage

---
 sim/coverage-exclusions-rv64gc.do |  2 ++
 src/fpu/postproc/cvtshiftcalc.sv  |  2 +-
 testbench/tests.vh                | 11 +++++++++--
 tests/coverage/fpu.S              | 22 ----------------------
 4 files changed, 12 insertions(+), 25 deletions(-)

diff --git a/sim/coverage-exclusions-rv64gc.do b/sim/coverage-exclusions-rv64gc.do
index 3c0e0dd48..36098d90d 100644
--- a/sim/coverage-exclusions-rv64gc.do
+++ b/sim/coverage-exclusions-rv64gc.do
@@ -49,6 +49,8 @@ coverage exclude -scope /dut/core/fpu/fpu/fdivsqrt/fdivsqrtfsm -linerange [GetLi
 # Division by zero never sets sticky/guard/overflow/round to cause inexact or underflow result, but check out of paranoia
 coverage exclude -scope /dut/core/fpu/fpu/postprocess/flags -linerange [GetLineNum ../src/fpu/postproc/flags.sv "assign FpInexact"] -item e 1 -fecexprrow 15 
 coverage exclude -scope /dut/core/fpu/fpu/postprocess/flags -linerange [GetLineNum ../src/fpu/postproc/flags.sv "assign Underflow"] -item e 1 -fecexprrow 22
+# Convert int to fp will never underflow
+coverage exclude -scope /dut/core/fpu/fpu/postprocess/cvtshiftcalc -linerange [GetLineNum ../src/fpu/postproc/cvtshiftcalc.sv "assign CvtResUf"] -item e 1 -fecexprrow 4
 
 ##################
 # Cache Exclusions
diff --git a/src/fpu/postproc/cvtshiftcalc.sv b/src/fpu/postproc/cvtshiftcalc.sv
index 8a35fa68f..8b7587e49 100644
--- a/src/fpu/postproc/cvtshiftcalc.sv
+++ b/src/fpu/postproc/cvtshiftcalc.sv
@@ -99,6 +99,6 @@ module cvtshiftcalc import cvw::*;  #(parameter cvw_t P) (
   // determine if the result underflows ??? -> fp
   //      - if the first 1 is shifted out of the result then the result underflows
   //      - can't underflow an integer to fp conversions
-  assign CvtResUf = ($signed(CvtCe) < $signed({{P.NE-$clog2(P.NF){1'b1}}, ResNegNF}))&~XZero; // dh 2/15/24 removed &~IntToFp, which is never limiting because int to fp will not underflow
+  assign CvtResUf = ($signed(CvtCe) < $signed({{P.NE-$clog2(P.NF){1'b1}}, ResNegNF}))&~XZero&~IntToFp; 
   
 endmodule
diff --git a/testbench/tests.vh b/testbench/tests.vh
index 11afd2224..95ebb74b3 100644
--- a/testbench/tests.vh
+++ b/testbench/tests.vh
@@ -45,8 +45,6 @@ string tvpaths[] = '{
 
   string coverage64gc[] = '{
     `COVERAGE,
-    "tlbmisc",
-    "tlbNAPOT",
     "ieu",
     "priv",
     "ebu",
@@ -55,6 +53,8 @@ string tvpaths[] = '{
     "fpu",
     "lsu",
     "vm64check",
+    "tlbmisc",
+    "tlbNAPOT",
     "tlbASID",
     "tlbGLB",
     "tlbMP",
@@ -2156,6 +2156,13 @@ string arch64zbs[] = '{
 
   string arch64zfad[] = '{
     `RISCVARCHTEST,
+    "rv64i_m/D_Zfa/src/fcvtmod.w.d_b1-01.S",
+    "rv64i_m/D_Zfa/src/fcvtmod.w.d_b22-01.S",
+    "rv64i_m/D_Zfa/src/fcvtmod.w.d_b23-01.S",
+    "rv64i_m/D_Zfa/src/fcvtmod.w.d_b24-01.S",
+    "rv64i_m/D_Zfa/src/fcvtmod.w.d_b27-01.S",
+    "rv64i_m/D_Zfa/src/fcvtmod.w.d_b28-01.S",
+    "rv64i_m/D_Zfa/src/fcvtmod.w.d_b29-01.S",
     "rv64i_m/D_Zfa/src/fleq_b1-01.S",
     "rv64i_m/D_Zfa/src/fleq_b19-01.S", 
     "rv64i_m/D_Zfa/src/fli.d-01.S",
diff --git a/tests/coverage/fpu.S b/tests/coverage/fpu.S
index a88ed8a51..497ba0207 100644
--- a/tests/coverage/fpu.S
+++ b/tests/coverage/fpu.S
@@ -198,28 +198,6 @@ main:
     fcvt.s.w ft2, zero
     fdiv.s ft3, ft1, ft2
 
-/*  These didn't make a difference 
-
-    // Test subtraction of identical denormalized numbers with to exercise FmaPreResultSubnorm logic with FmaSZero
-    li t0, 0xFFFFFFFF00000001
-    fmv.w.x ft1, t0        // smallest denorm
-    fsub.s ft1, ft1, ft1    // difference = 0
-
-    li t0, 0x0000000000000001
-    fmv.d.x ft1, t0        // smallest denorm
-    fsub.d ft1, ft1, ft1    // difference = 0
-
- // Test subtraction of identical denormalized numbers with to exercise FmaPreResultSubnorm logic with FmaSZero
-    li t0, 0xFFFFFFFF00100001
-    fmv.w.x ft1, t0        // almost largest denorm
-    fsub.s ft1, ft1, ft1    // difference = 0
-
-    li t0, 0x0001000000000001
-    fmv.d.x ft1, t0        // smallest denorm
-    fsub.d ft1, ft1, ft1    // difference = 0
-
-*/
-
     # Test floating point convert to integer and using result
     fcvt.w.s t0, f0
     add t1, t0, t0