From ea4dd4047c8361e23faeea321dbcf6bc576469b8 Mon Sep 17 00:00:00 2001
From: SarahW <pcem@pcem-emulator.co.uk>
Date: Fri, 24 Jan 2020 20:33:59 +0000
Subject: [PATCH] Added FENI/FDISI for 8087.

---
 src/x87_ops.h      |  6 ++++--
 src/x87_ops_misc.h | 27 +++++++++++++++++++++++++++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/x87_ops.h b/src/x87_ops.h
index 225d56c..361dcb7 100644
--- a/src/x87_ops.h
+++ b/src/x87_ops.h
@@ -10,6 +10,8 @@ static int rounding_modes[4] = {FE_TONEAREST, FE_DOWNWARD, FE_UPWARD, FE_TOWARDZ
 
 #define STATUS_ZERODIVIDE 4
 
+#define FPCW_DISI (1 << 7)
+
 #define x87_div(dst, src1, src2) do                             \
         {                                                       \
                 if (((double)src2) == 0.0)                      \
@@ -639,7 +641,7 @@ OpFn OP_TABLE(fpu_db_a16)[256] =
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
-        ILLEGAL,       opFNOP,        opFCLEX,       opFINIT,       opFNOP,        opFNOP,        ILLEGAL,       ILLEGAL,
+        opFENI,        opFDISI,       opFCLEX,       opFINIT,       opFNOP,        opFNOP,        ILLEGAL,       ILLEGAL,
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
@@ -679,7 +681,7 @@ OpFn OP_TABLE(fpu_db_a32)[256] =
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
-        ILLEGAL,       opFNOP,        opFCLEX,       opFINIT,       opFNOP,        opFNOP,        ILLEGAL,       ILLEGAL,
+        opFENI,        opFDISI,       opFCLEX,       opFINIT,       opFNOP,        opFNOP,        ILLEGAL,       ILLEGAL,
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
         ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,       ILLEGAL,
diff --git a/src/x87_ops_misc.h b/src/x87_ops_misc.h
index a5fc002..3a572cc 100644
--- a/src/x87_ops_misc.h
+++ b/src/x87_ops_misc.h
@@ -1,3 +1,30 @@
+static int opFDISI(uint32_t fetchdat)
+{
+        FP_ENTER();
+        cpu_state.pc++;
+        if (fpu_type == FPU_8087)
+        {
+                cpu_state.npxc |= FPCW_DISI;
+                CLOCK_CYCLES(x87_timings.fdisi_eni);
+        }
+        else
+                CLOCK_CYCLES(x87_timings.fnop);
+        return 0;
+}
+static int opFENI(uint32_t fetchdat)
+{
+        FP_ENTER();
+        cpu_state.pc++;
+        if (fpu_type == FPU_8087)
+        {
+                cpu_state.npxc &= ~FPCW_DISI;
+                CLOCK_CYCLES(x87_timings.fdisi_eni);
+        }
+        else
+                CLOCK_CYCLES(x87_timings.fnop);
+        return 0;
+}
+
 static int opFSTSW_AX(uint32_t fetchdat)
 {
         FP_ENTER();