From a4b8eba56bc3422b2cda2117364a3f6329c30332 Mon Sep 17 00:00:00 2001
From: SarahW <pcem@pcem-emulator.co.uk>
Date: Wed, 28 Mar 2018 20:33:18 +0100
Subject: [PATCH] Add better rounded value for FLDLN2. Fixes rendering in Zone
 Raiders.

---
 src/codegen_ops_fpu.h |  9 ++++++++-
 src/x87_ops.h         | 15 +++++++++++++++
 src/x87_ops_misc.h    |  2 +-
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/src/codegen_ops_fpu.h b/src/codegen_ops_fpu.h
index de7cf4c..5065094 100644
--- a/src/codegen_ops_fpu.h
+++ b/src/codegen_ops_fpu.h
@@ -634,5 +634,12 @@ opFLDimm(L2T, 3.3219280948873623)
 opFLDimm(L2E, 1.4426950408889634);
 opFLDimm(PI, 3.141592653589793);
 opFLDimm(EG2, 0.3010299956639812);
-opFLDimm(LN2, 0.693147180559945);
 opFLDimm(Z, 0.0)
+
+static uint32_t ropFLDLN2(uint8_t opcode, uint32_t fetchdat, uint32_t op_32, uint32_t op_pc, codeblock_t *block)
+{
+        FP_ENTER();
+        FP_LOAD_IMM_Q(0x3fe62e42fefa39f0ull);
+
+        return op_pc;
+}
diff --git a/src/x87_ops.h b/src/x87_ops.h
index 1bb5fd5..dc15866 100644
--- a/src/x87_ops.h
+++ b/src/x87_ops.h
@@ -43,6 +43,21 @@ static inline void x87_push(double i)
         cpu_state.tag[cpu_state.TOP&7] = (i == 0.0) ? 1 : 0;
 }
 
+static inline void x87_push_u64(uint64_t i)
+{
+        union
+        {
+                double d;
+                uint64_t ll;
+        } td;
+                
+        td.ll = i;
+
+        cpu_state.TOP=(cpu_state.TOP-1)&7;
+        cpu_state.ST[cpu_state.TOP] = td.d;
+        cpu_state.tag[cpu_state.TOP&7] = (td.d == 0.0) ? 1 : 0;
+}
+
 static inline double x87_pop()
 {
         double t = cpu_state.ST[cpu_state.TOP];
diff --git a/src/x87_ops_misc.h b/src/x87_ops_misc.h
index 806c4a6..4305487 100644
--- a/src/x87_ops_misc.h
+++ b/src/x87_ops_misc.h
@@ -460,7 +460,7 @@ static int opFLDLN2(uint32_t fetchdat)
         FP_ENTER();
         cpu_state.pc++;
         if (fplog) pclog("FLDLN2\n");
-        x87_push(0.693147180559945);
+        x87_push_u64(0x3fe62e42fefa39f0ull);
         CLOCK_CYCLES(8);
         return 0;
 }