1 files changed, 208 insertions, 0 deletions
diff --git a/src/core/arm/skyeye_common/armsupp.cpp b/src/core/arm/skyeye_common/armsupp.cpp
new file mode 100644
index 00000000..d31fb944
--- /dev/null
+++ b/src/core/arm/skyeye_common/armsupp.cpp
@@ -0,0 +1,208 @@
+/*  armsupp.c -- ARMulator support code:  ARM6 Instruction Emulator.
+    Copyright (C) 1994 Advanced RISC Machines Ltd.
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+#include "common/logging/log.h"
+
+#include "core/mem_map.h"
+#include "core/arm/skyeye_common/arm_regformat.h"
+#include "core/arm/skyeye_common/armstate.h"
+#include "core/arm/skyeye_common/armsupp.h"
+
+// Unsigned sum of absolute difference
+u8 ARMul_UnsignedAbsoluteDifference(u8 left, u8 right)
+{
+    if (left > right)
+        return left - right;
+
+    return right - left;
+}
+
+// Add with carry, indicates if a carry-out or signed overflow occurred.
+u32 AddWithCarry(u32 left, u32 right, u32 carry_in, bool* carry_out_occurred, bool* overflow_occurred)
+{
+    u64 unsigned_sum = (u64)left + (u64)right + (u64)carry_in;
+    s64 signed_sum = (s64)(s32)left + (s64)(s32)right + (s64)carry_in;
+    u64 result = (unsigned_sum & 0xFFFFFFFF);
+
+    if (carry_out_occurred)
+        *carry_out_occurred = (result != unsigned_sum);
+
+    if (overflow_occurred)
+        *overflow_occurred = ((s64)(s32)result != signed_sum);
+
+    return (u32)result;
+}
+
+// Compute whether an addition of A and B, giving RESULT, overflowed.
+bool AddOverflow(u32 a, u32 b, u32 result)
+{
+    return ((NEG(a) && NEG(b) && POS(result)) ||
+            (POS(a) && POS(b) && NEG(result)));
+}
+
+// Compute whether a subtraction of A and B, giving RESULT, overflowed.
+bool SubOverflow(u32 a, u32 b, u32 result)
+{
+    return ((NEG(a) && POS(b) && POS(result)) ||
+            (POS(a) && NEG(b) && NEG(result)));
+}
+
+// Returns true if the Q flag should be set as a result of overflow.
+bool ARMul_AddOverflowQ(u32 a, u32 b)
+{
+    u32 result = a + b;
+    if (((result ^ a) & (u32)0x80000000) && ((a ^ b) & (u32)0x80000000) == 0)
+        return true;
+
+    return false;
+}
+
+// 8-bit signed saturated addition
+u8 ARMul_SignedSaturatedAdd8(u8 left, u8 right)
+{
+    u8 result = left + right;
+
+    if (((result ^ left) & 0x80) && ((left ^ right) & 0x80) == 0) {
+        if (left & 0x80)
+            result = 0x80;
+        else
+            result = 0x7F;
+    }
+
+    return result;
+}
+
+// 8-bit signed saturated subtraction
+u8 ARMul_SignedSaturatedSub8(u8 left, u8 right)
+{
+    u8 result = left - right;
+
+    if (((result ^ left) & 0x80) && ((left ^ right) & 0x80) != 0) {
+        if (left & 0x80)
+            result = 0x80;
+        else
+            result = 0x7F;
+    }
+
+    return result;
+}
+
+// 16-bit signed saturated addition
+u16 ARMul_SignedSaturatedAdd16(u16 left, u16 right)
+{
+    u16 result = left + right;
+
+    if (((result ^ left) & 0x8000) && ((left ^ right) & 0x8000) == 0) {
+        if (left & 0x8000)
+            result = 0x8000;
+        else
+            result = 0x7FFF;
+    }
+
+    return result;
+}
+
+// 16-bit signed saturated subtraction
+u16 ARMul_SignedSaturatedSub16(u16 left, u16 right)
+{
+    u16 result = left - right;
+
+    if (((result ^ left) & 0x8000) && ((left ^ right) & 0x8000) != 0) {
+        if (left & 0x8000)
+            result = 0x8000;
+        else
+            result = 0x7FFF;
+    }
+
+    return result;
+}
+
+// 8-bit unsigned saturated addition
+u8 ARMul_UnsignedSaturatedAdd8(u8 left, u8 right)
+{
+    u8 result = left + right;
+
+    if (result < left)
+        result = 0xFF;
+
+    return result;
+}
+
+// 16-bit unsigned saturated addition
+u16 ARMul_UnsignedSaturatedAdd16(u16 left, u16 right)
+{
+    u16 result = left + right;
+
+    if (result < left)
+        result = 0xFFFF;
+
+    return result;
+}
+
+// 8-bit unsigned saturated subtraction
+u8 ARMul_UnsignedSaturatedSub8(u8 left, u8 right)
+{
+    if (left <= right)
+        return 0;
+
+    return left - right;
+}
+
+// 16-bit unsigned saturated subtraction
+u16 ARMul_UnsignedSaturatedSub16(u16 left, u16 right)
+{
+    if (left <= right)
+        return 0;
+
+    return left - right;
+}
+
+// Signed saturation.
+u32 ARMul_SignedSatQ(s32 value, u8 shift, bool* saturation_occurred)
+{
+    const u32 max = (1 << shift) - 1;
+    const s32 top = (value >> shift);
+
+    if (top > 0) {
+        *saturation_occurred = true;
+        return max;
+    }
+    else if (top < -1) {
+        *saturation_occurred = true;
+        return ~max;
+    }
+
+    *saturation_occurred = false;
+    return (u32)value;
+}
+
+// Unsigned saturation
+u32 ARMul_UnsignedSatQ(s32 value, u8 shift, bool* saturation_occurred)
+{
+    const u32 max = (1 << shift) - 1;
+
+    if (value < 0) {
+        *saturation_occurred = true;
+        return 0;
+    } else if ((u32)value > max) {
+        *saturation_occurred = true;
+        return max;
+    }
+
+    *saturation_occurred = false;
+    return (u32)value;
+}