From 9c2c89b7e1a93b52b53c567116b0d24bc4cb6ce7 Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Mon, 12 Jan 2015 00:01:46 -0500
Subject: [PATCH] dyncom: Add a helper function for addition with a carry
---
.../arm/dyncom/arm_dyncom_interpreter.cpp | 21 ++++++++-----------
src/core/arm/interpreter/armsupp.cpp | 16 ++++++++++++++
src/core/arm/skyeye_common/armdefs.h | 1 +
3 files changed, 26 insertions(+), 12 deletions(-)
diff --git a/src/core/arm/dyncom/arm_dyncom_interpreter.cpp b/src/core/arm/dyncom/arm_dyncom_interpreter.cpp
index bf864c7a7..4c0a8f5cb 100644
--- a/src/core/arm/dyncom/arm_dyncom_interpreter.cpp
+++ b/src/core/arm/dyncom/arm_dyncom_interpreter.cpp
@@ -4003,16 +4003,13 @@ unsigned InterpreterMainLoop(ARMul_State* state) {
}
ADC_INST:
{
- adc_inst *inst_cream = (adc_inst *)inst_base->component;
- if ((inst_base->cond == 0xe) || CondPassed(cpu, inst_base->cond)) {
- u32 left = RN;
- u32 right = SHIFTER_OPERAND;
+ if (inst_base->cond == 0xE || CondPassed(cpu, inst_base->cond)) {
+ adc_inst* const inst_cream = (adc_inst*)inst_base->component;
- u64 unsigned_sum = (left + right + cpu->CFlag);
- s64 signed_sum = (s64)(s32)left + (s64)(s32)right + (s64)cpu->CFlag;
- u32 result = (unsigned_sum & 0xFFFFFFFF);
+ bool carry;
+ bool overflow;
+ RD = AddWithCarry(RN, SHIFTER_OPERAND, cpu->CFlag, &carry, &overflow);
- RD = result;
if (inst_cream->S && (inst_cream->Rd == 15)) {
if (CurrentModeHasSPSR) {
cpu->Cpsr = cpu->Spsr_copy;
@@ -4020,10 +4017,10 @@ unsigned InterpreterMainLoop(ARMul_State* state) {
LOAD_NZCVT;
}
} else if (inst_cream->S) {
- UPDATE_NFLAG(result);
- UPDATE_ZFLAG(result);
- UPDATE_CFLAG_CARRY_FROM_ADD(left, right, cpu->CFlag);
- cpu->VFlag = ((s64)(s32)result != signed_sum);
+ UPDATE_NFLAG(RD);
+ UPDATE_ZFLAG(RD);
+ cpu->CFlag = carry;
+ cpu->VFlag = overflow;
}
if (inst_cream->Rd == 15) {
INC_PC(sizeof(adc_inst));
diff --git a/src/core/arm/interpreter/armsupp.cpp b/src/core/arm/interpreter/armsupp.cpp
index 68ac2a0ce..e2626eefb 100644
--- a/src/core/arm/interpreter/armsupp.cpp
+++ b/src/core/arm/interpreter/armsupp.cpp
@@ -418,6 +418,22 @@ ARMul_NegZero (ARMul_State * state, ARMword result)
}
}
+// 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(ARMword a, ARMword b, ARMword result)
{
diff --git a/src/core/arm/skyeye_common/armdefs.h b/src/core/arm/skyeye_common/armdefs.h
index 1b2cef451..560b51a9f 100644
--- a/src/core/arm/skyeye_common/armdefs.h
+++ b/src/core/arm/skyeye_common/armdefs.h
@@ -795,6 +795,7 @@ extern void ARMul_FixSPSR(ARMul_State*, ARMword, ARMword);
extern void ARMul_ConsolePrint(ARMul_State*, const char*, ...);
extern void ARMul_SelectProcessor(ARMul_State*, unsigned);
+extern u32 AddWithCarry(u32, u32, u32, bool*, bool*);
extern bool ARMul_AddOverflowQ(ARMword, ARMword);
extern u8 ARMul_SignedSaturatedAdd8(u8, u8);