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-rw-r--r--src/core/arm/interpreter/armsupp.cpp16
1 files changed, 16 insertions, 0 deletions
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)
418 } 418 }
419} 419}
420 420
421// Add with carry, indicates if a carry-out or signed overflow occurred.
422u32 AddWithCarry(u32 left, u32 right, u32 carry_in, bool* carry_out_occurred, bool* overflow_occurred)
423{
424 u64 unsigned_sum = (u64)left + (u64)right + (u64)carry_in;
425 s64 signed_sum = (s64)(s32)left + (s64)(s32)right + (s64)carry_in;
426 u64 result = (unsigned_sum & 0xFFFFFFFF);
427
428 if (carry_out_occurred)
429 *carry_out_occurred = (result != unsigned_sum);
430
431 if (overflow_occurred)
432 *overflow_occurred = ((s64)(s32)result != signed_sum);
433
434 return (u32)result;
435}
436
421// Compute whether an addition of A and B, giving RESULT, overflowed. 437// Compute whether an addition of A and B, giving RESULT, overflowed.
422bool AddOverflow(ARMword a, ARMword b, ARMword result) 438bool AddOverflow(ARMword a, ARMword b, ARMword result)
423{ 439{