Merge pull request #9675 from JosJuice/jit64-div-80000000

Jit64: Fix UB/infinite loop when compiling division by 0x80000000
dolphin-emu · Apr 26, 2021 · 51bf2dc · 51bf2dc
2 parents ac679eb + 7d4b87e
commit 51bf2dc
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Showing 2 changed files with 3 additions and 3 deletions.
diff --git a/Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp b/Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp
@@ -1480,9 +1480,9 @@ void Jit64::divwx(UGeckoInstruction inst)
       if (inst.OE)
         GenerateConstantOverflow(false);
     }
-    else if (MathUtil::IsPow2(divisor) || MathUtil::IsPow2(-divisor))
+    else if (MathUtil::IsPow2(divisor) || MathUtil::IsPow2(-static_cast<s64>(divisor)))
     {
-      u32 abs_val = std::abs(divisor);
+      const u32 abs_val = static_cast<u32>(std::abs(static_cast<s64>(divisor)));
 
       X64Reg tmp = RSCRATCH;
       if (Ra.IsSimpleReg() && Ra.GetSimpleReg() != Rd)

diff --git a/Source/Core/Core/PowerPC/JitCommon/DivUtils.h b/Source/Core/Core/PowerPC/JitCommon/DivUtils.h
@@ -16,7 +16,7 @@ struct Magic
 
 // Calculate the constants required to optimize a signed 32-bit integer division.
 // Taken from The PowerPC Compiler Writer's Guide and LLVM.
-// Divisor must not be -1, 0, and 1.
+// Divisor must not be -1, 0, 1 or INT_MIN.
 Magic SignedDivisionConstants(s32 divisor);
 
 }  // namespace JitCommon