Merge pull request #13852 from Sintendo/jitarm64-subfcx

JitArm64_Integer: subfcx optimizations

1 files changed, 35 insertions, 0 deletions

diff --git a/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp b/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
index 86027d425a..087a4cd907 100644
--- a/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
+++ b/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
@@ -1445,6 +1445,41 @@ void JitArm64::subfcx(UGeckoInstruction inst)
     if (inst.Rc)
       ComputeRC0(gpr.GetImm(d));
   }
+  else if (gpr.IsImm(a, 0))
+  {
+    if (d != b)
+    {
+      gpr.BindToRegister(d, false);
+      MOV(gpr.R(d), gpr.R(b));
+    }
+    ComputeCarry(true);
+    if (inst.Rc)
+      ComputeRC0(gpr.R(d));
+  }
+  else if (gpr.IsImm(a) && ((gpr.GetImm(a) & 0xFFF) == gpr.GetImm(a)))
+  {
+    gpr.BindToRegister(d, d == b);
+    CARRY_IF_NEEDED(SUB, SUBS, gpr.R(d), gpr.R(b), gpr.GetImm(a));
+    ComputeCarry();
+    if (inst.Rc)
+      ComputeRC0(gpr.R(d));
+  }
+  else if (gpr.IsImm(a) && ((gpr.GetImm(a) & 0xFFF000) == gpr.GetImm(a)))
+  {
+    gpr.BindToRegister(d, d == b);
+    CARRY_IF_NEEDED(SUB, SUBS, gpr.R(d), gpr.R(b), gpr.GetImm(a) >> 12, true);
+    ComputeCarry();
+    if (inst.Rc)
+      ComputeRC0(gpr.R(d));
+  }
+  else if (gpr.IsImm(b, 0))
+  {
+    gpr.BindToRegister(d, d == a);
+    CARRY_IF_NEEDED(NEG, NEGS, gpr.R(d), gpr.R(a));
+    ComputeCarry();
+    if (inst.Rc)
+      ComputeRC0(gpr.R(d));
+  }
   else
   {
     gpr.BindToRegister(d, d == a || d == b);