Merge pull request #9425 from Sintendo/jit64subfx

Jit64: subfx optimizations
dolphin-emu · Jan 15, 2021 · 0c2bc35 · 0c2bc35
2 parents 8f67a19 + df70077
commit 0c2bc35
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Showing 2 changed files with 58 additions and 6 deletions.
diff --git a/Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp b/Source/Core/Core/PowerPC/Jit64/Jit_Integer.cpp
@@ -933,13 +933,63 @@ void Jit64::subfx(UGeckoInstruction inst)
   JITDISABLE(bJITIntegerOff);
   int a = inst.RA, b = inst.RB, d = inst.RD;
 
-  if (gpr.IsImm(a) && gpr.IsImm(b))
+  if (a == b)
+  {
+    gpr.SetImmediate32(d, 0);
+    if (inst.OE)
+      GenerateConstantOverflow(false);
+  }
+  else if (gpr.IsImm(a, b))
   {
     s32 i = gpr.SImm32(b), j = gpr.SImm32(a);
     gpr.SetImmediate32(d, i - j);
     if (inst.OE)
       GenerateConstantOverflow((s64)i - (s64)j);
   }
+  else if (gpr.IsImm(a))
+  {
+    s32 j = gpr.SImm32(a);
+    RCOpArg Rb = gpr.Use(b, RCMode::Read);
+    RCX64Reg Rd = gpr.Bind(d, RCMode::Write);
+    RegCache::Realize(Rb, Rd);
+
+    if (j == 0)
+    {
+      if (d != b)
+        MOV(32, Rd, Rb);
+      if (inst.OE)
+        GenerateConstantOverflow(false);
+    }
+    else if (d == b)
+    {
+      SUB(32, Rd, Imm32(j));
+      if (inst.OE)
+        GenerateOverflow();
+    }
+    else if (Rb.IsSimpleReg() && !inst.OE)
+    {
+      LEA(32, Rd, MDisp(Rb.GetSimpleReg(), -j));
+    }
+    else
+    {
+      MOV(32, Rd, Rb);
+      SUB(32, Rd, Imm32(j));
+      if (inst.OE)
+        GenerateOverflow();
+    }
+  }
+  else if (gpr.IsImm(b) && gpr.Imm32(b) == 0)
+  {
+    RCOpArg Ra = gpr.Use(a, RCMode::Read);
+    RCX64Reg Rd = gpr.Bind(d, RCMode::Write);
+    RegCache::Realize(Ra, Rd);
+
+    if (d != a)
+      MOV(32, Rd, Ra);
+    NEG(32, Rd);
+    if (inst.OE)
+      GenerateOverflow();
+  }
   else
   {
     RCOpArg Ra = gpr.Use(a, RCMode::Read);
@@ -957,10 +1007,6 @@ void Jit64::subfx(UGeckoInstruction inst)
       MOV(32, Rd, Rb);
       SUB(32, Rd, R(RSCRATCH));
     }
-    else if (Rb.IsSimpleReg() && Ra.IsImm() && !inst.OE)
-    {
-      LEA(32, Rd, MDisp(Rb.GetSimpleReg(), -Ra.SImm32()));
-    }
     else
     {
       MOV(32, Rd, Rb);

diff --git a/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp b/Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp
@@ -856,7 +856,13 @@ void JitArm64::subfx(UGeckoInstruction inst)
 
   int a = inst.RA, b = inst.RB, d = inst.RD;
 
-  if (gpr.IsImm(a) && gpr.IsImm(b))
+  if (a == b)
+  {
+    gpr.SetImmediate(d, 0);
+    if (inst.Rc)
+      ComputeRC0(gpr.GetImm(d));
+  }
+  else if (gpr.IsImm(a) && gpr.IsImm(b))
   {
     u32 i = gpr.GetImm(a), j = gpr.GetImm(b);
     gpr.SetImmediate(d, j - i);