[llvm-commits] [llvm] r107899 - /llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp

[Jakob Stoklund Olesen]

Author: stoklund
Date: Thu Jul  8 14:46:30 2010
New Revision: 107899

URL: http://llvm.org/viewvc/llvm-project?rev=107899&view=rev
Log:
Teach the x86 floating point stackifier to handle COPY instructions.

This pass runs before COPY instructions are passed to copyPhysReg, so we simply
translate COPY to the proper pseudo instruction. Note that copyPhysReg does not
handle floating point stack copies.

Once COPY is used everywhere, this can be cleaned up a bit, and most of the
pseudo instructions can be removed.

Modified:
    llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp

Modified: llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp?rev=107899&r1=107898&r2=107899&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86FloatingPoint.cpp Thu Jul  8 14:46:30 2010
@@ -164,6 +164,8 @@
     void handleCompareFP(MachineBasicBlock::iterator &I);
     void handleCondMovFP(MachineBasicBlock::iterator &I);
     void handleSpecialFP(MachineBasicBlock::iterator &I);
+
+    bool translateCopy(MachineInstr*);
   };
   char FPS::ID = 0;
 }
@@ -237,7 +239,10 @@
     unsigned FPInstClass = Flags & X86II::FPTypeMask;
     if (MI->isInlineAsm())
       FPInstClass = X86II::SpecialFP;
-    
+
+    if (MI->isCopy() && translateCopy(MI))
+      FPInstClass = X86II::SpecialFP;
+
     if (FPInstClass == X86II::NotFP)
       continue;  // Efficiently ignore non-fp insts!
 
@@ -1206,3 +1211,33 @@
   I = MBB->erase(I);  // Remove the pseudo instruction
   --I;
 }
+
+// Translate a COPY instruction to a pseudo-op that handleSpecialFP understands.
+bool FPS::translateCopy(MachineInstr *MI) {
+  unsigned DstReg = MI->getOperand(0).getReg();
+  unsigned SrcReg = MI->getOperand(1).getReg();
+
+  if (DstReg == X86::ST0) {
+    MI->setDesc(TII->get(X86::FpSET_ST0_80));
+    MI->RemoveOperand(0);
+    return true;
+  }
+  if (DstReg == X86::ST1) {
+    MI->setDesc(TII->get(X86::FpSET_ST1_80));
+    MI->RemoveOperand(0);
+    return true;
+  }
+  if (SrcReg == X86::ST0) {
+    MI->setDesc(TII->get(X86::FpGET_ST0_80));
+    return true;
+  }
+  if (SrcReg == X86::ST1) {
+    MI->setDesc(TII->get(X86::FpGET_ST1_80));
+    return true;
+  }
+  if (X86::RFP80RegClass.contains(DstReg, SrcReg)) {
+    MI->setDesc(TII->get(X86::MOV_Fp8080));
+    return true;
+  }
+  return false;
+}