[X86] Merge the different SETcc instructions for each condition code into single instructions that store the condition code as an operand.

Summary:
This avoids needing an isel pattern for each condition code. And it removes translation switches for converting between SETcc instructions and condition codes.

Now the printer, encoder and disassembler take care of converting the immediate. We use InstAliases to handle the assembly matching. But we print using the asm string in the instruction definition. The instruction itself is marked IsCodeGenOnly=1 to hide it from the assembly parser.

Reviewers: andreadb, courbet, RKSimon, spatel, lebedev.ri

Reviewed By: andreadb

Subscribers: hiraditya, lebedev.ri, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60138

llvm-svn: 357801

1 files changed, 6 insertions, 8 deletions

diff --git a/llvm/lib/Target/X86/X86InstructionSelector.cpp b/llvm/lib/Target/X86/X86InstructionSelector.cpp
index 90ae6bb4df5..c105b4e63d9 100644
--- a/llvm/lib/Target/X86/X86InstructionSelector.cpp
+++ b/llvm/lib/Target/X86/X86InstructionSelector.cpp
@@ -947,7 +947,6 @@ bool X86InstructionSelector::selectCmp(MachineInstr &I,
   bool SwapArgs;
   std::tie(CC, SwapArgs) = X86::getX86ConditionCode(
       (CmpInst::Predicate)I.getOperand(1).getPredicate());
-  unsigned OpSet = X86::getSETFromCond(CC);
 
   unsigned LHS = I.getOperand(2).getReg();
   unsigned RHS = I.getOperand(3).getReg();
@@ -981,7 +980,7 @@ bool X86InstructionSelector::selectCmp(MachineInstr &I,
            .addReg(RHS);
 
   MachineInstr &SetInst = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
-                                   TII.get(OpSet), I.getOperand(0).getReg());
+                                   TII.get(X86::SETCCr), I.getOperand(0).getReg()).addImm(CC);
 
   constrainSelectedInstRegOperands(CmpInst, TII, TRI, RBI);
   constrainSelectedInstRegOperands(SetInst, TII, TRI, RBI);
@@ -1002,8 +1001,8 @@ bool X86InstructionSelector::selectFCmp(MachineInstr &I,
 
   // FCMP_OEQ and FCMP_UNE cannot be checked with a single instruction.
   static const uint16_t SETFOpcTable[2][3] = {
-      {X86::SETEr, X86::SETNPr, X86::AND8rr},
-      {X86::SETNEr, X86::SETPr, X86::OR8rr}};
+      {X86::COND_E, X86::COND_NP, X86::AND8rr},
+      {X86::COND_NE, X86::COND_P, X86::OR8rr}};
   const uint16_t *SETFOpc = nullptr;
   switch (Predicate) {
   default:
@@ -1043,9 +1042,9 @@ bool X86InstructionSelector::selectFCmp(MachineInstr &I,
     unsigned FlagReg1 = MRI.createVirtualRegister(&X86::GR8RegClass);
     unsigned FlagReg2 = MRI.createVirtualRegister(&X86::GR8RegClass);
     MachineInstr &Set1 = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
-                                  TII.get(SETFOpc[0]), FlagReg1);
+                                  TII.get(X86::SETCCr), FlagReg1).addImm(SETFOpc[0]);
     MachineInstr &Set2 = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
-                                  TII.get(SETFOpc[1]), FlagReg2);
+                                  TII.get(X86::SETCCr), FlagReg2).addImm(SETFOpc[1]);
     MachineInstr &Set3 = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
                                   TII.get(SETFOpc[2]), ResultReg)
                               .addReg(FlagReg1)
@@ -1063,7 +1062,6 @@ bool X86InstructionSelector::selectFCmp(MachineInstr &I,
   bool SwapArgs;
   std::tie(CC, SwapArgs) = X86::getX86ConditionCode(Predicate);
   assert(CC <= X86::LAST_VALID_COND && "Unexpected condition code.");
-  unsigned Opc = X86::getSETFromCond(CC);
 
   if (SwapArgs)
     std::swap(LhsReg, RhsReg);
@@ -1075,7 +1073,7 @@ bool X86InstructionSelector::selectFCmp(MachineInstr &I,
            .addReg(RhsReg);
 
   MachineInstr &Set =
-      *BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opc), ResultReg);
+      *BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(X86::SETCCr), ResultReg).addImm(CC);
   constrainSelectedInstRegOperands(CmpInst, TII, TRI, RBI);
   constrainSelectedInstRegOperands(Set, TII, TRI, RBI);
   I.eraseFromParent();