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

Summary:
Reorder the condition code enum to match their encodings. Move it to MC layer so it can be used by the scheduler models.

This avoids needing an isel pattern for each condition code. And it removes
translation switches for converting between CMOV 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.

This does complicate the scheduler models a little since we can't assign the
A and BE instructions to a separate class now.

I plan to make similar changes for SETcc and Jcc.

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

Reviewed By: RKSimon

Subscribers: gchatelet, hiraditya, kristina, lebedev.ri, jdoerfert, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60041

llvm-svn: 357800

1 files changed, 9 insertions, 6 deletions

diff --git a/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp b/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp
index 1d94f2a80a0..289c5f19b06 100644
--- a/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp
+++ b/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp
@@ -751,7 +751,7 @@ X86SpeculativeLoadHardeningPass::tracePredStateThroughCFG(
 
           for (X86::CondCode Cond : Conds) {
             int PredStateSizeInBytes = TRI->getRegSizeInBits(*PS->RC) / 8;
-            auto CMovOp = X86::getCMovFromCond(Cond, PredStateSizeInBytes);
+            auto CMovOp = X86::getCMovOpcode(PredStateSizeInBytes);
 
             unsigned UpdatedStateReg = MRI->createVirtualRegister(PS->RC);
             // Note that we intentionally use an empty debug location so that
@@ -759,7 +759,8 @@ X86SpeculativeLoadHardeningPass::tracePredStateThroughCFG(
             auto CMovI = BuildMI(CheckingMBB, InsertPt, DebugLoc(),
                                  TII->get(CMovOp), UpdatedStateReg)
                              .addReg(CurStateReg)
-                             .addReg(PS->PoisonReg);
+                             .addReg(PS->PoisonReg)
+                             .addImm(Cond);
             // If this is the last cmov and the EFLAGS weren't originally
             // live-in, mark them as killed.
             if (!LiveEFLAGS && Cond == Conds.back())
@@ -1176,12 +1177,13 @@ X86SpeculativeLoadHardeningPass::tracePredStateThroughIndirectBranches(
 
     // Now cmov over the predicate if the comparison wasn't equal.
     int PredStateSizeInBytes = TRI->getRegSizeInBits(*PS->RC) / 8;
-    auto CMovOp = X86::getCMovFromCond(X86::COND_NE, PredStateSizeInBytes);
+    auto CMovOp = X86::getCMovOpcode(PredStateSizeInBytes);
     unsigned UpdatedStateReg = MRI->createVirtualRegister(PS->RC);
     auto CMovI =
         BuildMI(MBB, InsertPt, DebugLoc(), TII->get(CMovOp), UpdatedStateReg)
             .addReg(PS->InitialReg)
-            .addReg(PS->PoisonReg);
+            .addReg(PS->PoisonReg)
+            .addImm(X86::COND_NE);
     CMovI->findRegisterUseOperand(X86::EFLAGS)->setIsKill(true);
     ++NumInstsInserted;
     LLVM_DEBUG(dbgs() << "  Inserting cmov: "; CMovI->dump(); dbgs() << "\n");
@@ -2545,12 +2547,13 @@ void X86SpeculativeLoadHardeningPass::tracePredStateThroughCall(
   // Now conditionally update the predicate state we just extracted if we ended
   // up at a different return address than expected.
   int PredStateSizeInBytes = TRI->getRegSizeInBits(*PS->RC) / 8;
-  auto CMovOp = X86::getCMovFromCond(X86::COND_NE, PredStateSizeInBytes);
+  auto CMovOp = X86::getCMovOpcode(PredStateSizeInBytes);
 
   unsigned UpdatedStateReg = MRI->createVirtualRegister(PS->RC);
   auto CMovI = BuildMI(MBB, InsertPt, Loc, TII->get(CMovOp), UpdatedStateReg)
                    .addReg(NewStateReg, RegState::Kill)
-                   .addReg(PS->PoisonReg);
+                   .addReg(PS->PoisonReg)
+                   .addImm(X86::COND_NE);
   CMovI->findRegisterUseOperand(X86::EFLAGS)->setIsKill(true);
   ++NumInstsInserted;
   LLVM_DEBUG(dbgs() << "  Inserting cmov: "; CMovI->dump(); dbgs() << "\n");