[AMDGPU] Divergence driven ISel. Assign register class for cross block values according to the divergence.

    Details: To make instruction selection really divergence driven it is necessary to assign
             the correct register classes to the cross block values beforehand. For the divergent targets
             same value type requires different register classes dependent on the value divergence.

    Reviewers: rampitec, nhaehnle

    Differential Revision: https://reviews.llvm.org/D59990

    This commit was reverted because of the build failure.
    The reason was mlformed patch.
    Build failure fixed.

llvm-svn: 361741

1 files changed, 10 insertions, 3 deletions

diff --git a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
index e42ed3505cf..14f5dbe6ad4 100644
--- a/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -2219,6 +2219,10 @@ bool SIInstrInfo::FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI,
       // These come before src2.
       removeModOperands(UseMI);
       UseMI.setDesc(get(NewOpc));
+      // It might happen that UseMI was commuted
+      // and we now have SGPR as SRC1. If so 2 inlined
+      // constant and SGPR are illegal.
+      legalizeOperands(UseMI);
 
       bool DeleteDef = MRI->hasOneNonDBGUse(Reg);
       if (DeleteDef)
@@ -3913,7 +3917,7 @@ void SIInstrInfo::legalizeGenericOperand(MachineBasicBlock &InsertMBB,
     return;
 
   // Try to eliminate the copy if it is copying an immediate value.
-  if (Def->isMoveImmediate())
+  if (Def->isMoveImmediate() && DstRC != &AMDGPU::VReg_1RegClass)
     FoldImmediate(*Copy, *Def, OpReg, &MRI);
 }
 
@@ -4147,7 +4151,10 @@ void SIInstrInfo::legalizeOperands(MachineInstr &MI,
     if (VRC || !RI.isSGPRClass(getOpRegClass(MI, 0))) {
       if (!VRC) {
         assert(SRC);
-        VRC = RI.getEquivalentVGPRClass(SRC);
+       if (getOpRegClass(MI, 0) == &AMDGPU::VReg_1RegClass) {
+          VRC = &AMDGPU::VReg_1RegClass;
+        } else
+          VRC = RI.getEquivalentVGPRClass(SRC);
       }
       RC = VRC;
     } else {
@@ -5309,7 +5316,7 @@ const TargetRegisterClass *SIInstrInfo::getDestEquivalentVGPRClass(
   case AMDGPU::INSERT_SUBREG:
   case AMDGPU::WQM:
   case AMDGPU::WWM:
-    if (RI.hasVGPRs(NewDstRC))
+    if (RI.hasVGPRs(NewDstRC) || NewDstRC == &AMDGPU::VReg_1RegClass)
       return nullptr;
 
     NewDstRC = RI.getEquivalentVGPRClass(NewDstRC);