[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, 4 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index d8ef10f58aa..8b405562904 100644
--- a/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -85,6 +85,7 @@ void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
   RegInfo = &MF->getRegInfo();
   const TargetFrameLowering *TFI = MF->getSubtarget().getFrameLowering();
   unsigned StackAlign = TFI->getStackAlignment();
+  DA = DAG->getDivergenceAnalysis();
 
   // Check whether the function can return without sret-demotion.
   SmallVector<ISD::OutputArg, 4> Outs;
@@ -345,9 +346,9 @@ void FunctionLoweringInfo::clear() {
 }
 
 /// CreateReg - Allocate a single virtual register for the given type.
-unsigned FunctionLoweringInfo::CreateReg(MVT VT) {
+unsigned FunctionLoweringInfo::CreateReg(MVT VT, bool isDivergent) {
   return RegInfo->createVirtualRegister(
-      MF->getSubtarget().getTargetLowering()->getRegClassFor(VT));
+      MF->getSubtarget().getTargetLowering()->getRegClassFor(VT, isDivergent));
 }
 
 /// CreateRegs - Allocate the appropriate number of virtual registers of
@@ -357,7 +358,7 @@ unsigned FunctionLoweringInfo::CreateReg(MVT VT) {
 /// In the case that the given value has struct or array type, this function
 /// will assign registers for each member or element.
 ///
-unsigned FunctionLoweringInfo::CreateRegs(Type *Ty) {
+unsigned FunctionLoweringInfo::CreateRegs(Type *Ty, bool isDivergent) {
   const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
 
   SmallVector<EVT, 4> ValueVTs;
@@ -370,13 +371,18 @@ unsigned FunctionLoweringInfo::CreateRegs(Type *Ty) {
 
     unsigned NumRegs = TLI->getNumRegisters(Ty->getContext(), ValueVT);
     for (unsigned i = 0; i != NumRegs; ++i) {
-      unsigned R = CreateReg(RegisterVT);
+      unsigned R = CreateReg(RegisterVT, isDivergent);
       if (!FirstReg) FirstReg = R;
     }
   }
   return FirstReg;
 }
 
+unsigned FunctionLoweringInfo::CreateRegs(const Value *V) {
+  return CreateRegs(V->getType(), DA && !TLI->requiresUniformRegister(*MF, V) &&
+                                      DA->isDivergent(V));
+}
+
 /// GetLiveOutRegInfo - Gets LiveOutInfo for a register, returning NULL if the
 /// register is a PHI destination and the PHI's LiveOutInfo is not valid. If
 /// the register's LiveOutInfo is for a smaller bit width, it is extended to