[GlobalISel] Make the InstructionSelector instance non-const, allowing state to be maintained.

Currently we can't keep any state in the selector object that we get from
subtarget. As a result we have to plumb through all our variables through
multiple functions. This change makes it non-const and adds a virtual init()
method to allow further state to be captured for each target.

AArch64 makes use of this in this patch to cache a call to hasFnAttribute()
which is expensive to call, and is used on each selection of G_BRCOND.

Differential Revision: https://reviews.llvm.org/D65984

llvm-svn: 368652

1 files changed, 3 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp b/llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp
index fb786bf08e6..517f13c40a4 100644
--- a/llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/InstructionSelect.cpp
@@ -66,9 +66,10 @@ bool InstructionSelect::runOnMachineFunction(MachineFunction &MF) {
   LLVM_DEBUG(dbgs() << "Selecting function: " << MF.getName() << '\n');
 
   const TargetPassConfig &TPC = getAnalysis<TargetPassConfig>();
-  const InstructionSelector *ISel = MF.getSubtarget().getInstructionSelector();
+  InstructionSelector *ISel = MF.getSubtarget().getInstructionSelector();
   CodeGenCoverage CoverageInfo;
   assert(ISel && "Cannot work without InstructionSelector");
+  ISel->setupMF(MF, CoverageInfo);
 
   // An optimization remark emitter. Used to report failures.
   MachineOptimizationRemarkEmitter MORE(MF, /*MBFI=*/nullptr);
@@ -124,7 +125,7 @@ bool InstructionSelect::runOnMachineFunction(MachineFunction &MF) {
         continue;
       }
 
-      if (!ISel->select(MI, CoverageInfo)) {
+      if (!ISel->select(MI)) {
         // FIXME: It would be nice to dump all inserted instructions.  It's
         // not obvious how, esp. considering select() can insert after MI.
         reportGISelFailure(MF, TPC, MORE, "gisel-select", "cannot select", MI);