[globalisel] Add GISelChangeObserver::changingInstr()

Summary:
In addition to knowing that an instruction is changed. It's also useful to
know when it's about to change. For example, it might print the instruction so
you can track the changes in a debug log, it might remove it from some queue
while it's being worked on, or it might want to change several instructions as
a single transaction and act on all the changes at once.

Added changingInstr() to all existing uses of changedInstr()

Reviewers: aditya_nandakumar

Reviewed By: aditya_nandakumar

Subscribers: rovka, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D55623

llvm-svn: 348992

1 files changed, 23 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index 197bf256584..6926c9cfc31 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -711,6 +711,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     }
     auto &TII = *MI.getMF()->getSubtarget().getInstrInfo();
     // Make the original instruction a trunc now, and update its source.
+    Observer.changingInstr(MI);
     MI.setDesc(TII.get(TargetOpcode::G_TRUNC));
     MI.getOperand(1).setReg(MIBNewOp->getOperand(0).getReg());
     Observer.changedInstr(MI);
@@ -726,6 +727,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     // Perform operation at larger width (any extension is fine here, high bits
     // don't affect the result) and then truncate the result back to the
     // original type.
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
     widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ANYEXT);
     widenScalarDst(MI, WideTy);
@@ -733,6 +735,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     return Legalized;
 
   case TargetOpcode::G_SHL:
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
     // The "number of bits to shift" operand must preserve its value as an
     // unsigned integer:
@@ -743,6 +746,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
 
   case TargetOpcode::G_SDIV:
   case TargetOpcode::G_SREM:
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_SEXT);
     widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_SEXT);
     widenScalarDst(MI, WideTy);
@@ -750,6 +754,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     return Legalized;
 
   case TargetOpcode::G_ASHR:
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_SEXT);
     // The "number of bits to shift" operand must preserve its value as an
     // unsigned integer:
@@ -761,6 +766,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
   case TargetOpcode::G_UDIV:
   case TargetOpcode::G_UREM:
   case TargetOpcode::G_LSHR:
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ZEXT);
     widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ZEXT);
     widenScalarDst(MI, WideTy);
@@ -773,6 +779,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     // Perform operation at larger width (any extension is fine here, high bits
     // don't affect the result) and then truncate the result back to the
     // original type.
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_ANYEXT);
     widenScalarSrc(MI, WideTy, 3, TargetOpcode::G_ANYEXT);
     widenScalarDst(MI, WideTy);
@@ -783,6 +790,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
   case TargetOpcode::G_FPTOUI:
     if (TypeIdx != 0)
       return UnableToLegalize;
+    Observer.changingInstr(MI);
     widenScalarDst(MI, WideTy);
     Observer.changedInstr(MI);
     return Legalized;
@@ -790,6 +798,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
   case TargetOpcode::G_SITOFP:
     if (TypeIdx != 1)
       return UnableToLegalize;
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_SEXT);
     Observer.changedInstr(MI);
     return Legalized;
@@ -797,6 +806,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
   case TargetOpcode::G_UITOFP:
     if (TypeIdx != 1)
       return UnableToLegalize;
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ZEXT);
     Observer.changedInstr(MI);
     return Legalized;
@@ -804,6 +814,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
   case TargetOpcode::G_INSERT:
     if (TypeIdx != 0)
       return UnableToLegalize;
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
     widenScalarDst(MI, WideTy);
     Observer.changedInstr(MI);
@@ -819,6 +830,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     LLVM_FALLTHROUGH;
   case TargetOpcode::G_SEXTLOAD:
   case TargetOpcode::G_ZEXTLOAD:
+    Observer.changingInstr(MI);
     widenScalarDst(MI, WideTy);
     Observer.changedInstr(MI);
     return Legalized;
@@ -828,6 +840,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
         WideTy != LLT::scalar(8))
       return UnableToLegalize;
 
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 0, TargetOpcode::G_ZEXT);
     Observer.changedInstr(MI);
     return Legalized;
@@ -836,6 +849,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     MachineOperand &SrcMO = MI.getOperand(1);
     LLVMContext &Ctx = MIRBuilder.getMF().getFunction().getContext();
     const APInt &Val = SrcMO.getCImm()->getValue().sext(WideTy.getSizeInBits());
+    Observer.changingInstr(MI);
     SrcMO.setCImm(ConstantInt::get(Ctx, Val));
 
     widenScalarDst(MI, WideTy);
@@ -857,6 +871,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     default:
       llvm_unreachable("Unhandled fp widen type");
     }
+    Observer.changingInstr(MI);
     SrcMO.setFPImm(ConstantFP::get(Ctx, Val));
 
     widenScalarDst(MI, WideTy, 0, TargetOpcode::G_FPTRUNC);
@@ -864,11 +879,13 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     return Legalized;
   }
   case TargetOpcode::G_BRCOND:
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 0, TargetOpcode::G_ANYEXT);
     Observer.changedInstr(MI);
     return Legalized;
 
   case TargetOpcode::G_FCMP:
+    Observer.changingInstr(MI);
     if (TypeIdx == 0)
       widenScalarDst(MI, WideTy);
     else {
@@ -879,6 +896,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     return Legalized;
 
   case TargetOpcode::G_ICMP:
+    Observer.changingInstr(MI);
     if (TypeIdx == 0)
       widenScalarDst(MI, WideTy);
     else {
@@ -894,6 +912,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
 
   case TargetOpcode::G_GEP:
     assert(TypeIdx == 1 && "unable to legalize pointer of GEP");
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_SEXT);
     Observer.changedInstr(MI);
     return Legalized;
@@ -901,6 +920,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
   case TargetOpcode::G_PHI: {
     assert(TypeIdx == 0 && "Expecting only Idx 0");
 
+    Observer.changingInstr(MI);
     for (unsigned I = 1; I < MI.getNumOperands(); I += 2) {
       MachineBasicBlock &OpMBB = *MI.getOperand(I + 1).getMBB();
       MIRBuilder.setInsertPt(OpMBB, OpMBB.getFirstTerminator());
@@ -916,6 +936,7 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
   case TargetOpcode::G_EXTRACT_VECTOR_ELT:
     if (TypeIdx != 2)
       return UnableToLegalize;
+    Observer.changingInstr(MI);
     widenScalarSrc(MI, WideTy, 2, TargetOpcode::G_SEXT);
     Observer.changedInstr(MI);
     return Legalized;
@@ -1152,6 +1173,7 @@ LegalizerHelper::lowerBitCount(MachineInstr &MI, unsigned TypeIdx, LLT Ty) {
     return UnableToLegalize;
   case TargetOpcode::G_CTLZ_ZERO_UNDEF: {
     // This trivially expands to CTLZ.
+    Observer.changingInstr(MI);
     MI.setDesc(TII.get(TargetOpcode::G_CTLZ));
     Observer.changedInstr(MI);
     return Legalized;
@@ -1201,6 +1223,7 @@ LegalizerHelper::lowerBitCount(MachineInstr &MI, unsigned TypeIdx, LLT Ty) {
   }
   case TargetOpcode::G_CTTZ_ZERO_UNDEF: {
     // This trivially expands to CTTZ.
+    Observer.changingInstr(MI);
     MI.setDesc(TII.get(TargetOpcode::G_CTTZ));
     Observer.changedInstr(MI);
     return Legalized;