[NFC]][PowerPC] Remove unused intrinsic for old CTR loop pass

Summary:

In the patch D62907 the PPC CTRLoops pass has been replaced by Generic
Hardware Loop pass, and it has imported some new intrinsic for Generic
Hardware Loop.

The old intrinsic used in PPC CTRLoops int_ppc_mtctr and
int_ppc_is_decremented_ctr_nonzero is been replaced by
int_set_loop_iterations and loop_decrement.

This patch is to remove above unused two instrinsic.

Reviewed By: shchenz

Differential Revision: https://reviews.llvm.org/D81539

llvm/include/llvm/IR/IntrinsicsPowerPC.td

@@ -41,15 +41,6 @@ let TargetPrefix = "ppc" in {  // All intrinsics start with "llvm.ppc.".
   // eieio instruction
   def int_ppc_eieio : Intrinsic<[],[],[]>;
 
-  // Intrinsics used to generate ctr-based loops. These should only be
-  // generated by the PowerPC backend!
-  // The branch intrinsic is marked as NoDuplicate because loop rotation will
-  // attempt to duplicate it forming loops where a block reachable from one
-  // instance of it can contain another.
-  def int_ppc_mtctr : Intrinsic<[], [llvm_anyint_ty], []>;
-  def int_ppc_is_decremented_ctr_nonzero :
-    Intrinsic<[llvm_i1_ty], [], [IntrNoDuplicate]>;
-
   // Intrinsics for [double]word extended forms of divide instructions
   def int_ppc_divwe : GCCBuiltin<"__builtin_divwe">,
                       Intrinsic<[llvm_i32_ty], [llvm_i32_ty, llvm_i32_ty],

llvm/lib/Target/PowerPC/PPCTargetTransformInfo.cpp

@@ -293,7 +293,7 @@ bool PPCTTIImpl::mightUseCTR(BasicBlock *BB, TargetLibraryInfo *LibInfo,
         if (F->getIntrinsicID() != Intrinsic::not_intrinsic) {
           switch (F->getIntrinsicID()) {
           default: continue;
-          // If we have a call to ppc_is_decremented_ctr_nonzero, or ppc_mtctr
+          // If we have a call to loop_decrement or set_loop_iterations,
           // we're definitely using CTR.
           case Intrinsic::set_loop_iterations:
           case Intrinsic::loop_decrement:

llvm/test/CodeGen/PowerPC/no-dup-of-bdnz.ll

@@ -6,11 +6,11 @@ target triple = "powerpc64le-unknown-linux-gnu"
 
 define void @test(i64 %arg.ssa, i64 %arg.nb) local_unnamed_addr {
 ; Ensure that loop rotation doesn't duplicate the call to
-; llvm.ppc.is.decremented.ctr.nonzero
+; llvm.loop.decrement
 ; CHECK-LABEL: test
-; CHECK: call i1 @llvm.ppc.is.decremented.ctr.nonzero
-; CHECK-NOT: call i1 @llvm.ppc.is.decremented.ctr.nonzero
-; CHECK: declare i1 @llvm.ppc.is.decremented.ctr.nonzero
+; CHECK: call i1 @llvm.loop.decrement
+; CHECK-NOT: call i1 @llvm.loop.decrement
+; CHECK: declare i1 @llvm.loop.decrement
 entry:
   switch i32 undef, label %BB_8 [
     i32 -2, label %BB_9
@@ -31,7 +31,7 @@ BB_2:                                          ; preds = %BB_1
 BB_3:                                          ; preds = %BB_1
   %1 = add i64 %arg.ssa, %bcount.1.us
   %2 = add i64 %1, 1
-  %3 = call i1 @llvm.ppc.is.decremented.ctr.nonzero()
+  %3 = call i1 @llvm.loop.decrement.i32(i32 1)
   br i1 %3, label %BB_4, label %BB_7
 
 BB_4:                                          ; preds = %BB_3
@@ -62,14 +62,14 @@ BB_11:                                         ; preds = %BB_11, %BB_10
   br i1 undef, label %BB_11, label %BB_12
 
 BB_12:                                         ; preds = %BB_11
-  call void @llvm.ppc.mtctr.i64(i64 %arg.nb)
+  call void @llvm.set.loop.iterations.i64(i64 %arg.nb)
   br label %BB_1
 }
 
 ; Function Attrs: nounwind
-declare void @llvm.ppc.mtctr.i64(i64) #0
+declare void @llvm.set.loop.iterations.i64(i64) #0
 
 ; Function Attrs: nounwind
-declare i1 @llvm.ppc.is.decremented.ctr.nonzero() #0
+declare i1 @llvm.loop.decrement.i32(i32) #0
 
 attributes #0 = { nounwind }