PPC: remove simd `nearest int` ops from codegen

On PPC we don't have the `ties to even` FP roundings enabled,
therefore their equivalent Simd op will never get emitted.

Once support is added, the flag needs to be set under
`SupportedMachineOperatorFlags` within the instruction selector.
Setting this flag affects both the scalar and Simd variants
of this op.

Change-Id: I7d486def103045d2dee7cb691927feb19c3e5ef4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2996747Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#75528}

src/compiler/backend/ppc/code-generator-ppc.cc

@@ -3344,10 +3344,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ xvrdpiz(i.OutputSimd128Register(), i.InputSimd128Register(0));
       break;
     }
-    case kPPC_F64x2NearestInt: {
-      __ xvrdpi(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      break;
-    }
     case kPPC_F32x4Ceil: {
       __ xvrspip(i.OutputSimd128Register(), i.InputSimd128Register(0));
       break;
@@ -3360,10 +3356,6 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ xvrspiz(i.OutputSimd128Register(), i.InputSimd128Register(0));
       break;
     }
-    case kPPC_F32x4NearestInt: {
-      __ xvrspi(i.OutputSimd128Register(), i.InputSimd128Register(0));
-      break;
-    }
     case kPPC_I64x2BitMask: {
       __ mov(kScratchReg,
              Operand(0x8080808080800040));  // Select 0 for the high bits.

src/compiler/backend/ppc/instruction-codes-ppc.h

@@ -218,7 +218,6 @@ namespace compiler {
   V(PPC_F64x2Ceil)                   \
   V(PPC_F64x2Floor)                  \
   V(PPC_F64x2Trunc)                  \
-  V(PPC_F64x2NearestInt)             \
   V(PPC_F64x2Pmin)                   \
   V(PPC_F64x2Pmax)                   \
   V(PPC_F64x2ConvertLowI32x4S)       \
@@ -247,7 +246,6 @@ namespace compiler {
   V(PPC_F32x4Ceil)                   \
   V(PPC_F32x4Floor)                  \
   V(PPC_F32x4Trunc)                  \
-  V(PPC_F32x4NearestInt)             \
   V(PPC_F32x4Pmin)                   \
   V(PPC_F32x4Pmax)                   \
   V(PPC_F32x4Qfma)                   \

src/compiler/backend/ppc/instruction-scheduler-ppc.cc

@@ -136,7 +136,6 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kPPC_F64x2Ceil:
     case kPPC_F64x2Floor:
     case kPPC_F64x2Trunc:
-    case kPPC_F64x2NearestInt:
     case kPPC_F64x2Pmin:
     case kPPC_F64x2Pmax:
     case kPPC_F64x2ConvertLowI32x4S:
@@ -167,7 +166,6 @@ int InstructionScheduler::GetTargetInstructionFlags(
     case kPPC_F32x4Ceil:
     case kPPC_F32x4Floor:
     case kPPC_F32x4Trunc:
-    case kPPC_F32x4NearestInt:
     case kPPC_F32x4Pmin:
     case kPPC_F32x4Pmax:
     case kPPC_F32x4DemoteF64x2Zero:

src/compiler/backend/ppc/instruction-selector-ppc.cc

@@ -1465,14 +1465,6 @@ void InstructionSelector::VisitFloat64RoundTiesAway(Node* node) {
   VisitRR(this, kPPC_RoundDouble, node);
 }
 
-void InstructionSelector::VisitFloat32RoundTiesEven(Node* node) {
-  UNREACHABLE();
-}
-
-void InstructionSelector::VisitFloat64RoundTiesEven(Node* node) {
-  UNREACHABLE();
-}
-
 void InstructionSelector::VisitFloat32Neg(Node* node) {
   VisitRR(this, kPPC_NegDouble, node);
 }
@@ -2300,7 +2292,6 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
   V(F64x2Ceil)                 \
   V(F64x2Floor)                \
   V(F64x2Trunc)                \
-  V(F64x2NearestInt)           \
   V(F64x2ConvertLowI32x4S)     \
   V(F64x2ConvertLowI32x4U)     \
   V(F64x2PromoteLowF32x4)      \
@@ -2314,7 +2305,6 @@ void InstructionSelector::VisitInt64AbsWithOverflow(Node* node) {
   V(F32x4Ceil)                 \
   V(F32x4Floor)                \
   V(F32x4Trunc)                \
-  V(F32x4NearestInt)           \
   V(F32x4DemoteF64x2Zero)      \
   V(I64x2Abs)                  \
   V(I64x2Neg)                  \
@@ -2697,6 +2687,18 @@ void InstructionSelector::AddOutputToSelectContinuation(OperandGenerator* g,
   UNREACHABLE();
 }
 
+void InstructionSelector::VisitFloat32RoundTiesEven(Node* node) {
+  UNREACHABLE();
+}
+
+void InstructionSelector::VisitFloat64RoundTiesEven(Node* node) {
+  UNREACHABLE();
+}
+
+void InstructionSelector::VisitF64x2NearestInt(Node* node) { UNREACHABLE(); }
+
+void InstructionSelector::VisitF32x4NearestInt(Node* node) { UNREACHABLE(); }
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {