[GlobalISel] Import llvm.stepvector (#115721)

Author: Thorsten Schütt

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

@@ -2597,6 +2597,10 @@ bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
     return translateExtractVector(CI, MIRBuilder);
   case Intrinsic::vector_insert:
     return translateInsertVector(CI, MIRBuilder);
+  case Intrinsic::stepvector: {
+    MIRBuilder.buildStepVector(getOrCreateVReg(CI), 1);
+    return true;
+  }
   case Intrinsic::prefetch: {
     Value *Addr = CI.getOperand(0);
     unsigned RW = cast<ConstantInt>(CI.getOperand(1))->getZExtValue();

llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp

@@ -811,8 +811,9 @@ MachineInstrBuilder MachineIRBuilder::buildInsert(const DstOp &Res,
 
 MachineInstrBuilder MachineIRBuilder::buildStepVector(const DstOp &Res,
                                                       unsigned Step) {
-  ConstantInt *CI =
-      ConstantInt::get(getMF().getFunction().getContext(), APInt(64, Step));
+  unsigned Bitwidth = Res.getLLTTy(*getMRI()).getElementType().getSizeInBits();
+  ConstantInt *CI = ConstantInt::get(getMF().getFunction().getContext(),
+                                     APInt(Bitwidth, Step));
   auto StepVector = buildInstr(TargetOpcode::G_STEP_VECTOR);
   StepVector->setDebugLoc(DebugLoc());
   Res.addDefToMIB(*getMRI(), StepVector);

llvm/test/CodeGen/AArch64/GlobalISel/irtranslator-stepvector.ll

@@ -0,0 +1,46 @@
+; NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+; RUN: llc -O0 -mtriple=aarch64-linux-gnu  -mattr=+sve -global-isel -aarch64-enable-gisel-sve=1 -stop-after=irtranslator %s -o - | FileCheck %s
+
+define <vscale x 2 x i64> @call_step_vector_i64() {
+  ; CHECK-LABEL: name: call_step_vector_i64
+  ; CHECK: bb.1.entry:
+  ; CHECK-NEXT:   [[STEP_VECTOR:%[0-9]+]]:_(<vscale x 2 x s64>) = G_STEP_VECTOR i64 1
+  ; CHECK-NEXT:   $z0 = COPY [[STEP_VECTOR]](<vscale x 2 x s64>)
+  ; CHECK-NEXT:   RET_ReallyLR implicit $z0
+entry:
+  %steps = call <vscale x 2 x i64> @llvm.stepvector.nxv2i64()
+  ret <vscale x 2 x i64> %steps
+}
+
+define <vscale x 4 x i32> @call_step_vector_i32() {
+  ; CHECK-LABEL: name: call_step_vector_i32
+  ; CHECK: bb.1.entry:
+  ; CHECK-NEXT:   [[STEP_VECTOR:%[0-9]+]]:_(<vscale x 4 x s32>) = G_STEP_VECTOR i32 1
+  ; CHECK-NEXT:   $z0 = COPY [[STEP_VECTOR]](<vscale x 4 x s32>)
+  ; CHECK-NEXT:   RET_ReallyLR implicit $z0
+entry:
+  %steps = call <vscale x 4 x i32> @llvm.stepvector.nxv4i32()
+  ret <vscale x 4 x i32> %steps
+}
+
+define <vscale x 8 x i16> @call_step_vector_i16() {
+  ; CHECK-LABEL: name: call_step_vector_i16
+  ; CHECK: bb.1.entry:
+  ; CHECK-NEXT:   [[STEP_VECTOR:%[0-9]+]]:_(<vscale x 8 x s16>) = G_STEP_VECTOR i16 1
+  ; CHECK-NEXT:   $z0 = COPY [[STEP_VECTOR]](<vscale x 8 x s16>)
+  ; CHECK-NEXT:   RET_ReallyLR implicit $z0
+entry:
+  %steps = call <vscale x 8 x i16> @llvm.stepvector.nxv8i16()
+  ret <vscale x 8 x i16> %steps
+}
+
+define <vscale x 16 x i8> @call_step_vector_i8() {
+  ; CHECK-LABEL: name: call_step_vector_i8
+  ; CHECK: bb.1.entry:
+  ; CHECK-NEXT:   [[STEP_VECTOR:%[0-9]+]]:_(<vscale x 16 x s8>) = G_STEP_VECTOR i8 1
+  ; CHECK-NEXT:   $z0 = COPY [[STEP_VECTOR]](<vscale x 16 x s8>)
+  ; CHECK-NEXT:   RET_ReallyLR implicit $z0
+entry:
+  %steps = call <vscale x 16 x i8> @llvm.stepvector.nxv16i8()
+  ret <vscale x 16 x i8> %steps
+}