check legal rvv types

Author: michaelmaitland

llvm/lib/Target/RISCV/GISel/RISCVCallLowering.cpp

@@ -297,6 +297,34 @@ struct RISCVCallReturnHandler : public RISCVIncomingValueHandler {
 RISCVCallLowering::RISCVCallLowering(const RISCVTargetLowering &TLI)
     : CallLowering(&TLI) {}
 
+/// Return true if scalable vector with ScalarTy is legal for lowering.
+static bool isLegalElementTypeForRVV(EVT ScalarTy,
+                                     const RISCVSubtarget &Subtarget) {
+  if (!ScalarTy.isSimple())
+    return false;
+  switch (ScalarTy.getSimpleVT().SimpleTy) {
+  case MVT::iPTR:
+    return Subtarget.is64Bit() ? Subtarget.hasVInstructionsI64() : true;
+  case MVT::i1:
+  case MVT::i8:
+  case MVT::i16:
+  case MVT::i32:
+    return true;
+  case MVT::i64:
+    return Subtarget.hasVInstructionsI64();
+  case MVT::f16:
+    return Subtarget.hasVInstructionsF16();
+  case MVT::bf16:
+    return Subtarget.hasVInstructionsBF16();
+  case MVT::f32:
+    return Subtarget.hasVInstructionsF32();
+  case MVT::f64:
+    return Subtarget.hasVInstructionsF64();
+  default:
+    return false;
+  }
+}
+
 // TODO: Support all argument types.
 // TODO: Remove IsLowerArgs argument by adding support for vectors in lowerCall.
 static bool isSupportedArgumentType(Type *T, const RISCVSubtarget &Subtarget,
@@ -311,7 +339,8 @@ static bool isSupportedArgumentType(Type *T, const RISCVSubtarget &Subtarget,
     return true;
   // TODO: Support fixed vector types.
   if (IsLowerArgs && T->isVectorTy() && Subtarget.hasVInstructions() &&
-      T->isScalableTy())
+      T->isScalableTy() &&
+      isLegalElementTypeForRVV(EVT::getEVT(T->getScalarType()), Subtarget))
     return true;
   return false;
 }

llvm/test/CodeGen/RISCV/GlobalISel/irtranslator/vec-args-bf16-err.ll

@@ -0,0 +1,16 @@
+; RUN: not --crash llc -mtriple=riscv32 -mattr=+v -global-isel -stop-after=irtranslator \
+; RUN:   -verify-machineinstrs < %s 2>&1 | FileCheck %s
+; RUN: not --crash llc -mtriple=riscv64 -mattr=+v -global-isel -stop-after=irtranslator \
+; RUN:   -verify-machineinstrs < %s 2>&1 | FileCheck %s
+
+; The purpose of this test is to show that the compiler throws an error when
+; there is no support for bf16 vectors. If the compiler did not throw an error,
+; then it will try to scalarize the argument to an s32, which may drop elements.
+define void @test_args_nxv1bf16(<vscale x 1 x bfloat> %a) {
+entry:
+  ret void
+}
+
+; CHECK: LLVM ERROR: unable to lower arguments: ptr (in function: test_args_nxv1bf16)
+
+

llvm/test/CodeGen/RISCV/GlobalISel/irtranslator/vec-args-f16-err.ll

@@ -0,0 +1,16 @@
+; RUN: not --crash llc -mtriple=riscv32 -mattr=+v -global-isel -stop-after=irtranslator \
+; RUN:   -verify-machineinstrs < %s 2>&1 | FileCheck %s
+; RUN: not --crash llc -mtriple=riscv64 -mattr=+v -global-isel -stop-after=irtranslator \
+; RUN:   -verify-machineinstrs < %s 2>&1 | FileCheck %s
+
+; The purpose of this test is to show that the compiler throws an error when
+; there is no support for f16 vectors. If the compiler did not throw an error,
+; then it will try to scalarize the argument to an s32, which may drop elements.
+define void @test_args_nxv1f16(<vscale x 1 x half> %a) {
+entry:
+  ret void
+}
+
+; CHECK: LLVM ERROR: unable to lower arguments: ptr (in function: test_args_nxv1f16)
+
+