riscv64: Add vconst lowerings

cranelift/codegen/src/isa/riscv64/inst.isle

@@ -1988,6 +1988,10 @@
 (decl gen_amode (Reg Offset32 Type) AMode)
 (extern constructor gen_amode gen_amode)
 
+;; Generates a AMode that points to a constant in the constant pool.
+(decl gen_const_amode (VCodeConstant) AMode)
+(extern constructor gen_const_amode gen_const_amode)
+
 (decl offset32_imm (i32) Offset32)
 (extern constructor offset32_imm offset32_imm)
 

cranelift/codegen/src/isa/riscv64/inst/args.rs

@@ -35,19 +35,47 @@ pub enum AMode {
  /// clobber pushes. See the diagram in the documentation for
  /// [crate::isa::riscv64::abi](the ABI module) for more details.
  NominalSPOffset(i64, Type),
+
+ /// A reference to a constant which is placed outside of the function's
+ /// body, typically at the end.
+ Const(VCodeConstant),
+
+ /// A reference to a label.
+ Label(MachLabel),
 }
 
 impl AMode {
- pub(crate) fn reg_offset(reg: Reg, imm: i64, ty: Type) -> AMode {
- AMode::RegOffset(reg, imm, ty)
+ pub(crate) fn with_allocs(self, allocs: &mut AllocationConsumer<'_>) -> Self {
+ match self {
+ AMode::RegOffset(reg, offset, ty) => AMode::RegOffset(allocs.next(reg), offset, ty),
+ AMode::SPOffset(..)
+ | AMode::FPOffset(..)
+ | AMode::NominalSPOffset(..)
+ | AMode::Const(..)
+ | AMode::Label(..) => self,
+ }
+ }
+
+ /// Returns the registers that known to the register allocator.
+ /// Keep this in sync with `with_allocs`.
+ pub(crate) fn get_allocatable_register(&self) -> Option<Reg> {
+ match self {
+ AMode::RegOffset(reg, ..) => Some(*reg),
+ AMode::SPOffset(..)
+ | AMode::FPOffset(..)
+ | AMode::NominalSPOffset(..)
+ | AMode::Const(..)
+ | AMode::Label(..) => None,
+ }
  }
 
- pub(crate) fn get_base_register(&self) -> Reg {
+ pub(crate) fn get_base_register(&self) -> Option<Reg> {
  match self {
- &AMode::RegOffset(reg, ..) => reg,
- &AMode::SPOffset(..) => stack_reg(),
- &AMode::FPOffset(..) => fp_reg(),
- &AMode::NominalSPOffset(..) => stack_reg(),
+ &AMode::RegOffset(reg, ..) => Some(reg),
+ &AMode::SPOffset(..) => Some(stack_reg()),
+ &AMode::FPOffset(..) => Some(fp_reg()),
+ &AMode::NominalSPOffset(..) => Some(stack_reg()),
+ &AMode::Const(..) | AMode::Label(..) => None,
  }
  }
 
@@ -64,35 +92,20 @@ impl AMode {
  &AMode::SPOffset(offset, _) => offset,
  &AMode::FPOffset(offset, _) => offset,
  &AMode::NominalSPOffset(offset, _) => offset,
+ &AMode::Const(_) | &AMode::Label(_) => 0,
  }
  }
 
  pub(crate) fn to_string_with_alloc(&self, allocs: &mut AllocationConsumer<'_>) -> String {
- let reg = self.get_base_register();
- let next = allocs.next(reg);
- let offset = self.get_offset();
- match self {
- &AMode::NominalSPOffset(..) => format!("{}", self),
- _ => format!("{}({})", offset, reg_name(next),),
- }
- }
-
- pub(crate) fn to_addr(&self, allocs: &mut AllocationConsumer<'_>) -> String {
- let reg = self.get_base_register();
- let next = allocs.next(reg);
- let offset = self.get_offset();
- match self {
- &AMode::NominalSPOffset(..) => format!("nsp{:+}", offset),
- _ => format!("{}{:+}", reg_name(next), offset),
- }
+ format!("{}", self.clone().with_allocs(allocs))
  }
 }
 
 impl Display for AMode {
  fn fmt(&self, f: &mut Formatter<'_>) -> Result {
  match self {
  &AMode::RegOffset(r, offset, ..) => {
- write!(f, "{}({:?})", offset, r)
+ write!(f, "{}({})", offset, reg_name(r))
  }
  &AMode::SPOffset(offset, ..) => {
  write!(f, "{}(sp)", offset)
@@ -103,6 +116,12 @@ impl Display for AMode {
  &AMode::FPOffset(offset, ..) => {
  write!(f, "{}(fp)", offset)
  }
+ &AMode::Const(addr, ..) => {
+ write!(f, "[const({})]", addr.as_u32())
+ }
+ &AMode::Label(label) => {
+ write!(f, "[label{}]", label.as_u32())
+ }
  }
  }
 }