diff options
Diffstat (limited to 'compiler/rustc_codegen_llvm/src/asm.rs')
| -rw-r--r-- | compiler/rustc_codegen_llvm/src/asm.rs | 1037 |
1 files changed, 1037 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs new file mode 100644 index 000000000..a53946995 --- /dev/null +++ b/compiler/rustc_codegen_llvm/src/asm.rs @@ -0,0 +1,1037 @@ +use crate::attributes; +use crate::builder::Builder; +use crate::common::Funclet; +use crate::context::CodegenCx; +use crate::llvm; +use crate::llvm_util; +use crate::type_::Type; +use crate::type_of::LayoutLlvmExt; +use crate::value::Value; + +use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece}; +use rustc_codegen_ssa::mir::operand::OperandValue; +use rustc_codegen_ssa::traits::*; +use rustc_data_structures::fx::FxHashMap; +use rustc_middle::ty::layout::TyAndLayout; +use rustc_middle::{bug, span_bug, ty::Instance}; +use rustc_span::{Pos, Span}; +use rustc_target::abi::*; +use rustc_target::asm::*; + +use libc::{c_char, c_uint}; +use smallvec::SmallVec; +use tracing::debug; + +impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> { + fn codegen_inline_asm( + &mut self, + template: &[InlineAsmTemplatePiece], + operands: &[InlineAsmOperandRef<'tcx, Self>], + options: InlineAsmOptions, + line_spans: &[Span], + instance: Instance<'_>, + dest_catch_funclet: Option<(Self::BasicBlock, Self::BasicBlock, Option<&Self::Funclet>)>, + ) { + let asm_arch = self.tcx.sess.asm_arch.unwrap(); + + // Collect the types of output operands + let mut constraints = vec![]; + let mut clobbers = vec![]; + let mut output_types = vec![]; + let mut op_idx = FxHashMap::default(); + let mut clobbered_x87 = false; + for (idx, op) in operands.iter().enumerate() { + match *op { + InlineAsmOperandRef::Out { reg, late, place } => { + let is_target_supported = |reg_class: InlineAsmRegClass| { + for &(_, feature) in reg_class.supported_types(asm_arch) { + if let Some(feature) = feature { + let codegen_fn_attrs = self.tcx.codegen_fn_attrs(instance.def_id()); + if self.tcx.sess.target_features.contains(&feature) + || codegen_fn_attrs.target_features.contains(&feature) + { + return true; + } + } else { + // Register class is unconditionally supported + return true; + } + } + false + }; + + let mut layout = None; + let ty = if let Some(ref place) = place { + layout = Some(&place.layout); + llvm_fixup_output_type(self.cx, reg.reg_class(), &place.layout) + } else if matches!( + reg.reg_class(), + InlineAsmRegClass::X86( + X86InlineAsmRegClass::mmx_reg | X86InlineAsmRegClass::x87_reg + ) + ) { + // Special handling for x87/mmx registers: we always + // clobber the whole set if one register is marked as + // clobbered. This is due to the way LLVM handles the + // FP stack in inline assembly. + if !clobbered_x87 { + clobbered_x87 = true; + clobbers.push("~{st}".to_string()); + for i in 1..=7 { + clobbers.push(format!("~{{st({})}}", i)); + } + } + continue; + } else if !is_target_supported(reg.reg_class()) + || reg.reg_class().is_clobber_only(asm_arch) + { + // We turn discarded outputs into clobber constraints + // if the target feature needed by the register class is + // disabled. This is necessary otherwise LLVM will try + // to actually allocate a register for the dummy output. + assert!(matches!(reg, InlineAsmRegOrRegClass::Reg(_))); + clobbers.push(format!("~{}", reg_to_llvm(reg, None))); + continue; + } else { + // If the output is discarded, we don't really care what + // type is used. We're just using this to tell LLVM to + // reserve the register. + dummy_output_type(self.cx, reg.reg_class()) + }; + output_types.push(ty); + op_idx.insert(idx, constraints.len()); + let prefix = if late { "=" } else { "=&" }; + constraints.push(format!("{}{}", prefix, reg_to_llvm(reg, layout))); + } + InlineAsmOperandRef::InOut { reg, late, in_value, out_place } => { + let layout = if let Some(ref out_place) = out_place { + &out_place.layout + } else { + // LLVM required tied operands to have the same type, + // so we just use the type of the input. + &in_value.layout + }; + let ty = llvm_fixup_output_type(self.cx, reg.reg_class(), layout); + output_types.push(ty); + op_idx.insert(idx, constraints.len()); + let prefix = if late { "=" } else { "=&" }; + constraints.push(format!("{}{}", prefix, reg_to_llvm(reg, Some(layout)))); + } + _ => {} + } + } + + // Collect input operands + let mut inputs = vec![]; + for (idx, op) in operands.iter().enumerate() { + match *op { + InlineAsmOperandRef::In { reg, value } => { + let llval = + llvm_fixup_input(self, value.immediate(), reg.reg_class(), &value.layout); + inputs.push(llval); + op_idx.insert(idx, constraints.len()); + constraints.push(reg_to_llvm(reg, Some(&value.layout))); + } + InlineAsmOperandRef::InOut { reg, late: _, in_value, out_place: _ } => { + let value = llvm_fixup_input( + self, + in_value.immediate(), + reg.reg_class(), + &in_value.layout, + ); + inputs.push(value); + constraints.push(format!("{}", op_idx[&idx])); + } + InlineAsmOperandRef::SymFn { instance } => { + inputs.push(self.cx.get_fn(instance)); + op_idx.insert(idx, constraints.len()); + constraints.push("s".to_string()); + } + InlineAsmOperandRef::SymStatic { def_id } => { + inputs.push(self.cx.get_static(def_id)); + op_idx.insert(idx, constraints.len()); + constraints.push("s".to_string()); + } + _ => {} + } + } + + // Build the template string + let mut template_str = String::new(); + for piece in template { + match *piece { + InlineAsmTemplatePiece::String(ref s) => { + if s.contains('$') { + for c in s.chars() { + if c == '$' { + template_str.push_str("$$"); + } else { + template_str.push(c); + } + } + } else { + template_str.push_str(s) + } + } + InlineAsmTemplatePiece::Placeholder { operand_idx, modifier, span: _ } => { + match operands[operand_idx] { + InlineAsmOperandRef::In { reg, .. } + | InlineAsmOperandRef::Out { reg, .. } + | InlineAsmOperandRef::InOut { reg, .. } => { + let modifier = modifier_to_llvm(asm_arch, reg.reg_class(), modifier); + if let Some(modifier) = modifier { + template_str.push_str(&format!( + "${{{}:{}}}", + op_idx[&operand_idx], modifier + )); + } else { + template_str.push_str(&format!("${{{}}}", op_idx[&operand_idx])); + } + } + InlineAsmOperandRef::Const { ref string } => { + // Const operands get injected directly into the template + template_str.push_str(string); + } + InlineAsmOperandRef::SymFn { .. } + | InlineAsmOperandRef::SymStatic { .. } => { + // Only emit the raw symbol name + template_str.push_str(&format!("${{{}:c}}", op_idx[&operand_idx])); + } + } + } + } + } + + constraints.append(&mut clobbers); + if !options.contains(InlineAsmOptions::PRESERVES_FLAGS) { + match asm_arch { + InlineAsmArch::AArch64 | InlineAsmArch::Arm => { + constraints.push("~{cc}".to_string()); + } + InlineAsmArch::X86 | InlineAsmArch::X86_64 => { + constraints.extend_from_slice(&[ + "~{dirflag}".to_string(), + "~{fpsr}".to_string(), + "~{flags}".to_string(), + ]); + } + InlineAsmArch::RiscV32 | InlineAsmArch::RiscV64 => { + constraints.extend_from_slice(&[ + "~{vtype}".to_string(), + "~{vl}".to_string(), + "~{vxsat}".to_string(), + "~{vxrm}".to_string(), + ]); + } + InlineAsmArch::Avr => { + constraints.push("~{sreg}".to_string()); + } + InlineAsmArch::Nvptx64 => {} + InlineAsmArch::PowerPC | InlineAsmArch::PowerPC64 => {} + InlineAsmArch::Hexagon => {} + InlineAsmArch::Mips | InlineAsmArch::Mips64 => {} + InlineAsmArch::S390x => {} + InlineAsmArch::SpirV => {} + InlineAsmArch::Wasm32 | InlineAsmArch::Wasm64 => {} + InlineAsmArch::Bpf => {} + InlineAsmArch::Msp430 => { + constraints.push("~{sr}".to_string()); + } + } + } + if !options.contains(InlineAsmOptions::NOMEM) { + // This is actually ignored by LLVM, but it's probably best to keep + // it just in case. LLVM instead uses the ReadOnly/ReadNone + // attributes on the call instruction to optimize. + constraints.push("~{memory}".to_string()); + } + let volatile = !options.contains(InlineAsmOptions::PURE); + let alignstack = !options.contains(InlineAsmOptions::NOSTACK); + let output_type = match &output_types[..] { + [] => self.type_void(), + [ty] => ty, + tys => self.type_struct(tys, false), + }; + let dialect = match asm_arch { + InlineAsmArch::X86 | InlineAsmArch::X86_64 + if !options.contains(InlineAsmOptions::ATT_SYNTAX) => + { + llvm::AsmDialect::Intel + } + _ => llvm::AsmDialect::Att, + }; + let result = inline_asm_call( + self, + &template_str, + &constraints.join(","), + &inputs, + output_type, + volatile, + alignstack, + dialect, + line_spans, + options.contains(InlineAsmOptions::MAY_UNWIND), + dest_catch_funclet, + ) + .unwrap_or_else(|| span_bug!(line_spans[0], "LLVM asm constraint validation failed")); + + let mut attrs = SmallVec::<[_; 2]>::new(); + if options.contains(InlineAsmOptions::PURE) { + if options.contains(InlineAsmOptions::NOMEM) { + attrs.push(llvm::AttributeKind::ReadNone.create_attr(self.cx.llcx)); + } else if options.contains(InlineAsmOptions::READONLY) { + attrs.push(llvm::AttributeKind::ReadOnly.create_attr(self.cx.llcx)); + } + attrs.push(llvm::AttributeKind::WillReturn.create_attr(self.cx.llcx)); + } else if options.contains(InlineAsmOptions::NOMEM) { + attrs.push(llvm::AttributeKind::InaccessibleMemOnly.create_attr(self.cx.llcx)); + } else { + // LLVM doesn't have an attribute to represent ReadOnly + SideEffect + } + attributes::apply_to_callsite(result, llvm::AttributePlace::Function, &{ attrs }); + + // Switch to the 'normal' basic block if we did an `invoke` instead of a `call` + if let Some((dest, _, _)) = dest_catch_funclet { + self.switch_to_block(dest); + } + + // Write results to outputs + for (idx, op) in operands.iter().enumerate() { + if let InlineAsmOperandRef::Out { reg, place: Some(place), .. } + | InlineAsmOperandRef::InOut { reg, out_place: Some(place), .. } = *op + { + let value = if output_types.len() == 1 { + result + } else { + self.extract_value(result, op_idx[&idx] as u64) + }; + let value = llvm_fixup_output(self, value, reg.reg_class(), &place.layout); + OperandValue::Immediate(value).store(self, place); + } + } + } +} + +impl<'tcx> AsmMethods<'tcx> for CodegenCx<'_, 'tcx> { + fn codegen_global_asm( + &self, + template: &[InlineAsmTemplatePiece], + operands: &[GlobalAsmOperandRef<'tcx>], + options: InlineAsmOptions, + _line_spans: &[Span], + ) { + let asm_arch = self.tcx.sess.asm_arch.unwrap(); + + // Default to Intel syntax on x86 + let intel_syntax = matches!(asm_arch, InlineAsmArch::X86 | InlineAsmArch::X86_64) + && !options.contains(InlineAsmOptions::ATT_SYNTAX); + + // Build the template string + let mut template_str = String::new(); + if intel_syntax { + template_str.push_str(".intel_syntax\n"); + } + for piece in template { + match *piece { + InlineAsmTemplatePiece::String(ref s) => template_str.push_str(s), + InlineAsmTemplatePiece::Placeholder { operand_idx, modifier: _, span: _ } => { + match operands[operand_idx] { + GlobalAsmOperandRef::Const { ref string } => { + // Const operands get injected directly into the + // template. Note that we don't need to escape $ + // here unlike normal inline assembly. + template_str.push_str(string); + } + GlobalAsmOperandRef::SymFn { instance } => { + let llval = self.get_fn(instance); + self.add_compiler_used_global(llval); + let symbol = llvm::build_string(|s| unsafe { + llvm::LLVMRustGetMangledName(llval, s); + }) + .expect("symbol is not valid UTF-8"); + template_str.push_str(&symbol); + } + GlobalAsmOperandRef::SymStatic { def_id } => { + let llval = self + .renamed_statics + .borrow() + .get(&def_id) + .copied() + .unwrap_or_else(|| self.get_static(def_id)); + self.add_compiler_used_global(llval); + let symbol = llvm::build_string(|s| unsafe { + llvm::LLVMRustGetMangledName(llval, s); + }) + .expect("symbol is not valid UTF-8"); + template_str.push_str(&symbol); + } + } + } + } + } + if intel_syntax { + template_str.push_str("\n.att_syntax\n"); + } + + unsafe { + llvm::LLVMRustAppendModuleInlineAsm( + self.llmod, + template_str.as_ptr().cast(), + template_str.len(), + ); + } + } +} + +pub(crate) fn inline_asm_call<'ll>( + bx: &mut Builder<'_, 'll, '_>, + asm: &str, + cons: &str, + inputs: &[&'ll Value], + output: &'ll llvm::Type, + volatile: bool, + alignstack: bool, + dia: llvm::AsmDialect, + line_spans: &[Span], + unwind: bool, + dest_catch_funclet: Option<( + &'ll llvm::BasicBlock, + &'ll llvm::BasicBlock, + Option<&Funclet<'ll>>, + )>, +) -> Option<&'ll Value> { + let volatile = if volatile { llvm::True } else { llvm::False }; + let alignstack = if alignstack { llvm::True } else { llvm::False }; + let can_throw = if unwind { llvm::True } else { llvm::False }; + + let argtys = inputs + .iter() + .map(|v| { + debug!("Asm Input Type: {:?}", *v); + bx.cx.val_ty(*v) + }) + .collect::<Vec<_>>(); + + debug!("Asm Output Type: {:?}", output); + let fty = bx.cx.type_func(&argtys, output); + unsafe { + // Ask LLVM to verify that the constraints are well-formed. + let constraints_ok = llvm::LLVMRustInlineAsmVerify(fty, cons.as_ptr().cast(), cons.len()); + debug!("constraint verification result: {:?}", constraints_ok); + if constraints_ok { + if unwind && llvm_util::get_version() < (13, 0, 0) { + bx.cx.sess().span_fatal( + line_spans[0], + "unwinding from inline assembly is only supported on llvm >= 13.", + ); + } + + let v = llvm::LLVMRustInlineAsm( + fty, + asm.as_ptr().cast(), + asm.len(), + cons.as_ptr().cast(), + cons.len(), + volatile, + alignstack, + dia, + can_throw, + ); + + let call = if let Some((dest, catch, funclet)) = dest_catch_funclet { + bx.invoke(fty, v, inputs, dest, catch, funclet) + } else { + bx.call(fty, v, inputs, None) + }; + + // Store mark in a metadata node so we can map LLVM errors + // back to source locations. See #17552. + let key = "srcloc"; + let kind = llvm::LLVMGetMDKindIDInContext( + bx.llcx, + key.as_ptr() as *const c_char, + key.len() as c_uint, + ); + + // srcloc contains one integer for each line of assembly code. + // Unfortunately this isn't enough to encode a full span so instead + // we just encode the start position of each line. + // FIXME: Figure out a way to pass the entire line spans. + let mut srcloc = vec![]; + if dia == llvm::AsmDialect::Intel && line_spans.len() > 1 { + // LLVM inserts an extra line to add the ".intel_syntax", so add + // a dummy srcloc entry for it. + // + // Don't do this if we only have 1 line span since that may be + // due to the asm template string coming from a macro. LLVM will + // default to the first srcloc for lines that don't have an + // associated srcloc. + srcloc.push(bx.const_i32(0)); + } + srcloc.extend(line_spans.iter().map(|span| bx.const_i32(span.lo().to_u32() as i32))); + let md = llvm::LLVMMDNodeInContext(bx.llcx, srcloc.as_ptr(), srcloc.len() as u32); + llvm::LLVMSetMetadata(call, kind, md); + + Some(call) + } else { + // LLVM has detected an issue with our constraints, bail out + None + } + } +} + +/// If the register is an xmm/ymm/zmm register then return its index. +fn xmm_reg_index(reg: InlineAsmReg) -> Option<u32> { + match reg { + InlineAsmReg::X86(reg) + if reg as u32 >= X86InlineAsmReg::xmm0 as u32 + && reg as u32 <= X86InlineAsmReg::xmm15 as u32 => + { + Some(reg as u32 - X86InlineAsmReg::xmm0 as u32) + } + InlineAsmReg::X86(reg) + if reg as u32 >= X86InlineAsmReg::ymm0 as u32 + && reg as u32 <= X86InlineAsmReg::ymm15 as u32 => + { + Some(reg as u32 - X86InlineAsmReg::ymm0 as u32) + } + InlineAsmReg::X86(reg) + if reg as u32 >= X86InlineAsmReg::zmm0 as u32 + && reg as u32 <= X86InlineAsmReg::zmm31 as u32 => + { + Some(reg as u32 - X86InlineAsmReg::zmm0 as u32) + } + _ => None, + } +} + +/// If the register is an AArch64 vector register then return its index. +fn a64_vreg_index(reg: InlineAsmReg) -> Option<u32> { + match reg { + InlineAsmReg::AArch64(reg) + if reg as u32 >= AArch64InlineAsmReg::v0 as u32 + && reg as u32 <= AArch64InlineAsmReg::v31 as u32 => + { + Some(reg as u32 - AArch64InlineAsmReg::v0 as u32) + } + _ => None, + } +} + +/// Converts a register class to an LLVM constraint code. +fn reg_to_llvm(reg: InlineAsmRegOrRegClass, layout: Option<&TyAndLayout<'_>>) -> String { + match reg { + // For vector registers LLVM wants the register name to match the type size. + InlineAsmRegOrRegClass::Reg(reg) => { + if let Some(idx) = xmm_reg_index(reg) { + let class = if let Some(layout) = layout { + match layout.size.bytes() { + 64 => 'z', + 32 => 'y', + _ => 'x', + } + } else { + // We use f32 as the type for discarded outputs + 'x' + }; + format!("{{{}mm{}}}", class, idx) + } else if let Some(idx) = a64_vreg_index(reg) { + let class = if let Some(layout) = layout { + match layout.size.bytes() { + 16 => 'q', + 8 => 'd', + 4 => 's', + 2 => 'h', + 1 => 'd', // We fixup i8 to i8x8 + _ => unreachable!(), + } + } else { + // We use i64x2 as the type for discarded outputs + 'q' + }; + format!("{{{}{}}}", class, idx) + } else if reg == InlineAsmReg::AArch64(AArch64InlineAsmReg::x30) { + // LLVM doesn't recognize x30 + "{lr}".to_string() + } else if reg == InlineAsmReg::Arm(ArmInlineAsmReg::r14) { + // LLVM doesn't recognize r14 + "{lr}".to_string() + } else { + format!("{{{}}}", reg.name()) + } + } + InlineAsmRegOrRegClass::RegClass(reg) => match reg { + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::reg) => "r", + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg) => "w", + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16) => "x", + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::preg) => { + unreachable!("clobber-only") + } + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg) => "r", + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low16) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low8) => "t", + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg_low16) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low8) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low4) => "x", + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg) => "w", + InlineAsmRegClass::Hexagon(HexagonInlineAsmRegClass::reg) => "r", + InlineAsmRegClass::Mips(MipsInlineAsmRegClass::reg) => "r", + InlineAsmRegClass::Mips(MipsInlineAsmRegClass::freg) => "f", + InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg16) => "h", + InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg32) => "r", + InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg64) => "l", + InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg) => "r", + InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => "b", + InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::freg) => "f", + InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::cr) + | InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::xer) => { + unreachable!("clobber-only") + } + InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::reg) => "r", + InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::freg) => "f", + InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::vreg) => { + unreachable!("clobber-only") + } + InlineAsmRegClass::X86(X86InlineAsmRegClass::reg) => "r", + InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd) => "Q", + InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_byte) => "q", + InlineAsmRegClass::X86(X86InlineAsmRegClass::xmm_reg) + | InlineAsmRegClass::X86(X86InlineAsmRegClass::ymm_reg) => "x", + InlineAsmRegClass::X86(X86InlineAsmRegClass::zmm_reg) => "v", + InlineAsmRegClass::X86(X86InlineAsmRegClass::kreg) => "^Yk", + InlineAsmRegClass::X86( + X86InlineAsmRegClass::x87_reg + | X86InlineAsmRegClass::mmx_reg + | X86InlineAsmRegClass::kreg0 + | X86InlineAsmRegClass::tmm_reg, + ) => unreachable!("clobber-only"), + InlineAsmRegClass::Wasm(WasmInlineAsmRegClass::local) => "r", + InlineAsmRegClass::Bpf(BpfInlineAsmRegClass::reg) => "r", + InlineAsmRegClass::Bpf(BpfInlineAsmRegClass::wreg) => "w", + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg) => "r", + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_upper) => "d", + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_pair) => "r", + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_iw) => "w", + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_ptr) => "e", + InlineAsmRegClass::S390x(S390xInlineAsmRegClass::reg) => "r", + InlineAsmRegClass::S390x(S390xInlineAsmRegClass::freg) => "f", + InlineAsmRegClass::Msp430(Msp430InlineAsmRegClass::reg) => "r", + InlineAsmRegClass::SpirV(SpirVInlineAsmRegClass::reg) => { + bug!("LLVM backend does not support SPIR-V") + } + InlineAsmRegClass::Err => unreachable!(), + } + .to_string(), + } +} + +/// Converts a modifier into LLVM's equivalent modifier. +fn modifier_to_llvm( + arch: InlineAsmArch, + reg: InlineAsmRegClass, + modifier: Option<char>, +) -> Option<char> { + match reg { + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::reg) => modifier, + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg) + | InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16) => { + if modifier == Some('v') { None } else { modifier } + } + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::preg) => { + unreachable!("clobber-only") + } + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg) => None, + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg_low16) => None, + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low16) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low8) => Some('P'), + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low8) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low4) => { + if modifier.is_none() { + Some('q') + } else { + modifier + } + } + InlineAsmRegClass::Hexagon(_) => None, + InlineAsmRegClass::Mips(_) => None, + InlineAsmRegClass::Nvptx(_) => None, + InlineAsmRegClass::PowerPC(_) => None, + InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::reg) + | InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::freg) => None, + InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::vreg) => { + unreachable!("clobber-only") + } + InlineAsmRegClass::X86(X86InlineAsmRegClass::reg) + | InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd) => match modifier { + None if arch == InlineAsmArch::X86_64 => Some('q'), + None => Some('k'), + Some('l') => Some('b'), + Some('h') => Some('h'), + Some('x') => Some('w'), + Some('e') => Some('k'), + Some('r') => Some('q'), + _ => unreachable!(), + }, + InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_byte) => None, + InlineAsmRegClass::X86(reg @ X86InlineAsmRegClass::xmm_reg) + | InlineAsmRegClass::X86(reg @ X86InlineAsmRegClass::ymm_reg) + | InlineAsmRegClass::X86(reg @ X86InlineAsmRegClass::zmm_reg) => match (reg, modifier) { + (X86InlineAsmRegClass::xmm_reg, None) => Some('x'), + (X86InlineAsmRegClass::ymm_reg, None) => Some('t'), + (X86InlineAsmRegClass::zmm_reg, None) => Some('g'), + (_, Some('x')) => Some('x'), + (_, Some('y')) => Some('t'), + (_, Some('z')) => Some('g'), + _ => unreachable!(), + }, + InlineAsmRegClass::X86(X86InlineAsmRegClass::kreg) => None, + InlineAsmRegClass::X86( + X86InlineAsmRegClass::x87_reg + | X86InlineAsmRegClass::mmx_reg + | X86InlineAsmRegClass::kreg0 + | X86InlineAsmRegClass::tmm_reg, + ) => { + unreachable!("clobber-only") + } + InlineAsmRegClass::Wasm(WasmInlineAsmRegClass::local) => None, + InlineAsmRegClass::Bpf(_) => None, + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_pair) + | InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_iw) + | InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_ptr) => match modifier { + Some('h') => Some('B'), + Some('l') => Some('A'), + _ => None, + }, + InlineAsmRegClass::Avr(_) => None, + InlineAsmRegClass::S390x(_) => None, + InlineAsmRegClass::Msp430(_) => None, + InlineAsmRegClass::SpirV(SpirVInlineAsmRegClass::reg) => { + bug!("LLVM backend does not support SPIR-V") + } + InlineAsmRegClass::Err => unreachable!(), + } +} + +/// Type to use for outputs that are discarded. It doesn't really matter what +/// the type is, as long as it is valid for the constraint code. +fn dummy_output_type<'ll>(cx: &CodegenCx<'ll, '_>, reg: InlineAsmRegClass) -> &'ll Type { + match reg { + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::reg) => cx.type_i32(), + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg) + | InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16) => { + cx.type_vector(cx.type_i64(), 2) + } + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::preg) => { + unreachable!("clobber-only") + } + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::reg) => cx.type_i32(), + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg_low16) => cx.type_f32(), + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low16) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::dreg_low8) => cx.type_f64(), + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low8) + | InlineAsmRegClass::Arm(ArmInlineAsmRegClass::qreg_low4) => { + cx.type_vector(cx.type_i64(), 2) + } + InlineAsmRegClass::Hexagon(HexagonInlineAsmRegClass::reg) => cx.type_i32(), + InlineAsmRegClass::Mips(MipsInlineAsmRegClass::reg) => cx.type_i32(), + InlineAsmRegClass::Mips(MipsInlineAsmRegClass::freg) => cx.type_f32(), + InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg16) => cx.type_i16(), + InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg32) => cx.type_i32(), + InlineAsmRegClass::Nvptx(NvptxInlineAsmRegClass::reg64) => cx.type_i64(), + InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg) => cx.type_i32(), + InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::reg_nonzero) => cx.type_i32(), + InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::freg) => cx.type_f64(), + InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::cr) + | InlineAsmRegClass::PowerPC(PowerPCInlineAsmRegClass::xer) => { + unreachable!("clobber-only") + } + InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::reg) => cx.type_i32(), + InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::freg) => cx.type_f32(), + InlineAsmRegClass::RiscV(RiscVInlineAsmRegClass::vreg) => { + unreachable!("clobber-only") + } + InlineAsmRegClass::X86(X86InlineAsmRegClass::reg) + | InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd) => cx.type_i32(), + InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_byte) => cx.type_i8(), + InlineAsmRegClass::X86(X86InlineAsmRegClass::xmm_reg) + | InlineAsmRegClass::X86(X86InlineAsmRegClass::ymm_reg) + | InlineAsmRegClass::X86(X86InlineAsmRegClass::zmm_reg) => cx.type_f32(), + InlineAsmRegClass::X86(X86InlineAsmRegClass::kreg) => cx.type_i16(), + InlineAsmRegClass::X86( + X86InlineAsmRegClass::x87_reg + | X86InlineAsmRegClass::mmx_reg + | X86InlineAsmRegClass::kreg0 + | X86InlineAsmRegClass::tmm_reg, + ) => { + unreachable!("clobber-only") + } + InlineAsmRegClass::Wasm(WasmInlineAsmRegClass::local) => cx.type_i32(), + InlineAsmRegClass::Bpf(BpfInlineAsmRegClass::reg) => cx.type_i64(), + InlineAsmRegClass::Bpf(BpfInlineAsmRegClass::wreg) => cx.type_i32(), + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg) => cx.type_i8(), + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_upper) => cx.type_i8(), + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_pair) => cx.type_i16(), + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_iw) => cx.type_i16(), + InlineAsmRegClass::Avr(AvrInlineAsmRegClass::reg_ptr) => cx.type_i16(), + InlineAsmRegClass::S390x(S390xInlineAsmRegClass::reg) => cx.type_i32(), + InlineAsmRegClass::S390x(S390xInlineAsmRegClass::freg) => cx.type_f64(), + InlineAsmRegClass::Msp430(Msp430InlineAsmRegClass::reg) => cx.type_i16(), + InlineAsmRegClass::SpirV(SpirVInlineAsmRegClass::reg) => { + bug!("LLVM backend does not support SPIR-V") + } + InlineAsmRegClass::Err => unreachable!(), + } +} + +/// Helper function to get the LLVM type for a Scalar. Pointers are returned as +/// the equivalent integer type. +fn llvm_asm_scalar_type<'ll>(cx: &CodegenCx<'ll, '_>, scalar: Scalar) -> &'ll Type { + match scalar.primitive() { + Primitive::Int(Integer::I8, _) => cx.type_i8(), + Primitive::Int(Integer::I16, _) => cx.type_i16(), + Primitive::Int(Integer::I32, _) => cx.type_i32(), + Primitive::Int(Integer::I64, _) => cx.type_i64(), + Primitive::F32 => cx.type_f32(), + Primitive::F64 => cx.type_f64(), + Primitive::Pointer => cx.type_isize(), + _ => unreachable!(), + } +} + +/// Fix up an input value to work around LLVM bugs. +fn llvm_fixup_input<'ll, 'tcx>( + bx: &mut Builder<'_, 'll, 'tcx>, + mut value: &'ll Value, + reg: InlineAsmRegClass, + layout: &TyAndLayout<'tcx>, +) -> &'ll Value { + match (reg, layout.abi) { + (InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg), Abi::Scalar(s)) => { + if let Primitive::Int(Integer::I8, _) = s.primitive() { + let vec_ty = bx.cx.type_vector(bx.cx.type_i8(), 8); + bx.insert_element(bx.const_undef(vec_ty), value, bx.const_i32(0)) + } else { + value + } + } + (InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16), Abi::Scalar(s)) => { + let elem_ty = llvm_asm_scalar_type(bx.cx, s); + let count = 16 / layout.size.bytes(); + let vec_ty = bx.cx.type_vector(elem_ty, count); + if let Primitive::Pointer = s.primitive() { + value = bx.ptrtoint(value, bx.cx.type_isize()); + } + bx.insert_element(bx.const_undef(vec_ty), value, bx.const_i32(0)) + } + ( + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16), + Abi::Vector { element, count }, + ) if layout.size.bytes() == 8 => { + let elem_ty = llvm_asm_scalar_type(bx.cx, element); + let vec_ty = bx.cx.type_vector(elem_ty, count); + let indices: Vec<_> = (0..count * 2).map(|x| bx.const_i32(x as i32)).collect(); + bx.shuffle_vector(value, bx.const_undef(vec_ty), bx.const_vector(&indices)) + } + (InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd), Abi::Scalar(s)) + if s.primitive() == Primitive::F64 => + { + bx.bitcast(value, bx.cx.type_i64()) + } + ( + InlineAsmRegClass::X86(X86InlineAsmRegClass::xmm_reg | X86InlineAsmRegClass::zmm_reg), + Abi::Vector { .. }, + ) if layout.size.bytes() == 64 => bx.bitcast(value, bx.cx.type_vector(bx.cx.type_f64(), 8)), + ( + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg | ArmInlineAsmRegClass::sreg_low16), + Abi::Scalar(s), + ) => { + if let Primitive::Int(Integer::I32, _) = s.primitive() { + bx.bitcast(value, bx.cx.type_f32()) + } else { + value + } + } + ( + InlineAsmRegClass::Arm( + ArmInlineAsmRegClass::dreg + | ArmInlineAsmRegClass::dreg_low8 + | ArmInlineAsmRegClass::dreg_low16, + ), + Abi::Scalar(s), + ) => { + if let Primitive::Int(Integer::I64, _) = s.primitive() { + bx.bitcast(value, bx.cx.type_f64()) + } else { + value + } + } + (InlineAsmRegClass::Mips(MipsInlineAsmRegClass::reg), Abi::Scalar(s)) => { + match s.primitive() { + // MIPS only supports register-length arithmetics. + Primitive::Int(Integer::I8 | Integer::I16, _) => bx.zext(value, bx.cx.type_i32()), + Primitive::F32 => bx.bitcast(value, bx.cx.type_i32()), + Primitive::F64 => bx.bitcast(value, bx.cx.type_i64()), + _ => value, + } + } + _ => value, + } +} + +/// Fix up an output value to work around LLVM bugs. +fn llvm_fixup_output<'ll, 'tcx>( + bx: &mut Builder<'_, 'll, 'tcx>, + mut value: &'ll Value, + reg: InlineAsmRegClass, + layout: &TyAndLayout<'tcx>, +) -> &'ll Value { + match (reg, layout.abi) { + (InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg), Abi::Scalar(s)) => { + if let Primitive::Int(Integer::I8, _) = s.primitive() { + bx.extract_element(value, bx.const_i32(0)) + } else { + value + } + } + (InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16), Abi::Scalar(s)) => { + value = bx.extract_element(value, bx.const_i32(0)); + if let Primitive::Pointer = s.primitive() { + value = bx.inttoptr(value, layout.llvm_type(bx.cx)); + } + value + } + ( + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16), + Abi::Vector { element, count }, + ) if layout.size.bytes() == 8 => { + let elem_ty = llvm_asm_scalar_type(bx.cx, element); + let vec_ty = bx.cx.type_vector(elem_ty, count * 2); + let indices: Vec<_> = (0..count).map(|x| bx.const_i32(x as i32)).collect(); + bx.shuffle_vector(value, bx.const_undef(vec_ty), bx.const_vector(&indices)) + } + (InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd), Abi::Scalar(s)) + if s.primitive() == Primitive::F64 => + { + bx.bitcast(value, bx.cx.type_f64()) + } + ( + InlineAsmRegClass::X86(X86InlineAsmRegClass::xmm_reg | X86InlineAsmRegClass::zmm_reg), + Abi::Vector { .. }, + ) if layout.size.bytes() == 64 => bx.bitcast(value, layout.llvm_type(bx.cx)), + ( + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg | ArmInlineAsmRegClass::sreg_low16), + Abi::Scalar(s), + ) => { + if let Primitive::Int(Integer::I32, _) = s.primitive() { + bx.bitcast(value, bx.cx.type_i32()) + } else { + value + } + } + ( + InlineAsmRegClass::Arm( + ArmInlineAsmRegClass::dreg + | ArmInlineAsmRegClass::dreg_low8 + | ArmInlineAsmRegClass::dreg_low16, + ), + Abi::Scalar(s), + ) => { + if let Primitive::Int(Integer::I64, _) = s.primitive() { + bx.bitcast(value, bx.cx.type_i64()) + } else { + value + } + } + (InlineAsmRegClass::Mips(MipsInlineAsmRegClass::reg), Abi::Scalar(s)) => { + match s.primitive() { + // MIPS only supports register-length arithmetics. + Primitive::Int(Integer::I8, _) => bx.trunc(value, bx.cx.type_i8()), + Primitive::Int(Integer::I16, _) => bx.trunc(value, bx.cx.type_i16()), + Primitive::F32 => bx.bitcast(value, bx.cx.type_f32()), + Primitive::F64 => bx.bitcast(value, bx.cx.type_f64()), + _ => value, + } + } + _ => value, + } +} + +/// Output type to use for llvm_fixup_output. +fn llvm_fixup_output_type<'ll, 'tcx>( + cx: &CodegenCx<'ll, 'tcx>, + reg: InlineAsmRegClass, + layout: &TyAndLayout<'tcx>, +) -> &'ll Type { + match (reg, layout.abi) { + (InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg), Abi::Scalar(s)) => { + if let Primitive::Int(Integer::I8, _) = s.primitive() { + cx.type_vector(cx.type_i8(), 8) + } else { + layout.llvm_type(cx) + } + } + (InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16), Abi::Scalar(s)) => { + let elem_ty = llvm_asm_scalar_type(cx, s); + let count = 16 / layout.size.bytes(); + cx.type_vector(elem_ty, count) + } + ( + InlineAsmRegClass::AArch64(AArch64InlineAsmRegClass::vreg_low16), + Abi::Vector { element, count }, + ) if layout.size.bytes() == 8 => { + let elem_ty = llvm_asm_scalar_type(cx, element); + cx.type_vector(elem_ty, count * 2) + } + (InlineAsmRegClass::X86(X86InlineAsmRegClass::reg_abcd), Abi::Scalar(s)) + if s.primitive() == Primitive::F64 => + { + cx.type_i64() + } + ( + InlineAsmRegClass::X86(X86InlineAsmRegClass::xmm_reg | X86InlineAsmRegClass::zmm_reg), + Abi::Vector { .. }, + ) if layout.size.bytes() == 64 => cx.type_vector(cx.type_f64(), 8), + ( + InlineAsmRegClass::Arm(ArmInlineAsmRegClass::sreg | ArmInlineAsmRegClass::sreg_low16), + Abi::Scalar(s), + ) => { + if let Primitive::Int(Integer::I32, _) = s.primitive() { + cx.type_f32() + } else { + layout.llvm_type(cx) + } + } + ( + InlineAsmRegClass::Arm( + ArmInlineAsmRegClass::dreg + | ArmInlineAsmRegClass::dreg_low8 + | ArmInlineAsmRegClass::dreg_low16, + ), + Abi::Scalar(s), + ) => { + if let Primitive::Int(Integer::I64, _) = s.primitive() { + cx.type_f64() + } else { + layout.llvm_type(cx) + } + } + (InlineAsmRegClass::Mips(MipsInlineAsmRegClass::reg), Abi::Scalar(s)) => { + match s.primitive() { + // MIPS only supports register-length arithmetics. + Primitive::Int(Integer::I8 | Integer::I16, _) => cx.type_i32(), + Primitive::F32 => cx.type_i32(), + Primitive::F64 => cx.type_i64(), + _ => layout.llvm_type(cx), + } + } + _ => layout.llvm_type(cx), + } +} |