1 //! IBM Z 64-bit Instruction Set Architecture.
2 
3 use crate::dominator_tree::DominatorTree;
4 use crate::ir::{self, Function, Type};
5 use crate::isa::s390x::settings as s390x_settings;
6 #[cfg(feature = "unwind")]
7 use crate::isa::unwind::systemv::RegisterMappingError;
8 use crate::isa::{Builder as IsaBuilder, FunctionAlignment, IsaFlagsHashKey, TargetIsa};
9 use crate::machinst::{
10     CompiledCode, CompiledCodeStencil, MachInst, MachTextSectionBuilder, Reg, SigSet,
11     TextSectionBuilder, VCode, compile,
12 };
13 use crate::result::CodegenResult;
14 use crate::settings as shared_settings;
15 use alloc::string::String;
16 use alloc::{boxed::Box, vec::Vec};
17 use core::fmt;
18 use cranelift_control::ControlPlane;
19 use target_lexicon::{Architecture, Triple};
20 
21 // New backend:
22 mod abi;
23 pub(crate) mod inst;
24 mod lower;
25 mod settings;
26 
27 use self::inst::EmitInfo;
28 
29 /// A IBM Z backend.
30 pub struct S390xBackend {
31     triple: Triple,
32     flags: shared_settings::Flags,
33     isa_flags: s390x_settings::Flags,
34 }
35 
36 impl S390xBackend {
37     /// Create a new IBM Z backend with the given (shared) flags.
38     pub fn new_with_flags(
39         triple: Triple,
40         flags: shared_settings::Flags,
41         isa_flags: s390x_settings::Flags,
42     ) -> S390xBackend {
43         S390xBackend {
44             triple,
45             flags,
46             isa_flags,
47         }
48     }
49 
50     /// This performs lowering to VCode, register-allocates the code, computes block layout and
51     /// finalizes branches. The result is ready for binary emission.
52     fn compile_vcode(
53         &self,
54         func: &Function,
55         domtree: &DominatorTree,
56         ctrl_plane: &mut ControlPlane,
57     ) -> CodegenResult<(VCode<inst::Inst>, regalloc2::Output)> {
58         let emit_info = EmitInfo::new(self.isa_flags.clone());
59         let sigs = SigSet::new::<abi::S390xMachineDeps>(func, &self.flags)?;
60         let abi = abi::S390xCallee::new(func, self, &self.isa_flags, &sigs)?;
61         compile::compile::<S390xBackend>(func, domtree, self, abi, emit_info, sigs, ctrl_plane)
62     }
63 }
64 
65 impl TargetIsa for S390xBackend {
66     fn compile_function(
67         &self,
68         func: &Function,
69         domtree: &DominatorTree,
70         want_disasm: bool,
71         ctrl_plane: &mut ControlPlane,
72     ) -> CodegenResult<CompiledCodeStencil> {
73         let flags = self.flags();
74         let (vcode, regalloc_result) = self.compile_vcode(func, domtree, ctrl_plane)?;
75 
76         let emit_result = vcode.emit(&regalloc_result, want_disasm, flags, ctrl_plane);
77         let value_labels_ranges = emit_result.value_labels_ranges;
78         let buffer = emit_result.buffer;
79 
80         if let Some(disasm) = emit_result.disasm.as_ref() {
81             log::debug!("disassembly:\n{disasm}");
82         }
83 
84         Ok(CompiledCodeStencil {
85             buffer,
86             vcode: emit_result.disasm,
87             value_labels_ranges,
88             bb_starts: emit_result.bb_offsets,
89             bb_edges: emit_result.bb_edges,
90         })
91     }
92 
93     fn name(&self) -> &'static str {
94         "s390x"
95     }
96 
97     fn triple(&self) -> &Triple {
98         &self.triple
99     }
100 
101     fn flags(&self) -> &shared_settings::Flags {
102         &self.flags
103     }
104 
105     fn isa_flags(&self) -> Vec<shared_settings::Value> {
106         self.isa_flags.iter().collect()
107     }
108 
109     fn isa_flags_hash_key(&self) -> IsaFlagsHashKey<'_> {
110         IsaFlagsHashKey(self.isa_flags.hash_key())
111     }
112 
113     fn dynamic_vector_bytes(&self, _dyn_ty: Type) -> u32 {
114         16
115     }
116 
117     #[cfg(feature = "unwind")]
118     fn emit_unwind_info(
119         &self,
120         result: &CompiledCode,
121         kind: crate::isa::unwind::UnwindInfoKind,
122     ) -> CodegenResult<Option<crate::isa::unwind::UnwindInfo>> {
123         use crate::isa::unwind::UnwindInfo;
124         use crate::isa::unwind::UnwindInfoKind;
125         Ok(match kind {
126             UnwindInfoKind::SystemV => {
127                 let mapper = self::inst::unwind::systemv::RegisterMapper;
128                 Some(UnwindInfo::SystemV(
129                     crate::isa::unwind::systemv::create_unwind_info_from_insts(
130                         &result.buffer.unwind_info[..],
131                         result.buffer.data().len(),
132                         &mapper,
133                     )?,
134                 ))
135             }
136             _ => None,
137         })
138     }
139 
140     #[cfg(feature = "unwind")]
141     fn create_systemv_cie(&self) -> Option<gimli::write::CommonInformationEntry> {
142         Some(inst::unwind::systemv::create_cie())
143     }
144 
145     #[cfg(feature = "unwind")]
146     fn map_regalloc_reg_to_dwarf(&self, reg: Reg) -> Result<u16, RegisterMappingError> {
147         inst::unwind::systemv::map_reg(reg).map(|reg| reg.0)
148     }
149 
150     fn text_section_builder(&self, num_funcs: usize) -> Box<dyn TextSectionBuilder> {
151         Box::new(MachTextSectionBuilder::<inst::Inst>::new(num_funcs))
152     }
153 
154     fn function_alignment(&self) -> FunctionAlignment {
155         inst::Inst::function_alignment()
156     }
157 
158     fn page_size_align_log2(&self) -> u8 {
159         debug_assert_eq!(1 << 12, 0x1000);
160         12
161     }
162 
163     #[cfg(feature = "disas")]
164     fn to_capstone(&self) -> Result<capstone::Capstone, capstone::Error> {
165         use capstone::prelude::*;
166         let mut cs = Capstone::new()
167             .sysz()
168             .mode(arch::sysz::ArchMode::Default)
169             .build()?;
170 
171         cs.set_skipdata(true)?;
172 
173         Ok(cs)
174     }
175 
176     fn pretty_print_reg(&self, reg: Reg, _size: u8) -> String {
177         inst::regs::pretty_print_reg(reg)
178     }
179 
180     fn has_native_fma(&self) -> bool {
181         true
182     }
183 
184     fn has_round(&self) -> bool {
185         true
186     }
187 
188     fn has_blendv_lowering(&self, _: Type) -> bool {
189         self.isa_flags.has_vxrs_ext3()
190     }
191 
192     fn has_x86_pshufb_lowering(&self) -> bool {
193         false
194     }
195 
196     fn has_x86_pmulhrsw_lowering(&self) -> bool {
197         false
198     }
199 
200     fn has_x86_pmaddubsw_lowering(&self) -> bool {
201         false
202     }
203 
204     fn default_argument_extension(&self) -> ir::ArgumentExtension {
205         // This is copied/carried over from a historical piece of code in
206         // Wasmtime:
207         //
208         // https://github.com/bytecodealliance/wasmtime/blob/a018a5a9addb77d5998021a0150192aa955c71bf/crates/cranelift/src/lib.rs#L366-L374
209         //
210         // Whether or not it is still applicable here is unsure, but it's left
211         // the same as-is for now to reduce the likelihood of problems arising.
212         ir::ArgumentExtension::Uext
213     }
214 }
215 
216 impl fmt::Display for S390xBackend {
217     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
218         f.debug_struct("MachBackend")
219             .field("name", &self.name())
220             .field("triple", &self.triple())
221             .field("flags", &format!("{}", self.flags()))
222             .finish()
223     }
224 }
225 
226 /// Create a new `isa::Builder`.
227 pub fn isa_builder(triple: Triple) -> IsaBuilder {
228     assert!(triple.architecture == Architecture::S390x);
229     IsaBuilder {
230         triple,
231         setup: s390x_settings::builder(),
232         constructor: |triple, shared_flags, builder| {
233             let isa_flags = s390x_settings::Flags::new(&shared_flags, builder);
234             let backend = S390xBackend::new_with_flags(triple, shared_flags, isa_flags);
235             Ok(backend.wrapped())
236         },
237     }
238 }
239