diff options
| -rw-r--r-- | src/Sema.zig | 67 |
1 files changed, 61 insertions, 6 deletions
diff --git a/src/Sema.zig b/src/Sema.zig index d4c49973a1..42b43d656f 100644 --- a/src/Sema.zig +++ b/src/Sema.zig @@ -2711,17 +2711,72 @@ fn zirAllocComptime(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileErr fn zirMakePtrConst(sema: *Sema, block: *Block, inst: Zir.Inst.Index) CompileError!Air.Inst.Ref { const inst_data = sema.code.instructions.items(.data)[inst].un_node; - const ptr = try sema.resolveInst(inst_data.operand); - const ptr_ty = sema.typeOf(ptr); - var ptr_info = ptr_ty.ptrInfo().data; + const src = inst_data.src(); + const alloc = try sema.resolveInst(inst_data.operand); + const alloc_ty = sema.typeOf(alloc); + + var ptr_info = alloc_ty.ptrInfo().data; + const elem_ty = ptr_info.pointee_type; + + // Detect if all stores to an `.alloc` were comptime known. + ct: { + var search_index: usize = block.instructions.items.len; + const air_tags = sema.air_instructions.items(.tag); + const air_datas = sema.air_instructions.items(.data); + + const store_inst = while (true) { + if (search_index == 0) break :ct; + search_index -= 1; + + const candidate = block.instructions.items[search_index]; + switch (air_tags[candidate]) { + .dbg_stmt => continue, + .store => break candidate, + else => break :ct, + } + } else unreachable; // TODO shouldn't need this + + while (true) { + if (search_index == 0) break :ct; + search_index -= 1; + + const candidate = block.instructions.items[search_index]; + switch (air_tags[candidate]) { + .dbg_stmt => continue, + .alloc => { + if (Air.indexToRef(candidate) != alloc) break :ct; + break; + }, + else => break :ct, + } + } + + const store_op = air_datas[store_inst].bin_op; + const store_val = (try sema.resolveMaybeUndefVal(block, src, store_op.rhs)) orelse break :ct; + if (store_op.lhs != alloc) break :ct; + + // Remove all the unnecessary runtime instructions. + block.instructions.shrinkRetainingCapacity(search_index); + + var anon_decl = try block.startAnonDecl(src); + defer anon_decl.deinit(); + return sema.analyzeDeclRef(try anon_decl.finish( + try elem_ty.copy(anon_decl.arena()), + try store_val.copy(anon_decl.arena()), + ptr_info.@"align", + )); + } + ptr_info.mutable = false; const const_ptr_ty = try Type.ptr(sema.arena, sema.mod, ptr_info); - if (try sema.resolveMaybeUndefVal(block, inst_data.src(), ptr)) |val| { + // Detect if a comptime value simply needs to have its type changed. + if (try sema.resolveMaybeUndefVal(block, inst_data.src(), alloc)) |val| { return sema.addConstant(const_ptr_ty, val); } - try sema.requireRuntimeBlock(block, inst_data.src()); - return block.addBitCast(const_ptr_ty, ptr); + + try sema.requireRuntimeBlock(block, src); + return block.addBitCast(const_ptr_ty, alloc); } fn zirAllocInferredComptime( |