1 //! Emulation of a subset of the cpuid x86 instruction.
5 /// Emulates a subset of the cpuid x86 instruction.
7 /// This emulates an intel cpu with sse and sse2 support, but which doesn't support anything else.
8 pub(crate) fn codegen_cpuid_call<'tcx>(
9 fx: &mut FunctionCx<'_, '_, 'tcx>,
12 ) -> (Value, Value, Value, Value) {
13 let leaf_0 = fx.bcx.create_block();
14 let leaf_1 = fx.bcx.create_block();
15 let leaf_7 = fx.bcx.create_block();
16 let leaf_8000_0000 = fx.bcx.create_block();
17 let leaf_8000_0001 = fx.bcx.create_block();
18 let unsupported_leaf = fx.bcx.create_block();
20 let dest = fx.bcx.create_block();
21 let eax = fx.bcx.append_block_param(dest, types::I32);
22 let ebx = fx.bcx.append_block_param(dest, types::I32);
23 let ecx = fx.bcx.append_block_param(dest, types::I32);
24 let edx = fx.bcx.append_block_param(dest, types::I32);
26 let mut switch = cranelift_frontend::Switch::new();
27 switch.set_entry(0, leaf_0);
28 switch.set_entry(1, leaf_1);
29 switch.set_entry(7, leaf_7);
30 switch.set_entry(0x8000_0000, leaf_8000_0000);
31 switch.set_entry(0x8000_0001, leaf_8000_0001);
32 switch.emit(&mut fx.bcx, leaf, unsupported_leaf);
34 fx.bcx.switch_to_block(leaf_0);
35 let max_basic_leaf = fx.bcx.ins().iconst(types::I32, 1);
36 let vend0 = fx.bcx.ins().iconst(types::I32, i64::from(u32::from_le_bytes(*b"Genu")));
37 let vend2 = fx.bcx.ins().iconst(types::I32, i64::from(u32::from_le_bytes(*b"ineI")));
38 let vend1 = fx.bcx.ins().iconst(types::I32, i64::from(u32::from_le_bytes(*b"ntel")));
39 fx.bcx.ins().jump(dest, &[max_basic_leaf, vend0, vend1, vend2]);
41 fx.bcx.switch_to_block(leaf_1);
42 let cpu_signature = fx.bcx.ins().iconst(types::I32, 0);
43 let additional_information = fx.bcx.ins().iconst(types::I32, 0);
44 let ecx_features = fx.bcx.ins().iconst(types::I32, 0);
45 let edx_features = fx.bcx.ins().iconst(types::I32, 1 << 25 /* sse */ | 1 << 26 /* sse2 */);
46 fx.bcx.ins().jump(dest, &[cpu_signature, additional_information, ecx_features, edx_features]);
48 fx.bcx.switch_to_block(leaf_7);
49 // This leaf technically has subleaves, but we just return zero for all subleaves.
50 let zero = fx.bcx.ins().iconst(types::I32, 0);
51 fx.bcx.ins().jump(dest, &[zero, zero, zero, zero]);
53 fx.bcx.switch_to_block(leaf_8000_0000);
54 let extended_max_basic_leaf = fx.bcx.ins().iconst(types::I32, 0);
55 let zero = fx.bcx.ins().iconst(types::I32, 0);
56 fx.bcx.ins().jump(dest, &[extended_max_basic_leaf, zero, zero, zero]);
58 fx.bcx.switch_to_block(leaf_8000_0001);
59 let zero = fx.bcx.ins().iconst(types::I32, 0);
60 let proc_info_ecx = fx.bcx.ins().iconst(types::I32, 0);
61 let proc_info_edx = fx.bcx.ins().iconst(types::I32, 0);
62 fx.bcx.ins().jump(dest, &[zero, zero, proc_info_ecx, proc_info_edx]);
64 fx.bcx.switch_to_block(unsupported_leaf);
65 crate::trap::trap_unreachable(
67 "__cpuid_count arch intrinsic doesn't yet support specified leaf",
70 fx.bcx.switch_to_block(dest);