diff --git a/cranelift/codegen/src/isa/x64/lower.rs b/cranelift/codegen/src/isa/x64/lower.rs index 6bd6ea7b72..da29a04314 100644 --- a/cranelift/codegen/src/isa/x64/lower.rs +++ b/cranelift/codegen/src/isa/x64/lower.rs @@ -7202,24 +7202,34 @@ impl LowerBackend for X64Backend { Opcode::BrTable => { let jt_size = targets.len() - 1; - assert!(jt_size <= u32::max_value() as usize); + assert!(jt_size <= u32::MAX as usize); let jt_size = jt_size as u32; + let ty = ctx.input_ty(branches[0], 0); + let ext_spec = match ty { + types::I128 => panic!("BrTable unimplemented for I128"), + types::I64 => ExtSpec::ZeroExtendTo64, + _ => ExtSpec::ZeroExtendTo32, + }; + let idx = extend_input_to_reg( ctx, InsnInput { insn: branches[0], input: 0, }, - ExtSpec::ZeroExtendTo32, + ext_spec, ); // Bounds-check (compute flags from idx - jt_size) and branch to default. - ctx.emit(Inst::cmp_rmi_r( - OperandSize::Size32, - RegMemImm::imm(jt_size), - idx, - )); + // We only support u32::MAX entries, but we compare the full 64 bit register + // when doing the bounds check. + let cmp_size = if ty == types::I64 { + OperandSize::Size64 + } else { + OperandSize::Size32 + }; + ctx.emit(Inst::cmp_rmi_r(cmp_size, RegMemImm::imm(jt_size), idx)); // Emit the compound instruction that does: // diff --git a/cranelift/filetests/filetests/runtests/br_table.clif b/cranelift/filetests/filetests/runtests/br_table.clif index 836e5da8ec..16718d4e76 100644 --- a/cranelift/filetests/filetests/runtests/br_table.clif +++ b/cranelift/filetests/filetests/runtests/br_table.clif @@ -1,6 +1,7 @@ test interpret test run target aarch64 +target x86_64 machinst target s390x diff --git a/cranelift/frontend/src/switch.rs b/cranelift/frontend/src/switch.rs index 507c2be206..7be8c8d0aa 100644 --- a/cranelift/frontend/src/switch.rs +++ b/cranelift/frontend/src/switch.rs @@ -264,24 +264,19 @@ impl Switch { } }; - let discr = if bx.func.dfg.value_type(discr).bits() > 32 { - // Check for overflow of cast to u32. + let discr = if bx.func.dfg.value_type(discr).bits() > 64 { + // Check for overflow of cast to u32. This is the max supported jump table entries. let new_block = bx.create_block(); let bigger_than_u32 = bx.ins() - .icmp_imm(IntCC::UnsignedGreaterThan, discr, u32::max_value() as i64); + .icmp_imm(IntCC::UnsignedGreaterThan, discr, u32::MAX as i64); bx.ins().brnz(bigger_than_u32, otherwise, &[]); bx.ins().jump(new_block, &[]); bx.seal_block(new_block); bx.switch_to_block(new_block); - // Cast to u32, as br_table is not implemented for integers bigger than 32bits. - let discr = if bx.func.dfg.value_type(discr) == types::I128 { - bx.ins().isplit(discr).0 - } else { - discr - }; - bx.ins().ireduce(types::I32, discr) + // Cast to u64, as br_table is not implemented for i128 + bx.ins().isplit(discr).0 } else { discr }; @@ -616,13 +611,7 @@ block0: jump block4 block4: - v1 = icmp_imm.i64 ugt v0, 0xffff_ffff - brnz v1, block3 - jump block5 - -block5: - v2 = ireduce.i32 v0 - br_table v2, block3, jt0" + br_table.i64 v0, block3, jt0" ); } @@ -663,8 +652,7 @@ block4: block5: v2, v3 = isplit.i128 v0 - v4 = ireduce.i32 v2 - br_table v4, block3, jt0" + br_table v2, block3, jt0" ); } }