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Simplify jump table instructions and add missing conversion;

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This makes non-legalized jump table instructions operate on operands with
pointer-sized types. This means we need to extend smaller types into the
pointer-sized operand, when the two don't match.
This commit is contained in:
Benjamin Bouvier
2019-08-01 17:05:38 +02:00
parent f0d7438728
commit 627ba24b59
5 changed files with 27 additions and 27 deletions
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19
cranelift/codegen/src/legalizer/mod.rs
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@@ -240,29 +240,34 @@ fn expand_br_table_jt(
// $addr = iadd $base, $rel_addr
// indirect_jump_table_br $addr, $jt
let table_size = func.jump_tables[table].len();
let addr_ty = isa.pointer_type();
let entry_ty = I32;
let ebb = func.layout.pp_ebb(inst);
let jump_table_ebb = func.dfg.make_ebb();
let mut pos = FuncCursor::new(func).at_inst(inst);
pos.use_srcloc(inst);
// Bounds check
// Bounds check.
let table_size = pos.func.jump_tables[table].len() as i64;
let oob = pos
.ins()
.icmp_imm(IntCC::UnsignedGreaterThanOrEqual, arg, table_size as i64);
.icmp_imm(IntCC::UnsignedGreaterThanOrEqual, arg, table_size);
pos.ins().brnz(oob, default_ebb, &[]);
pos.ins().jump(jump_table_ebb, &[]);
pos.insert_ebb(jump_table_ebb);
let addr_ty = isa.pointer_type();
let arg = if pos.func.dfg.value_type(arg) == addr_ty {
arg
} else {
pos.ins().uextend(addr_ty, arg)
};
let base_addr = pos.ins().jump_table_base(addr_ty, table);
let entry = pos
.ins()
.jump_table_entry(addr_ty, arg, base_addr, entry_ty.bytes() as u8, table);
.jump_table_entry(arg, base_addr, I32.bytes() as u8, table);
let addr = pos.ins().iadd(base_addr, entry);
pos.ins().indirect_jump_table_br(addr, table);