diff --git a/yjit/src/backend/arm64/mod.rs b/yjit/src/backend/arm64/mod.rs index 092df6326f..a62ea45e7e 100644 --- a/yjit/src/backend/arm64/mod.rs +++ b/yjit/src/backend/arm64/mod.rs @@ -431,12 +431,33 @@ impl Assembler } } }, - Insn::And { left, right, .. } | - Insn::Or { left, right, .. } | - Insn::Xor { left, right, .. } => { + Insn::And { left, right, out } | + Insn::Or { left, right, out } | + Insn::Xor { left, right, out } => { let (opnd0, opnd1) = split_boolean_operands(asm, *left, *right); *left = opnd0; *right = opnd1; + + // Since these instructions are lowered to an instruction that have 2 input + // registers and an output register, look to merge with an `Insn::Mov` that + // follows which puts the output in another register. For example: + // `Add a, b => out` followed by `Mov c, out` becomes `Add a, b => c`. + if let (Opnd::Reg(_), Opnd::Reg(_), Some(Insn::Mov { dest, src })) = (left, right, iterator.peek()) { + if live_ranges[index] == index + 1 { + // Check after potentially lowering a stack operand to a register operand + let lowered_dest = if let Opnd::Stack { .. } = dest { + asm.lower_stack_opnd(dest) + } else { + *dest + }; + if out == src && matches!(lowered_dest, Opnd::Reg(_)) { + *out = lowered_dest; + iterator.map_insn_index(asm); + iterator.next_unmapped(); // Pop merged Insn::Mov + } + } + } + asm.push_insn(insn); }, Insn::CCall { opnds, fptr, .. } => {