diff options
Diffstat (limited to 'compiler/rustc_codegen_cranelift/src/codegen_i128.rs')
| -rw-r--r-- | compiler/rustc_codegen_cranelift/src/codegen_i128.rs | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/compiler/rustc_codegen_cranelift/src/codegen_i128.rs b/compiler/rustc_codegen_cranelift/src/codegen_i128.rs new file mode 100644 index 00000000000..e998403dea6 --- /dev/null +++ b/compiler/rustc_codegen_cranelift/src/codegen_i128.rs @@ -0,0 +1,165 @@ +//! Replaces 128-bit operators with lang item calls where necessary + +use crate::prelude::*; + +pub(crate) fn maybe_codegen<'tcx>( + fx: &mut FunctionCx<'_, 'tcx, impl Module>, + bin_op: BinOp, + checked: bool, + lhs: CValue<'tcx>, + rhs: CValue<'tcx>, +) -> Option<CValue<'tcx>> { + if lhs.layout().ty != fx.tcx.types.u128 && lhs.layout().ty != fx.tcx.types.i128 { + return None; + } + + let lhs_val = lhs.load_scalar(fx); + let rhs_val = rhs.load_scalar(fx); + + let is_signed = type_sign(lhs.layout().ty); + + match bin_op { + BinOp::BitAnd | BinOp::BitOr | BinOp::BitXor => { + assert!(!checked); + return None; + } + BinOp::Add | BinOp::Sub if !checked => return None, + BinOp::Add => { + let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter()); + return Some(if is_signed { + fx.easy_call("__rust_i128_addo", &[lhs, rhs], out_ty) + } else { + fx.easy_call("__rust_u128_addo", &[lhs, rhs], out_ty) + }); + } + BinOp::Sub => { + let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter()); + return Some(if is_signed { + fx.easy_call("__rust_i128_subo", &[lhs, rhs], out_ty) + } else { + fx.easy_call("__rust_u128_subo", &[lhs, rhs], out_ty) + }); + } + BinOp::Offset => unreachable!("offset should only be used on pointers, not 128bit ints"), + BinOp::Mul => { + let res = if checked { + let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter()); + if is_signed { + fx.easy_call("__rust_i128_mulo", &[lhs, rhs], out_ty) + } else { + fx.easy_call("__rust_u128_mulo", &[lhs, rhs], out_ty) + } + } else { + let val_ty = if is_signed { + fx.tcx.types.i128 + } else { + fx.tcx.types.u128 + }; + fx.easy_call("__multi3", &[lhs, rhs], val_ty) + }; + return Some(res); + } + BinOp::Div => { + assert!(!checked); + if is_signed { + Some(fx.easy_call("__divti3", &[lhs, rhs], fx.tcx.types.i128)) + } else { + Some(fx.easy_call("__udivti3", &[lhs, rhs], fx.tcx.types.u128)) + } + } + BinOp::Rem => { + assert!(!checked); + if is_signed { + Some(fx.easy_call("__modti3", &[lhs, rhs], fx.tcx.types.i128)) + } else { + Some(fx.easy_call("__umodti3", &[lhs, rhs], fx.tcx.types.u128)) + } + } + BinOp::Lt | BinOp::Le | BinOp::Eq | BinOp::Ge | BinOp::Gt | BinOp::Ne => { + assert!(!checked); + return None; + } + BinOp::Shl | BinOp::Shr => { + let is_overflow = if checked { + // rhs >= 128 + + // FIXME support non 128bit rhs + /*let (rhs_lsb, rhs_msb) = fx.bcx.ins().isplit(rhs_val); + let rhs_msb_gt_0 = fx.bcx.ins().icmp_imm(IntCC::NotEqual, rhs_msb, 0); + let rhs_lsb_ge_128 = fx.bcx.ins().icmp_imm(IntCC::SignedGreaterThan, rhs_lsb, 127); + let is_overflow = fx.bcx.ins().bor(rhs_msb_gt_0, rhs_lsb_ge_128);*/ + let is_overflow = fx.bcx.ins().bconst(types::B1, false); + + Some(fx.bcx.ins().bint(types::I8, is_overflow)) + } else { + None + }; + + // Optimize `val >> 64`, because compiler_builtins uses it to deconstruct an 128bit + // integer into its lsb and msb. + // https://github.com/rust-lang-nursery/compiler-builtins/blob/79a6a1603d5672cbb9187ff41ff4d9b5048ac1cb/src/int/mod.rs#L217 + if resolve_value_imm(fx.bcx.func, rhs_val) == Some(64) { + let (lhs_lsb, lhs_msb) = fx.bcx.ins().isplit(lhs_val); + let all_zeros = fx.bcx.ins().iconst(types::I64, 0); + let val = match (bin_op, is_signed) { + (BinOp::Shr, false) => { + let val = fx.bcx.ins().iconcat(lhs_msb, all_zeros); + Some(CValue::by_val(val, fx.layout_of(fx.tcx.types.u128))) + } + (BinOp::Shr, true) => { + let sign = fx.bcx.ins().icmp_imm(IntCC::SignedLessThan, lhs_msb, 0); + let all_ones = fx.bcx.ins().iconst(types::I64, u64::MAX as i64); + let all_sign_bits = fx.bcx.ins().select(sign, all_zeros, all_ones); + + let val = fx.bcx.ins().iconcat(lhs_msb, all_sign_bits); + Some(CValue::by_val(val, fx.layout_of(fx.tcx.types.i128))) + } + (BinOp::Shl, _) => { + let val_ty = if is_signed { + fx.tcx.types.i128 + } else { + fx.tcx.types.u128 + }; + let val = fx.bcx.ins().iconcat(all_zeros, lhs_lsb); + Some(CValue::by_val(val, fx.layout_of(val_ty))) + } + _ => None, + }; + if let Some(val) = val { + if let Some(is_overflow) = is_overflow { + let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter()); + let val = val.load_scalar(fx); + return Some(CValue::by_val_pair(val, is_overflow, fx.layout_of(out_ty))); + } else { + return Some(val); + } + } + } + + let truncated_rhs = clif_intcast(fx, rhs_val, types::I32, false); + let truncated_rhs = CValue::by_val(truncated_rhs, fx.layout_of(fx.tcx.types.u32)); + let val = match (bin_op, is_signed) { + (BinOp::Shl, false) => { + fx.easy_call("__ashlti3", &[lhs, truncated_rhs], fx.tcx.types.u128) + } + (BinOp::Shl, true) => { + fx.easy_call("__ashlti3", &[lhs, truncated_rhs], fx.tcx.types.i128) + } + (BinOp::Shr, false) => { + fx.easy_call("__lshrti3", &[lhs, truncated_rhs], fx.tcx.types.u128) + } + (BinOp::Shr, true) => { + fx.easy_call("__ashrti3", &[lhs, truncated_rhs], fx.tcx.types.i128) + } + (_, _) => unreachable!(), + }; + if let Some(is_overflow) = is_overflow { + let out_ty = fx.tcx.mk_tup([lhs.layout().ty, fx.tcx.types.bool].iter()); + let val = val.load_scalar(fx); + Some(CValue::by_val_pair(val, is_overflow, fx.layout_of(out_ty))) + } else { + Some(val) + } + } + } +} |