let dest = CPlace::for_ptr(Pointer::new(mem_addr), a.layout());
dest.write_cvalue(fx, a);
};
+ "llvm.x86.addcarry.64", (v c_in, c a, c b) {
+ llvm_add_sub(
+ fx,
+ BinOp::Add,
+ ret,
+ c_in,
+ a,
+ b
+ );
+ };
+ "llvm.x86.subborrow.64", (v b_in, c a, c b) {
+ llvm_add_sub(
+ fx,
+ BinOp::Sub,
+ ret,
+ b_in,
+ a,
+ b
+ );
+ };
}
if let Some((_, dest)) = destination {
// llvm.x86.avx2.pshuf.b
// llvm.x86.avx2.psrli.w
// llvm.x86.sse2.psrli.w
+
+fn llvm_add_sub<'tcx>(
+ fx: &mut FunctionCx<'_, '_, 'tcx>,
+ bin_op: BinOp,
+ ret: CPlace<'tcx>,
+ cb_in: Value,
+ a: CValue<'tcx>,
+ b: CValue<'tcx>,
+) {
+ assert_eq!(
+ a.layout().ty,
+ fx.tcx.types.u64,
+ "llvm.x86.addcarry.64/llvm.x86.subborrow.64 second operand must be u64"
+ );
+ assert_eq!(
+ b.layout().ty,
+ fx.tcx.types.u64,
+ "llvm.x86.addcarry.64/llvm.x86.subborrow.64 third operand must be u64"
+ );
+
+ // c + carry -> c + first intermediate carry or borrow respectively
+ let int0 = crate::num::codegen_checked_int_binop(fx, bin_op, a, b);
+ let c = int0.value_field(fx, mir::Field::new(0));
+ let cb0 = int0.value_field(fx, mir::Field::new(1)).load_scalar(fx);
+
+ // c + carry -> c + second intermediate carry or borrow respectively
+ let cb_in_as_u64 = fx.bcx.ins().uextend(types::I64, cb_in);
+ let cb_in_as_u64 = CValue::by_val(cb_in_as_u64, fx.layout_of(fx.tcx.types.u64));
+ let int1 = crate::num::codegen_checked_int_binop(fx, bin_op, c, cb_in_as_u64);
+ let (c, cb1) = int1.load_scalar_pair(fx);
+
+ // carry0 | carry1 -> carry or borrow respectively
+ let cb_out = fx.bcx.ins().bor(cb0, cb1);
+
+ let layout = fx.layout_of(fx.tcx.mk_tup([fx.tcx.types.u8, fx.tcx.types.u64].iter()));
+ let val = CValue::by_val_pair(cb_out, c, layout);
+ ret.write_cvalue(fx, val);
+}