Implement most 128bit binops

Author: bjorn3

example/std_example.rs

@@ -3,23 +3,5 @@
 use std::io::Write;
 
 fn main() {
-    assert_eq!((1u128 + 2) as u16, 3);
-}
-
-#[derive(PartialEq)]
-enum LoopState {
-    Continue(()),
-    Break(())
-}
-
-pub enum Instruction {
-    Increment,
-    Loop,
-}
-
-fn map(a: Option<(u8, Box<Instruction>)>) -> Option<Box<Instruction>> {
-    match a {
-        None => None,
-        Some((_, instr)) => Some(instr),
-    }
+    assert_eq!(1u128 + 2, 3);
 }

src/abi.rs

@@ -846,7 +846,7 @@ pub fn codegen_drop<'a, 'tcx: 'a>(
                 );
                 drop_place.write_place_ref(fx, arg_place);
                 let arg_value = arg_place.to_cvalue(fx);
-                crate::abi::codegen_call_inner(
+                codegen_call_inner(
                     fx,
                     None,
                     drop_fn_ty,

src/base.rs

@@ -783,18 +783,8 @@ pub fn trans_int_binop<'a, 'tcx: 'a>(
         );
     }
 
-    if lhs.layout().ty == fx.tcx.types.u128 || lhs.layout().ty == fx.tcx.types.i128 {
-        if out_ty == fx.tcx.types.bool {
-            let layout = fx.layout_of(fx.tcx.types.bool);
-            let val = fx.bcx.ins().iconst(types::I8, 0);
-            return CValue::by_val(val, layout);
-        } else {
-            let layout = fx.layout_of(out_ty);
-            let a = fx.bcx.ins().iconst(types::I64, 42);
-            let b = fx.bcx.ins().iconst(types::I64, 0);
-            let val = fx.bcx.ins().iconcat(a, b);
-            return CValue::by_val(val, layout);
-        }
+    if let Some(res) = crate::codegen_i128::maybe_codegen(fx, bin_op, false, signed, lhs, rhs, out_ty) {
+        return res;
     }
 
     binop_match! {
@@ -846,14 +836,8 @@ pub fn trans_checked_int_binop<'a, 'tcx: 'a>(
 
     let lhs = in_lhs.load_scalar(fx);
     let rhs = in_rhs.load_scalar(fx);
-    let res = if in_lhs.layout().ty == fx.tcx.types.u128 || in_lhs.layout().ty == fx.tcx.types.i128 {
-        match (bin_op, signed) {
-            _ => {
-                let a = fx.bcx.ins().iconst(types::I64, 42);
-                let b = fx.bcx.ins().iconst(types::I64, 0);
-                fx.bcx.ins().iconcat(a, b)
-            }
-        }
+    let res = if let Some(res) = crate::codegen_i128::maybe_codegen(fx, bin_op, true, signed, in_lhs, in_rhs, out_ty) {
+        return res;
     } else {
         match bin_op {
             BinOp::Add => fx.bcx.ins().iadd(lhs, rhs),

src/codegen_i128.rs

@@ -0,0 +1,107 @@
+//! Replaces 128-bit operators with lang item calls
+
+use crate::prelude::*;
+
+pub fn maybe_codegen<'a, 'tcx>(
+    fx: &mut FunctionCx<'a, 'tcx, impl Backend>,
+    bin_op: BinOp,
+    checked: bool,
+    is_signed: bool,
+    lhs: CValue<'tcx>,
+    rhs: CValue<'tcx>,
+    out_ty: Ty<'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);
+
+    match bin_op {
+        BinOp::Add | BinOp::Sub | BinOp::BitAnd | BinOp::BitOr | BinOp::BitXor => return None,
+        BinOp::Offset => unreachable!("offset should only be used on pointers, not 128bit ints"),
+        BinOp::Mul => {
+            let res = if checked {
+                if is_signed {
+                    let oflow_place = CPlace::new_stack_slot(fx, fx.tcx.types.i32);
+                    let oflow_addr = oflow_place.to_addr(fx);
+                    let oflow_addr = CValue::by_val(oflow_addr, fx.layout_of(fx.tcx.mk_mut_ptr(fx.tcx.types.i32)));
+                    let val = fx.easy_call("__muloti4", &[lhs, rhs, oflow_addr], fx.tcx.types.i128);
+                    let val = val.load_scalar(fx);
+                    let oflow = oflow_place.to_cvalue(fx).load_scalar(fx);
+                    let oflow = fx.bcx.ins().icmp_imm(IntCC::NotEqual, oflow, 0);
+                    let oflow = fx.bcx.ins().bint(types::I8, oflow);
+                    CValue::by_val_pair(val, oflow, fx.layout_of(out_ty))
+                } else {
+                    // FIXME implement it
+                let out_layout = fx.layout_of(out_ty);
+                    return Some(crate::trap::trap_unreachable_ret_value(fx, out_layout, format!("unimplemented 128bit checked binop unsigned mul")));
+                }
+            } 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 => {
+            let res = if checked {
+                // FIXME implement it
+                let out_layout = fx.layout_of(out_ty);
+                return Some(crate::trap::trap_unreachable_ret_value(fx, out_layout, format!("unimplemented 128bit checked binop div")));
+            } else {
+                if is_signed {
+                    fx.easy_call("__divti3", &[lhs, rhs], fx.tcx.types.i128)
+                } else {
+                    fx.easy_call("__udivti3", &[lhs, rhs], fx.tcx.types.u128)
+                }
+            };
+            return Some(res);
+        }
+        BinOp::Rem => {
+            let res = if checked {
+                // FIXME implement it
+                let out_layout = fx.layout_of(out_ty);
+                return Some(crate::trap::trap_unreachable_ret_value(fx, out_layout, format!("unimplemented 128bit checked binop rem")));
+            } else {
+                if is_signed {
+                    fx.easy_call("__modti3", &[lhs, rhs], fx.tcx.types.i128)
+                } else {
+                    fx.easy_call("__umodti3", &[lhs, rhs], fx.tcx.types.u128)
+                }
+            };
+            return Some(res);
+        }
+        BinOp::Lt | BinOp::Le | BinOp::Eq | BinOp::Ge | BinOp::Gt | BinOp::Ne => {
+            assert!(!checked);
+            let (lhs_lsb, lhs_msb) = fx.bcx.ins().isplit(lhs_val);
+            let (rhs_lsb, rhs_msb) = fx.bcx.ins().isplit(rhs_val);
+            let res = match (bin_op, is_signed) {
+                (BinOp::Eq, _) => {
+                    let lsb_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_lsb, rhs_lsb);
+                    let msb_eq = fx.bcx.ins().icmp(IntCC::Equal, lhs_msb, rhs_msb);
+                    fx.bcx.ins().band(lsb_eq, msb_eq)
+                }
+                (BinOp::Ne, _) => {
+                    let lsb_ne = fx.bcx.ins().icmp(IntCC::NotEqual, lhs_lsb, rhs_lsb);
+                    let msb_ne = fx.bcx.ins().icmp(IntCC::NotEqual, lhs_msb, rhs_msb);
+                    fx.bcx.ins().bor(lsb_ne, msb_ne)
+                }
+                _ => {
+                    // FIXME implement it
+                    let out_layout = fx.layout_of(out_ty);
+                    return Some(crate::trap::trap_unreachable_ret_value(fx, out_layout, format!("unimplemented 128bit binop {:?}", bin_op)));
+                },
+            };
+
+            let res = fx.bcx.ins().bint(types::I8, res);
+            let res = CValue::by_val(res, fx.layout_of(fx.tcx.types.bool));
+            return Some(res);
+        }
+        BinOp::Shl | BinOp::Shr => {
+            // FIXME implement it
+            let out_layout = fx.layout_of(out_ty);
+            return Some(crate::trap::trap_unreachable_ret_value(fx, out_layout, format!("unimplemented 128bit binop {:?}", bin_op)));
+        }
+    }
+}

src/lib.rs

@@ -34,6 +34,7 @@ mod allocator;
 mod analyze;
 mod archive;
 mod base;
+mod codegen_i128;
 mod common;
 mod constant;
 mod debuginfo;