Rollup merge of #107085 - tmiasko:custom-mir-operators, r=oli-obk

Custom MIR: Support binary and unary operations

Lower binary and unary operations directly to corresponding unchecked MIR
operations. Ultimately this might not be syntax we want, but it allows for
experimentation in the meantime.

r? ````@oli-obk```` ````@JakobDegen````

compiler/rustc_mir_build/src/build/custom/parse/instruction.rs

@@ -147,6 +147,12 @@ fn parse_rvalue(&self, expr_id: ExprId) -> PResult<Rvalue<'tcx>> {
             ExprKind::AddressOf { mutability, arg } => Ok(
                 Rvalue::AddressOf(*mutability, self.parse_place(*arg)?)
             ),
+            ExprKind::Binary { op, lhs, rhs } =>  Ok(
+                Rvalue::BinaryOp(*op, Box::new((self.parse_operand(*lhs)?, self.parse_operand(*rhs)?)))
+            ),
+            ExprKind::Unary { op, arg } => Ok(
+                Rvalue::UnaryOp(*op, self.parse_operand(*arg)?)
+            ),
             _ => self.parse_operand(expr_id).map(Rvalue::Use),
         )
     }

tests/mir-opt/building/custom/operators.f.built.after.mir

@@ -0,0 +1,26 @@
+// MIR for `f` after built
+
+fn f(_1: i32, _2: bool) -> i32 {
+    let mut _0: i32;                     // return place in scope 0 at $DIR/operators.rs:+0:30: +0:33
+
+    bb0: {
+        _1 = Neg(_1);                    // scope 0 at $DIR/operators.rs:+2:9: +2:15
+        _2 = Not(_2);                    // scope 0 at $DIR/operators.rs:+3:9: +3:15
+        _1 = Add(_1, _1);                // scope 0 at $DIR/operators.rs:+4:9: +4:18
+        _1 = Sub(_1, _1);                // scope 0 at $DIR/operators.rs:+5:9: +5:18
+        _1 = Mul(_1, _1);                // scope 0 at $DIR/operators.rs:+6:9: +6:18
+        _1 = Div(_1, _1);                // scope 0 at $DIR/operators.rs:+7:9: +7:18
+        _1 = Rem(_1, _1);                // scope 0 at $DIR/operators.rs:+8:9: +8:18
+        _1 = BitXor(_1, _1);             // scope 0 at $DIR/operators.rs:+9:9: +9:18
+        _1 = BitAnd(_1, _1);             // scope 0 at $DIR/operators.rs:+10:9: +10:18
+        _1 = Shl(_1, _1);                // scope 0 at $DIR/operators.rs:+11:9: +11:19
+        _1 = Shr(_1, _1);                // scope 0 at $DIR/operators.rs:+12:9: +12:19
+        _2 = Eq(_1, _1);                 // scope 0 at $DIR/operators.rs:+13:9: +13:19
+        _2 = Lt(_1, _1);                 // scope 0 at $DIR/operators.rs:+14:9: +14:18
+        _2 = Le(_1, _1);                 // scope 0 at $DIR/operators.rs:+15:9: +15:19
+        _2 = Ge(_1, _1);                 // scope 0 at $DIR/operators.rs:+16:9: +16:19
+        _2 = Gt(_1, _1);                 // scope 0 at $DIR/operators.rs:+17:9: +17:18
+        _0 = _1;                         // scope 0 at $DIR/operators.rs:+18:9: +18:16
+        return;                          // scope 0 at $DIR/operators.rs:+19:9: +19:17
+    }
+}

tests/mir-opt/building/custom/operators.rs

@@ -0,0 +1,28 @@
+// compile-flags: --crate-type=lib
+#![feature(custom_mir, core_intrinsics, inline_const)]
+use std::intrinsics::mir::*;
+
+// EMIT_MIR operators.f.built.after.mir
+#[custom_mir(dialect = "built")]
+pub fn f(a: i32, b: bool) -> i32 {
+    mir!({
+        a = -a;
+        b = !b;
+        a = a + a;
+        a = a - a;
+        a = a * a;
+        a = a / a;
+        a = a % a;
+        a = a ^ a;
+        a = a & a;
+        a = a << a;
+        a = a >> a;
+        b = a == a;
+        b = a < a;
+        b = a <= a;
+        b = a >= a;
+        b = a > a;
+        RET = a;
+        Return()
+    })
+}