Auto merge of rust-lang#83663 - AngelicosPhosphoros:simplify_binary_and_to_get_better_asm, r=nagisa

Simplify logical operations CFG

This is basically same commit as e38e954 which was reverted later in 676953f
In both cases, this changes weren't benchmarked.
e38e954 leads to missed optimization described in [this issue](rust-lang#62993)
676953f leads to missed optimization described in [this issue](rust-lang#83623)

Author: bors

compiler/rustc_mir_build/src/build/expr/into.rs

@@ -111,60 +111,49 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             ExprKind::LogicalOp { op, lhs, rhs } => {
                 // And:
                 //
-                // [block: If(lhs)] -true-> [else_block: If(rhs)] -true-> [true_block]
-                //        |                          | (false)
-                //        +----------false-----------+------------------> [false_block]
+                // [block: If(lhs)] -true-> [else_block: dest = (rhs)]
+                //        | (false)
+                //  [shortcurcuit_block: dest = false]
                 //
                 // Or:
                 //
-                // [block: If(lhs)] -false-> [else_block: If(rhs)] -true-> [true_block]
-                //        | (true)                   | (false)
-                //  [true_block]               [false_block]
+                // [block: If(lhs)] -false-> [else_block: dest = (rhs)]
+                //        | (true)
+                //  [shortcurcuit_block: dest = true]
 
-                let (true_block, false_block, mut else_block, join_block) = (
-                    this.cfg.start_new_block(),
+                let (shortcircuit_block, mut else_block, join_block) = (
                     this.cfg.start_new_block(),
                     this.cfg.start_new_block(),
                     this.cfg.start_new_block(),
                 );
 
                 let lhs = unpack!(block = this.as_local_operand(block, lhs));
                 let blocks = match op {
-                    LogicalOp::And => (else_block, false_block),
-                    LogicalOp::Or => (true_block, else_block),
+                    LogicalOp::And => (else_block, shortcircuit_block),
+                    LogicalOp::Or => (shortcircuit_block, else_block),
                 };
                 let term = TerminatorKind::if_(this.tcx, lhs, blocks.0, blocks.1);
                 this.cfg.terminate(block, source_info, term);
 
-                let rhs = unpack!(else_block = this.as_local_operand(else_block, rhs));
-                let term = TerminatorKind::if_(this.tcx, rhs, true_block, false_block);
-                this.cfg.terminate(else_block, source_info, term);
-
                 this.cfg.push_assign_constant(
-                    true_block,
+                    shortcircuit_block,
                     source_info,
                     destination,
                     Constant {
                         span: expr_span,
                         user_ty: None,
-                        literal: ty::Const::from_bool(this.tcx, true).into(),
+                        literal: match op {
+                            LogicalOp::And => ty::Const::from_bool(this.tcx, false).into(),
+                            LogicalOp::Or => ty::Const::from_bool(this.tcx, true).into(),
+                        },
                     },
                 );
+                this.cfg.goto(shortcircuit_block, source_info, join_block);
 
-                this.cfg.push_assign_constant(
-                    false_block,
-                    source_info,
-                    destination,
-                    Constant {
-                        span: expr_span,
-                        user_ty: None,
-                        literal: ty::Const::from_bool(this.tcx, false).into(),
-                    },
-                );
+                let rhs = unpack!(else_block = this.as_local_operand(else_block, rhs));
+                this.cfg.push_assign(else_block, source_info, destination, Rvalue::Use(rhs));
+                this.cfg.goto(else_block, source_info, join_block);
 
-                // Link up both branches:
-                this.cfg.goto(true_block, source_info, join_block);
-                this.cfg.goto(false_block, source_info, join_block);
                 join_block.unit()
             }
             ExprKind::Loop { body } => {

src/test/codegen/issue-83623-SIMD-PartialEq.rs

@@ -0,0 +1,46 @@
+// This test checks that jumps generated by logical operators can be optimized away
+
+// compile-flags: -Copt-level=3
+// only-64bit
+
+#![crate_type="lib"]
+
+pub struct Blueprint {
+    pub fuel_tank_size: u32,
+    pub payload: u32,
+    pub wheel_diameter: u32,
+    pub wheel_width: u32,
+    pub storage: u32,
+}
+
+// && chains should not prevent SIMD optimizations for primitives
+impl PartialEq for Blueprint{
+    fn eq(&self, other: &Self)->bool{
+       // CHECK-NOT: call{{.*}}bcmp
+       // CHECK-NOT: call{{.*}}memcmp
+       // CHECK-NOT: br {{.*}}
+       self.fuel_tank_size == other.fuel_tank_size
+            && self.payload == other.payload
+            && self.wheel_diameter == other.wheel_diameter
+            && self.wheel_width == other.wheel_width
+            && self.storage == other.storage
+    }
+}
+
+#[derive(PartialEq)]
+pub struct Blueprint2 {
+    pub fuel_tank_size: u32,
+    pub payload: u32,
+    pub wheel_diameter: u32,
+    pub wheel_width: u32,
+    pub storage: u32,
+}
+
+// Derived PartialEq should not generate jumps and should use SIMD
+#[no_mangle]
+pub fn partial_eq_should_not_jump(a: &Blueprint2, b:&Blueprint2)->bool{
+    // CHECK-NOT: call{{.*}}bcmp
+    // CHECK-NOT: call{{.*}}memcmp
+    // CHECK-NOT: br {{.*}}
+    a==b
+}