Rollup merge of #63431 - andjo403:revert_mir_simplification, r=matthewjasper

Revert "Simplify MIR generation for logical ops"

This reverts commit e38e954a0d249f88d0a55504f70d6055e865a931.

llvm were not able to optimize the code that well with the simplified mir.

Closes: #62993
This commit is contained in:
Mazdak Farrokhzad 2019-08-12 10:58:16 +02:00 committed by GitHub
commit e19ce5d16a
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@ -79,17 +79,18 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
ExprKind::LogicalOp { op, lhs, rhs } => {
// And:
//
// [block: If(lhs)] -true-> [else_block: dest = (rhs)]
// | (false)
// [shortcurcuit_block: dest = false]
// [block: If(lhs)] -true-> [else_block: If(rhs)] -true-> [true_block]
// | | (false)
// +----------false-----------+------------------> [false_block]
//
// Or:
//
// [block: If(lhs)] -false-> [else_block: dest = (rhs)]
// | (true)
// [shortcurcuit_block: dest = true]
// [block: If(lhs)] -false-> [else_block: If(rhs)] -true-> [true_block]
// | (true) | (false)
// [true_block] [false_block]
let (shortcircuit_block, mut else_block, join_block) = (
let (true_block, false_block, mut else_block, join_block) = (
this.cfg.start_new_block(),
this.cfg.start_new_block(),
this.cfg.start_new_block(),
this.cfg.start_new_block(),
@ -97,41 +98,47 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
let lhs = unpack!(block = this.as_local_operand(block, lhs));
let blocks = match op {
LogicalOp::And => (else_block, shortcircuit_block),
LogicalOp::Or => (shortcircuit_block, else_block),
LogicalOp::And => (else_block, false_block),
LogicalOp::Or => (true_block, else_block),
};
let term = TerminatorKind::if_(this.hir.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.hir.tcx(), rhs, true_block, false_block);
this.cfg.terminate(else_block, source_info, term);
this.cfg.push_assign_constant(
shortcircuit_block,
true_block,
source_info,
destination,
Constant {
span: expr_span,
ty: this.hir.bool_ty(),
user_ty: None,
literal: match op {
LogicalOp::And => this.hir.false_literal(),
LogicalOp::Or => this.hir.true_literal(),
},
literal: this.hir.true_literal(),
},
);
this.cfg.push_assign_constant(
false_block,
source_info,
destination,
Constant {
span: expr_span,
ty: this.hir.bool_ty(),
user_ty: None,
literal: this.hir.false_literal(),
},
);
this.cfg.terminate(
shortcircuit_block,
true_block,
source_info,
TerminatorKind::Goto { target: join_block },
);
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.terminate(
else_block,
false_block,
source_info,
TerminatorKind::Goto { target: join_block },
);