From e5447a22222ecc6a650e75282cb9931b910854b2 Mon Sep 17 00:00:00 2001
From: Simon Vandel Sillesen <simon.vandel@gmail.com>
Date: Sun, 13 Sep 2020 10:47:20 +0200
Subject: [PATCH] Fix #76432
Only insert StorageDeads if we actually removed one.
Fixes an issue where we added StorageDead to a place with no StorageLive
---
.../transform/simplify_comparison_integral.rs | 43 +++----
src/test/mir-opt/issue_76432.rs | 16 +++
...76432.test.SimplifyComparisonIntegral.diff | 116 ++++++++++++++++++
3 files changed, 154 insertions(+), 21 deletions(-)
create mode 100644 src/test/mir-opt/issue_76432.rs
create mode 100644 src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
diff --git a/compiler/rustc_mir/src/transform/simplify_comparison_integral.rs b/compiler/rustc_mir/src/transform/simplify_comparison_integral.rs
index a450a75d091ef..9b460c9ecb1be 100644
--- a/compiler/rustc_mir/src/transform/simplify_comparison_integral.rs
+++ b/compiler/rustc_mir/src/transform/simplify_comparison_integral.rs
@@ -61,26 +61,6 @@ impl<'tcx> MirPass<'tcx> for SimplifyComparisonIntegral {
_ => unreachable!(),
}
- let terminator = bb.terminator_mut();
-
- // add StorageDead for the place switched on at the top of each target
- for bb_idx in new_targets.iter() {
- storage_deads_to_insert.push((
- *bb_idx,
- Statement {
- source_info: terminator.source_info,
- kind: StatementKind::StorageDead(opt.to_switch_on.local),
- },
- ));
- }
-
- terminator.kind = TerminatorKind::SwitchInt {
- discr: Operand::Move(opt.to_switch_on),
- switch_ty: opt.branch_value_ty,
- values: vec![new_value].into(),
- targets: new_targets,
- };
-
// delete comparison statement if it the value being switched on was moved, which means it can not be user later on
if opt.can_remove_bin_op_stmt {
bb.statements[opt.bin_op_stmt_idx].make_nop();
@@ -106,14 +86,35 @@ impl<'tcx> MirPass<'tcx> for SimplifyComparisonIntegral {
}
}
+ let terminator = bb.terminator();
+
// remove StorageDead (if it exists) being used in the assign of the comparison
for (stmt_idx, stmt) in bb.statements.iter().enumerate() {
if !matches!(stmt.kind, StatementKind::StorageDead(local) if local == opt.to_switch_on.local)
{
continue;
}
- storage_deads_to_remove.push((stmt_idx, opt.bb_idx))
+ storage_deads_to_remove.push((stmt_idx, opt.bb_idx));
+ // if we have StorageDeads to remove then make sure to insert them at the top of each target
+ for bb_idx in new_targets.iter() {
+ storage_deads_to_insert.push((
+ *bb_idx,
+ Statement {
+ source_info: terminator.source_info,
+ kind: StatementKind::StorageDead(opt.to_switch_on.local),
+ },
+ ));
+ }
}
+
+ let terminator = bb.terminator_mut();
+
+ terminator.kind = TerminatorKind::SwitchInt {
+ discr: Operand::Move(opt.to_switch_on),
+ switch_ty: opt.branch_value_ty,
+ values: vec![new_value].into(),
+ targets: new_targets,
+ };
}
for (idx, bb_idx) in storage_deads_to_remove {
diff --git a/src/test/mir-opt/issue_76432.rs b/src/test/mir-opt/issue_76432.rs
new file mode 100644
index 0000000000000..c8b405ca8eaaf
--- /dev/null
+++ b/src/test/mir-opt/issue_76432.rs
@@ -0,0 +1,16 @@
+// Check that we do not insert StorageDead at each target if StorageDead was never seen
+
+// EMIT_MIR issue_76432.test.SimplifyComparisonIntegral.diff
+use std::fmt::Debug;
+
+fn test<T: Copy + Debug + PartialEq>(x: T) {
+ let v: &[T] = &[x, x, x];
+ match v {
+ [ref v1, ref v2, ref v3] => [v1 as *const _, v2 as *const _, v3 as *const _],
+ _ => unreachable!(),
+ };
+}
+
+fn main() {
+ test(0u32);
+}
diff --git a/src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff b/src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
new file mode 100644
index 0000000000000..499134b69919f
--- /dev/null
+++ b/src/test/mir-opt/issue_76432.test.SimplifyComparisonIntegral.diff
@@ -0,0 +1,116 @@
+- // MIR for `test` before SimplifyComparisonIntegral
++ // MIR for `test` after SimplifyComparisonIntegral
+
+ fn test(_1: T) -> () {
+ debug x => _1; // in scope 0 at $DIR/issue_76432.rs:6:38: 6:39
+ let mut _0: (); // return place in scope 0 at $DIR/issue_76432.rs:6:44: 6:44
+ let _2: &[T]; // in scope 0 at $DIR/issue_76432.rs:7:9: 7:10
+ let mut _3: &[T; 3]; // in scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+ let _4: &[T; 3]; // in scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+ let _5: [T; 3]; // in scope 0 at $DIR/issue_76432.rs:7:20: 7:29
+ let mut _6: T; // in scope 0 at $DIR/issue_76432.rs:7:21: 7:22
+ let mut _7: T; // in scope 0 at $DIR/issue_76432.rs:7:24: 7:25
+ let mut _8: T; // in scope 0 at $DIR/issue_76432.rs:7:27: 7:28
+ let _9: [*const T; 3]; // in scope 0 at $DIR/issue_76432.rs:8:5: 11:6
+ let mut _10: usize; // in scope 0 at $DIR/issue_76432.rs:9:9: 9:33
+ let mut _11: usize; // in scope 0 at $DIR/issue_76432.rs:9:9: 9:33
+ let mut _12: bool; // in scope 0 at $DIR/issue_76432.rs:9:9: 9:33
+ let mut _16: *const T; // in scope 0 at $DIR/issue_76432.rs:9:38: 9:52
+ let mut _17: *const T; // in scope 0 at $DIR/issue_76432.rs:9:38: 9:52
+ let mut _18: *const T; // in scope 0 at $DIR/issue_76432.rs:9:54: 9:68
+ let mut _19: *const T; // in scope 0 at $DIR/issue_76432.rs:9:54: 9:68
+ let mut _20: *const T; // in scope 0 at $DIR/issue_76432.rs:9:70: 9:84
+ let mut _21: *const T; // in scope 0 at $DIR/issue_76432.rs:9:70: 9:84
+ let mut _22: !; // in scope 0 at $SRC_DIR/std/src/macros.rs:LL:COL
+ scope 1 {
+ debug v => _2; // in scope 1 at $DIR/issue_76432.rs:7:9: 7:10
+ let _13: &T; // in scope 1 at $DIR/issue_76432.rs:9:10: 9:16
+ let _14: &T; // in scope 1 at $DIR/issue_76432.rs:9:18: 9:24
+ let _15: &T; // in scope 1 at $DIR/issue_76432.rs:9:26: 9:32
+ scope 2 {
+ debug v1 => _13; // in scope 2 at $DIR/issue_76432.rs:9:10: 9:16
+ debug v2 => _14; // in scope 2 at $DIR/issue_76432.rs:9:18: 9:24
+ debug v3 => _15; // in scope 2 at $DIR/issue_76432.rs:9:26: 9:32
+ }
+ }
+
+ bb0: {
+ StorageLive(_2); // scope 0 at $DIR/issue_76432.rs:7:9: 7:10
+ StorageLive(_3); // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+ StorageLive(_4); // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+ StorageLive(_5); // scope 0 at $DIR/issue_76432.rs:7:20: 7:29
+ StorageLive(_6); // scope 0 at $DIR/issue_76432.rs:7:21: 7:22
+ _6 = _1; // scope 0 at $DIR/issue_76432.rs:7:21: 7:22
+ StorageLive(_7); // scope 0 at $DIR/issue_76432.rs:7:24: 7:25
+ _7 = _1; // scope 0 at $DIR/issue_76432.rs:7:24: 7:25
+ StorageLive(_8); // scope 0 at $DIR/issue_76432.rs:7:27: 7:28
+ _8 = _1; // scope 0 at $DIR/issue_76432.rs:7:27: 7:28
+ _5 = [move _6, move _7, move _8]; // scope 0 at $DIR/issue_76432.rs:7:20: 7:29
+ StorageDead(_8); // scope 0 at $DIR/issue_76432.rs:7:28: 7:29
+ StorageDead(_7); // scope 0 at $DIR/issue_76432.rs:7:28: 7:29
+ StorageDead(_6); // scope 0 at $DIR/issue_76432.rs:7:28: 7:29
+ _4 = &_5; // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+ _3 = _4; // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+ _2 = move _3 as &[T] (Pointer(Unsize)); // scope 0 at $DIR/issue_76432.rs:7:19: 7:29
+ StorageDead(_3); // scope 0 at $DIR/issue_76432.rs:7:28: 7:29
+ StorageDead(_4); // scope 0 at $DIR/issue_76432.rs:7:29: 7:30
+ StorageLive(_9); // scope 1 at $DIR/issue_76432.rs:8:5: 11:6
+ _10 = Len((*_2)); // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
+ _11 = const 3_usize; // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
+- _12 = Eq(move _10, const 3_usize); // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
+- switchInt(move _12) -> [false: bb1, otherwise: bb2]; // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
++ nop; // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
++ switchInt(move _10) -> [3_usize: bb2, otherwise: bb1]; // scope 1 at $DIR/issue_76432.rs:9:9: 9:33
+ }
+
+ bb1: {
+ StorageLive(_22); // scope 1 at $SRC_DIR/std/src/macros.rs:LL:COL
+ begin_panic::<&str>(const "internal error: entered unreachable code"); // scope 1 at $SRC_DIR/std/src/macros.rs:LL:COL
+ // mir::Constant
+ // + span: $SRC_DIR/std/src/macros.rs:LL:COL
+ // + literal: Const { ty: fn(&str) -> ! {std::rt::begin_panic::<&str>}, val: Value(Scalar(<ZST>)) }
+ // ty::Const
+ // + ty: &str
+ // + val: Value(Slice { data: Allocation { bytes: [105, 110, 116, 101, 114, 110, 97, 108, 32, 101, 114, 114, 111, 114, 58, 32, 101, 110, 116, 101, 114, 101, 100, 32, 117, 110, 114, 101, 97, 99, 104, 97, 98, 108, 101, 32, 99, 111, 100, 101], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1099511627775], len: Size { raw: 40 } }, size: Size { raw: 40 }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 40 })
+ // mir::Constant
+ // + span: $SRC_DIR/core/src/macros/mod.rs:LL:COL
+ // + literal: Const { ty: &str, val: Value(Slice { data: Allocation { bytes: [105, 110, 116, 101, 114, 110, 97, 108, 32, 101, 114, 114, 111, 114, 58, 32, 101, 110, 116, 101, 114, 101, 100, 32, 117, 110, 114, 101, 97, 99, 104, 97, 98, 108, 101, 32, 99, 111, 100, 101], relocations: Relocations(SortedMap { data: [] }), init_mask: InitMask { blocks: [1099511627775], len: Size { raw: 40 } }, size: Size { raw: 40 }, align: Align { pow2: 0 }, mutability: Not, extra: () }, start: 0, end: 40 }) }
+ }
+
+ bb2: {
+ StorageLive(_13); // scope 1 at $DIR/issue_76432.rs:9:10: 9:16
+ _13 = &(*_2)[0 of 3]; // scope 1 at $DIR/issue_76432.rs:9:10: 9:16
+ StorageLive(_14); // scope 1 at $DIR/issue_76432.rs:9:18: 9:24
+ _14 = &(*_2)[1 of 3]; // scope 1 at $DIR/issue_76432.rs:9:18: 9:24
+ StorageLive(_15); // scope 1 at $DIR/issue_76432.rs:9:26: 9:32
+ _15 = &(*_2)[2 of 3]; // scope 1 at $DIR/issue_76432.rs:9:26: 9:32
+ StorageLive(_16); // scope 2 at $DIR/issue_76432.rs:9:38: 9:52
+ StorageLive(_17); // scope 2 at $DIR/issue_76432.rs:9:38: 9:52
+ _17 = &raw const (*_13); // scope 2 at $DIR/issue_76432.rs:9:38: 9:40
+ _16 = _17; // scope 2 at $DIR/issue_76432.rs:9:38: 9:52
+ StorageLive(_18); // scope 2 at $DIR/issue_76432.rs:9:54: 9:68
+ StorageLive(_19); // scope 2 at $DIR/issue_76432.rs:9:54: 9:68
+ _19 = &raw const (*_14); // scope 2 at $DIR/issue_76432.rs:9:54: 9:56
+ _18 = _19; // scope 2 at $DIR/issue_76432.rs:9:54: 9:68
+ StorageLive(_20); // scope 2 at $DIR/issue_76432.rs:9:70: 9:84
+ StorageLive(_21); // scope 2 at $DIR/issue_76432.rs:9:70: 9:84
+ _21 = &raw const (*_15); // scope 2 at $DIR/issue_76432.rs:9:70: 9:72
+ _20 = _21; // scope 2 at $DIR/issue_76432.rs:9:70: 9:84
+ _9 = [move _16, move _18, move _20]; // scope 2 at $DIR/issue_76432.rs:9:37: 9:85
+ StorageDead(_21); // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+ StorageDead(_20); // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+ StorageDead(_19); // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+ StorageDead(_18); // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+ StorageDead(_17); // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+ StorageDead(_16); // scope 2 at $DIR/issue_76432.rs:9:84: 9:85
+ StorageDead(_15); // scope 1 at $DIR/issue_76432.rs:9:84: 9:85
+ StorageDead(_14); // scope 1 at $DIR/issue_76432.rs:9:84: 9:85
+ StorageDead(_13); // scope 1 at $DIR/issue_76432.rs:9:84: 9:85
+ StorageDead(_9); // scope 1 at $DIR/issue_76432.rs:11:6: 11:7
+ _0 = const (); // scope 0 at $DIR/issue_76432.rs:6:44: 12:2
+ StorageDead(_5); // scope 0 at $DIR/issue_76432.rs:12:1: 12:2
+ StorageDead(_2); // scope 0 at $DIR/issue_76432.rs:12:1: 12:2
+ return; // scope 0 at $DIR/issue_76432.rs:12:2: 12:2
+ }
+ }
+