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scottmcmscottmcm
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What if we always run ReorderBasicBlocks?
1 parent 0b45675 commit 2bf23e3

21 files changed

+213
-207
lines changed

‎compiler/rustc_mir_transform/src/prettify.rs‎

Lines changed: 6 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -18,18 +18,18 @@ use rustc_session::Session;
1818
pub(super) struct ReorderBasicBlocks;
1919

2020
impl<'tcx> crate::MirPass<'tcx> for ReorderBasicBlocks {
21-
fn is_enabled(&self, _session: &Session) -> bool {
22-
false
21+
fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
22+
sess.mir_opt_level() > 1
2323
}
2424

2525
fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
26-
let rpo: IndexVec<BasicBlock, BasicBlock> =
27-
body.basic_blocks.reverse_postorder().iter().copied().collect();
28-
if rpo.iter().is_sorted() {
26+
let rpo = body.basic_blocks.reverse_postorder();
27+
if rpo.is_sorted() {
2928
return;
3029
}
3130

32-
let mut updater = BasicBlockUpdater { map: rpo.invert_bijective_mapping(), tcx };
31+
let mut updater =
32+
BasicBlockUpdater { map: IndexSlice::from_raw(rpo).invert_bijective_mapping(), tcx };
3333
debug_assert_eq!(updater.map[START_BLOCK], START_BLOCK);
3434
updater.visit_body(body);
3535

‎tests/codegen/hint/cold_path.rs‎

Lines changed: 6 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -26,10 +26,10 @@ pub fn test1(x: bool) {
2626
}
2727

2828
// CHECK-LABEL: @test1(
29-
// CHECK: br i1 %x, label %bb1, label %bb2, !prof ![[NUM:[0-9]+]]
30-
// CHECK: bb2:
31-
// CHECK: path_b
29+
// CHECK: br i1 %x, label %bb3, label %bb1, !prof ![[NUM:[0-9]+]]
3230
// CHECK: bb1:
31+
// CHECK: path_b
32+
// CHECK: bb3:
3333
// CHECK: path_a
3434
}
3535

@@ -44,10 +44,11 @@ pub fn test2(x: i32) {
4444
}
4545

4646
// CHECK-LABEL: @test2(
47-
// CHECK: br i1 %_2, label %bb2, label %bb1, !prof ![[NUM]]
47+
// CHECK: %_2 = icmp sgt i32 %x, 0
48+
// CHECK: br i1 %_2, label %bb3, label %bb1, !prof ![[NUM]]
4849
// CHECK: bb1:
4950
// CHECK: path_b
50-
// CHECK: bb2:
51+
// CHECK: bb3:
5152
// CHECK: path_a
5253
}
5354

‎tests/codegen/hint/likely.rs‎

Lines changed: 15 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -25,10 +25,10 @@ pub fn test1(x: bool) {
2525
}
2626

2727
// CHECK-LABEL: @test1(
28-
// CHECK: br i1 %x, label %bb2, label %bb3, !prof ![[NUM:[0-9]+]]
29-
// CHECK: bb3:
28+
// CHECK: br i1 %x, label %bb3, label %bb1, !prof ![[NUM:[0-9]+]]
29+
// CHECK: bb1:
3030
// CHECK: path_b
31-
// CHECK: bb2:
31+
// CHECK: bb3:
3232
// CHECK: path_a
3333
}
3434

@@ -40,10 +40,10 @@ pub fn test2(x: i32) {
4040
}
4141

4242
// CHECK-LABEL: @test2(
43-
// CHECK: br i1 %_2, label %bb2, label %bb3, !prof ![[NUM]]
44-
// CHECK: bb3:
43+
// CHECK: br i1 %_2, label %bb3, label %bb1, !prof ![[NUM]]
44+
// CHECK: bb1:
4545
// CHECK: path_b
46-
// CHECK: bb2:
46+
// CHECK: bb3:
4747
// CHECK: path_a
4848
}
4949

@@ -55,10 +55,10 @@ pub fn test3(x: i8) {
5555
}
5656

5757
// CHECK-LABEL: @test3(
58-
// CHECK: br i1 %_2, label %bb2, label %bb3, !prof ![[NUM]]
59-
// CHECK: bb3:
58+
// CHECK: br i1 %_2, label %bb3, label %bb1, !prof ![[NUM]]
59+
// CHECK: bb1:
6060
// CHECK: path_b
61-
// CHECK: bb2:
61+
// CHECK: bb3:
6262
// CHECK: path_a
6363
}
6464

@@ -69,11 +69,14 @@ pub fn test4(x: u64) {
6969
_ => path_b(),
7070
}
7171

72+
// Note that LLVM seems to flip this one, for some reason
73+
7274
// CHECK-LABEL: @test4(
73-
// CHECK: br i1 %0, label %bb3, label %bb2, !prof ![[NUM2:[0-9]+]]
74-
// CHECK: bb3:
75+
// CHECK: %0 = icmp eq i64 %x, 33
76+
// CHECK: br i1 %0, label %bb1, label %bb3, !prof ![[NUM2:[0-9]+]]
77+
// CHECK: bb1:
7578
// CHECK: path_a
76-
// CHECK: bb2:
79+
// CHECK: bb3:
7780
// CHECK: path_b
7881
}
7982

‎tests/codegen/hint/unlikely.rs‎

Lines changed: 12 additions & 8 deletions
Original file line numberDiff line numberDiff line change
@@ -25,8 +25,8 @@ pub fn test1(x: bool) {
2525
}
2626

2727
// CHECK-LABEL: @test1(
28-
// CHECK: br i1 %x, label %bb2, label %bb4, !prof ![[NUM:[0-9]+]]
29-
// CHECK: bb4:
28+
// CHECK: br i1 %x, label %bb2, label %bb1, !prof ![[NUM:[0-9]+]]
29+
// CHECK: bb1:
3030
// CHECK: path_b
3131
// CHECK: bb2:
3232
// CHECK: path_a
@@ -40,8 +40,8 @@ pub fn test2(x: i32) {
4040
}
4141

4242
// CHECK-LABEL: @test2(
43-
// CHECK: br i1 %_2, label %bb2, label %bb4, !prof ![[NUM]]
44-
// CHECK: bb4:
43+
// CHECK: br i1 %_2, label %bb2, label %bb1, !prof ![[NUM]]
44+
// CHECK: bb1:
4545
// CHECK: path_b
4646
// CHECK: bb2:
4747
// CHECK: path_a
@@ -55,8 +55,8 @@ pub fn test3(x: i8) {
5555
}
5656

5757
// CHECK-LABEL: @test3(
58-
// CHECK: br i1 %_2, label %bb2, label %bb4, !prof ![[NUM]]
59-
// CHECK: bb4:
58+
// CHECK: br i1 %_2, label %bb2, label %bb1, !prof ![[NUM]]
59+
// CHECK: bb1:
6060
// CHECK: path_b
6161
// CHECK: bb2:
6262
// CHECK: path_a
@@ -69,12 +69,16 @@ pub fn test4(x: u64) {
6969
_ => path_b(),
7070
}
7171

72+
// Note that LLVM seems to flip this one, for some reason
73+
7274
// CHECK-LABEL: @test4(
73-
// CHECK: br i1 %0, label %bb4, label %bb2, !prof ![[NUM2:[0-9]+]]
74-
// CHECK: bb4:
75+
// CHECK: %0 = icmp eq i64 %x, 33
76+
// CHECK: br i1 %0, label %bb1, label %bb2, !prof ![[NUM2:[0-9]+]]
77+
// CHECK: bb1:
7578
// CHECK: path_a
7679
// CHECK: bb2:
7780
// CHECK: path_b
7881
}
7982

8083
// CHECK: ![[NUM]] = !{!"branch_weights", {{(!"expected", )?}}i32 1, i32 2000}
84+
// CHECK: ![[NUM2]] = !{!"branch_weights", {{(!"expected", )?}}i32 2000, i32 1}

‎tests/codegen/intrinsics/cold_path3.rs‎

Lines changed: 9 additions & 9 deletions
Original file line numberDiff line numberDiff line change
@@ -45,11 +45,11 @@ pub fn test(x: Option<u32>) {
4545
}
4646

4747
// CHECK-LABEL: @test(
48-
// CHECK: switch i32 %1, label %bb1 [
49-
// CHECK: i32 0, label %bb6
50-
// CHECK: i32 1, label %bb5
51-
// CHECK: i32 2, label %bb4
52-
// CHECK: i32 3, label %bb3
48+
// CHECK: switch i32 %1, label %bb8 [
49+
// CHECK: i32 0, label %bb2
50+
// CHECK: i32 1, label %bb3
51+
// CHECK: i32 2, label %bb5
52+
// CHECK: i32 3, label %bb6
5353
// CHECK: ], !prof ![[NUM1:[0-9]+]]
5454
}
5555

@@ -76,10 +76,10 @@ pub fn test2(x: Option<u32>) {
7676
}
7777

7878
// CHECK-LABEL: @test2(
79-
// CHECK: switch i32 %1, label %bb1 [
80-
// CHECK: i32 10, label %bb5
81-
// CHECK: i32 11, label %bb4
82-
// CHECK: i32 13, label %bb3
79+
// CHECK: switch i32 %1, label %bb7 [
80+
// CHECK: i32 10, label %bb2
81+
// CHECK: i32 11, label %bb3
82+
// CHECK: i32 13, label %bb5
8383
// CHECK: ], !prof ![[NUM2:[0-9]+]]
8484
}
8585

‎tests/codegen/intrinsics/likely.rs‎

Lines changed: 3 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -26,10 +26,10 @@ pub fn test_likely(x: bool) {
2626
}
2727

2828
// CHECK-LABEL: @test_likely(
29-
// CHECK: br i1 %x, label %bb2, label %bb3, !prof ![[NUM:[0-9]+]]
30-
// CHECK: bb3:
29+
// CHECK: br i1 %x, label %bb3, label %bb1, !prof ![[NUM:[0-9]+]]
30+
// CHECK: bb1:
3131
// CHECK-NOT: cold_path
3232
// CHECK: path_b
33-
// CHECK: bb2:
33+
// CHECK: bb3:
3434
// CHECK: path_a
3535
// CHECK: ![[NUM]] = !{!"branch_weights", {{(!"expected", )?}}i32 2000, i32 1}

‎tests/codegen/intrinsics/unlikely.rs‎

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -26,8 +26,8 @@ pub fn test_unlikely(x: bool) {
2626
}
2727

2828
// CHECK-LABEL: @test_unlikely(
29-
// CHECK: br i1 %x, label %bb2, label %bb4, !prof ![[NUM:[0-9]+]]
30-
// CHECK: bb4:
29+
// CHECK: br i1 %x, label %bb2, label %bb1, !prof ![[NUM:[0-9]+]]
30+
// CHECK: bb1:
3131
// CHECK: path_b
3232
// CHECK: bb2:
3333
// CHECK-NOT: cold_path

‎tests/mir-opt/dont_reset_cast_kind_without_updating_operand.test.GVN.32bit.panic-abort.diff‎

Lines changed: 22 additions & 22 deletions
Original file line numberDiff line numberDiff line change
@@ -84,8 +84,8 @@
8484
StorageLive(_17);
8585
StorageLive(_19);
8686
_19 = const false;
87-
- switchInt(move _19) -> [0: bb6, otherwise: bb5];
88-
+ switchInt(const false) -> [0: bb6, otherwise: bb5];
87+
- switchInt(move _19) -> [0: bb3, otherwise: bb2];
88+
+ switchInt(const false) -> [0: bb3, otherwise: bb2];
8989
}
9090

9191
bb1: {
@@ -95,15 +95,29 @@
9595
}
9696

9797
bb2: {
98-
unreachable;
98+
- _20 = Layout::from_size_align_unchecked::precondition_check(copy _11, copy _12) -> [return: bb3, unwind unreachable];
99+
+ _20 = Layout::from_size_align_unchecked::precondition_check(const 0_usize, const 1_usize) -> [return: bb3, unwind unreachable];
99100
}
100101

101102
bb3: {
102-
- _18 = handle_alloc_error(move _14) -> unwind unreachable;
103-
+ _18 = handle_alloc_error(const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }}) -> unwind unreachable;
103+
StorageDead(_19);
104+
StorageLive(_21);
105+
- _21 = copy _12 as std::ptr::Alignment (Transmute);
106+
- _14 = Layout { size: copy _11, align: move _21 };
107+
+ _21 = const std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0);
108+
+ _14 = const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }};
109+
StorageDead(_21);
110+
StorageLive(_15);
111+
- _15 = std::alloc::Global::alloc_impl(const alloc::alloc::exchange_malloc::promoted[0], copy _14, const false) -> [return: bb4, unwind unreachable];
112+
+ _15 = std::alloc::Global::alloc_impl(const alloc::alloc::exchange_malloc::promoted[0], const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }}, const false) -> [return: bb4, unwind unreachable];
104113
}
105114

106115
bb4: {
116+
_16 = discriminant(_15);
117+
switchInt(move _16) -> [0: bb5, 1: bb6, otherwise: bb7];
118+
}
119+
120+
bb5: {
107121
_17 = copy ((_15 as Ok).0: std::ptr::NonNull<[u8]>);
108122
StorageLive(_22);
109123
_22 = copy _17 as *mut [u8] (Transmute);
@@ -150,27 +164,13 @@
150164
drop(_3) -> [return: bb1, unwind unreachable];
151165
}
152166

153-
bb5: {
154-
- _20 = Layout::from_size_align_unchecked::precondition_check(copy _11, copy _12) -> [return: bb6, unwind unreachable];
155-
+ _20 = Layout::from_size_align_unchecked::precondition_check(const 0_usize, const 1_usize) -> [return: bb6, unwind unreachable];
156-
}
157-
158167
bb6: {
159-
StorageDead(_19);
160-
StorageLive(_21);
161-
- _21 = copy _12 as std::ptr::Alignment (Transmute);
162-
- _14 = Layout { size: copy _11, align: move _21 };
163-
+ _21 = const std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0);
164-
+ _14 = const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }};
165-
StorageDead(_21);
166-
StorageLive(_15);
167-
- _15 = std::alloc::Global::alloc_impl(const alloc::alloc::exchange_malloc::promoted[0], copy _14, const false) -> [return: bb7, unwind unreachable];
168-
+ _15 = std::alloc::Global::alloc_impl(const alloc::alloc::exchange_malloc::promoted[0], const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }}, const false) -> [return: bb7, unwind unreachable];
168+
- _18 = handle_alloc_error(move _14) -> unwind unreachable;
169+
+ _18 = handle_alloc_error(const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }}) -> unwind unreachable;
169170
}
170171

171172
bb7: {
172-
_16 = discriminant(_15);
173-
switchInt(move _16) -> [0: bb4, 1: bb3, otherwise: bb2];
173+
unreachable;
174174
}
175175
+ }
176176
+

‎tests/mir-opt/dont_reset_cast_kind_without_updating_operand.test.GVN.64bit.panic-abort.diff‎

Lines changed: 22 additions & 22 deletions
Original file line numberDiff line numberDiff line change
@@ -84,8 +84,8 @@
8484
StorageLive(_17);
8585
StorageLive(_19);
8686
_19 = const false;
87-
- switchInt(move _19) -> [0: bb6, otherwise: bb5];
88-
+ switchInt(const false) -> [0: bb6, otherwise: bb5];
87+
- switchInt(move _19) -> [0: bb3, otherwise: bb2];
88+
+ switchInt(const false) -> [0: bb3, otherwise: bb2];
8989
}
9090

9191
bb1: {
@@ -95,15 +95,29 @@
9595
}
9696

9797
bb2: {
98-
unreachable;
98+
- _20 = Layout::from_size_align_unchecked::precondition_check(copy _11, copy _12) -> [return: bb3, unwind unreachable];
99+
+ _20 = Layout::from_size_align_unchecked::precondition_check(const 0_usize, const 1_usize) -> [return: bb3, unwind unreachable];
99100
}
100101

101102
bb3: {
102-
- _18 = handle_alloc_error(move _14) -> unwind unreachable;
103-
+ _18 = handle_alloc_error(const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }}) -> unwind unreachable;
103+
StorageDead(_19);
104+
StorageLive(_21);
105+
- _21 = copy _12 as std::ptr::Alignment (Transmute);
106+
- _14 = Layout { size: copy _11, align: move _21 };
107+
+ _21 = const std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0);
108+
+ _14 = const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }};
109+
StorageDead(_21);
110+
StorageLive(_15);
111+
- _15 = std::alloc::Global::alloc_impl(const alloc::alloc::exchange_malloc::promoted[0], copy _14, const false) -> [return: bb4, unwind unreachable];
112+
+ _15 = std::alloc::Global::alloc_impl(const alloc::alloc::exchange_malloc::promoted[0], const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }}, const false) -> [return: bb4, unwind unreachable];
104113
}
105114

106115
bb4: {
116+
_16 = discriminant(_15);
117+
switchInt(move _16) -> [0: bb5, 1: bb6, otherwise: bb7];
118+
}
119+
120+
bb5: {
107121
_17 = copy ((_15 as Ok).0: std::ptr::NonNull<[u8]>);
108122
StorageLive(_22);
109123
_22 = copy _17 as *mut [u8] (Transmute);
@@ -150,27 +164,13 @@
150164
drop(_3) -> [return: bb1, unwind unreachable];
151165
}
152166

153-
bb5: {
154-
- _20 = Layout::from_size_align_unchecked::precondition_check(copy _11, copy _12) -> [return: bb6, unwind unreachable];
155-
+ _20 = Layout::from_size_align_unchecked::precondition_check(const 0_usize, const 1_usize) -> [return: bb6, unwind unreachable];
156-
}
157-
158167
bb6: {
159-
StorageDead(_19);
160-
StorageLive(_21);
161-
- _21 = copy _12 as std::ptr::Alignment (Transmute);
162-
- _14 = Layout { size: copy _11, align: move _21 };
163-
+ _21 = const std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0);
164-
+ _14 = const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }};
165-
StorageDead(_21);
166-
StorageLive(_15);
167-
- _15 = std::alloc::Global::alloc_impl(const alloc::alloc::exchange_malloc::promoted[0], copy _14, const false) -> [return: bb7, unwind unreachable];
168-
+ _15 = std::alloc::Global::alloc_impl(const alloc::alloc::exchange_malloc::promoted[0], const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }}, const false) -> [return: bb7, unwind unreachable];
168+
- _18 = handle_alloc_error(move _14) -> unwind unreachable;
169+
+ _18 = handle_alloc_error(const Layout {{ size: 0_usize, align: std::ptr::Alignment(std::ptr::alignment::AlignmentEnum::_Align1Shl0) }}) -> unwind unreachable;
169170
}
170171

171172
bb7: {
172-
_16 = discriminant(_15);
173-
switchInt(move _16) -> [0: bb4, 1: bb3, otherwise: bb2];
173+
unreachable;
174174
}
175175
+ }
176176
+

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