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Use Copy in the SwitchInt terminator

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Move can be used only when both the compared operand and the operand on switch are move operands.
This commit directly changes to Copy, because I don't know if Move has beneficial.
This commit is contained in:
dianqk 2026-01-10 20:27:08 +08:00
parent ac80ccec5f
commit 37f83fb11d
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16 changed files with 23 additions and 24 deletions
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2
compiler/rustc_mir_transform/src/simplify_comparison_integral.rs
View file

@ -135,7 +135,7 @@ impl<'tcx> crate::MirPass<'tcx> for SimplifyComparisonIntegral {
let terminator = bb.terminator_mut();
terminator.kind =
TerminatorKind::SwitchInt { discr: Operand::Move(opt.to_switch_on), targets };
TerminatorKind::SwitchInt { discr: Operand::Copy(opt.to_switch_on), targets };
}
for (idx, bb_idx) in storage_deads_to_remove {

2
tests/mir-opt/funky_arms.float_to_exponential_common.GVN.32bit.panic-abort.diff
View file

@ -74,7 +74,7 @@
_23 = copy (((*_1).0: std::fmt::FormattingOptions).0: u32);
_22 = BitAnd(move _23, const core::fmt::flags::PRECISION_FLAG);
StorageDead(_23);
switchInt(move _22) -> [0: bb10, otherwise: bb11];
switchInt(copy _22) -> [0: bb10, otherwise: bb11];
}
bb4: {

2
tests/mir-opt/funky_arms.float_to_exponential_common.GVN.32bit.panic-unwind.diff
View file

@ -74,7 +74,7 @@
_23 = copy (((*_1).0: std::fmt::FormattingOptions).0: u32);
_22 = BitAnd(move _23, const core::fmt::flags::PRECISION_FLAG);
StorageDead(_23);
switchInt(move _22) -> [0: bb10, otherwise: bb11];
switchInt(copy _22) -> [0: bb10, otherwise: bb11];
}
bb4: {

2
tests/mir-opt/funky_arms.float_to_exponential_common.GVN.64bit.panic-abort.diff
View file

@ -74,7 +74,7 @@
_23 = copy (((*_1).0: std::fmt::FormattingOptions).0: u32);
_22 = BitAnd(move _23, const core::fmt::flags::PRECISION_FLAG);
StorageDead(_23);
switchInt(move _22) -> [0: bb10, otherwise: bb11];
switchInt(copy _22) -> [0: bb10, otherwise: bb11];
}
bb4: {

2
tests/mir-opt/funky_arms.float_to_exponential_common.GVN.64bit.panic-unwind.diff
View file

@ -74,7 +74,7 @@
_23 = copy (((*_1).0: std::fmt::FormattingOptions).0: u32);
_22 = BitAnd(move _23, const core::fmt::flags::PRECISION_FLAG);
StorageDead(_23);
switchInt(move _22) -> [0: bb10, otherwise: bb11];
switchInt(copy _22) -> [0: bb10, otherwise: bb11];
}
bb4: {

2
tests/mir-opt/if_condition_int.dont_remove_comparison.SimplifyComparisonIntegral.diff
View file

@ -21,7 +21,7 @@
_2 = Eq(copy _1, const 17_i8);
StorageDead(_3);
- switchInt(copy _2) -> [0: bb2, otherwise: bb1];
+ switchInt(move _1) -> [17: bb1, otherwise: bb2];
+ switchInt(copy _1) -> [17: bb1, otherwise: bb2];
}
bb1: {

2
tests/mir-opt/if_condition_int.opt_char.SimplifyComparisonIntegral.diff
View file

@ -14,7 +14,7 @@
- _2 = Eq(copy _1, const 'x');
- switchInt(move _2) -> [0: bb2, otherwise: bb1];
+ nop;
+ switchInt(move _1) -> [120: bb1, otherwise: bb2];
+ switchInt(copy _1) -> [120: bb1, otherwise: bb2];
}
bb1: {

2
tests/mir-opt/if_condition_int.opt_i8.SimplifyComparisonIntegral.diff
View file

@ -14,7 +14,7 @@
- _2 = Eq(copy _1, const 42_i8);
- switchInt(move _2) -> [0: bb2, otherwise: bb1];
+ nop;
+ switchInt(move _1) -> [42: bb1, otherwise: bb2];
+ switchInt(copy _1) -> [42: bb1, otherwise: bb2];
}
bb1: {

4
tests/mir-opt/if_condition_int.opt_multiple_ifs.SimplifyComparisonIntegral.diff
View file

@ -16,7 +16,7 @@
- _2 = Eq(copy _1, const 42_u32);
- switchInt(move _2) -> [0: bb2, otherwise: bb1];
+ nop;
+ switchInt(move _1) -> [42: bb1, otherwise: bb2];
+ switchInt(copy _1) -> [42: bb1, otherwise: bb2];
}
bb1: {
@ -33,7 +33,7 @@
- _4 = Ne(copy _1, const 21_u32);
- switchInt(move _4) -> [0: bb4, otherwise: bb3];
+ nop;
+ switchInt(move _1) -> [21: bb4, otherwise: bb3];
+ switchInt(copy _1) -> [21: bb4, otherwise: bb3];
}
bb3: {

2
tests/mir-opt/if_condition_int.opt_negative.SimplifyComparisonIntegral.diff
View file

@ -14,7 +14,7 @@
- _2 = Eq(copy _1, const -42_i32);
- switchInt(move _2) -> [0: bb2, otherwise: bb1];
+ nop;
+ switchInt(move _1) -> [4294967254: bb1, otherwise: bb2];
+ switchInt(copy _1) -> [4294967254: bb1, otherwise: bb2];
}
bb1: {

2
tests/mir-opt/if_condition_int.opt_u32.SimplifyComparisonIntegral.diff
View file

@ -14,7 +14,7 @@
- _2 = Eq(copy _1, const 42_u32);
- switchInt(move _2) -> [0: bb2, otherwise: bb1];
+ nop;
+ switchInt(move _1) -> [42: bb1, otherwise: bb2];
+ switchInt(copy _1) -> [42: bb1, otherwise: bb2];
}
bb1: {

15
tests/mir-opt/if_condition_int.rs
View file

@ -10,8 +10,7 @@ use core::intrinsics::mir::*;
// EMIT_MIR if_condition_int.opt_u32.SimplifyComparisonIntegral.diff
fn opt_u32(x: u32) -> u32 {
// CHECK-LABEL: fn opt_u32(
// FIXME: This should be copy.
// CHECK: switchInt(move _1) -> [42: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: switchInt(copy _1) -> [42: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: [[BB1]]:
// CHECK: _0 = const 0_u32;
// CHECK: [[BB2]]:
@ -34,7 +33,7 @@ fn dont_opt_bool(x: bool) -> u32 {
// EMIT_MIR if_condition_int.opt_char.SimplifyComparisonIntegral.diff
fn opt_char(x: char) -> u32 {
// CHECK-LABEL: fn opt_char(
// CHECK: switchInt(move _1) -> [120: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: switchInt(copy _1) -> [120: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: [[BB1]]:
// CHECK: _0 = const 0_u32;
// CHECK: [[BB2]]:
@ -45,7 +44,7 @@ fn opt_char(x: char) -> u32 {
// EMIT_MIR if_condition_int.opt_i8.SimplifyComparisonIntegral.diff
fn opt_i8(x: i8) -> u32 {
// CHECK-LABEL: fn opt_i8(
// CHECK: switchInt(move _1) -> [42: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: switchInt(copy _1) -> [42: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: [[BB1]]:
// CHECK: _0 = const 0_u32;
// CHECK: [[BB2]]:
@ -56,7 +55,7 @@ fn opt_i8(x: i8) -> u32 {
// EMIT_MIR if_condition_int.opt_negative.SimplifyComparisonIntegral.diff
fn opt_negative(x: i32) -> u32 {
// CHECK-LABEL: fn opt_negative(
// CHECK: switchInt(move _1) -> [4294967254: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: switchInt(copy _1) -> [4294967254: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: [[BB1]]:
// CHECK: _0 = const 0_u32;
// CHECK: [[BB2]]:
@ -67,11 +66,11 @@ fn opt_negative(x: i32) -> u32 {
// EMIT_MIR if_condition_int.opt_multiple_ifs.SimplifyComparisonIntegral.diff
fn opt_multiple_ifs(x: u32) -> u32 {
// CHECK-LABEL: fn opt_multiple_ifs(
// CHECK: switchInt(move _1) -> [42: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: switchInt(copy _1) -> [42: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: [[BB1]]:
// CHECK: _0 = const 0_u32;
// CHECK: [[BB2]]:
// CHECK: switchInt(move _1) -> [21: [[BB4:bb.*]], otherwise: [[BB3:bb.*]]];
// CHECK: switchInt(copy _1) -> [21: [[BB4:bb.*]], otherwise: [[BB3:bb.*]]];
// CHECK: [[BB3]]:
// CHECK: _0 = const 1_u32;
// CHECK: [[BB4]]:
@ -90,7 +89,7 @@ fn opt_multiple_ifs(x: u32) -> u32 {
fn dont_remove_comparison(a: i8) -> i32 {
// CHECK-LABEL: fn dont_remove_comparison(
// CHECK: [[b:_.*]] = Eq(copy _1, const 17_i8);
// CHECK: switchInt(move _1) -> [17: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: switchInt(copy _1) -> [17: [[BB1:bb.*]], otherwise: [[BB2:bb.*]]];
// CHECK: [[BB1]]:
// CHECK: [[cast_1:_.*]] = copy [[b]] as i32 (IntToInt);
// CHECK: _0 = Add(const 100_i32, move [[cast_1]]);

2
tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.32bit.panic-abort.mir
View file

@ -28,7 +28,7 @@ fn num_to_digit(_1: char) -> u32 {
StorageLive(_3);
_3 = discriminant(_2);
StorageDead(_2);
switchInt(move _3) -> [1: bb2, otherwise: bb7];
switchInt(copy _3) -> [1: bb2, otherwise: bb7];
}
bb2: {

2
tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.32bit.panic-unwind.mir
View file

@ -28,7 +28,7 @@ fn num_to_digit(_1: char) -> u32 {
StorageLive(_3);
_3 = discriminant(_2);
StorageDead(_2);
switchInt(move _3) -> [1: bb2, otherwise: bb7];
switchInt(copy _3) -> [1: bb2, otherwise: bb7];
}
bb2: {

2
tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.64bit.panic-abort.mir
View file

@ -28,7 +28,7 @@ fn num_to_digit(_1: char) -> u32 {
StorageLive(_3);
_3 = discriminant(_2);
StorageDead(_2);
switchInt(move _3) -> [1: bb2, otherwise: bb7];
switchInt(copy _3) -> [1: bb2, otherwise: bb7];
}
bb2: {

2
tests/mir-opt/issues/issue_59352.num_to_digit.PreCodegen.after.64bit.panic-unwind.mir
View file

@ -28,7 +28,7 @@ fn num_to_digit(_1: char) -> u32 {
StorageLive(_3);
_3 = discriminant(_2);
StorageDead(_2);
switchInt(move _3) -> [1: bb2, otherwise: bb7];
switchInt(copy _3) -> [1: bb2, otherwise: bb7];
}
bb2: {