Commit f0bfba2

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Disable jump threading UnOp::Not for non-bool

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+55

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+55

-2

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Lines changed: 8 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -494,8 +494,16 @@ impl<'a, 'tcx> TOFinder<'a, 'tcx> {`
`494`	`494`	`}`
`495`	`495`	`// Transfer the conditions on the copy rhs, after inversing polarity.`
`496`	`496`	`Rvalue::UnaryOp(UnOp::Not, Operand::Move(place) \| Operand::Copy(place)) => {`
	`497`	`+ if !place.ty(self.body, self.tcx).ty.is_bool() {`
	`498`	`+ // Constructing the conditions by inverting the polarity`
	`499`	`+ // of equality is only correct for bools. That is to say,`
	`500`	+ // `!a == b` is not `a != b` for integers greater than 1 bit.
	`501`	`+ return;`
	`502`	`+ }`
`497`	`503`	`let Some(conditions) = state.try_get_idx(lhs, &self.map) else { return };`
`498`	`504`	`let Some(place) = self.map.find(place.as_ref()) else { return };`
	`505`	`+ // FIXME: I think This could be generalized to not bool if we`
	`506`	`+ // actually perform a logical not on the condition's value.`
`499`	`507`	`let conds = conditions.map(self.arena, Condition::inv);`
`500`	`508`	`state.insert_value_idx(place, conds, &self.map);`
`501`	`509`	`}`

Lines changed: 46 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,46 @@`
	`1`	+- // MIR for `bitwise_not` before JumpThreading
	`2`	++ // MIR for `bitwise_not` after JumpThreading
	`3`	`+`
	`4`	`+ fn bitwise_not() -> i32 {`
	`5`	`+ let mut _0: i32;`
	`6`	`+ let mut _1: i32;`
	`7`	`+ let mut _2: bool;`
	`8`	`+ let mut _3: i32;`
	`9`	`+ let mut _4: i32;`
	`10`	`+ scope 1 {`
	`11`	`+ debug a => _1;`
	`12`	`+ }`
	`13`	`+`
	`14`	`+ bb0: {`
	`15`	`+ StorageLive(_1);`
	`16`	`+ _1 = const 0_i32;`
	`17`	`+ _1 = const 1_i32;`
	`18`	`+ StorageLive(_2);`
	`19`	`+ StorageLive(_3);`
	`20`	`+ StorageLive(_4);`
	`21`	`+ _4 = copy _1;`
	`22`	`+ _3 = Not(move _4);`
	`23`	`+ StorageDead(_4);`
	`24`	`+ _2 = Eq(move _3, const 0_i32);`
	`25`	`+ switchInt(move _2) -> [0: bb2, otherwise: bb1];`
	`26`	`+ }`
	`27`	`+`
	`28`	`+ bb1: {`
	`29`	`+ StorageDead(_3);`
	`30`	`+ _0 = const 1_i32;`
	`31`	`+ goto -> bb3;`
	`32`	`+ }`
	`33`	`+`
	`34`	`+ bb2: {`
	`35`	`+ StorageDead(_3);`
	`36`	`+ _0 = const 0_i32;`
	`37`	`+ goto -> bb3;`
	`38`	`+ }`
	`39`	`+`
	`40`	`+ bb3: {`
	`41`	`+ StorageDead(_2);`
	`42`	`+ StorageDead(_1);`
	`43`	`+ return;`
	`44`	`+ }`
	`45`	`+ }`
	`46`	`+`

Lines changed: 1 addition & 2 deletions

Original file line number	Diff line number	Diff line change
`@@ -22,8 +22,7 @@`
`22`	`22`	`_3 = Not(move _4);`
`23`	`23`	`StorageDead(_4);`
`24`	`24`	`_2 = Eq(move _3, const 0_i32);`
`25`		`-- switchInt(move _2) -> [0: bb2, otherwise: bb1];`
`26`		`-+ goto -> bb1;`
	`25`	`+ switchInt(move _2) -> [0: bb2, otherwise: bb1];`
`27`	`26`	`}`
`28`	`27`
`29`	`28`	`bb1: {`

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