From 1e88f130a347f8b223031eafe75c0772ccfec00c Mon Sep 17 00:00:00 2001 From: Wesley Wiser Date: Mon, 8 Jun 2020 08:14:45 -0400 Subject: [PATCH] Stop allowing `Indirect(..)` values to be propagated Closes #72679 Closes #72372 Closes #72285 --- src/librustc_mir/transform/const_prop.rs | 1 - src/test/mir-opt/const_prop/discriminant.rs | 5 ++ .../32bit/rustc.main.ConstProp.diff | 75 +++++++++---------- .../64bit/rustc.main.ConstProp.diff | 75 +++++++++---------- 4 files changed, 73 insertions(+), 83 deletions(-) diff --git a/src/librustc_mir/transform/const_prop.rs b/src/librustc_mir/transform/const_prop.rs index 97e5b8bc047f0..39548d8a535f7 100644 --- a/src/librustc_mir/transform/const_prop.rs +++ b/src/librustc_mir/transform/const_prop.rs @@ -707,7 +707,6 @@ impl<'mir, 'tcx> ConstPropagator<'mir, 'tcx> { ScalarMaybeUninit::Scalar(l), ScalarMaybeUninit::Scalar(r), )) => l.is_bits() && r.is_bits(), - interpret::Operand::Indirect(_) if mir_opt_level >= 2 => true, _ => false, } } diff --git a/src/test/mir-opt/const_prop/discriminant.rs b/src/test/mir-opt/const_prop/discriminant.rs index 04541b94ad780..13e8eb3e44e1a 100644 --- a/src/test/mir-opt/const_prop/discriminant.rs +++ b/src/test/mir-opt/const_prop/discriminant.rs @@ -1,5 +1,10 @@ // compile-flags: -O +// FIXME(wesleywiser): Ideally, we could const-prop away all of this and just be left with +// `let x = 42` but that doesn't work because const-prop doesn't support `Operand::Indirect` +// and `InterpCx::eval_place()` always forces an allocation which creates the `Indirect`. +// Fixing either of those will allow us to const-prop this away. + // EMIT_MIR_FOR_EACH_BIT_WIDTH // EMIT_MIR rustc.main.ConstProp.diff fn main() { diff --git a/src/test/mir-opt/const_prop/discriminant/32bit/rustc.main.ConstProp.diff b/src/test/mir-opt/const_prop/discriminant/32bit/rustc.main.ConstProp.diff index 9979ea9549891..1c873f53f378a 100644 --- a/src/test/mir-opt/const_prop/discriminant/32bit/rustc.main.ConstProp.diff +++ b/src/test/mir-opt/const_prop/discriminant/32bit/rustc.main.ConstProp.diff @@ -2,100 +2,93 @@ + // MIR for `main` after ConstProp fn main() -> () { - let mut _0: (); // return place in scope 0 at $DIR/discriminant.rs:5:11: 5:11 - let _1: i32; // in scope 0 at $DIR/discriminant.rs:6:9: 6:10 - let mut _2: i32; // in scope 0 at $DIR/discriminant.rs:6:13: 6:64 - let mut _3: std::option::Option; // in scope 0 at $DIR/discriminant.rs:6:34: 6:44 - let mut _4: isize; // in scope 0 at $DIR/discriminant.rs:6:21: 6:31 + let mut _0: (); // return place in scope 0 at $DIR/discriminant.rs:10:11: 10:11 + let _1: i32; // in scope 0 at $DIR/discriminant.rs:11:9: 11:10 + let mut _2: i32; // in scope 0 at $DIR/discriminant.rs:11:13: 11:64 + let mut _3: std::option::Option; // in scope 0 at $DIR/discriminant.rs:11:34: 11:44 + let mut _4: isize; // in scope 0 at $DIR/discriminant.rs:11:21: 11:31 scope 1 { - debug x => _1; // in scope 1 at $DIR/discriminant.rs:6:9: 6:10 + debug x => _1; // in scope 1 at $DIR/discriminant.rs:11:9: 11:10 } bb0: { - StorageLive(_1); // scope 0 at $DIR/discriminant.rs:6:9: 6:10 - StorageLive(_2); // scope 0 at $DIR/discriminant.rs:6:13: 6:64 - StorageLive(_3); // scope 0 at $DIR/discriminant.rs:6:34: 6:44 -- _3 = std::option::Option::::Some(const true); // scope 0 at $DIR/discriminant.rs:6:34: 6:44 -+ _3 = const std::option::Option::::Some(true); // scope 0 at $DIR/discriminant.rs:6:34: 6:44 + StorageLive(_1); // scope 0 at $DIR/discriminant.rs:11:9: 11:10 + StorageLive(_2); // scope 0 at $DIR/discriminant.rs:11:13: 11:64 + StorageLive(_3); // scope 0 at $DIR/discriminant.rs:11:34: 11:44 +- _3 = std::option::Option::::Some(const true); // scope 0 at $DIR/discriminant.rs:11:34: 11:44 ++ _3 = const std::option::Option::::Some(true); // scope 0 at $DIR/discriminant.rs:11:34: 11:44 // ty::Const - // + ty: bool + // + ty: std::option::Option // + val: Value(Scalar(0x01)) // mir::Constant -- // + span: $DIR/discriminant.rs:6:39: 6:43 +- // + span: $DIR/discriminant.rs:11:39: 11:43 - // + literal: Const { ty: bool, val: Value(Scalar(0x01)) } -- _4 = discriminant(_3); // scope 0 at $DIR/discriminant.rs:6:21: 6:31 -- switchInt(move _4) -> [1isize: bb2, otherwise: bb1]; // scope 0 at $DIR/discriminant.rs:6:21: 6:31 -+ // + span: $DIR/discriminant.rs:6:34: 6:44 +- _4 = discriminant(_3); // scope 0 at $DIR/discriminant.rs:11:21: 11:31 +- switchInt(move _4) -> [1isize: bb2, otherwise: bb1]; // scope 0 at $DIR/discriminant.rs:11:21: 11:31 ++ // + span: $DIR/discriminant.rs:11:34: 11:44 + // + literal: Const { ty: std::option::Option, val: Value(Scalar(0x01)) } -+ _4 = const 1isize; // scope 0 at $DIR/discriminant.rs:6:21: 6:31 ++ _4 = const 1isize; // scope 0 at $DIR/discriminant.rs:11:21: 11:31 + // ty::Const + // + ty: isize + // + val: Value(Scalar(0x00000001)) + // mir::Constant -+ // + span: $DIR/discriminant.rs:6:21: 6:31 ++ // + span: $DIR/discriminant.rs:11:21: 11:31 + // + literal: Const { ty: isize, val: Value(Scalar(0x00000001)) } -+ switchInt(const 1isize) -> [1isize: bb2, otherwise: bb1]; // scope 0 at $DIR/discriminant.rs:6:21: 6:31 ++ switchInt(const 1isize) -> [1isize: bb2, otherwise: bb1]; // scope 0 at $DIR/discriminant.rs:11:21: 11:31 + // ty::Const + // + ty: isize + // + val: Value(Scalar(0x00000001)) + // mir::Constant -+ // + span: $DIR/discriminant.rs:6:21: 6:31 ++ // + span: $DIR/discriminant.rs:11:21: 11:31 + // + literal: Const { ty: isize, val: Value(Scalar(0x00000001)) } } bb1: { - _2 = const 10i32; // scope 0 at $DIR/discriminant.rs:6:59: 6:61 + _2 = const 10i32; // scope 0 at $DIR/discriminant.rs:11:59: 11:61 // ty::Const // + ty: i32 // + val: Value(Scalar(0x0000000a)) // mir::Constant - // + span: $DIR/discriminant.rs:6:59: 6:61 + // + span: $DIR/discriminant.rs:11:59: 11:61 // + literal: Const { ty: i32, val: Value(Scalar(0x0000000a)) } - goto -> bb4; // scope 0 at $DIR/discriminant.rs:6:13: 6:64 + goto -> bb4; // scope 0 at $DIR/discriminant.rs:11:13: 11:64 } bb2: { -- switchInt(((_3 as Some).0: bool)) -> [false: bb1, otherwise: bb3]; // scope 0 at $DIR/discriminant.rs:6:26: 6:30 -+ switchInt(const true) -> [false: bb1, otherwise: bb3]; // scope 0 at $DIR/discriminant.rs:6:26: 6:30 -+ // ty::Const -+ // + ty: bool -+ // + val: Value(Scalar(0x01)) -+ // mir::Constant -+ // + span: $DIR/discriminant.rs:6:26: 6:30 -+ // + literal: Const { ty: bool, val: Value(Scalar(0x01)) } + switchInt(((_3 as Some).0: bool)) -> [false: bb1, otherwise: bb3]; // scope 0 at $DIR/discriminant.rs:11:26: 11:30 } bb3: { - _2 = const 42i32; // scope 0 at $DIR/discriminant.rs:6:47: 6:49 + _2 = const 42i32; // scope 0 at $DIR/discriminant.rs:11:47: 11:49 // ty::Const // + ty: i32 // + val: Value(Scalar(0x0000002a)) // mir::Constant - // + span: $DIR/discriminant.rs:6:47: 6:49 + // + span: $DIR/discriminant.rs:11:47: 11:49 // + literal: Const { ty: i32, val: Value(Scalar(0x0000002a)) } - goto -> bb4; // scope 0 at $DIR/discriminant.rs:6:13: 6:64 + goto -> bb4; // scope 0 at $DIR/discriminant.rs:11:13: 11:64 } bb4: { - _1 = Add(move _2, const 0i32); // scope 0 at $DIR/discriminant.rs:6:13: 6:68 + _1 = Add(move _2, const 0i32); // scope 0 at $DIR/discriminant.rs:11:13: 11:68 // ty::Const // + ty: i32 // + val: Value(Scalar(0x00000000)) // mir::Constant - // + span: $DIR/discriminant.rs:6:67: 6:68 + // + span: $DIR/discriminant.rs:11:67: 11:68 // + literal: Const { ty: i32, val: Value(Scalar(0x00000000)) } - StorageDead(_2); // scope 0 at $DIR/discriminant.rs:6:67: 6:68 - StorageDead(_3); // scope 0 at $DIR/discriminant.rs:6:68: 6:69 - _0 = const (); // scope 0 at $DIR/discriminant.rs:5:11: 7:2 + StorageDead(_2); // scope 0 at $DIR/discriminant.rs:11:67: 11:68 + StorageDead(_3); // scope 0 at $DIR/discriminant.rs:11:68: 11:69 + _0 = const (); // scope 0 at $DIR/discriminant.rs:10:11: 12:2 // ty::Const // + ty: () // + val: Value(Scalar()) // mir::Constant - // + span: $DIR/discriminant.rs:5:11: 7:2 + // + span: $DIR/discriminant.rs:10:11: 12:2 // + literal: Const { ty: (), val: Value(Scalar()) } - StorageDead(_1); // scope 0 at $DIR/discriminant.rs:7:1: 7:2 - return; // scope 0 at $DIR/discriminant.rs:7:2: 7:2 + StorageDead(_1); // scope 0 at $DIR/discriminant.rs:12:1: 12:2 + return; // scope 0 at $DIR/discriminant.rs:12:2: 12:2 } } diff --git a/src/test/mir-opt/const_prop/discriminant/64bit/rustc.main.ConstProp.diff b/src/test/mir-opt/const_prop/discriminant/64bit/rustc.main.ConstProp.diff index ec0341e3de251..75b4b7e5a62ba 100644 --- a/src/test/mir-opt/const_prop/discriminant/64bit/rustc.main.ConstProp.diff +++ b/src/test/mir-opt/const_prop/discriminant/64bit/rustc.main.ConstProp.diff @@ -2,100 +2,93 @@ + // MIR for `main` after ConstProp fn main() -> () { - let mut _0: (); // return place in scope 0 at $DIR/discriminant.rs:5:11: 5:11 - let _1: i32; // in scope 0 at $DIR/discriminant.rs:6:9: 6:10 - let mut _2: i32; // in scope 0 at $DIR/discriminant.rs:6:13: 6:64 - let mut _3: std::option::Option; // in scope 0 at $DIR/discriminant.rs:6:34: 6:44 - let mut _4: isize; // in scope 0 at $DIR/discriminant.rs:6:21: 6:31 + let mut _0: (); // return place in scope 0 at $DIR/discriminant.rs:10:11: 10:11 + let _1: i32; // in scope 0 at $DIR/discriminant.rs:11:9: 11:10 + let mut _2: i32; // in scope 0 at $DIR/discriminant.rs:11:13: 11:64 + let mut _3: std::option::Option; // in scope 0 at $DIR/discriminant.rs:11:34: 11:44 + let mut _4: isize; // in scope 0 at $DIR/discriminant.rs:11:21: 11:31 scope 1 { - debug x => _1; // in scope 1 at $DIR/discriminant.rs:6:9: 6:10 + debug x => _1; // in scope 1 at $DIR/discriminant.rs:11:9: 11:10 } bb0: { - StorageLive(_1); // scope 0 at $DIR/discriminant.rs:6:9: 6:10 - StorageLive(_2); // scope 0 at $DIR/discriminant.rs:6:13: 6:64 - StorageLive(_3); // scope 0 at $DIR/discriminant.rs:6:34: 6:44 -- _3 = std::option::Option::::Some(const true); // scope 0 at $DIR/discriminant.rs:6:34: 6:44 -+ _3 = const std::option::Option::::Some(true); // scope 0 at $DIR/discriminant.rs:6:34: 6:44 + StorageLive(_1); // scope 0 at $DIR/discriminant.rs:11:9: 11:10 + StorageLive(_2); // scope 0 at $DIR/discriminant.rs:11:13: 11:64 + StorageLive(_3); // scope 0 at $DIR/discriminant.rs:11:34: 11:44 +- _3 = std::option::Option::::Some(const true); // scope 0 at $DIR/discriminant.rs:11:34: 11:44 ++ _3 = const std::option::Option::::Some(true); // scope 0 at $DIR/discriminant.rs:11:34: 11:44 // ty::Const - // + ty: bool + // + ty: std::option::Option // + val: Value(Scalar(0x01)) // mir::Constant -- // + span: $DIR/discriminant.rs:6:39: 6:43 +- // + span: $DIR/discriminant.rs:11:39: 11:43 - // + literal: Const { ty: bool, val: Value(Scalar(0x01)) } -- _4 = discriminant(_3); // scope 0 at $DIR/discriminant.rs:6:21: 6:31 -- switchInt(move _4) -> [1isize: bb2, otherwise: bb1]; // scope 0 at $DIR/discriminant.rs:6:21: 6:31 -+ // + span: $DIR/discriminant.rs:6:34: 6:44 +- _4 = discriminant(_3); // scope 0 at $DIR/discriminant.rs:11:21: 11:31 +- switchInt(move _4) -> [1isize: bb2, otherwise: bb1]; // scope 0 at $DIR/discriminant.rs:11:21: 11:31 ++ // + span: $DIR/discriminant.rs:11:34: 11:44 + // + literal: Const { ty: std::option::Option, val: Value(Scalar(0x01)) } -+ _4 = const 1isize; // scope 0 at $DIR/discriminant.rs:6:21: 6:31 ++ _4 = const 1isize; // scope 0 at $DIR/discriminant.rs:11:21: 11:31 + // ty::Const + // + ty: isize + // + val: Value(Scalar(0x0000000000000001)) + // mir::Constant -+ // + span: $DIR/discriminant.rs:6:21: 6:31 ++ // + span: $DIR/discriminant.rs:11:21: 11:31 + // + literal: Const { ty: isize, val: Value(Scalar(0x0000000000000001)) } -+ switchInt(const 1isize) -> [1isize: bb2, otherwise: bb1]; // scope 0 at $DIR/discriminant.rs:6:21: 6:31 ++ switchInt(const 1isize) -> [1isize: bb2, otherwise: bb1]; // scope 0 at $DIR/discriminant.rs:11:21: 11:31 + // ty::Const + // + ty: isize + // + val: Value(Scalar(0x0000000000000001)) + // mir::Constant -+ // + span: $DIR/discriminant.rs:6:21: 6:31 ++ // + span: $DIR/discriminant.rs:11:21: 11:31 + // + literal: Const { ty: isize, val: Value(Scalar(0x0000000000000001)) } } bb1: { - _2 = const 10i32; // scope 0 at $DIR/discriminant.rs:6:59: 6:61 + _2 = const 10i32; // scope 0 at $DIR/discriminant.rs:11:59: 11:61 // ty::Const // + ty: i32 // + val: Value(Scalar(0x0000000a)) // mir::Constant - // + span: $DIR/discriminant.rs:6:59: 6:61 + // + span: $DIR/discriminant.rs:11:59: 11:61 // + literal: Const { ty: i32, val: Value(Scalar(0x0000000a)) } - goto -> bb4; // scope 0 at $DIR/discriminant.rs:6:13: 6:64 + goto -> bb4; // scope 0 at $DIR/discriminant.rs:11:13: 11:64 } bb2: { -- switchInt(((_3 as Some).0: bool)) -> [false: bb1, otherwise: bb3]; // scope 0 at $DIR/discriminant.rs:6:26: 6:30 -+ switchInt(const true) -> [false: bb1, otherwise: bb3]; // scope 0 at $DIR/discriminant.rs:6:26: 6:30 -+ // ty::Const -+ // + ty: bool -+ // + val: Value(Scalar(0x01)) -+ // mir::Constant -+ // + span: $DIR/discriminant.rs:6:26: 6:30 -+ // + literal: Const { ty: bool, val: Value(Scalar(0x01)) } + switchInt(((_3 as Some).0: bool)) -> [false: bb1, otherwise: bb3]; // scope 0 at $DIR/discriminant.rs:11:26: 11:30 } bb3: { - _2 = const 42i32; // scope 0 at $DIR/discriminant.rs:6:47: 6:49 + _2 = const 42i32; // scope 0 at $DIR/discriminant.rs:11:47: 11:49 // ty::Const // + ty: i32 // + val: Value(Scalar(0x0000002a)) // mir::Constant - // + span: $DIR/discriminant.rs:6:47: 6:49 + // + span: $DIR/discriminant.rs:11:47: 11:49 // + literal: Const { ty: i32, val: Value(Scalar(0x0000002a)) } - goto -> bb4; // scope 0 at $DIR/discriminant.rs:6:13: 6:64 + goto -> bb4; // scope 0 at $DIR/discriminant.rs:11:13: 11:64 } bb4: { - _1 = Add(move _2, const 0i32); // scope 0 at $DIR/discriminant.rs:6:13: 6:68 + _1 = Add(move _2, const 0i32); // scope 0 at $DIR/discriminant.rs:11:13: 11:68 // ty::Const // + ty: i32 // + val: Value(Scalar(0x00000000)) // mir::Constant - // + span: $DIR/discriminant.rs:6:67: 6:68 + // + span: $DIR/discriminant.rs:11:67: 11:68 // + literal: Const { ty: i32, val: Value(Scalar(0x00000000)) } - StorageDead(_2); // scope 0 at $DIR/discriminant.rs:6:67: 6:68 - StorageDead(_3); // scope 0 at $DIR/discriminant.rs:6:68: 6:69 - _0 = const (); // scope 0 at $DIR/discriminant.rs:5:11: 7:2 + StorageDead(_2); // scope 0 at $DIR/discriminant.rs:11:67: 11:68 + StorageDead(_3); // scope 0 at $DIR/discriminant.rs:11:68: 11:69 + _0 = const (); // scope 0 at $DIR/discriminant.rs:10:11: 12:2 // ty::Const // + ty: () // + val: Value(Scalar()) // mir::Constant - // + span: $DIR/discriminant.rs:5:11: 7:2 + // + span: $DIR/discriminant.rs:10:11: 12:2 // + literal: Const { ty: (), val: Value(Scalar()) } - StorageDead(_1); // scope 0 at $DIR/discriminant.rs:7:1: 7:2 - return; // scope 0 at $DIR/discriminant.rs:7:2: 7:2 + StorageDead(_1); // scope 0 at $DIR/discriminant.rs:12:1: 12:2 + return; // scope 0 at $DIR/discriminant.rs:12:2: 12:2 } }