Auto merge of #38523 - camlorn:disable_field_reordering, r=nikomatsakis

Disable field reordering

This was decided via IRC and needs a backport to beta.  Basically, #37429 broke servo, and probably needs an announcement and opt-in flag.  I didn't run all tests locally but think I've already reverted all the ones that need to be reverted.

r? @nikomatsakis
This commit is contained in:
bors 2016-12-23 21:36:59 +00:00
commit 4d07320d01
5 changed files with 36 additions and 36 deletions

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@ -575,6 +575,10 @@ fn new(dl: &TargetDataLayout, fields: &Vec<&'a Layout>,
});
}
// Disable field reordering until we can decide what to do.
// The odd pattern here avoids a warning about the value never being read.
if can_optimize { can_optimize = false }
let (optimize, sort_ascending) = match kind {
StructKind::AlwaysSizedUnivariant => (can_optimize, false),
StructKind::MaybeUnsizedUnivariant => (can_optimize, false),

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@ -31,10 +31,6 @@ enum e3 {
a([u16; 0], u8), b
}
// Test struct field reordering to make sure it actually reorders.
struct WillOptimize1(u8, u16, u8);
struct WillOptimize2 { a: u8, b: u16, c: u8}
pub fn main() {
assert_eq!(size_of::<u8>(), 1 as usize);
assert_eq!(size_of::<u32>(), 4 as usize);
@ -58,7 +54,4 @@ pub fn main() {
assert_eq!(size_of::<e1>(), 8 as usize);
assert_eq!(size_of::<e2>(), 8 as usize);
assert_eq!(size_of::<e3>(), 4 as usize);
assert_eq!(size_of::<WillOptimize1>(), 4);
assert_eq!(size_of::<WillOptimize2>(), 4);
}

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@ -1,22 +1,25 @@
print-type-size type: `IndirectNonZero<u32>`: 12 bytes, alignment: 4 bytes
print-type-size field `.nested`: 8 bytes
print-type-size field `.post`: 2 bytes
print-type-size type: `IndirectNonZero<u32>`: 20 bytes, alignment: 4 bytes
print-type-size field `.pre`: 1 bytes
print-type-size end padding: 1 bytes
print-type-size type: `MyOption<IndirectNonZero<u32>>`: 12 bytes, alignment: 4 bytes
print-type-size variant `Some`: 12 bytes
print-type-size field `.0`: 12 bytes
print-type-size type: `EmbeddedDiscr`: 8 bytes, alignment: 4 bytes
print-type-size variant `Record`: 7 bytes
print-type-size field `.val`: 4 bytes
print-type-size field `.post`: 2 bytes
print-type-size padding: 3 bytes
print-type-size field `.nested`: 12 bytes, alignment: 4 bytes
print-type-size field `.post`: 2 bytes
print-type-size end padding: 2 bytes
print-type-size type: `MyOption<IndirectNonZero<u32>>`: 20 bytes, alignment: 4 bytes
print-type-size variant `Some`: 20 bytes
print-type-size field `.0`: 20 bytes
print-type-size type: `EmbeddedDiscr`: 12 bytes, alignment: 4 bytes
print-type-size variant `Record`: 10 bytes
print-type-size field `.pre`: 1 bytes
print-type-size end padding: 1 bytes
print-type-size type: `NestedNonZero<u32>`: 8 bytes, alignment: 4 bytes
print-type-size field `.val`: 4 bytes
print-type-size field `.post`: 2 bytes
print-type-size padding: 3 bytes
print-type-size field `.val`: 4 bytes, alignment: 4 bytes
print-type-size field `.post`: 2 bytes
print-type-size end padding: 2 bytes
print-type-size type: `NestedNonZero<u32>`: 12 bytes, alignment: 4 bytes
print-type-size field `.pre`: 1 bytes
print-type-size end padding: 1 bytes
print-type-size padding: 3 bytes
print-type-size field `.val`: 4 bytes, alignment: 4 bytes
print-type-size field `.post`: 2 bytes
print-type-size end padding: 2 bytes
print-type-size type: `MyOption<core::nonzero::NonZero<u32>>`: 4 bytes, alignment: 4 bytes
print-type-size variant `Some`: 4 bytes
print-type-size field `.0`: 4 bytes

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@ -1,11 +1,13 @@
print-type-size type: `Padded`: 12 bytes, alignment: 4 bytes
print-type-size field `.g`: 4 bytes
print-type-size field `.h`: 2 bytes
print-type-size type: `Padded`: 16 bytes, alignment: 4 bytes
print-type-size field `.a`: 1 bytes
print-type-size field `.b`: 1 bytes
print-type-size padding: 2 bytes
print-type-size field `.g`: 4 bytes, alignment: 4 bytes
print-type-size field `.c`: 1 bytes
print-type-size padding: 1 bytes
print-type-size field `.h`: 2 bytes, alignment: 2 bytes
print-type-size field `.d`: 1 bytes
print-type-size end padding: 2 bytes
print-type-size end padding: 3 bytes
print-type-size type: `Packed`: 10 bytes, alignment: 1 bytes
print-type-size field `.a`: 1 bytes
print-type-size field `.b`: 1 bytes

View file

@ -1,12 +1,10 @@
print-type-size type: `E1`: 12 bytes, alignment: 4 bytes
print-type-size discriminant: 1 bytes
print-type-size variant `A`: 7 bytes
print-type-size discriminant: 4 bytes
print-type-size variant `A`: 5 bytes
print-type-size field `.0`: 4 bytes
print-type-size field `.1`: 1 bytes
print-type-size padding: 2 bytes
print-type-size field `.0`: 4 bytes, alignment: 4 bytes
print-type-size variant `B`: 11 bytes
print-type-size padding: 3 bytes
print-type-size field `.0`: 8 bytes, alignment: 4 bytes
print-type-size variant `B`: 8 bytes
print-type-size field `.0`: 8 bytes
print-type-size type: `E2`: 12 bytes, alignment: 4 bytes
print-type-size discriminant: 1 bytes
print-type-size variant `A`: 7 bytes
@ -17,7 +15,7 @@ print-type-size variant `B`: 11 bytes
print-type-size padding: 3 bytes
print-type-size field `.0`: 8 bytes, alignment: 4 bytes
print-type-size type: `S`: 8 bytes, alignment: 4 bytes
print-type-size field `.g`: 4 bytes
print-type-size field `.a`: 1 bytes
print-type-size field `.b`: 1 bytes
print-type-size end padding: 2 bytes
print-type-size padding: 2 bytes
print-type-size field `.g`: 4 bytes, alignment: 4 bytes