rust/tests/mir-opt/pre-codegen/checked_ops.checked_shl.PreCodegen.after.mir
Scott McMurray 3ec4eeddef [libs] Simplify unchecked_{shl,shr}
There's no need for the `const_eval_select` dance here.  And while I originally wrote the `.try_into().unwrap_unchecked()` implementation here, it's kinda a mess in MIR -- this new one is substantially simpler, as shown by the old one being above the inlining threshold but the new one being below it.
2023-06-16 16:03:19 -07:00

80 lines
1.9 KiB
Rust

// MIR for `checked_shl` after PreCodegen
fn checked_shl(_1: u32, _2: u32) -> Option<u32> {
debug x => _1;
debug rhs => _2;
let mut _0: std::option::Option<u32>;
scope 1 (inlined core::num::<impl u32>::checked_shl) {
debug self => _1;
debug rhs => _2;
let mut _7: u32;
let mut _8: bool;
scope 2 {
debug a => _7;
debug b => _6;
}
scope 3 (inlined core::num::<impl u32>::overflowing_shl) {
debug self => _1;
debug rhs => _2;
let mut _5: u32;
let mut _6: bool;
scope 4 (inlined core::num::<impl u32>::wrapping_shl) {
debug self => _1;
debug rhs => _2;
let mut _3: u32;
let mut _4: u32;
scope 5 {
scope 6 (inlined core::num::<impl u32>::unchecked_shl) {
debug self => _1;
debug rhs => _4;
scope 7 {
}
}
}
}
}
}
bb0: {
StorageLive(_6);
StorageLive(_7);
StorageLive(_5);
StorageLive(_4);
StorageLive(_3);
_3 = const 31_u32;
_4 = BitAnd(_2, move _3);
StorageDead(_3);
_5 = unchecked_shl::<u32>(_1, _4) -> [return: bb1, unwind unreachable];
}
bb1: {
StorageDead(_4);
_6 = Ge(_2, const _);
_7 = move _5;
StorageDead(_5);
StorageLive(_8);
_8 = unlikely(_6) -> [return: bb2, unwind unreachable];
}
bb2: {
switchInt(move _8) -> [0: bb3, otherwise: bb4];
}
bb3: {
_0 = Option::<u32>::Some(_7);
goto -> bb5;
}
bb4: {
_0 = Option::<u32>::None;
goto -> bb5;
}
bb5: {
StorageDead(_8);
StorageDead(_7);
StorageDead(_6);
return;
}
}