Rollup merge of #75886 - erikdesjardins:index, r=nikic

Test that bounds checks are elided for [..index] after .position()

Closes #73396.

This was fixed by the LLVM 11 update in #73526.
This commit is contained in:
Dylan DPC 2020-09-16 01:30:38 +02:00 committed by GitHub
commit 056c7b09ff
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// min-llvm-version: 11.0.0
// compile-flags: -O
// ignore-debug: the debug assertions get in the way
#![crate_type = "lib"]
// Make sure no bounds checks are emitted when slicing or indexing
// with an index from `position()` or `rposition()`.
// CHECK-LABEL: @position_slice_to_no_bounds_check
#[no_mangle]
pub fn position_slice_to_no_bounds_check(s: &[u8]) -> &[u8] {
// CHECK-NOT: panic
// CHECK-NOT: slice_index_len_fail
if let Some(idx) = s.iter().position(|b| *b == b'\\') {
&s[..idx]
} else {
s
}
}
// CHECK-LABEL: @position_slice_from_no_bounds_check
#[no_mangle]
pub fn position_slice_from_no_bounds_check(s: &[u8]) -> &[u8] {
// CHECK-NOT: panic
// CHECK-NOT: slice_index_len_fail
if let Some(idx) = s.iter().position(|b| *b == b'\\') {
&s[idx..]
} else {
s
}
}
// CHECK-LABEL: @position_index_no_bounds_check
#[no_mangle]
pub fn position_index_no_bounds_check(s: &[u8]) -> u8 {
// CHECK-NOT: panic
// CHECK-NOT: slice_index_len_fail
if let Some(idx) = s.iter().position(|b| *b == b'\\') {
s[idx]
} else {
42
}
}
// CHECK-LABEL: @rposition_slice_to_no_bounds_check
#[no_mangle]
pub fn rposition_slice_to_no_bounds_check(s: &[u8]) -> &[u8] {
// CHECK-NOT: panic
// CHECK-NOT: slice_index_len_fail
if let Some(idx) = s.iter().rposition(|b| *b == b'\\') {
&s[..idx]
} else {
s
}
}
// CHECK-LABEL: @rposition_slice_from_no_bounds_check
#[no_mangle]
pub fn rposition_slice_from_no_bounds_check(s: &[u8]) -> &[u8] {
// CHECK-NOT: panic
// CHECK-NOT: slice_index_len_fail
if let Some(idx) = s.iter().rposition(|b| *b == b'\\') {
&s[idx..]
} else {
s
}
}
// CHECK-LABEL: @rposition_index_no_bounds_check
#[no_mangle]
pub fn rposition_index_no_bounds_check(s: &[u8]) -> u8 {
// CHECK-NOT: panic
// CHECK-NOT: slice_index_len_fail
if let Some(idx) = s.iter().rposition(|b| *b == b'\\') {
s[idx]
} else {
42
}
}