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Optimize SliceIndex<str> for RangeInclusive

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Replace `self.end() == usize::MAX` and `self.end() + 1 > slice.len()`
with `self.end() >= slice.len()`. Same reasoning as previous commit.

Also consolidate the str panicking functions into function.
This commit is contained in:
Karl Meakin 2025-07-25 21:57:44 +01:00
parent 625b18027d
commit 262cd76333
6 changed files with 97 additions and 81 deletions
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20
tests/codegen-llvm/str-range-indexing.rs
View file

@ -35,18 +35,18 @@ macro_rules! tests {
// CHECK: ret
tests!(Range<usize>, get_range, index_range);
// 9 comparisons required:
// end != usize::MAX && start <= end + 1
// && (start == 0 || (start >= len && start == len) || bytes[start] >= -0x40)
// && ( (end + 1 >= len && end + 1 == len) || bytes[end + 1] >= -0x40)
// 7 comparisons required:
// end < len && start <= end + 1
// && (start == 0 || start >= len || bytes[start] >= -0x40)
// && ( end + 1 >= len || bytes[end + 1] >= -0x40)
// CHECK-LABEL: @get_range_inclusive
// CHECK-COUNT-9: %{{.+}} = icmp
// CHECK-COUNT-7: %{{.+}} = icmp
// CHECK-NOT: %{{.+}} = icmp
// CHECK: ret
// CHECK-LABEL: @index_range_inclusive
// CHECK-COUNT-9: %{{.+}} = icmp
// CHECK-COUNT-7: %{{.+}} = icmp
// CHECK-NOT: %{{.+}} = icmp
// CHECK: ret
tests!(RangeInclusive<usize>, get_range_inclusive, index_range_inclusive);
@ -65,16 +65,16 @@ tests!(RangeInclusive<usize>, get_range_inclusive, index_range_inclusive);
// CHECK: ret
tests!(RangeTo<usize>, get_range_to, index_range_to);
// 4 comparisons required:
// end != usize::MAX && (end + 1 >= len && end + 1 == len) || bytes[end + 1] >= -0x40)
// 3 comparisons required:
// end < len && (end + 1 >= len || bytes[end + 1] >= -0x40)
// CHECK-LABEL: @get_range_to_inclusive
// CHECK-COUNT-4: %{{.+}} = icmp
// CHECK-COUNT-3: %{{.+}} = icmp
// CHECK-NOT: %{{.+}} = icmp
// CHECK: ret
// CHECK-LABEL: @index_range_to_inclusive
// CHECK-COUNT-4: %{{.+}} = icmp
// CHECK-COUNT-3: %{{.+}} = icmp
// CHECK-NOT: %{{.+}} = icmp
// CHECK: ret
tests!(RangeToInclusive<usize>, get_range_to_inclusive, index_range_to_inclusive);

2
tests/ui/intrinsics/const-eval-select-backtrace-std.run.stderr
View file

@ -1,4 +1,4 @@
thread 'main' ($TID) panicked at $DIR/const-eval-select-backtrace-std.rs:6:8:
byte index 1 is out of bounds of ``
start byte index 1 is out of bounds of ``
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace