Rollup merge of #145137 - Kmeakin:km/optimize-slice-index-panicking, r=jhpratt

Consolidate panicking functions in `slice/index.rs`

Consolidate all the panicking functions in `slice/index.rs` to use a single `slice_index_fail` function, similar to how it is done in `str/traits.rs`.

Split off from https://github.com/rust-lang/rust/pull/145024

8 files changed, 24 insertions, 32 deletions

diff --git a/tests/codegen-llvm/binary-search-index-no-bound-check.rs b/tests/codegen-llvm/binary-search-index-no-bound-check.rs
index d59c0beec64..8322c4179bd 100644
--- a/tests/codegen-llvm/binary-search-index-no-bound-check.rs
+++ b/tests/codegen-llvm/binary-search-index-no-bound-check.rs
@@ -8,8 +8,7 @@
 #[no_mangle]
 pub fn binary_search_index_no_bounds_check(s: &[u8]) -> u8 {
     // CHECK-NOT: panic
-    // CHECK-NOT: slice_start_index_len_fail
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK-NOT: panic_bounds_check
     if let Ok(idx) = s.binary_search(&b'\\') { s[idx] } else { 42 }
 }
diff --git a/tests/codegen-llvm/integer-overflow.rs b/tests/codegen-llvm/integer-overflow.rs
index 80362247a86..df7845be06d 100644
--- a/tests/codegen-llvm/integer-overflow.rs
+++ b/tests/codegen-llvm/integer-overflow.rs
@@ -10,7 +10,7 @@ pub struct S1<'a> {
 // CHECK-LABEL: @slice_no_index_order
 #[no_mangle]
 pub fn slice_no_index_order<'a>(s: &'a mut S1, n: usize) -> &'a [u8] {
-    // CHECK-NOT: slice_index_order_fail
+    // CHECK-COUNT-1: slice_index_fail
     let d = &s.data[s.position..s.position + n];
     s.position += n;
     return d;
@@ -19,6 +19,6 @@ pub fn slice_no_index_order<'a>(s: &'a mut S1, n: usize) -> &'a [u8] {
 // CHECK-LABEL: @test_check
 #[no_mangle]
 pub fn test_check<'a>(s: &'a mut S1, x: usize, y: usize) -> &'a [u8] {
-    // CHECK: slice_index_order_fail
+    // CHECK-COUNT-1: slice_index_fail
     &s.data[x..y]
 }
diff --git a/tests/codegen-llvm/issues/issue-113757-bounds-check-after-cmp-max.rs b/tests/codegen-llvm/issues/issue-113757-bounds-check-after-cmp-max.rs
index d495adf9980..0db8a5220ec 100644
--- a/tests/codegen-llvm/issues/issue-113757-bounds-check-after-cmp-max.rs
+++ b/tests/codegen-llvm/issues/issue-113757-bounds-check-after-cmp-max.rs
@@ -5,7 +5,7 @@
 use std::cmp::max;
 
 // CHECK-LABEL: @foo
-// CHECK-NOT: slice_start_index_len_fail
+// CHECK-NOT: slice_index_fail
 // CHECK-NOT: unreachable
 #[no_mangle]
 pub fn foo(v: &mut Vec<u8>, size: usize) -> Option<&mut [u8]> {
diff --git a/tests/codegen-llvm/issues/issue-27130.rs b/tests/codegen-llvm/issues/issue-27130.rs
index 594e02af097..3e53c5cffd6 100644
--- a/tests/codegen-llvm/issues/issue-27130.rs
+++ b/tests/codegen-llvm/issues/issue-27130.rs
@@ -6,7 +6,7 @@
 #[no_mangle]
 pub fn trim_in_place(a: &mut &[u8]) {
     while a.first() == Some(&42) {
-        // CHECK-NOT: slice_index_order_fail
+        // CHECK-NOT: slice_index_fail
         *a = &a[1..];
     }
 }
@@ -15,7 +15,7 @@ pub fn trim_in_place(a: &mut &[u8]) {
 #[no_mangle]
 pub fn trim_in_place2(a: &mut &[u8]) {
     while let Some(&42) = a.first() {
-        // CHECK-NOT: slice_index_order_fail
+        // CHECK-COUNT-1: slice_index_fail
         *a = &a[2..];
     }
 }
diff --git a/tests/codegen-llvm/issues/issue-69101-bounds-check.rs b/tests/codegen-llvm/issues/issue-69101-bounds-check.rs
index 953b79aa263..f1857a9ce89 100644
--- a/tests/codegen-llvm/issues/issue-69101-bounds-check.rs
+++ b/tests/codegen-llvm/issues/issue-69101-bounds-check.rs
@@ -10,7 +10,7 @@
 // CHECK-LABEL: @already_sliced_no_bounds_check
 #[no_mangle]
 pub fn already_sliced_no_bounds_check(a: &[u8], b: &[u8], c: &mut [u8]) {
-    // CHECK: slice_end_index_len_fail
+    // CHECK: slice_index_fail
     // CHECK-NOT: panic_bounds_check
     let _ = (&a[..2048], &b[..2048], &mut c[..2048]);
     for i in 0..1024 {
@@ -21,7 +21,7 @@ pub fn already_sliced_no_bounds_check(a: &[u8], b: &[u8], c: &mut [u8]) {
 // CHECK-LABEL: @already_sliced_no_bounds_check_exact
 #[no_mangle]
 pub fn already_sliced_no_bounds_check_exact(a: &[u8], b: &[u8], c: &mut [u8]) {
-    // CHECK: slice_end_index_len_fail
+    // CHECK: slice_index_fail
     // CHECK-NOT: panic_bounds_check
     let _ = (&a[..1024], &b[..1024], &mut c[..1024]);
     for i in 0..1024 {
@@ -33,7 +33,7 @@ pub fn already_sliced_no_bounds_check_exact(a: &[u8], b: &[u8], c: &mut [u8]) {
 // CHECK-LABEL: @already_sliced_bounds_check
 #[no_mangle]
 pub fn already_sliced_bounds_check(a: &[u8], b: &[u8], c: &mut [u8]) {
-    // CHECK: slice_end_index_len_fail
+    // CHECK: slice_index_fail
     // CHECK: panic_bounds_check
     let _ = (&a[..1023], &b[..2048], &mut c[..2048]);
     for i in 0..1024 {
diff --git a/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs b/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs
index 1e2c25babe0..8a2200478aa 100644
--- a/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs
+++ b/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs
@@ -8,8 +8,7 @@
 #[no_mangle]
 pub fn position_slice_to_no_bounds_check(s: &[u8]) -> &[u8] {
     // CHECK-NOT: panic
-    // CHECK-NOT: slice_start_index_len_fail
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK-NOT: panic_bounds_check
     // CHECK-NOT: unreachable
     if let Some(idx) = s.iter().position(|b| *b == b'\\') { &s[..idx] } else { s }
@@ -19,8 +18,7 @@ pub fn position_slice_to_no_bounds_check(s: &[u8]) -> &[u8] {
 #[no_mangle]
 pub fn position_slice_from_no_bounds_check(s: &[u8]) -> &[u8] {
     // CHECK-NOT: panic
-    // CHECK-NOT: slice_start_index_len_fail
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK-NOT: panic_bounds_check
     // CHECK-NOT: unreachable
     if let Some(idx) = s.iter().position(|b| *b == b'\\') { &s[idx..] } else { s }
@@ -30,8 +28,7 @@ pub fn position_slice_from_no_bounds_check(s: &[u8]) -> &[u8] {
 #[no_mangle]
 pub fn position_index_no_bounds_check(s: &[u8]) -> u8 {
     // CHECK-NOT: panic
-    // CHECK-NOT: slice_start_index_len_fail
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK-NOT: panic_bounds_check
     // CHECK-NOT: unreachable
     if let Some(idx) = s.iter().position(|b| *b == b'\\') { s[idx] } else { 42 }
@@ -40,8 +37,7 @@ pub fn position_index_no_bounds_check(s: &[u8]) -> u8 {
 #[no_mangle]
 pub fn rposition_slice_to_no_bounds_check(s: &[u8]) -> &[u8] {
     // CHECK-NOT: panic
-    // CHECK-NOT: slice_start_index_len_fail
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK-NOT: panic_bounds_check
     // CHECK-NOT: unreachable
     if let Some(idx) = s.iter().rposition(|b| *b == b'\\') { &s[..idx] } else { s }
@@ -51,8 +47,7 @@ pub fn rposition_slice_to_no_bounds_check(s: &[u8]) -> &[u8] {
 #[no_mangle]
 pub fn rposition_slice_from_no_bounds_check(s: &[u8]) -> &[u8] {
     // CHECK-NOT: panic
-    // CHECK-NOT: slice_start_index_len_fail
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK-NOT: panic_bounds_check
     // CHECK-NOT: unreachable
     if let Some(idx) = s.iter().rposition(|b| *b == b'\\') { &s[idx..] } else { s }
@@ -62,8 +57,7 @@ pub fn rposition_slice_from_no_bounds_check(s: &[u8]) -> &[u8] {
 #[no_mangle]
 pub fn rposition_index_no_bounds_check(s: &[u8]) -> u8 {
     // CHECK-NOT: panic
-    // CHECK-NOT: slice_start_index_len_fail
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK-NOT: panic_bounds_check
     // CHECK-NOT: unreachable
     if let Some(idx) = s.iter().rposition(|b| *b == b'\\') { s[idx] } else { 42 }
diff --git a/tests/codegen-llvm/slice-last-elements-optimization.rs b/tests/codegen-llvm/slice-last-elements-optimization.rs
index b90f91d7b17..d982cda709d 100644
--- a/tests/codegen-llvm/slice-last-elements-optimization.rs
+++ b/tests/codegen-llvm/slice-last-elements-optimization.rs
@@ -1,19 +1,18 @@
 //@ compile-flags: -Copt-level=3
-//@ only-x86_64
 //@ min-llvm-version: 20
 #![crate_type = "lib"]
 
 // This test verifies that LLVM 20 properly optimizes the bounds check
 // when accessing the last few elements of a slice with proper conditions.
 // Previously, this would generate an unreachable branch to
-// slice_start_index_len_fail even when the bounds check was provably safe.
+// slice_index_fail even when the bounds check was provably safe.
 
 // CHECK-LABEL: @last_four_initial(
 #[no_mangle]
 pub fn last_four_initial(s: &[u8]) -> &[u8] {
-    // Previously this would generate a branch to slice_start_index_len_fail
+    // Previously this would generate a branch to slice_index_fail
     // that is unreachable. The LLVM 20 fix should eliminate this branch.
-    // CHECK-NOT: slice_start_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK-NOT: unreachable
     let start = if s.len() <= 4 { 0 } else { s.len() - 4 };
     &s[start..]
@@ -23,7 +22,7 @@ pub fn last_four_initial(s: &[u8]) -> &[u8] {
 #[no_mangle]
 pub fn last_four_optimized(s: &[u8]) -> &[u8] {
     // This version was already correctly optimized before the fix in LLVM 20.
-    // CHECK-NOT: slice_start_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK-NOT: unreachable
     if s.len() <= 4 { &s[0..] } else { &s[s.len() - 4..] }
 }
@@ -32,6 +31,6 @@ pub fn last_four_optimized(s: &[u8]) -> &[u8] {
 // CHECK-LABEL: @test_bounds_check_happens(
 #[no_mangle]
 pub fn test_bounds_check_happens(s: &[u8], i: usize) -> &[u8] {
-    // CHECK: slice_start_index_len_fail
+    // CHECK: slice_index_fail
     &s[i..]
 }
diff --git a/tests/codegen-llvm/slice-reverse.rs b/tests/codegen-llvm/slice-reverse.rs
index e58d1c1d9d8..c31cff5010b 100644
--- a/tests/codegen-llvm/slice-reverse.rs
+++ b/tests/codegen-llvm/slice-reverse.rs
@@ -8,10 +8,10 @@
 #[no_mangle]
 pub fn slice_reverse_u8(slice: &mut [u8]) {
     // CHECK-NOT: panic_bounds_check
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK: shufflevector <{{[0-9]+}} x i8>
     // CHECK-NOT: panic_bounds_check
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     slice.reverse();
 }
 
@@ -19,9 +19,9 @@ pub fn slice_reverse_u8(slice: &mut [u8]) {
 #[no_mangle]
 pub fn slice_reverse_i32(slice: &mut [i32]) {
     // CHECK-NOT: panic_bounds_check
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     // CHECK: shufflevector <{{[0-9]+}} x i32>
     // CHECK-NOT: panic_bounds_check
-    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: slice_index_fail
     slice.reverse();
 }