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authorGuillaume Gomez <guillaume1.gomez@gmail.com>2025-07-21 14:34:12 +0200
committerGuillaume Gomez <guillaume1.gomez@gmail.com>2025-07-22 14:28:48 +0200
commita27f3e3fd1e4d16160f8885b6b06665b5319f56c (patch)
treeb033935392cbadf6f85d2dbddf433a88e323aeeb /tests/codegen-llvm/issues/issue-69101-bounds-check.rs
parented93c1783b404d728d4809973a0550eb33cd293f (diff)
downloadrust-a27f3e3fd1e4d16160f8885b6b06665b5319f56c.tar.gz
rust-a27f3e3fd1e4d16160f8885b6b06665b5319f56c.zip
Rename `tests/codegen` into `tests/codegen-llvm`
Diffstat (limited to 'tests/codegen-llvm/issues/issue-69101-bounds-check.rs')
-rw-r--r--tests/codegen-llvm/issues/issue-69101-bounds-check.rs42
1 files changed, 42 insertions, 0 deletions
diff --git a/tests/codegen-llvm/issues/issue-69101-bounds-check.rs b/tests/codegen-llvm/issues/issue-69101-bounds-check.rs
new file mode 100644
index 00000000000..953b79aa263
--- /dev/null
+++ b/tests/codegen-llvm/issues/issue-69101-bounds-check.rs
@@ -0,0 +1,42 @@
+//@ compile-flags: -Copt-level=3
+#![crate_type = "lib"]
+
+// Make sure no bounds checks are emitted in the loop when upfront slicing
+// ensures that the slices are big enough.
+// In particular, bounds checks were not always optimized out if the upfront
+// check was for a greater len than the loop requires.
+// (i.e. `already_sliced_no_bounds_check` was not always optimized even when
+// `already_sliced_no_bounds_check_exact` was)
+// 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-NOT: panic_bounds_check
+    let _ = (&a[..2048], &b[..2048], &mut c[..2048]);
+    for i in 0..1024 {
+        c[i] = a[i] ^ b[i];
+    }
+}
+
+// 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-NOT: panic_bounds_check
+    let _ = (&a[..1024], &b[..1024], &mut c[..1024]);
+    for i in 0..1024 {
+        c[i] = a[i] ^ b[i];
+    }
+}
+
+// Make sure we're checking for the right thing: there can be a panic if the slice is too small.
+// 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: panic_bounds_check
+    let _ = (&a[..1023], &b[..2048], &mut c[..2048]);
+    for i in 0..1024 {
+        c[i] = a[i] ^ b[i];
+    }
+}