Auto merge of rust-lang#125347 - tesuji:needtests, r=nikic

Add codegen tests for E-needs-test

close rust-lang#36010
close rust-lang#68667
close rust-lang#74938
close rust-lang#83585
close rust-lang#93036
close rust-lang#109328
close rust-lang#110797
close rust-lang#111508
close rust-lang#112509
close rust-lang#113757
close rust-lang#120440
close rust-lang#118392
close rust-lang#71096

r? nikic

tests/assembly/issue-83585-small-pod-struct-equality.rs

@@ -0,0 +1,28 @@
+//@ assembly-output: emit-asm
+//@ compile-flags:-Copt-level=3
+//@ only-x86_64
+
+#![crate_type = "lib"]
+
+type T = u8;
+type T1 = (T, T, T, T, T, T, T, T);
+type T2 = [T; 8];
+
+// CHECK-LABEL: foo1a
+// CHECK: cmp
+// CHECK-NEXT: sete
+// CHECK-NEXT: ret
+#[no_mangle]
+pub fn foo1a(a: T1, b: T1) -> bool {
+    a == b
+}
+
+// CHECK-LABEL: foo1b
+// CHECK: mov
+// CHECK-NEXT: cmp
+// CHECK-NEXT: sete
+// CHECK-NEXT: ret
+#[no_mangle]
+pub fn foo1b(a: &T1, b: &T1) -> bool {
+    a == b
+}

tests/codegen/issues/issue-109328-split_first.rs

@@ -0,0 +1,16 @@
+//@ compile-flags: -O
+
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @foo
+// CHECK-NEXT: {{.*}}:
+// CHECK-NEXT: getelementptr inbounds
+// CHECK-NEXT: load [[TYPE:i(32|64)]]
+// CHECK-NEXT: icmp eq [[TYPE]]
+// CHECK-NEXT: br i1
+#[no_mangle]
+pub fn foo(input: &mut &[u64]) -> Option<u64> {
+    let (first, rest) = input.split_first()?;
+    *input = rest;
+    Some(*first)
+}

tests/codegen/issues/issue-110797-enum-jump-same.rs

@@ -0,0 +1,26 @@
+//@ compile-flags: -O
+//@ min-llvm-version: 18
+
+#![crate_type = "lib"]
+
+pub enum K {
+    A(Box<[i32]>),
+    B(Box<[u8]>),
+    C(Box<[String]>),
+    D(Box<[u16]>),
+}
+
+// CHECK-LABEL: @get_len
+// CHECK-NEXT: {{.*}}:
+// CHECK-NEXT: getelementptr inbounds
+// CHECK-NEXT: load [[TYPE:i(32|64)]]
+// CHECK-NEXT: ret [[TYPE]]
+#[no_mangle]
+pub fn get_len(arg: &K) -> usize {
+    match arg {
+        K::A(ref lst) => lst.len(),
+        K::B(ref lst) => lst.len(),
+        K::C(ref lst) => lst.len(),
+        K::D(ref lst) => lst.len(),
+    }
+}

tests/codegen/issues/issue-111508-vec-tryinto-array.rs

@@ -0,0 +1,22 @@
+//@ compile-flags: -O
+// This regress since Rust version 1.72.
+//@ min-llvm-version: 18.1.4
+
+#![crate_type = "lib"]
+
+use std::convert::TryInto;
+
+const N: usize = 24;
+
+// CHECK-LABEL: @example
+// CHECK-NOT: unwrap_failed
+#[no_mangle]
+pub fn example(a: Vec<u8>) -> u8 {
+    if a.len() != 32 {
+        return 0;
+    }
+
+    let a: [u8; 32] = a.try_into().unwrap();
+
+    a[15] + a[N]
+}

tests/codegen/issues/issue-112509-slice-get-andthen-get.rs

@@ -0,0 +1,12 @@
+//@ compile-flags: -O
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @write_u8_variant_a
+// CHECK-NEXT: {{.*}}:
+// CHECK-NEXT: getelementptr
+// CHECK-NEXT: icmp ugt
+#[no_mangle]
+pub fn write_u8_variant_a(bytes: &mut [u8], buf: u8, offset: usize) -> Option<&mut [u8]> {
+    let buf = buf.to_le_bytes();
+    bytes.get_mut(offset..).and_then(|bytes| bytes.get_mut(..buf.len()))
+}

tests/codegen/issues/issue-113757-bounds-check-after-cmp-max.rs

@@ -0,0 +1,18 @@
+// in Rust 1.73, -O and opt-level=3 optimizes differently
+//@ compile-flags: -C opt-level=3
+#![crate_type = "lib"]
+
+use std::cmp::max;
+
+// CHECK-LABEL: @foo
+// CHECK-NOT: slice_start_index_len_fail
+// CHECK-NOT: unreachable
+#[no_mangle]
+pub fn foo(v: &mut Vec<u8>, size: usize) -> Option<&mut [u8]> {
+    if v.len() > max(1, size) {
+        let start = v.len() - size;
+        Some(&mut v[start..])
+    } else {
+        None
+    }
+}

tests/codegen/issues/issue-118392.rs

@@ -0,0 +1,11 @@
+//@ compile-flags: -O
+//@ min-llvm-version: 18
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @div2
+// CHECK: ashr i32 %a, 1
+// CHECK-NEXT: ret i32
+#[no_mangle]
+pub fn div2(a: i32) -> i32 {
+    a.div_euclid(2)
+}

tests/codegen/issues/issue-36010-some-box-is_some.rs

@@ -0,0 +1,28 @@
+#![crate_type = "lib"]
+
+//@ compile-flags: -O
+
+use std::mem;
+
+fn foo<T>(a: &mut T, b: T) -> bool {
+    let b = Some(mem::replace(a, b));
+    let ret = b.is_some();
+    mem::forget(b);
+    return ret;
+}
+
+// CHECK-LABEL: @foo_u32
+// CHECK: store i32
+// CHECK-NEXT: ret i1 true
+#[no_mangle]
+pub fn foo_u32(a: &mut u32, b: u32) -> bool {
+    foo(a, b)
+}
+
+// CHECK-LABEL: @foo_box
+// CHECK: store ptr
+// CHECK-NEXT: ret i1 true
+#[no_mangle]
+pub fn foo_box(a: &mut Box<u32>, b: Box<u32>) -> bool {
+    foo(a, b)
+}

tests/codegen/issues/issue-68667-unwrap-combinators.rs

@@ -0,0 +1,15 @@
+#![crate_type = "lib"]
+
+//@ compile-flags: -O
+
+// MIR inlining now optimizes this code.
+
+// CHECK-LABEL: @unwrap_combinators
+// CHECK: icmp
+// CHECK-NEXT: icmp
+// CHECK-NEXT: select i1
+// CHECK-NEXT: ret i1
+#[no_mangle]
+pub fn unwrap_combinators(a: Option<i32>, b: i32) -> bool {
+    a.map(|t| t >= b).unwrap_or(false)
+}

tests/codegen/issues/issue-74938-array-split-at.rs

@@ -0,0 +1,14 @@
+//@ compile-flags: -O
+
+#![crate_type = "lib"]
+
+const N: usize = 3;
+pub type T = u8;
+
+// CHECK-LABEL: @split_multiple
+// CHECK-NOT: unreachable
+#[no_mangle]
+pub fn split_multiple(slice: &[T]) -> (&[T], &[T]) {
+    let len = slice.len() / N;
+    slice.split_at(len * N)
+}

tests/codegen/issues/issue-93036-assert-index.rs

@@ -0,0 +1,14 @@
+//@ compile-flags: -O
+
+#![crate_type = "lib"]
+
+#[no_mangle]
+// CHECK-LABEL: @foo
+// CHECK-NOT: unreachable
+pub fn foo(arr: &mut [u32]) {
+    for i in 0..arr.len() {
+        for j in 0..i {
+            assert!(j < arr.len());
+        }
+    }
+}

tests/codegen/slice-pointer-nonnull-unwrap.rs

@@ -0,0 +1,19 @@
+//@ compile-flags: -O
+//@ min-llvm-version: 18
+#![crate_type = "lib"]
+
+use std::ptr::NonNull;
+
+// CHECK-LABEL: @slice_ptr_len_1
+// CHECK-NEXT: {{.*}}:
+// CHECK-NEXT: ret {{i(32|64)}} %ptr.1
+#[no_mangle]
+pub fn slice_ptr_len_1(ptr: *const [u8]) -> usize {
+    let ptr = ptr.cast_mut();
+    if let Some(ptr) = NonNull::new(ptr) {
+        ptr.len()
+    } else {
+        // We know ptr is null, so we know ptr.wrapping_byte_add(1) is not null.
+        NonNull::new(ptr.wrapping_byte_add(1)).unwrap().len()
+    }
+}