summary refs log tree commit diff
path: root/tests/codegen-llvm/enum
diff options
context:
space:
mode:
Diffstat (limited to 'tests/codegen-llvm/enum')
-rw-r--r--tests/codegen-llvm/enum/enum-aggregate.rs126
-rw-r--r--tests/codegen-llvm/enum/enum-bounds-check-derived-idx.rs24
-rw-r--r--tests/codegen-llvm/enum/enum-bounds-check-issue-13926.rs18
-rw-r--r--tests/codegen-llvm/enum/enum-bounds-check-issue-82871.rs18
-rw-r--r--tests/codegen-llvm/enum/enum-bounds-check.rs27
-rw-r--r--tests/codegen-llvm/enum/enum-debug-clike.rs28
-rw-r--r--tests/codegen-llvm/enum/enum-debug-niche-2.rs47
-rw-r--r--tests/codegen-llvm/enum/enum-debug-niche.rs35
-rw-r--r--tests/codegen-llvm/enum/enum-debug-tagged.rs31
-rw-r--r--tests/codegen-llvm/enum/enum-discriminant-eq.rs229
-rw-r--r--tests/codegen-llvm/enum/enum-discriminant-value.rs27
-rw-r--r--tests/codegen-llvm/enum/enum-early-otherwise-branch.rs25
-rw-r--r--tests/codegen-llvm/enum/enum-match.rs779
-rw-r--r--tests/codegen-llvm/enum/enum-transparent-extract.rs31
-rw-r--r--tests/codegen-llvm/enum/enum-two-variants-match.rs130
-rw-r--r--tests/codegen-llvm/enum/enum-u128.rs25
-rw-r--r--tests/codegen-llvm/enum/unreachable_enum_default_branch.rs40
17 files changed, 1640 insertions, 0 deletions
diff --git a/tests/codegen-llvm/enum/enum-aggregate.rs b/tests/codegen-llvm/enum/enum-aggregate.rs
new file mode 100644
index 00000000000..0161e5f3fa1
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-aggregate.rs
@@ -0,0 +1,126 @@
+//@ compile-flags: -Copt-level=0 -Cno-prepopulate-passes
+//@ min-llvm-version: 19
+//@ only-64bit
+
+#![crate_type = "lib"]
+
+use std::cmp::Ordering;
+use std::num::NonZero;
+use std::ptr::NonNull;
+
+#[no_mangle]
+fn make_some_bool(x: bool) -> Option<bool> {
+    // CHECK-LABEL: i8 @make_some_bool(i1 zeroext %x)
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: %[[WIDER:.+]] = zext i1 %x to i8
+    // CHECK-NEXT: ret i8 %[[WIDER]]
+    Some(x)
+}
+
+#[no_mangle]
+fn make_none_bool() -> Option<bool> {
+    // CHECK-LABEL: i8 @make_none_bool()
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: ret i8 2
+    None
+}
+
+#[no_mangle]
+fn make_some_ordering(x: Ordering) -> Option<Ordering> {
+    // CHECK-LABEL: i8 @make_some_ordering(i8 %x)
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: ret i8 %x
+    Some(x)
+}
+
+#[no_mangle]
+fn make_some_u16(x: u16) -> Option<u16> {
+    // CHECK-LABEL: { i16, i16 } @make_some_u16(i16 %x)
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: %0 = insertvalue { i16, i16 } { i16 1, i16 poison }, i16 %x, 1
+    // CHECK-NEXT: ret { i16, i16 } %0
+    Some(x)
+}
+
+#[no_mangle]
+fn make_none_u16() -> Option<u16> {
+    // CHECK-LABEL: { i16, i16 } @make_none_u16()
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: ret { i16, i16 } { i16 0, i16 undef }
+    None
+}
+
+#[no_mangle]
+fn make_some_nzu32(x: NonZero<u32>) -> Option<NonZero<u32>> {
+    // CHECK-LABEL: i32 @make_some_nzu32(i32 %x)
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: ret i32 %x
+    Some(x)
+}
+
+#[no_mangle]
+fn make_ok_ptr(x: NonNull<u16>) -> Result<NonNull<u16>, usize> {
+    // CHECK-LABEL: { i64, ptr } @make_ok_ptr(ptr %x)
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: %0 = insertvalue { i64, ptr } { i64 0, ptr poison }, ptr %x, 1
+    // CHECK-NEXT: ret { i64, ptr } %0
+    Ok(x)
+}
+
+#[no_mangle]
+fn make_ok_int(x: usize) -> Result<usize, NonNull<u16>> {
+    // CHECK-LABEL: { i64, ptr } @make_ok_int(i64 %x)
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: %[[NOPROV:.+]] = getelementptr i8, ptr null, i64 %x
+    // CHECK-NEXT: %[[R:.+]] = insertvalue { i64, ptr } { i64 0, ptr poison }, ptr %[[NOPROV]], 1
+    // CHECK-NEXT: ret { i64, ptr } %[[R]]
+    Ok(x)
+}
+
+#[no_mangle]
+fn make_some_ref(x: &u16) -> Option<&u16> {
+    // CHECK-LABEL: ptr @make_some_ref(ptr align 2 %x)
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: ret ptr %x
+    Some(x)
+}
+
+#[no_mangle]
+fn make_none_ref<'a>() -> Option<&'a u16> {
+    // CHECK-LABEL: ptr @make_none_ref()
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: ret ptr null
+    None
+}
+
+#[inline(never)]
+fn make_err_generic<E>(e: E) -> Result<u32, E> {
+    // CHECK-LABEL: define{{.+}}make_err_generic
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: call void @llvm.trap()
+    // CHECK-NEXT: ret i32 poison
+    Err(e)
+}
+
+#[no_mangle]
+fn make_uninhabited_err_indirectly(n: Never) -> Result<u32, Never> {
+    // CHECK-LABEL: i32 @make_uninhabited_err_indirectly()
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: call{{.+}}make_err_generic
+    make_err_generic(n)
+}
+
+#[no_mangle]
+fn make_fully_uninhabited_result(v: u32, n: Never) -> Result<(u32, Never), (Never, u32)> {
+    // Actually reaching this would be UB, so we don't actually build a result.
+
+    // CHECK-LABEL: { i32, i32 } @make_fully_uninhabited_result(i32 %v)
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: call void @llvm.trap()
+    // CHECK-NEXT: call void @llvm.trap()
+    // CHECK-NEXT: call void @llvm.trap()
+    // CHECK-NEXT: unreachable
+    Ok((v, n))
+}
+
+enum Never {}
diff --git a/tests/codegen-llvm/enum/enum-bounds-check-derived-idx.rs b/tests/codegen-llvm/enum/enum-bounds-check-derived-idx.rs
new file mode 100644
index 00000000000..a5785f4addf
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-bounds-check-derived-idx.rs
@@ -0,0 +1,24 @@
+// This test checks an optimization that is not guaranteed to work. This test case should not block
+// a future LLVM update.
+//@ compile-flags: -Copt-level=3
+
+#![crate_type = "lib"]
+
+pub enum Bar {
+    A = 1,
+    B = 3,
+}
+
+// CHECK-LABEL: @lookup_inc
+#[no_mangle]
+pub fn lookup_inc(buf: &[u8; 5], f: Bar) -> u8 {
+    // CHECK-NOT: panic_bounds_check
+    buf[f as usize + 1]
+}
+
+// CHECK-LABEL: @lookup_dec
+#[no_mangle]
+pub fn lookup_dec(buf: &[u8; 5], f: Bar) -> u8 {
+    // CHECK-NOT: panic_bounds_check
+    buf[f as usize - 1]
+}
diff --git a/tests/codegen-llvm/enum/enum-bounds-check-issue-13926.rs b/tests/codegen-llvm/enum/enum-bounds-check-issue-13926.rs
new file mode 100644
index 00000000000..6e8e5035b0d
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-bounds-check-issue-13926.rs
@@ -0,0 +1,18 @@
+// This test checks an optimization that is not guaranteed to work. This test case should not block
+// a future LLVM update.
+//@ compile-flags: -Copt-level=3
+
+#![crate_type = "lib"]
+
+#[repr(u8)]
+pub enum Exception {
+    Low = 5,
+    High = 10,
+}
+
+// CHECK-LABEL: @access
+#[no_mangle]
+pub fn access(array: &[usize; 12], exc: Exception) -> usize {
+    // CHECK-NOT: panic_bounds_check
+    array[(exc as u8 - 4) as usize]
+}
diff --git a/tests/codegen-llvm/enum/enum-bounds-check-issue-82871.rs b/tests/codegen-llvm/enum/enum-bounds-check-issue-82871.rs
new file mode 100644
index 00000000000..3b8a146838a
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-bounds-check-issue-82871.rs
@@ -0,0 +1,18 @@
+//@ compile-flags: -C opt-level=0
+
+#![crate_type = "lib"]
+
+#[repr(C)]
+pub enum E {
+    A,
+}
+
+// CHECK-LABEL: @index
+#[no_mangle]
+pub fn index(x: &[u32; 3], ind: E) -> u32 {
+    // Canary: we should be able to optimize out the bounds check, but we need
+    // to track the range of the discriminant result in order to be able to do that.
+    // oli-obk tried to add that, but that caused miscompilations all over the place.
+    // CHECK: panic_bounds_check
+    x[ind as usize]
+}
diff --git a/tests/codegen-llvm/enum/enum-bounds-check.rs b/tests/codegen-llvm/enum/enum-bounds-check.rs
new file mode 100644
index 00000000000..5362598ca7c
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-bounds-check.rs
@@ -0,0 +1,27 @@
+//@ compile-flags: -Copt-level=3
+
+#![crate_type = "lib"]
+
+pub enum Foo {
+    A,
+    B,
+}
+
+// CHECK-LABEL: @lookup
+#[no_mangle]
+pub fn lookup(buf: &[u8; 2], f: Foo) -> u8 {
+    // CHECK-NOT: panic_bounds_check
+    buf[f as usize]
+}
+
+pub enum Bar {
+    A = 2,
+    B = 3,
+}
+
+// CHECK-LABEL: @lookup_unmodified
+#[no_mangle]
+pub fn lookup_unmodified(buf: &[u8; 5], f: Bar) -> u8 {
+    // CHECK-NOT: panic_bounds_check
+    buf[f as usize]
+}
diff --git a/tests/codegen-llvm/enum/enum-debug-clike.rs b/tests/codegen-llvm/enum/enum-debug-clike.rs
new file mode 100644
index 00000000000..89c803cce5e
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-debug-clike.rs
@@ -0,0 +1,28 @@
+// This tests that debug info for "c-like" enums is properly emitted.
+// This is ignored for the fallback mode on MSVC due to problems with PDB.
+
+//
+//@ ignore-msvc
+//@ ignore-wasi wasi codegens the main symbol differently
+
+//@ compile-flags: -g -C no-prepopulate-passes
+
+// CHECK-LABEL: @main
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_enumeration_type,{{.*}}name: "E",{{.*}}flags: DIFlagEnumClass,{{.*}}
+// CHECK: {{.*}}DIEnumerator{{.*}}name: "A",{{.*}}value: {{[0-9].*}}
+// CHECK: {{.*}}DIEnumerator{{.*}}name: "B",{{.*}}value: {{[0-9].*}}
+// CHECK: {{.*}}DIEnumerator{{.*}}name: "C",{{.*}}value: {{[0-9].*}}
+
+#![allow(dead_code)]
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+
+enum E {
+    A,
+    B,
+    C,
+}
+
+pub fn main() {
+    let e = E::C;
+}
diff --git a/tests/codegen-llvm/enum/enum-debug-niche-2.rs b/tests/codegen-llvm/enum/enum-debug-niche-2.rs
new file mode 100644
index 00000000000..80a4081f15b
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-debug-niche-2.rs
@@ -0,0 +1,47 @@
+//! This tests that optimized enum debug info accurately reflects the enum layout.
+//! This is ignored for the fallback mode on MSVC due to problems with PDB.
+//!
+//@ compile-flags: -g -C no-prepopulate-passes
+//@ ignore-msvc
+//
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_variant_part,{{.*}}size: 32,{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "Placeholder",{{.*}}extraData: i32 -1{{[,)].*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "Error",{{.*}}extraData: i32 0{{[,)].*}}
+#![feature(never_type)]
+
+#[derive(Copy, Clone)]
+pub struct Entity {
+    private: std::num::NonZero<u32>,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq)]
+pub struct Declaration;
+
+impl TypeFamily for Declaration {
+    type Base = Base;
+    type Placeholder = !;
+
+    fn intern_base_data(_: BaseKind<Self>) {}
+}
+
+#[derive(Copy, Clone)]
+pub struct Base;
+
+pub trait TypeFamily: Copy + 'static {
+    type Base: Copy;
+    type Placeholder: Copy;
+
+    fn intern_base_data(_: BaseKind<Self>);
+}
+
+#[derive(Copy, Clone)]
+pub enum BaseKind<F: TypeFamily> {
+    Named(Entity),
+    Placeholder(F::Placeholder),
+    Error,
+}
+
+pub fn main() {
+    let x = BaseKind::Error::<Declaration>;
+    let y = 7;
+}
diff --git a/tests/codegen-llvm/enum/enum-debug-niche.rs b/tests/codegen-llvm/enum/enum-debug-niche.rs
new file mode 100644
index 00000000000..59e8b8a78b4
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-debug-niche.rs
@@ -0,0 +1,35 @@
+// This tests that optimized enum debug info accurately reflects the enum layout.
+// This is ignored for the fallback mode on MSVC due to problems with PDB.
+
+//@ ignore-msvc
+//@ ignore-wasi wasi codegens the main symbol differently
+
+//@ compile-flags: -g -C no-prepopulate-passes
+
+// CHECK-LABEL: @main
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_variant_part,{{.*}}discriminator:{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "A",{{.*}}extraData:{{.*}}
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_structure_type,{{.*}}name: "A",{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "B",{{.*}}extraData:{{.*}}
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_structure_type,{{.*}}name: "B",{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "C",{{.*}}extraData:{{.*}}
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_structure_type,{{.*}}name: "C",{{.*}}
+// CHECK-NOT: {{.*}}DIDerivedType{{.*}}name: "D",{{.*}}extraData:{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "D",{{.*}}
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_structure_type,{{.*}}name: "D",{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}flags: DIFlagArtificial{{.*}}
+
+#![allow(dead_code)]
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+
+enum E {
+    A,
+    B,
+    C,
+    D(bool),
+}
+
+pub fn main() {
+    let e = E::D(true);
+}
diff --git a/tests/codegen-llvm/enum/enum-debug-tagged.rs b/tests/codegen-llvm/enum/enum-debug-tagged.rs
new file mode 100644
index 00000000000..e8f147665b0
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-debug-tagged.rs
@@ -0,0 +1,31 @@
+// This tests that debug info for tagged (ordinary) enums is properly emitted.
+// This is ignored for the fallback mode on MSVC due to problems with PDB.
+
+//@ ignore-msvc
+//@ ignore-wasi wasi codegens the main symbol differently
+
+//@ compile-flags: -g -C no-prepopulate-passes
+
+// CHECK-LABEL: @main
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_structure_type,{{.*}}name: "E",{{.*}}
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_variant_part,{{.*}}discriminator:{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "A",{{.*}}extraData:{{.*}}
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_structure_type,{{.*}}name: "A",{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "__0",{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "B",{{.*}}extraData:{{.*}}
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_structure_type,{{.*}}name: "B",{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}name: "__0",{{.*}}
+// CHECK: {{.*}}DIDerivedType{{.*}}tag: DW_TAG_member,{{.*}}flags: DIFlagArtificial{{.*}}
+
+#![allow(dead_code)]
+#![allow(unused_variables)]
+#![allow(unused_assignments)]
+
+enum E {
+    A(u32),
+    B(u32),
+}
+
+pub fn main() {
+    let e = E::A(23);
+}
diff --git a/tests/codegen-llvm/enum/enum-discriminant-eq.rs b/tests/codegen-llvm/enum/enum-discriminant-eq.rs
new file mode 100644
index 00000000000..d599685c2e5
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-discriminant-eq.rs
@@ -0,0 +1,229 @@
+//@ compile-flags: -Copt-level=3 -Zmerge-functions=disabled
+//@ min-llvm-version: 20
+//@ only-64bit
+//@ revisions: LLVM20 LLVM21
+//@ [LLVM21] min-llvm-version: 21
+//@ [LLVM20] max-llvm-major-version: 20
+
+// The `derive(PartialEq)` on enums with field-less variants compares discriminants,
+// so make sure we emit that in some reasonable way.
+
+#![crate_type = "lib"]
+#![feature(ascii_char)]
+#![feature(core_intrinsics)]
+#![feature(repr128)]
+
+use std::ascii::Char as AC;
+use std::cmp::Ordering;
+use std::intrinsics::discriminant_value;
+use std::num::NonZero;
+
+// A type that's bigger than `isize`, unlike the usual cases that have small tags.
+#[repr(u128)]
+pub enum Giant {
+    Two = 2,
+    Three = 3,
+    Four = 4,
+}
+
+#[unsafe(no_mangle)]
+pub fn opt_bool_eq_discr(a: Option<bool>, b: Option<bool>) -> bool {
+    // CHECK-LABEL: @opt_bool_eq_discr(
+    // CHECK: %[[A:.+]] = icmp ne i8 %a, 2
+    // CHECK: %[[B:.+]] = icmp eq i8 %b, 2
+    // CHECK: %[[R:.+]] = xor i1 %[[A]], %[[B]]
+    // CHECK: ret i1 %[[R]]
+
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn opt_ord_eq_discr(a: Option<Ordering>, b: Option<Ordering>) -> bool {
+    // CHECK-LABEL: @opt_ord_eq_discr(
+    // CHECK: %[[A:.+]] = icmp ne i8 %a, 2
+    // CHECK: %[[B:.+]] = icmp eq i8 %b, 2
+    // CHECK: %[[R:.+]] = xor i1 %[[A]], %[[B]]
+    // CHECK: ret i1 %[[R]]
+
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn opt_nz32_eq_discr(a: Option<NonZero<u32>>, b: Option<NonZero<u32>>) -> bool {
+    // CHECK-LABEL: @opt_nz32_eq_discr(
+    // CHECK: %[[A:.+]] = icmp ne i32 %a, 0
+    // CHECK: %[[B:.+]] = icmp eq i32 %b, 0
+    // CHECK: %[[R:.+]] = xor i1 %[[A]], %[[B]]
+    // CHECK: ret i1 %[[R]]
+
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn opt_ac_eq_discr(a: Option<AC>, b: Option<AC>) -> bool {
+    // CHECK-LABEL: @opt_ac_eq_discr(
+    // CHECK: %[[A:.+]] = icmp ne i8 %a, -128
+    // CHECK: %[[B:.+]] = icmp eq i8 %b, -128
+    // CHECK: %[[R:.+]] = xor i1 %[[A]], %[[B]]
+    // CHECK: ret i1 %[[R]]
+
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn opt_giant_eq_discr(a: Option<Giant>, b: Option<Giant>) -> bool {
+    // CHECK-LABEL: @opt_giant_eq_discr(
+    // CHECK: %[[A:.+]] = icmp ne i128 %a, 1
+    // CHECK: %[[B:.+]] = icmp eq i128 %b, 1
+    // CHECK: %[[R:.+]] = xor i1 %[[A]], %[[B]]
+    // CHECK: ret i1 %[[R]]
+
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+pub enum Mid<T> {
+    Before,
+    Thing(T),
+    After,
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_bool_eq_discr(a: Mid<bool>, b: Mid<bool>) -> bool {
+    // CHECK-LABEL: @mid_bool_eq_discr(
+
+    // CHECK: %[[A_REL_DISCR:.+]] = add nsw i8 %a, -2
+    // CHECK: %[[A_IS_NICHE:.+]] = icmp samesign ugt i8 %a, 1
+    // CHECK: %[[A_NOT_HOLE:.+]] = icmp ne i8 %[[A_REL_DISCR]], 1
+    // CHECK: tail call void @llvm.assume(i1 %[[A_NOT_HOLE]])
+    // CHECK: %[[A_DISCR:.+]] = select i1 %[[A_IS_NICHE]], i8 %[[A_REL_DISCR]], i8 1
+
+    // CHECK: %[[B_REL_DISCR:.+]] = add nsw i8 %b, -2
+    // CHECK: %[[B_IS_NICHE:.+]] = icmp samesign ugt i8 %b, 1
+    // CHECK: %[[B_NOT_HOLE:.+]] = icmp ne i8 %[[B_REL_DISCR]], 1
+    // CHECK: tail call void @llvm.assume(i1 %[[B_NOT_HOLE]])
+    // CHECK: %[[B_DISCR:.+]] = select i1 %[[B_IS_NICHE]], i8 %[[B_REL_DISCR]], i8 1
+
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_ord_eq_discr(a: Mid<Ordering>, b: Mid<Ordering>) -> bool {
+    // CHECK-LABEL: @mid_ord_eq_discr(
+
+    // CHECK: %[[A_REL_DISCR:.+]] = add nsw i8 %a, -2
+    // CHECK: %[[A_IS_NICHE:.+]] = icmp sgt i8 %a, 1
+    // CHECK: %[[A_NOT_HOLE:.+]] = icmp ne i8 %[[A_REL_DISCR]], 1
+    // CHECK: tail call void @llvm.assume(i1 %[[A_NOT_HOLE]])
+    // CHECK: %[[A_DISCR:.+]] = select i1 %[[A_IS_NICHE]], i8 %[[A_REL_DISCR]], i8 1
+
+    // CHECK: %[[B_REL_DISCR:.+]] = add nsw i8 %b, -2
+    // CHECK: %[[B_IS_NICHE:.+]] = icmp sgt i8 %b, 1
+    // CHECK: %[[B_NOT_HOLE:.+]] = icmp ne i8 %[[B_REL_DISCR]], 1
+    // CHECK: tail call void @llvm.assume(i1 %[[B_NOT_HOLE]])
+    // CHECK: %[[B_DISCR:.+]] = select i1 %[[B_IS_NICHE]], i8 %[[B_REL_DISCR]], i8 1
+
+    // CHECK: %[[R:.+]] = icmp eq i8 %[[A_DISCR]], %[[B_DISCR]]
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_nz32_eq_discr(a: Mid<NonZero<u32>>, b: Mid<NonZero<u32>>) -> bool {
+    // CHECK-LABEL: @mid_nz32_eq_discr(
+    // CHECK: %[[R:.+]] = icmp eq i32 %a.0, %b.0
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_ac_eq_discr(a: Mid<AC>, b: Mid<AC>) -> bool {
+    // CHECK-LABEL: @mid_ac_eq_discr(
+
+    // LLVM20: %[[A_REL_DISCR:.+]] = xor i8 %a, -128
+    // CHECK: %[[A_IS_NICHE:.+]] = icmp slt i8 %a, 0
+    // CHECK: %[[A_NOT_HOLE:.+]] = icmp ne i8 %a, -127
+    // CHECK: tail call void @llvm.assume(i1 %[[A_NOT_HOLE]])
+    // LLVM20: %[[A_DISCR:.+]] = select i1 %[[A_IS_NICHE]], i8 %[[A_REL_DISCR]], i8 1
+
+    // LLVM20: %[[B_REL_DISCR:.+]] = xor i8 %b, -128
+    // CHECK: %[[B_IS_NICHE:.+]] = icmp slt i8 %b, 0
+    // CHECK: %[[B_NOT_HOLE:.+]] = icmp ne i8 %b, -127
+    // CHECK: tail call void @llvm.assume(i1 %[[B_NOT_HOLE]])
+    // LLVM20: %[[B_DISCR:.+]] = select i1 %[[B_IS_NICHE]], i8 %[[B_REL_DISCR]], i8 1
+
+    // LLVM21: %[[A_DISCR:.+]] = select i1 %[[A_IS_NICHE]], i8 %a, i8 -127
+    // LLVM21: %[[B_DISCR:.+]] = select i1 %[[B_IS_NICHE]], i8 %b, i8 -127
+
+    // CHECK: %[[R:.+]] = icmp eq i8 %[[A_DISCR]], %[[B_DISCR]]
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+// FIXME: This should be improved once our LLVM fork picks up the fix for
+// <https://github.com/llvm/llvm-project/issues/134024>
+#[unsafe(no_mangle)]
+pub fn mid_giant_eq_discr(a: Mid<Giant>, b: Mid<Giant>) -> bool {
+    // CHECK-LABEL: @mid_giant_eq_discr(
+
+    // CHECK: %[[A_TRUNC:.+]] = trunc nuw nsw i128 %a to i64
+    // CHECK: %[[A_REL_DISCR:.+]] = add nsw i64 %[[A_TRUNC]], -5
+    // CHECK: %[[A_IS_NICHE:.+]] = icmp samesign ugt i128 %a, 4
+    // CHECK: %[[A_NOT_HOLE:.+]] = icmp ne i64 %[[A_REL_DISCR]], 1
+    // CHECK: tail call void @llvm.assume(i1 %[[A_NOT_HOLE]])
+    // CHECK: %[[A_DISCR:.+]] = select i1 %[[A_IS_NICHE]], i64 %[[A_REL_DISCR]], i64 1
+
+    // CHECK: %[[B_TRUNC:.+]] = trunc nuw nsw i128 %b to i64
+    // CHECK: %[[B_REL_DISCR:.+]] = add nsw i64 %[[B_TRUNC]], -5
+    // CHECK: %[[B_IS_NICHE:.+]] = icmp samesign ugt i128 %b, 4
+    // CHECK: %[[B_NOT_HOLE:.+]] = icmp ne i64 %[[B_REL_DISCR]], 1
+    // CHECK: tail call void @llvm.assume(i1 %[[B_NOT_HOLE]])
+    // CHECK: %[[B_DISCR:.+]] = select i1 %[[B_IS_NICHE]], i64 %[[B_REL_DISCR]], i64 1
+
+    // CHECK: %[[R:.+]] = icmp eq i64 %[[A_DISCR]], %[[B_DISCR]]
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == discriminant_value(&b)
+}
+
+// In niche-encoded enums, testing for the untagged variant should optimize to a
+// straight-forward comparison looking for the natural range of the payload value.
+
+#[unsafe(no_mangle)]
+pub fn mid_bool_is_thing(a: Mid<bool>) -> bool {
+    // CHECK-LABEL: @mid_bool_is_thing(
+    // CHECK: %[[R:.+]] = icmp samesign ult i8 %a, 2
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == 1
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_ord_is_thing(a: Mid<Ordering>) -> bool {
+    // CHECK-LABEL: @mid_ord_is_thing(
+    // CHECK: %[[R:.+]] = icmp slt i8 %a, 2
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == 1
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_nz32_is_thing(a: Mid<NonZero<u32>>) -> bool {
+    // CHECK-LABEL: @mid_nz32_is_thing(
+    // CHECK: %[[R:.+]] = icmp eq i32 %a.0, 1
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == 1
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_ac_is_thing(a: Mid<AC>) -> bool {
+    // CHECK-LABEL: @mid_ac_is_thing(
+    // CHECK: %[[R:.+]] = icmp sgt i8 %a, -1
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == 1
+}
+
+#[unsafe(no_mangle)]
+pub fn mid_giant_is_thing(a: Mid<Giant>) -> bool {
+    // CHECK-LABEL: @mid_giant_is_thing(
+    // CHECK: %[[R:.+]] = icmp samesign ult i128 %a, 5
+    // CHECK: ret i1 %[[R]]
+    discriminant_value(&a) == 1
+}
diff --git a/tests/codegen-llvm/enum/enum-discriminant-value.rs b/tests/codegen-llvm/enum/enum-discriminant-value.rs
new file mode 100644
index 00000000000..d6b0c6d6c10
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-discriminant-value.rs
@@ -0,0 +1,27 @@
+// Verify that DIEnumerator uses isUnsigned flag when appropriate.
+//
+//@ compile-flags: -g -C no-prepopulate-passes
+
+#[repr(i64)]
+pub enum I64 {
+    I64Min = i64::MIN,
+    I64Max = i64::MAX,
+}
+
+#[repr(u64)]
+pub enum U64 {
+    U64Min = u64::MIN,
+    U64Max = u64::MAX,
+}
+
+fn main() {
+    let _a = I64::I64Min;
+    let _b = I64::I64Max;
+    let _c = U64::U64Min;
+    let _d = U64::U64Max;
+}
+
+// CHECK: !DIEnumerator(name: "I64Min", value: -9223372036854775808)
+// CHECK: !DIEnumerator(name: "I64Max", value: 9223372036854775807)
+// CHECK: !DIEnumerator(name: "U64Min", value: 0, isUnsigned: true)
+// CHECK: !DIEnumerator(name: "U64Max", value: 18446744073709551615, isUnsigned: true)
diff --git a/tests/codegen-llvm/enum/enum-early-otherwise-branch.rs b/tests/codegen-llvm/enum/enum-early-otherwise-branch.rs
new file mode 100644
index 00000000000..8d39d8e9b74
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-early-otherwise-branch.rs
@@ -0,0 +1,25 @@
+//@ compile-flags: -Copt-level=3
+
+#![crate_type = "lib"]
+
+pub enum Enum {
+    A(u32),
+    B(u32),
+    C(u32),
+}
+
+#[no_mangle]
+pub fn foo(lhs: &Enum, rhs: &Enum) -> bool {
+    // CHECK-LABEL: define{{.*}}i1 @foo(
+    // CHECK-NOT: switch
+    // CHECK-NOT: br
+    // CHECK: [[SELECT:%.*]] = select
+    // CHECK-NEXT: ret i1 [[SELECT]]
+    // CHECK-NEXT: }
+    match (lhs, rhs) {
+        (Enum::A(lhs), Enum::A(rhs)) => lhs == rhs,
+        (Enum::B(lhs), Enum::B(rhs)) => lhs == rhs,
+        (Enum::C(lhs), Enum::C(rhs)) => lhs == rhs,
+        _ => false,
+    }
+}
diff --git a/tests/codegen-llvm/enum/enum-match.rs b/tests/codegen-llvm/enum/enum-match.rs
new file mode 100644
index 00000000000..57db44ec74e
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-match.rs
@@ -0,0 +1,779 @@
+//@ compile-flags: -Copt-level=1
+//@ only-64bit
+
+#![crate_type = "lib"]
+#![feature(core_intrinsics)]
+
+// Check each of the 3 cases for `codegen_get_discr`.
+
+// FIXME: once our min-bar LLVM has `range` attributes, update the various
+// tests here to no longer have the `range`s and `nsw`s as optional.
+
+// Case 0: One tagged variant.
+pub enum Enum0 {
+    A(bool),
+    B,
+}
+
+// CHECK-LABEL: define{{( dso_local)?}} noundef{{( range\(i8 [0-9]+, [0-9]+\))?}} i8 @match0(i8{{.+}}%0)
+// CHECK-NEXT: start:
+// CHECK-NEXT: %[[IS_B:.+]] = icmp eq i8 %0, 2
+// CHECK-NEXT: %[[TRUNC:.+]] = and i8 %0, 1
+// CHECK-NEXT: %[[R:.+]] = select i1 %[[IS_B]], i8 13, i8 %[[TRUNC]]
+// CHECK-NEXT: ret i8 %[[R]]
+#[no_mangle]
+pub fn match0(e: Enum0) -> u8 {
+    use Enum0::*;
+    match e {
+        A(b) => b as u8,
+        B => 13,
+    }
+}
+
+// Case 1: Niche values are on a boundary for `range`.
+pub enum Enum1 {
+    A(bool),
+    B,
+    C,
+}
+
+// CHECK-LABEL: define{{( dso_local)?}} noundef{{( range\(i8 [0-9]+, [0-9]+\))?}} i8 @match1(i8{{.+}}%0)
+// CHECK-NEXT: start:
+// CHECK-NEXT: %[[REL_VAR:.+]] = add{{( nsw)?}} i8 %0, -2
+// CHECK-NEXT: %[[REL_VAR_WIDE:.+]] = zext i8 %[[REL_VAR]] to i64
+// CHECK-NEXT: %[[IS_NICHE:.+]] = icmp{{( samesign)?}} ugt i8 %0, 1
+// CHECK-NEXT: %[[NICHE_DISCR:.+]] = add nuw nsw i64 %[[REL_VAR_WIDE]], 1
+// CHECK-NEXT: %[[DISCR:.+]] = select i1 %[[IS_NICHE]], i64 %[[NICHE_DISCR]], i64 0
+// CHECK-NEXT: switch i64 %[[DISCR]]
+#[no_mangle]
+pub fn match1(e: Enum1) -> u8 {
+    use Enum1::*;
+    match e {
+        A(b) => b as u8,
+        B => 13,
+        C => 100,
+    }
+}
+
+// Case 2: Special cases don't apply.
+#[rustfmt::skip]
+pub enum X {
+    _2=2, _3, _4, _5, _6, _7, _8, _9, _10, _11,
+    _12, _13, _14, _15, _16, _17, _18, _19, _20,
+    _21, _22, _23, _24, _25, _26, _27, _28, _29,
+    _30, _31, _32, _33, _34, _35, _36, _37, _38,
+    _39, _40, _41, _42, _43, _44, _45, _46, _47,
+    _48, _49, _50, _51, _52, _53, _54, _55, _56,
+    _57, _58, _59, _60, _61, _62, _63, _64, _65,
+    _66, _67, _68, _69, _70, _71, _72, _73, _74,
+    _75, _76, _77, _78, _79, _80, _81, _82, _83,
+    _84, _85, _86, _87, _88, _89, _90, _91, _92,
+    _93, _94, _95, _96, _97, _98, _99, _100, _101,
+    _102, _103, _104, _105, _106, _107, _108, _109,
+    _110, _111, _112, _113, _114, _115, _116, _117,
+    _118, _119, _120, _121, _122, _123, _124, _125,
+    _126, _127, _128, _129, _130, _131, _132, _133,
+    _134, _135, _136, _137, _138, _139, _140, _141,
+    _142, _143, _144, _145, _146, _147, _148, _149,
+    _150, _151, _152, _153, _154, _155, _156, _157,
+    _158, _159, _160, _161, _162, _163, _164, _165,
+    _166, _167, _168, _169, _170, _171, _172, _173,
+    _174, _175, _176, _177, _178, _179, _180, _181,
+    _182, _183, _184, _185, _186, _187, _188, _189,
+    _190, _191, _192, _193, _194, _195, _196, _197,
+    _198, _199, _200, _201, _202, _203, _204, _205,
+    _206, _207, _208, _209, _210, _211, _212, _213,
+    _214, _215, _216, _217, _218, _219, _220, _221,
+    _222, _223, _224, _225, _226, _227, _228, _229,
+    _230, _231, _232, _233, _234, _235, _236, _237,
+    _238, _239, _240, _241, _242, _243, _244, _245,
+    _246, _247, _248, _249, _250, _251, _252, _253,
+}
+
+pub enum Enum2 {
+    A(X),
+    B,
+    C,
+    D,
+    E,
+}
+
+// CHECK-LABEL: define{{( dso_local)?}} noundef{{( range\(i8 [0-9]+, -?[0-9]+\))?}} i8 @match2(i8{{.+}}%0)
+// CHECK-NEXT: start:
+// CHECK-NEXT: %[[REL_VAR:.+]] = add i8 %0, 2
+// CHECK-NEXT: %[[REL_VAR_WIDE:.+]] = zext i8 %[[REL_VAR]] to i64
+// CHECK-NEXT: %[[IS_NICHE:.+]] = icmp ult i8 %[[REL_VAR]], 4
+// CHECK-NEXT: %[[NICHE_DISCR:.+]] = add nuw nsw i64 %[[REL_VAR_WIDE]], 1
+// CHECK-NEXT: %[[DISCR:.+]] = select i1 %[[IS_NICHE]], i64 %[[NICHE_DISCR]], i64 0
+// CHECK-NEXT: switch i64 %[[DISCR]]
+#[no_mangle]
+pub fn match2(e: Enum2) -> u8 {
+    use Enum2::*;
+    match e {
+        A(b) => b as u8,
+        B => 13,
+        C => 100,
+        D => 200,
+        E => 250,
+    }
+}
+
+// And make sure it works even if the niched scalar is a pointer.
+// (For example, that we don't try to `sub` on pointers.)
+
+// CHECK-LABEL: define{{( dso_local)?}} noundef{{( range\(i16 -?[0-9]+, -?[0-9]+\))?}} i16 @match3(ptr{{.+}}%0)
+// CHECK-NEXT: start:
+// CHECK-NEXT: %[[IS_NULL:.+]] = icmp eq ptr %0, null
+// CHECK-NEXT: br i1 %[[IS_NULL]]
+#[no_mangle]
+pub fn match3(e: Option<&u8>) -> i16 {
+    match e {
+        Some(r) => *r as _,
+        None => -1,
+    }
+}
+
+// If the untagged variant is in the middle, there's an impossible value that's
+// not reflected in the `range` parameter attribute, so we assume it away.
+
+#[derive(PartialEq)]
+pub enum MiddleNiche {
+    A,
+    B,
+    C(bool),
+    D,
+    E,
+}
+
+// CHECK-LABEL: define{{( dso_local)?}} noundef{{( range\(i8 -?[0-9]+, -?[0-9]+\))?}} i8 @match4(i8{{.+}}%0)
+// CHECK-NEXT: start:
+// CHECK-NEXT: %[[REL_VAR:.+]] = add{{( nsw)?}} i8 %0, -2
+// CHECK-NEXT: %[[NOT_IMPOSSIBLE:.+]] = icmp ne i8 %[[REL_VAR]], 2
+// CHECK-NEXT: call void @llvm.assume(i1 %[[NOT_IMPOSSIBLE]])
+// CHECK-NEXT: %[[NOT_NICHE:.+]] = icmp{{( samesign)?}} ult i8 %0, 2
+// CHECK-NEXT: %[[DISCR:.+]] = select i1 %[[NOT_NICHE]], i8 2, i8 %[[REL_VAR]]
+// CHECK-NEXT: switch i8 %[[DISCR]]
+#[no_mangle]
+pub fn match4(e: MiddleNiche) -> u8 {
+    use MiddleNiche::*;
+    match e {
+        A => 13,
+        B => 100,
+        C(b) => b as u8,
+        D => 200,
+        E => 250,
+    }
+}
+
+// CHECK-LABEL: define{{.+}}i1 @match4_is_c(i8{{.+}}%e)
+// CHECK-NEXT: start
+// CHECK-NEXT: %[[NOT_IMPOSSIBLE:.+]] = icmp ne i8 %e, 4
+// CHECK-NEXT: call void @llvm.assume(i1 %[[NOT_IMPOSSIBLE]])
+// CHECK-NEXT: %[[IS_C:.+]] = icmp{{( samesign)?}} ult i8 %e, 2
+// CHECK-NEXT: ret i1 %[[IS_C]]
+#[no_mangle]
+pub fn match4_is_c(e: MiddleNiche) -> bool {
+    // Before #139098, this couldn't optimize out the `select` because it looked
+    // like it was possible for a `2` to be produced on both sides.
+
+    std::intrinsics::discriminant_value(&e) == 2
+}
+
+// You have to do something pretty obnoxious to get a variant index that doesn't
+// fit in the tag size, but it's possible
+
+pub enum Never {}
+
+pub enum HugeVariantIndex {
+    V000(Never),
+    V001(Never),
+    V002(Never),
+    V003(Never),
+    V004(Never),
+    V005(Never),
+    V006(Never),
+    V007(Never),
+    V008(Never),
+    V009(Never),
+    V010(Never),
+    V011(Never),
+    V012(Never),
+    V013(Never),
+    V014(Never),
+    V015(Never),
+    V016(Never),
+    V017(Never),
+    V018(Never),
+    V019(Never),
+    V020(Never),
+    V021(Never),
+    V022(Never),
+    V023(Never),
+    V024(Never),
+    V025(Never),
+    V026(Never),
+    V027(Never),
+    V028(Never),
+    V029(Never),
+    V030(Never),
+    V031(Never),
+    V032(Never),
+    V033(Never),
+    V034(Never),
+    V035(Never),
+    V036(Never),
+    V037(Never),
+    V038(Never),
+    V039(Never),
+    V040(Never),
+    V041(Never),
+    V042(Never),
+    V043(Never),
+    V044(Never),
+    V045(Never),
+    V046(Never),
+    V047(Never),
+    V048(Never),
+    V049(Never),
+    V050(Never),
+    V051(Never),
+    V052(Never),
+    V053(Never),
+    V054(Never),
+    V055(Never),
+    V056(Never),
+    V057(Never),
+    V058(Never),
+    V059(Never),
+    V060(Never),
+    V061(Never),
+    V062(Never),
+    V063(Never),
+    V064(Never),
+    V065(Never),
+    V066(Never),
+    V067(Never),
+    V068(Never),
+    V069(Never),
+    V070(Never),
+    V071(Never),
+    V072(Never),
+    V073(Never),
+    V074(Never),
+    V075(Never),
+    V076(Never),
+    V077(Never),
+    V078(Never),
+    V079(Never),
+    V080(Never),
+    V081(Never),
+    V082(Never),
+    V083(Never),
+    V084(Never),
+    V085(Never),
+    V086(Never),
+    V087(Never),
+    V088(Never),
+    V089(Never),
+    V090(Never),
+    V091(Never),
+    V092(Never),
+    V093(Never),
+    V094(Never),
+    V095(Never),
+    V096(Never),
+    V097(Never),
+    V098(Never),
+    V099(Never),
+    V100(Never),
+    V101(Never),
+    V102(Never),
+    V103(Never),
+    V104(Never),
+    V105(Never),
+    V106(Never),
+    V107(Never),
+    V108(Never),
+    V109(Never),
+    V110(Never),
+    V111(Never),
+    V112(Never),
+    V113(Never),
+    V114(Never),
+    V115(Never),
+    V116(Never),
+    V117(Never),
+    V118(Never),
+    V119(Never),
+    V120(Never),
+    V121(Never),
+    V122(Never),
+    V123(Never),
+    V124(Never),
+    V125(Never),
+    V126(Never),
+    V127(Never),
+    V128(Never),
+    V129(Never),
+    V130(Never),
+    V131(Never),
+    V132(Never),
+    V133(Never),
+    V134(Never),
+    V135(Never),
+    V136(Never),
+    V137(Never),
+    V138(Never),
+    V139(Never),
+    V140(Never),
+    V141(Never),
+    V142(Never),
+    V143(Never),
+    V144(Never),
+    V145(Never),
+    V146(Never),
+    V147(Never),
+    V148(Never),
+    V149(Never),
+    V150(Never),
+    V151(Never),
+    V152(Never),
+    V153(Never),
+    V154(Never),
+    V155(Never),
+    V156(Never),
+    V157(Never),
+    V158(Never),
+    V159(Never),
+    V160(Never),
+    V161(Never),
+    V162(Never),
+    V163(Never),
+    V164(Never),
+    V165(Never),
+    V166(Never),
+    V167(Never),
+    V168(Never),
+    V169(Never),
+    V170(Never),
+    V171(Never),
+    V172(Never),
+    V173(Never),
+    V174(Never),
+    V175(Never),
+    V176(Never),
+    V177(Never),
+    V178(Never),
+    V179(Never),
+    V180(Never),
+    V181(Never),
+    V182(Never),
+    V183(Never),
+    V184(Never),
+    V185(Never),
+    V186(Never),
+    V187(Never),
+    V188(Never),
+    V189(Never),
+    V190(Never),
+    V191(Never),
+    V192(Never),
+    V193(Never),
+    V194(Never),
+    V195(Never),
+    V196(Never),
+    V197(Never),
+    V198(Never),
+    V199(Never),
+    V200(Never),
+    V201(Never),
+    V202(Never),
+    V203(Never),
+    V204(Never),
+    V205(Never),
+    V206(Never),
+    V207(Never),
+    V208(Never),
+    V209(Never),
+    V210(Never),
+    V211(Never),
+    V212(Never),
+    V213(Never),
+    V214(Never),
+    V215(Never),
+    V216(Never),
+    V217(Never),
+    V218(Never),
+    V219(Never),
+    V220(Never),
+    V221(Never),
+    V222(Never),
+    V223(Never),
+    V224(Never),
+    V225(Never),
+    V226(Never),
+    V227(Never),
+    V228(Never),
+    V229(Never),
+    V230(Never),
+    V231(Never),
+    V232(Never),
+    V233(Never),
+    V234(Never),
+    V235(Never),
+    V236(Never),
+    V237(Never),
+    V238(Never),
+    V239(Never),
+    V240(Never),
+    V241(Never),
+    V242(Never),
+    V243(Never),
+    V244(Never),
+    V245(Never),
+    V246(Never),
+    V247(Never),
+    V248(Never),
+    V249(Never),
+    V250(Never),
+    V251(Never),
+    V252(Never),
+    V253(Never),
+    V254(Never),
+    V255(Never),
+    V256(Never),
+
+    Possible257,
+    Bool258(bool),
+    Possible259,
+}
+
+// CHECK-LABEL: define{{( dso_local)?}} noundef{{( range\(i8 [0-9]+, [0-9]+\))?}} i8 @match5(i8{{.+}}%0)
+// CHECK-NEXT: start:
+// CHECK-NEXT: %[[REL_VAR:.+]] = add{{( nsw)?}} i8 %0, -2
+// CHECK-NEXT: %[[REL_VAR_WIDE:.+]] = zext i8 %[[REL_VAR]] to i64
+// CHECK-NEXT: %[[IS_NICHE:.+]] = icmp{{( samesign)?}} ugt i8 %0, 1
+// CHECK-NEXT: %[[NICHE_DISCR:.+]] = add nuw nsw i64 %[[REL_VAR_WIDE]], 257
+// CHECK-NEXT: %[[NOT_IMPOSSIBLE:.+]] = icmp ne i64 %[[NICHE_DISCR]], 258
+// CHECK-NEXT: call void @llvm.assume(i1 %[[NOT_IMPOSSIBLE]])
+// CHECK-NEXT: %[[DISCR:.+]] = select i1 %[[IS_NICHE]], i64 %[[NICHE_DISCR]], i64 258
+// CHECK-NEXT: switch i64 %[[DISCR]],
+// CHECK-NEXT:   i64 257,
+// CHECK-NEXT:   i64 258,
+// CHECK-NEXT:   i64 259,
+#[no_mangle]
+pub fn match5(e: HugeVariantIndex) -> u8 {
+    use HugeVariantIndex::*;
+    match e {
+        Possible257 => 13,
+        Bool258(b) => b as u8,
+        Possible259 => 100,
+    }
+}
+
+// Make an enum where the niche tags wrap both as signed and as unsigned, to hit
+// the most-fallback case where there's just nothing smart to do.
+
+pub enum E10Through65 {
+    D10 = 10,
+    D11 = 11,
+    D12 = 12,
+    D13 = 13,
+    D14 = 14,
+    D15 = 15,
+    D16 = 16,
+    D17 = 17,
+    D18 = 18,
+    D19 = 19,
+    D20 = 20,
+    D21 = 21,
+    D22 = 22,
+    D23 = 23,
+    D24 = 24,
+    D25 = 25,
+    D26 = 26,
+    D27 = 27,
+    D28 = 28,
+    D29 = 29,
+    D30 = 30,
+    D31 = 31,
+    D32 = 32,
+    D33 = 33,
+    D34 = 34,
+    D35 = 35,
+    D36 = 36,
+    D37 = 37,
+    D38 = 38,
+    D39 = 39,
+    D40 = 40,
+    D41 = 41,
+    D42 = 42,
+    D43 = 43,
+    D44 = 44,
+    D45 = 45,
+    D46 = 46,
+    D47 = 47,
+    D48 = 48,
+    D49 = 49,
+    D50 = 50,
+    D51 = 51,
+    D52 = 52,
+    D53 = 53,
+    D54 = 54,
+    D55 = 55,
+    D56 = 56,
+    D57 = 57,
+    D58 = 58,
+    D59 = 59,
+    D60 = 60,
+    D61 = 61,
+    D62 = 62,
+    D63 = 63,
+    D64 = 64,
+    D65 = 65,
+}
+
+pub enum Tricky {
+    Untagged(E10Through65),
+    V001,
+    V002,
+    V003,
+    V004,
+    V005,
+    V006,
+    V007,
+    V008,
+    V009,
+    V010,
+    V011,
+    V012,
+    V013,
+    V014,
+    V015,
+    V016,
+    V017,
+    V018,
+    V019,
+    V020,
+    V021,
+    V022,
+    V023,
+    V024,
+    V025,
+    V026,
+    V027,
+    V028,
+    V029,
+    V030,
+    V031,
+    V032,
+    V033,
+    V034,
+    V035,
+    V036,
+    V037,
+    V038,
+    V039,
+    V040,
+    V041,
+    V042,
+    V043,
+    V044,
+    V045,
+    V046,
+    V047,
+    V048,
+    V049,
+    V050,
+    V051,
+    V052,
+    V053,
+    V054,
+    V055,
+    V056,
+    V057,
+    V058,
+    V059,
+    V060,
+    V061,
+    V062,
+    V063,
+    V064,
+    V065,
+    V066,
+    V067,
+    V068,
+    V069,
+    V070,
+    V071,
+    V072,
+    V073,
+    V074,
+    V075,
+    V076,
+    V077,
+    V078,
+    V079,
+    V080,
+    V081,
+    V082,
+    V083,
+    V084,
+    V085,
+    V086,
+    V087,
+    V088,
+    V089,
+    V090,
+    V091,
+    V092,
+    V093,
+    V094,
+    V095,
+    V096,
+    V097,
+    V098,
+    V099,
+    V100,
+    V101,
+    V102,
+    V103,
+    V104,
+    V105,
+    V106,
+    V107,
+    V108,
+    V109,
+    V110,
+    V111,
+    V112,
+    V113,
+    V114,
+    V115,
+    V116,
+    V117,
+    V118,
+    V119,
+    V120,
+    V121,
+    V122,
+    V123,
+    V124,
+    V125,
+    V126,
+    V127,
+    V128,
+    V129,
+    V130,
+    V131,
+    V132,
+    V133,
+    V134,
+    V135,
+    V136,
+    V137,
+    V138,
+    V139,
+    V140,
+    V141,
+    V142,
+    V143,
+    V144,
+    V145,
+    V146,
+    V147,
+    V148,
+    V149,
+    V150,
+    V151,
+    V152,
+    V153,
+    V154,
+    V155,
+    V156,
+    V157,
+    V158,
+    V159,
+    V160,
+    V161,
+    V162,
+    V163,
+    V164,
+    V165,
+    V166,
+    V167,
+    V168,
+    V169,
+    V170,
+    V171,
+    V172,
+    V173,
+    V174,
+    V175,
+    V176,
+    V177,
+    V178,
+    V179,
+    V180,
+    V181,
+    V182,
+    V183,
+    V184,
+    V185,
+    V186,
+    V187,
+    V188,
+    V189,
+    V190,
+    V191,
+    V192,
+    V193,
+    V194,
+    V195,
+    V196,
+    V197,
+    V198,
+    V199,
+    V200,
+}
+
+const _: () = assert!(std::intrinsics::discriminant_value(&Tricky::V100) == 100);
+
+// CHECK-LABEL: define noundef{{( range\(i8 [0-9]+, [0-9]+\))?}} i8 @discriminant6(i8 noundef %e)
+// CHECK-NEXT: start:
+// CHECK-NEXT: %[[REL_VAR:.+]] = add i8 %e, -66
+// CHECK-NEXT: %[[IS_NICHE:.+]] = icmp ult i8 %[[REL_VAR]], -56
+// CHECK-NEXT: %[[TAGGED_DISCR:.+]] = add i8 %e, -65
+// CHECK-NEXT: %[[DISCR:.+]] = select i1 %[[IS_NICHE]], i8 %[[TAGGED_DISCR]], i8 0
+// CHECK-NEXT: ret i8 %[[DISCR]]
+#[no_mangle]
+pub fn discriminant6(e: Tricky) -> u8 {
+    std::intrinsics::discriminant_value(&e) as _
+}
+
+// Case from <https://github.com/rust-lang/rust/issues/104519>,
+// where sign-extension is important.
+
+pub enum OpenResult {
+    Ok(()),
+    Err(()),
+    TransportErr(TransportErr),
+}
+
+#[repr(i32)]
+pub enum TransportErr {
+    UnknownMethod = -2,
+}
+
+#[no_mangle]
+pub fn match7(result: OpenResult) -> u8 {
+    // CHECK-LABEL: define noundef{{( range\(i8 [0-9]+, [0-9]+\))?}} i8 @match7(i32{{.+}}%result)
+    // CHECK-NEXT: start:
+    // CHECK-NEXT: %[[NOT_OK:.+]] = icmp ne i32 %result, -1
+    // CHECK-NEXT: %[[RET:.+]] = zext i1 %[[NOT_OK]] to i8
+    // CHECK-NEXT: ret i8 %[[RET]]
+    match result {
+        OpenResult::Ok(()) => 0,
+        _ => 1,
+    }
+}
diff --git a/tests/codegen-llvm/enum/enum-transparent-extract.rs b/tests/codegen-llvm/enum/enum-transparent-extract.rs
new file mode 100644
index 00000000000..c5efb8d472b
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-transparent-extract.rs
@@ -0,0 +1,31 @@
+//@ compile-flags: -Copt-level=0
+//@ only-64bit
+
+#![crate_type = "lib"]
+
+use std::ops::ControlFlow;
+
+pub enum Never {}
+
+#[no_mangle]
+pub fn make_unmake_result_never(x: i32) -> i32 {
+    // CHECK-LABEL: define i32 @make_unmake_result_never(i32 %x)
+    // CHECK: start:
+    // CHECK-NEXT: ret i32 %x
+
+    let y: Result<i32, Never> = Ok(x);
+    let Ok(z) = y;
+    z
+}
+
+#[no_mangle]
+pub fn extract_control_flow_never(x: ControlFlow<&str, Never>) -> &str {
+    // CHECK-LABEL: define { ptr, i64 } @extract_control_flow_never(ptr align 1 %x.0, i64 %x.1)
+    // CHECK: start:
+    // CHECK-NEXT: %[[P0:.+]] = insertvalue { ptr, i64 } poison, ptr %x.0, 0
+    // CHECK-NEXT: %[[P1:.+]] = insertvalue { ptr, i64 } %[[P0]], i64 %x.1, 1
+    // CHECK-NEXT: ret { ptr, i64 } %[[P1]]
+
+    let ControlFlow::Break(s) = x;
+    s
+}
diff --git a/tests/codegen-llvm/enum/enum-two-variants-match.rs b/tests/codegen-llvm/enum/enum-two-variants-match.rs
new file mode 100644
index 00000000000..12d9edc4d62
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-two-variants-match.rs
@@ -0,0 +1,130 @@
+//@ compile-flags: -Copt-level=3 -C no-prepopulate-passes
+//@ only-64bit (because these discriminants are isize)
+
+#![crate_type = "lib"]
+
+// This directly tests what we emit for these matches, rather than what happens
+// after optimization, so it doesn't need to worry about extra flags on the
+// instructions and is less susceptible to being broken on LLVM updates.
+
+// CHECK-LABEL: @option_match
+#[no_mangle]
+pub fn option_match(x: Option<i32>) -> u16 {
+    // CHECK-NOT: %x = alloca
+    // CHECK: %[[OUT:.+]] = alloca [2 x i8]
+    // CHECK-NOT: %x = alloca
+
+    // CHECK: %[[DISCR:.+]] = zext i32 %x.0 to i64
+    // CHECK: %[[COND:.+]] = trunc nuw i64 %[[DISCR]] to i1
+    // CHECK: br i1 %[[COND]], label %[[TRUE:[a-z0-9]+]], label %[[FALSE:[a-z0-9]+]]
+
+    // CHECK: [[TRUE]]:
+    // CHECK: store i16 13, ptr %[[OUT]]
+
+    // CHECK: [[FALSE]]:
+    // CHECK: store i16 42, ptr %[[OUT]]
+
+    // CHECK: %[[RET:.+]] = load i16, ptr %[[OUT]]
+    // CHECK: ret i16 %[[RET]]
+    match x {
+        Some(_) => 13,
+        None => 42,
+    }
+}
+
+// CHECK-LABEL: @result_match
+#[no_mangle]
+pub fn result_match(x: Result<u64, i64>) -> u16 {
+    // CHECK-NOT: %x = alloca
+    // CHECK: %[[OUT:.+]] = alloca [2 x i8]
+    // CHECK-NOT: %x = alloca
+
+    // CHECK: %[[COND:.+]] = trunc nuw i64 %x.0 to i1
+    // CHECK: br i1 %[[COND]], label %[[TRUE:[a-z0-9]+]], label %[[FALSE:[a-z0-9]+]]
+
+    // CHECK: [[TRUE]]:
+    // CHECK: store i16 13, ptr %[[OUT]]
+
+    // CHECK: [[FALSE]]:
+    // CHECK: store i16 42, ptr %[[OUT]]
+
+    // CHECK: %[[RET:.+]] = load i16, ptr %[[OUT]]
+    // CHECK: ret i16 %[[RET]]
+    match x {
+        Err(_) => 13,
+        Ok(_) => 42,
+    }
+}
+
+// CHECK-LABEL: @option_bool_match(
+#[no_mangle]
+pub fn option_bool_match(x: Option<bool>) -> char {
+    // CHECK: %[[RAW:.+]] = load i8, ptr %x
+    // CHECK: %[[IS_NONE:.+]] = icmp eq i8 %[[RAW]], 2
+    // CHECK: %[[OPT_DISCR:.+]] = select i1 %[[IS_NONE]], i64 0, i64 1
+    // CHECK: %[[OPT_DISCR_T:.+]] = trunc nuw i64 %[[OPT_DISCR]] to i1
+    // CHECK: br i1 %[[OPT_DISCR_T]], label %[[BB_SOME:.+]], label %[[BB_NONE:.+]]
+
+    // CHECK: [[BB_SOME]]:
+    // CHECK: %[[FIELD:.+]] = load i8, ptr %x
+    // CHECK: %[[FIELD_T:.+]] = trunc nuw i8 %[[FIELD]] to i1
+    // CHECK: br i1 %[[FIELD_T]]
+    match x {
+        None => 'n',
+        Some(false) => 'f',
+        Some(true) => 't',
+    }
+}
+
+use std::cmp::Ordering::{self, *};
+// CHECK-LABEL: @option_ordering_match(
+#[no_mangle]
+pub fn option_ordering_match(x: Option<Ordering>) -> char {
+    // CHECK: %[[RAW:.+]] = load i8, ptr %x
+    // CHECK: %[[IS_NONE:.+]] = icmp eq i8 %[[RAW]], 2
+    // CHECK: %[[OPT_DISCR:.+]] = select i1 %[[IS_NONE]], i64 0, i64 1
+    // CHECK: %[[OPT_DISCR_T:.+]] = trunc nuw i64 %[[OPT_DISCR]] to i1
+    // CHECK: br i1 %[[OPT_DISCR_T]], label %[[BB_SOME:.+]], label %[[BB_NONE:.+]]
+
+    // CHECK: [[BB_SOME]]:
+    // CHECK: %[[FIELD:.+]] = load i8, ptr %x
+    // CHECK: switch i8 %[[FIELD]], label %[[UNREACHABLE:.+]] [
+    // CHECK-NEXT: i8 -1, label
+    // CHECK-NEXT: i8 0, label
+    // CHECK-NEXT: i8 1, label
+    // CHECK-NEXT: ]
+
+    // CHECK: [[UNREACHABLE]]:
+    // CHECK-NEXT: unreachable
+    match x {
+        None => '?',
+        Some(Less) => '<',
+        Some(Equal) => '=',
+        Some(Greater) => '>',
+    }
+}
+
+// CHECK-LABEL: @option_nonzero_match(
+#[no_mangle]
+pub fn option_nonzero_match(x: Option<std::num::NonZero<u16>>) -> u16 {
+    // CHECK: %[[OUT:.+]] = alloca [2 x i8]
+
+    // CHECK: %[[IS_NONE:.+]] = icmp eq i16 %x, 0
+    // CHECK: %[[OPT_DISCR:.+]] = select i1 %[[IS_NONE]], i64 0, i64 1
+    // CHECK: %[[OPT_DISCR_T:.+]] = trunc nuw i64 %[[OPT_DISCR]] to i1
+    // CHECK: br i1 %[[OPT_DISCR_T]], label %[[BB_SOME:.+]], label %[[BB_NONE:.+]]
+
+    // CHECK: [[BB_SOME]]:
+    // CHECK: store i16 987, ptr %[[OUT]]
+
+    // CHECK: [[BB_NONE]]:
+    // CHECK: store i16 123, ptr %[[OUT]]
+
+    // CHECK: %[[RET:.+]] = load i16, ptr %[[OUT]]
+    // CHECK: ret i16 %[[RET]]
+
+    match x {
+        None => 123,
+        Some(_) => 987,
+    }
+}
diff --git a/tests/codegen-llvm/enum/enum-u128.rs b/tests/codegen-llvm/enum/enum-u128.rs
new file mode 100644
index 00000000000..2676669f3e3
--- /dev/null
+++ b/tests/codegen-llvm/enum/enum-u128.rs
@@ -0,0 +1,25 @@
+// This tests that debug info for "c-like" 128bit enums is properly emitted.
+// This is ignored for the fallback mode on MSVC due to problems with PDB.
+
+//
+//@ ignore-msvc
+//@ ignore-wasi wasi codegens the main symbol differently
+
+//@ compile-flags: -g -C no-prepopulate-passes
+
+// CHECK-LABEL: @main
+// CHECK: {{.*}}DICompositeType{{.*}}tag: DW_TAG_enumeration_type,{{.*}}name: "Foo",{{.*}}flags: DIFlagEnumClass,{{.*}}
+// CHECK: {{.*}}DIEnumerator{{.*}}name: "Lo",{{.*}}value: 0,{{.*}}
+// CHECK: {{.*}}DIEnumerator{{.*}}name: "Hi",{{.*}}value: 18446744073709551616,{{.*}}
+// CHECK: {{.*}}DIEnumerator{{.*}}name: "Bar",{{.*}}value: 18446745000000000123,{{.*}}
+
+#[repr(u128)]
+pub enum Foo {
+    Lo,
+    Hi = 1 << 64,
+    Bar = 18_446_745_000_000_000_123,
+}
+
+pub fn main() {
+    let foo = Foo::Bar;
+}
diff --git a/tests/codegen-llvm/enum/unreachable_enum_default_branch.rs b/tests/codegen-llvm/enum/unreachable_enum_default_branch.rs
new file mode 100644
index 00000000000..55b165fc111
--- /dev/null
+++ b/tests/codegen-llvm/enum/unreachable_enum_default_branch.rs
@@ -0,0 +1,40 @@
+//@ compile-flags: -Copt-level=3
+
+#![crate_type = "lib"]
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub struct Int(u32);
+
+const A: Int = Int(201);
+const B: Int = Int(270);
+const C: Int = Int(153);
+
+// The code is from https://github.com/rust-lang/rust/issues/119520.
+// This code will basically turn into `matches!(x.partial_cmp(&A), Some(Greater | Equal))`.
+// The otherwise branch must be `Less`.
+// CHECK-LABEL: @implicit_match(
+// CHECK-SAME: [[TMP0:%.*]])
+// CHECK-NEXT:  start:
+// CHECK-NEXT:    [[TMP1:%.*]] = add i32 [[TMP0]], -201
+// CHECK-NEXT:    icmp ult i32 [[TMP1]], 70
+// CHECK-NEXT:    icmp eq i32 [[TMP0]], 153
+// CHECK-NEXT:    [[SPEC_SELECT:%.*]] = or i1
+// CHECK-NEXT:    ret i1 [[SPEC_SELECT]]
+#[no_mangle]
+pub fn implicit_match(x: Int) -> bool {
+    (x >= A && x <= B) || x == C
+}
+
+// The code is from https://github.com/rust-lang/rust/issues/110097.
+// We expect it to generate the same optimized code as a full match.
+// CHECK-LABEL: @if_let(
+// CHECK: start:
+// CHECK-NOT: zext
+// CHECK: select
+// CHECK-NEXT: insertvalue
+// CHECK-NEXT: insertvalue
+// CHECK-NEXT: ret
+#[no_mangle]
+pub fn if_let(val: Result<i32, ()>) -> Result<i32, ()> {
+    if let Ok(x) = val { Ok(x * 2) } else { Err(()) }
+}