[InstCombine] Add additional tests for unreachable code (NFC)

diff --git a/llvm/test/Transforms/InstCombine/unreachable-code.ll b/llvm/test/Transforms/InstCombine/unreachable-code.ll
new file mode 100644 (file)
index 0000000..391d73f
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/unreachable-code.ll
@@ -0,0 +1,150 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+; RUN: opt -S -passes=instcombine < %s | FileCheck %s
+
+declare void @dummy()
+
+define void @br_true(i1 %x) {
+; CHECK-LABEL: define void @br_true
+; CHECK-SAME: (i1 [[X:%.*]]) {
+; CHECK-NEXT:    br i1 true, label [[IF:%.*]], label [[ELSE:%.*]]
+; CHECK:       if:
+; CHECK-NEXT:    call void @dummy()
+; CHECK-NEXT:    ret void
+; CHECK:       else:
+; CHECK-NEXT:    ret void
+;
+  %c = or i1 %x, true
+  br i1 %c, label %if, label %else
+
+if:
+  call void @dummy()
+  ret void
+
+else:
+  call void @dummy()
+  ret void
+}
+
+define void @br_false(i1 %x) {
+; CHECK-LABEL: define void @br_false
+; CHECK-SAME: (i1 [[X:%.*]]) {
+; CHECK-NEXT:    br i1 false, label [[IF:%.*]], label [[ELSE:%.*]]
+; CHECK:       if:
+; CHECK-NEXT:    ret void
+; CHECK:       else:
+; CHECK-NEXT:    call void @dummy()
+; CHECK-NEXT:    ret void
+;
+  %c = and i1 %x, false
+  br i1 %c, label %if, label %else
+
+if:
+  call void @dummy()
+  ret void
+
+else:
+  call void @dummy()
+  ret void
+}
+
+define void @br_undef(i1 %x) {
+; CHECK-LABEL: define void @br_undef
+; CHECK-SAME: (i1 [[X:%.*]]) {
+; CHECK-NEXT:    br i1 undef, label [[IF:%.*]], label [[ELSE:%.*]]
+; CHECK:       if:
+; CHECK-NEXT:    call void @dummy()
+; CHECK-NEXT:    ret void
+; CHECK:       else:
+; CHECK-NEXT:    call void @dummy()
+; CHECK-NEXT:    ret void
+;
+  %c = xor i1 %x, undef
+  br i1 %c, label %if, label %else
+
+if:
+  call void @dummy()
+  ret void
+
+else:
+  call void @dummy()
+  ret void
+}
+
+define void @switch_case(i32 %x) {
+; CHECK-LABEL: define void @switch_case
+; CHECK-SAME: (i32 [[X:%.*]]) {
+; CHECK-NEXT:    switch i32 0, label [[DEFAULT:%.*]] [
+; CHECK-NEXT:    i32 0, label [[CASE0:%.*]]
+; CHECK-NEXT:    ]
+; CHECK:       case0:
+; CHECK-NEXT:    call void @dummy()
+; CHECK-NEXT:    ret void
+; CHECK:       default:
+; CHECK-NEXT:    ret void
+;
+  %v = and i32 %x, 0
+  switch i32 %v, label %default [
+  i32 0, label %case0
+  ]
+
+case0:
+  call void @dummy()
+  ret void
+
+default:
+  call void @dummy()
+  ret void
+}
+
+define void @switch_default(i32 %x) {
+; CHECK-LABEL: define void @switch_default
+; CHECK-SAME: (i32 [[X:%.*]]) {
+; CHECK-NEXT:    switch i32 -1, label [[DEFAULT:%.*]] [
+; CHECK-NEXT:    i32 0, label [[CASE0:%.*]]
+; CHECK-NEXT:    ]
+; CHECK:       case0:
+; CHECK-NEXT:    ret void
+; CHECK:       default:
+; CHECK-NEXT:    call void @dummy()
+; CHECK-NEXT:    ret void
+;
+  %v = or i32 %x, -1
+  switch i32 %v, label %default [
+  i32 0, label %case0
+  ]
+
+case0:
+  call void @dummy()
+  ret void
+
+default:
+  call void @dummy()
+  ret void
+}
+
+define void @switch_undef(i32 %x) {
+; CHECK-LABEL: define void @switch_undef
+; CHECK-SAME: (i32 [[X:%.*]]) {
+; CHECK-NEXT:    switch i32 undef, label [[DEFAULT:%.*]] [
+; CHECK-NEXT:    i32 0, label [[CASE0:%.*]]
+; CHECK-NEXT:    ]
+; CHECK:       case0:
+; CHECK-NEXT:    call void @dummy()
+; CHECK-NEXT:    ret void
+; CHECK:       default:
+; CHECK-NEXT:    call void @dummy()
+; CHECK-NEXT:    ret void
+;
+  %v = xor i32 %x, undef
+  switch i32 %v, label %default [
+  i32 0, label %case0
+  ]
+
+case0:
+  call void @dummy()
+  ret void
+
+default:
+  call void @dummy()
+  ret void
+}