[clang] [Sema] Fix -Wunreachable-code false negative when operands differ only by implicit casts (PR #149972)

[M. Zeeshan Siddiqui via cfe-commits]

================
@@ -1,16 +1,33 @@
-// RUN: %clang_cc1 -verify -Wunreachable-code %s
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -verify -Wunreachable-code %s
+// RUN: %clang_cc1 -triple aarch64-unknown-linux-gnu -target-feature +fullfp16 -verify -Wunreachable-code %s
+// REQUIRES: aarch64-registered-target
 
-// Previously this test will crash
-static void test(__fp16& x) {
-  if (x != 0 || x != 1.0) { // expected-note{{}} no-crash
-      x = 0.9;
-    } else
-      x = 0.8; // expected-warning{{code will never be executed}}
+// =======  __fp16 version  =======
+static void test_fp16(__fp16 &x) {
+  if (x != 0 || x != 1.0) {           // expected-note {{}} no-crash
+    x = 0.9;
+  } else
+    x = 0.8;                          // expected-warning{{code will never be executed}}
 }
 
-static void test2(__fp16& x) {
-  if (x != 1 && x == 1.0) { // expected-note{{}} no-crash
-      x = 0.9; // expected-warning{{code will never be executed}}
-    } else
-      x = 0.8;
+static void test_fp16_b(__fp16 &x) {
+  if (x != 1 && x == 1.0) {           // expected-note {{}} no-crash
+    x = 0.9;                          // expected-warning{{code will never be executed}}
+  } else
+    x = 0.8;
 }
+
+// =======  _Float16 version  =======
+static void test_f16(_Float16 &x) {
+  if (x != 0 || x != 1.0) {           // expected-note {{}} no-crash
+    x = 0.9;
+  } else
+    x = 0.8;                          // expected-warning{{code will never be executed}}
+}
+
+static void test_f16_b(_Float16 &x) {
+  if (x != 1 && x == 1.0) {           // expected-note {{}} no-crash
+    x = 0.9;                          // expected-warning{{code will never be executed}}
+  } else
+    x = 0.8;
+}
----------------
codemzs wrote:

Done

https://github.com/llvm/llvm-project/pull/149972