[clang] [CLANG] Fixes the issue with using bool in builtin_bswapg (PR #169285)

[Ebin Jose via cfe-commits]

https://github.com/ebinjose02 updated https://github.com/llvm/llvm-project/pull/169285

>From 4baf6aac54499c5fdbeab33a4dc956487b4b5c02 Mon Sep 17 00:00:00 2001
From: ebinjose02 <ebin371 at gmail.com>
Date: Mon, 24 Nov 2025 07:02:26 +0000
Subject: [PATCH 1/2] Fixes #168690 Prevents assertion in CGBuiltin for i1 -
 returns identity. Created test file for the same.

---
 clang/lib/CodeGen/CGBuiltin.cpp     | 2 ++
 clang/test/CodeGen/builtin_bswapg.c | 8 ++++++++
 2 files changed, 10 insertions(+)
 create mode 100644 clang/test/CodeGen/builtin_bswapg.c

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 93f691e4c2267..8bcc2c8e7d8fe 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -3653,6 +3653,8 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
     Value *ArgValue = EmitScalarExpr(E->getArg(0));
     llvm::IntegerType *IntTy = cast<llvm::IntegerType>(ArgValue->getType());
     assert(IntTy && "LLVM's __builtin_bswapg only supports integer variants");
+    if (IntTy->getBitWidth() == 1)
+      return RValue::get(ArgValue);
     assert(((IntTy->getBitWidth() % 16 == 0 && IntTy->getBitWidth() != 0) ||
             IntTy->getBitWidth() == 8) &&
            "LLVM's __builtin_bswapg only supports integer variants that has a "
diff --git a/clang/test/CodeGen/builtin_bswapg.c b/clang/test/CodeGen/builtin_bswapg.c
new file mode 100644
index 0000000000000..35f4728d15d3a
--- /dev/null
+++ b/clang/test/CodeGen/builtin_bswapg.c
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -triple x86_64 -O0 -emit-llvm -o - %s | FileCheck %s
+#include <stdbool.h>
+bool test_bswapg(bool c) {
+  return __builtin_bswapg(c);
+}
+
+// CHECK-LABEL: define{{.*}} i1 @_Z11test_bswapgb(
+// CHECK: ret i1 %{{.*}}

>From 2da2524e161a8d84dc1a3cdd9de6350b33830502 Mon Sep 17 00:00:00 2001
From: ebinjose02 <ebin371 at gmail.com>
Date: Tue, 2 Dec 2025 06:28:01 +0000
Subject: [PATCH 2/2] Modified CGBuiltins Added test to an already existin test
 file

---
 clang/lib/CodeGen/CGBuiltin.cpp     |  7 ++-----
 clang/test/CodeGen/builtin_bswapg.c |  8 --------
 clang/test/CodeGen/builtins.c       | 12 +++++++++---
 3 files changed, 11 insertions(+), 16 deletions(-)
 delete mode 100644 clang/test/CodeGen/builtin_bswapg.c

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 8bcc2c8e7d8fe..d640bd79553ad 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -3653,14 +3653,11 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
     Value *ArgValue = EmitScalarExpr(E->getArg(0));
     llvm::IntegerType *IntTy = cast<llvm::IntegerType>(ArgValue->getType());
     assert(IntTy && "LLVM's __builtin_bswapg only supports integer variants");
-    if (IntTy->getBitWidth() == 1)
+    if (IntTy->getBitWidth() == 1 || IntTy->getBitWidth() == 8)
       return RValue::get(ArgValue);
-    assert(((IntTy->getBitWidth() % 16 == 0 && IntTy->getBitWidth() != 0) ||
-            IntTy->getBitWidth() == 8) &&
+    assert(((IntTy->getBitWidth() % 16 == 0 && IntTy->getBitWidth() != 0)) &&
            "LLVM's __builtin_bswapg only supports integer variants that has a "
            "multiple of 16 bits as well as a single byte");
-    if (IntTy->getBitWidth() == 8)
-      return RValue::get(ArgValue);
     return RValue::get(
         emitBuiltinWithOneOverloadedType<1>(*this, E, Intrinsic::bswap));
   }
diff --git a/clang/test/CodeGen/builtin_bswapg.c b/clang/test/CodeGen/builtin_bswapg.c
deleted file mode 100644
index 35f4728d15d3a..0000000000000
--- a/clang/test/CodeGen/builtin_bswapg.c
+++ /dev/null
@@ -1,8 +0,0 @@
-// RUN: %clang_cc1 -triple x86_64 -O0 -emit-llvm -o - %s | FileCheck %s
-#include <stdbool.h>
-bool test_bswapg(bool c) {
-  return __builtin_bswapg(c);
-}
-
-// CHECK-LABEL: define{{.*}} i1 @_Z11test_bswapgb(
-// CHECK: ret i1 %{{.*}}
diff --git a/clang/test/CodeGen/builtins.c b/clang/test/CodeGen/builtins.c
index a97e8932acf61..3545588aec654 100644
--- a/clang/test/CodeGen/builtins.c
+++ b/clang/test/CodeGen/builtins.c
@@ -916,9 +916,10 @@ void test_builtin_ctzg(unsigned char uc, unsigned short us, unsigned int ui,
 
 #endif
 
+#include <stdbool.h>
 // CHECK-LABEL: define{{.*}} void @test_builtin_bswapg
 void test_builtin_bswapg(unsigned char uc, unsigned short us, unsigned int ui,
-                       unsigned long ul, unsigned long long ull,
+                       unsigned long ul, unsigned long long ull, bool b,
 #ifdef __SIZEOF_INT128__
                        unsigned __int128 ui128,
 #endif
@@ -929,9 +930,14 @@ void test_builtin_bswapg(unsigned char uc, unsigned short us, unsigned int ui,
   int x = 0;
   x = x * 2;
 #endif
+  b = __builtin_bswapg(b);
+  // CHECK: %{{.*}} = load i8, ptr %b.addr
+  // CHECK: %{{.*}} = trunc i8 %{{.*}} to i1
+  // CHECK: %{{.*}} = zext i1 %{{.*}} to i8
+  // CHECK: store i8 %{{.*}}, ptr %b.addr
   uc = __builtin_bswapg(uc);
-  // CHECK: %1 = load i8, ptr %uc.addr
-  // CHECK: store i8 %1, ptr %uc.addr
+  // CHECK: %{{.*}} = load i8, ptr %uc.addr
+  // CHECK: store i8 %{{.*}}, ptr %uc.addr
   us = __builtin_bswapg(us);
   // CHECK: call i16 @llvm.bswap.i16
   ui = __builtin_bswapg(ui);