[clang] [clang][LoongArch] Ensure `target("lasx")` implies LSX support (PR #153542)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: None (Ami-zhang)

<details>
<summary>Changes</summary>

Currently, `__attribute__((target("lasx")))` does not automatically
enable LSX support, causing Clang to fail with `-mno-lsx`. Since
LASX depends on LSX, enabling LASX should implicitly enable LSX to
avoid clang error.
    
Fixes #<!-- -->149512.

---
Full diff: https://github.com/llvm/llvm-project/pull/153542.diff


2 Files Affected:

- (modified) clang/lib/Basic/Targets/LoongArch.cpp (+6-1) 
- (added) clang/test/CodeGen/LoongArch/targetattr-lasx.c (+16) 


``````````diff
diff --git a/clang/lib/Basic/Targets/LoongArch.cpp b/clang/lib/Basic/Targets/LoongArch.cpp
index f6915df1520b7..33001b23f48c6 100644
--- a/clang/lib/Basic/Targets/LoongArch.cpp
+++ b/clang/lib/Basic/Targets/LoongArch.cpp
@@ -460,7 +460,12 @@ LoongArchTargetInfo::parseTargetAttr(StringRef Features) const {
       break;
 
     case AttrFeatureKind::Feature:
-      Ret.Features.push_back("+" + Value.str());
+      if (Value == "lasx") {
+        Ret.Features.push_back("+lasx");
+        Ret.Features.push_back("+lsx");
+      } else {
+        Ret.Features.push_back("+" + Value.str());
+      }
       break;
     }
   }
diff --git a/clang/test/CodeGen/LoongArch/targetattr-lasx.c b/clang/test/CodeGen/LoongArch/targetattr-lasx.c
new file mode 100644
index 0000000000000..28b06605289a8
--- /dev/null
+++ b/clang/test/CodeGen/LoongArch/targetattr-lasx.c
@@ -0,0 +1,16 @@
+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py UTC_ARGS: --check-globals all --version 5
+// RUN: %clang_cc1 -triple loongarch64 -target-feature -lsx -emit-llvm %s -o - | FileCheck %s
+
+__attribute__((target("lasx")))
+// CHECK-LABEL: define dso_local void @testlasx(
+// CHECK-SAME: ) #[[ATTR0:[0-9]+]] {
+// CHECK-NEXT:  [[ENTRY:.*:]]
+// CHECK-NEXT:    ret void
+//
+void testlasx() {}
+//.
+// CHECK: attributes #[[ATTR0]] = { noinline nounwind optnone "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-features"="+64bit,+lasx,+lsx" }
+//.
+// CHECK: [[META0:![0-9]+]] = !{i32 1, !"wchar_size", i32 4}
+// CHECK: [[META1:![0-9]+]] = !{!"{{.*}}clang version {{.*}}"}
+//.

``````````

</details>


https://github.com/llvm/llvm-project/pull/153542