[clang] [llvm] [LoongArch] [CodeGen] Add options for Clang to generate LoongArch-specific frecipe & frsqrte instructions (PR #109917)

[Lu Weining via cfe-commits]

================
@@ -0,0 +1,30 @@
+/// Test -m[no]frecipe options.
+
+// RUN: %clang --target=loongarch64 -mfrecipe -fsyntax-only %s -### 2>&1 | \
+// RUN:     FileCheck %s --check-prefix=CC1-FRECIPE
+// RUN: %clang --target=loongarch64 -mno-frecipe -fsyntax-only %s -### 2>&1 | \
+// RUN:     FileCheck %s --check-prefix=CC1-NO-FRECIPE
+// RUN: %clang --target=loongarch64 -mno-frecipe -mfrecipe -fsyntax-only %s -### 2>&1 | \
+// RUN:     FileCheck %s --check-prefix=CC1-FRECIPE
+// RUN: %clang --target=loongarch64  -mfrecipe -mno-frecipe -fsyntax-only %s -### 2>&1 | \
+// RUN:     FileCheck %s --check-prefix=CC1-NO-FRECIPE
+
+// RUN: %clang --target=loongarch64 -mfrecipe -S -emit-llvm %s -o - | \
+// RUN: FileCheck %s --check-prefix=IR-FRECIPE
+// RUN: %clang --target=loongarch64 -mno-frecipe -S -emit-llvm %s -o - | \
+// RUN: FileCheck %s --check-prefix=IR-NO-FRECIPE
+// RUN: %clang --target=loongarch64 -mno-frecipe -mfrecipe -S -emit-llvm %s -o - | \
+// RUN: FileCheck %s --check-prefix=IR-FRECIPE
+// RUN: %clang --target=loongarch64 -mfrecipe -mno-frecipe -S -emit-llvm %s -o - | \
+// RUN: FileCheck %s --check-prefix=IR-NO-FRECIPE
+
+
+// CC1-FRECIPE: "-target-feature" "+frecipe"
+// CC1-NO-FRECIPE: "-target-feature" "-frecipe"
+
+// IR-FRECIPE: attributes #[[#]] ={{.*}}"target-features"="{{(.*,)?}}+frecipe{{(,.*)?}}"
+// IR-NO-FRECIPE: attributes #[[#]] ={{.*}}"target-features"="{{(.*,)?}}-frecipe{{(,.*)?}}"
+
+int foo(void) {
+    return  42;
----------------
SixWeining wrote:

```suggestion
  return 42;
```

https://github.com/llvm/llvm-project/pull/109917