[WebAssembly] Add preprocessor define for half-precision

[aheejin]

This adds the preprocessor define for the half-precision feature and also adds preprocessor tests.

[llvmbot]

@llvm/pr-subscribers-backend-webassembly

@llvm/pr-subscribers-clang

Author: Heejin Ahn (aheejin)

Changes

This adds the preprocessor define for the half-precision feature and also adds preprocessor tests.

---

Full diff: https://github.com/llvm/llvm-project/pull/90528.diff

2 Files Affected:

• (modified) clang/lib/Basic/Targets/WebAssembly.cpp (+2)
• (modified) clang/test/Preprocessor/wasm-target-features.c (+12)

diff --git a/clang/lib/Basic/Targets/WebAssembly.cpp b/clang/lib/Basic/Targets/WebAssembly.cpp
index 0db7b668d8a0ac..1f0418b21c1f86 100644
--- a/clang/lib/Basic/Targets/WebAssembly.cpp
+++ b/clang/lib/Basic/Targets/WebAssembly.cpp
@@ -100,6 +100,8 @@ void WebAssemblyTargetInfo::getTargetDefines(const LangOptions &Opts,
     Builder.defineMacro("__wasm_extended_const__");
   if (HasMultiMemory)
     Builder.defineMacro("__wasm_multimemory__");
+  if (HasHalfPrecision)
+    Builder.defineMacro("__wasm_half_precision__");
 
   Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_1");
   Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2");
diff --git a/clang/test/Preprocessor/wasm-target-features.c b/clang/test/Preprocessor/wasm-target-features.c
index 19bd918543dfea..72ecc60a6e7898 100644
--- a/clang/test/Preprocessor/wasm-target-features.c
+++ b/clang/test/Preprocessor/wasm-target-features.c
@@ -43,6 +43,15 @@
 //
 // EXTENDED-CONST: #define __wasm_extended_const__ 1{{$}}
 
+// RUN: %clang -E -dM %s -o - 2>&1 \
+// RUN:     -target wasm32-unknown-unknown -mhalf-precision \
+// RUN:   | FileCheck %s -check-prefix=HALF-PRECISION
+// RUN: %clang -E -dM %s -o - 2>&1 \
+// RUN:     -target wasm64-unknown-unknown -mhalf-precision \
+// RUN:   | FileCheck %s -check-prefix=HALF-PRECISION
+//
+// HALF-PRECISION: #define __wasm_half_precision__ 1{{$}}
+
 // RUN: %clang -E -dM %s -o - 2>&1 \
 // RUN:     -target wasm32-unknown-unknown -mmultimemory \
 // RUN:   | FileCheck %s -check-prefix=MULTIMEMORY
@@ -135,6 +144,7 @@
 // MVP-NOT: #define __wasm_bulk_memory__ 1{{$}}
 // MVP-NOT: #define __wasm_exception_handling__ 1{{$}}
 // MVP-NOT: #define __wasm_extended_const__ 1{{$}}
+// MVP-NOT: #define __wasm_half_precision__ 1{{$}}
 // MVP-NOT: #define __wasm_multimemory__ 1{{$}}
 // MVP-NOT: #define __wasm_multivalue__ 1{{$}}
 // MVP-NOT: #define __wasm_mutable_globals__ 1{{$}}
@@ -168,6 +178,7 @@
 // GENERIC-NOT: #define __wasm_bulk_memory__ 1{{$}}
 // GENERIC-NOT: #define __wasm_exception_handling__ 1{{$}}
 // GENERIC-NOT: #define __wasm_extended_const__ 1{{$}}
+// GENERIC-NOT: #define __wasm_half_precision__ 1{{$}}
 // GENERIC-NOT: #define __wasm_multimemory__ 1{{$}}
 // GENERIC-NOT: #define __wasm_nontrapping_fptoint__ 1{{$}}
 // GENERIC-NOT: #define __wasm_relaxed_simd__ 1{{$}}
@@ -183,6 +194,7 @@
 //
 // BLEEDING-EDGE-INCLUDE-DAG: #define __wasm_atomics__ 1{{$}}
 // BLEEDING-EDGE-INCLUDE-DAG: #define __wasm_bulk_memory__ 1{{$}}
+// BLEEDING-EDGE-INCLUDE-DAG: #define __wasm_half_precision__ 1{{$}}
 // BLEEDING-EDGE-INCLUDE-DAG: #define __wasm_multimemory__ 1{{$}}
 // BLEEDING-EDGE-INCLUDE-DAG: #define __wasm_multivalue__ 1{{$}}
 // BLEEDING-EDGE-INCLUDE-DAG: #define __wasm_mutable_globals__ 1{{$}}

[aheejin]

cc @brendandahl (I couldn't add you as a reviewer because you didn't pop up in the reviewers list)

Also, this just adds the preprocessor directive, but I'm wondering whether you really meant to add this to bleeding-edge: d9fd0dd#r141495634