[WebAssembly] Enable extended-const feature by default

Author: sbc100

clang/docs/ReleaseNotes.rst

@@ -235,6 +235,13 @@ NetBSD Support
 WebAssembly Support
 ^^^^^^^^^^^^^^^^^^^
 
+The default target CPU, "generic", now enables the `-mextended-const`
+flag, which correspond to the [Extended Const] proposal, which is
+[widely implemented in engines].
+
+[Extended Const]: https://github.com/WebAssembly/extended-const
+[widely implemented in engines]: https://webassembly.org/features/
+
 AVR Support
 ^^^^^^^^^^^
 

clang/lib/Basic/Targets/WebAssembly.cpp

@@ -168,6 +168,7 @@ bool WebAssemblyTargetInfo::initFeatureMap(
     Features["bulk-memory"] = true;
     Features["bulk-memory-opt"] = true;
     Features["call-indirect-overlong"] = true;
+    Features["extended-const"] = true;
     Features["multivalue"] = true;
     Features["mutable-globals"] = true;
     Features["nontrapping-fptoint"] = true;

clang/test/Preprocessor/wasm-target-features.c

@@ -164,6 +164,7 @@
 // RUN:   | FileCheck %s -check-prefix=GENERIC-INCLUDE
 //
 // GENERIC-INCLUDE-DAG: #define __wasm_bulk_memory__ 1{{$}}
+// GENERIC-INCLUDE-DAG: #define __wasm_extended_const__ 1{{$}}
 // GENERIC-INCLUDE-DAG: #define __wasm_multivalue__ 1{{$}}
 // GENERIC-INCLUDE-DAG: #define __wasm_mutable_globals__ 1{{$}}
 // GENERIC-INCLUDE-DAG: #define __wasm_nontrapping_fptoint__ 1{{$}}
@@ -179,7 +180,6 @@
 //
 // GENERIC-NOT: #define __wasm_atomics__ 1{{$}}
 // GENERIC-NOT: #define __wasm_exception_handling__ 1{{$}}
-// GENERIC-NOT: #define __wasm_extended_const__ 1{{$}}
 // GENERIC-NOT: #define __wasm__fp16__ 1{{$}}
 // GENERIC-NOT: #define __wasm_multimemory__ 1{{$}}
 // GENERIC-NOT: #define __wasm_relaxed_simd__ 1{{$}}

llvm/docs/ReleaseNotes.md

@@ -110,6 +110,13 @@ Changes to the RISC-V Backend
 Changes to the WebAssembly Backend
 ----------------------------------
 
+The default target CPU, "generic", now enables the `-mextended-const`
+flag, which correspond to the [Extended Const] proposal, which is
+[widely implemented in engines].
+
+[Extended Const]: https://github.com/WebAssembly/extended-const
+[widely implemented in engines]: https://webassembly.org/features/
+
 Changes to the Windows Target
 -----------------------------
 

llvm/lib/Target/WebAssembly/WebAssembly.td

@@ -123,9 +123,10 @@ def : ProcessorModel<"mvp", NoSchedModel, []>;
 // the importance of the features.
 def : ProcessorModel<"generic", NoSchedModel,
                       [FeatureBulkMemory, FeatureBulkMemoryOpt,
-                       FeatureCallIndirectOverlong, FeatureMultivalue,
-                       FeatureMutableGlobals, FeatureNontrappingFPToInt,
-                       FeatureReferenceTypes, FeatureSignExt]>;
+                       FeatureCallIndirectOverlong, FeatureExtendedConst,
+                       FeatureMultivalue, FeatureMutableGlobals,
+                       FeatureNontrappingFPToInt, FeatureReferenceTypes,
+                       FeatureSignExt]>;
 
 // Lime1: <https://github.com/WebAssembly/tool-conventions/blob/main/Lime.md#lime1>
 def : ProcessorModel<"lime1", NoSchedModel,

llvm/test/CodeGen/WebAssembly/target-features-cpus.ll

@@ -14,7 +14,7 @@ target triple = "wasm32-unknown-unknown"
 
 ; generic: +call-indirect-overlong, +multivalue, +mutable-globals, +reference-types, +sign-ext
 ; GENERIC-LABEL: .custom_section.target_features,"",@
-; GENERIC-NEXT: .int8  8
+; GENERIC-NEXT: .int8  9
 ; GENERIC-NEXT: .int8  43
 ; GENERIC-NEXT: .int8  11
 ; GENERIC-NEXT: .ascii  "bulk-memory"
@@ -25,6 +25,9 @@ target triple = "wasm32-unknown-unknown"
 ; GENERIC-NEXT: .int8  22
 ; GENERIC-NEXT: .ascii  "call-indirect-overlong"
 ; GENERIC-NEXT: .int8  43
+; GENERIC-NEXT: .int8  14
+; GENERIC-NEXT: .ascii  "extended-const"
+; GENERIC-NEXT: .int8  43
 ; GENERIC-NEXT: .int8  10
 ; GENERIC-NEXT: .ascii  "multivalue"
 ; GENERIC-NEXT: .int8  43