[WebAssembly] Add Emscripten OS definition + small_printf

The Emscripten OS provides a definition of __EMSCRIPTEN__, and also that it
supports iprintf optimizations.

Also define small_printf optimizations, which is a printf with float support
but not long double (which in wasm can be useful since long doubles are 128
bit and force linking of float128 emulation code). This part is based on
sunfish's https://reviews.llvm.org/D57620 (which can't land yet since
the WASI integration isn't ready yet).

Differential Revision: https://reviews.llvm.org/D60167

llvm-svn: 357552

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/lib/Basic/Targets.cpp b/clang/lib/Basic/Targets.cpp
index e6fcf934504..e9af3713dfb 100644
--- a/clang/lib/Basic/Targets.cpp
+++ b/clang/lib/Basic/Targets.cpp
@@ -576,6 +576,8 @@ TargetInfo *AllocateTarget(const llvm::Triple &Triple,
     switch (Triple.getOS()) {
       case llvm::Triple::WASI:
         return new WASITargetInfo<WebAssembly32TargetInfo>(Triple, Opts);
+      case llvm::Triple::Emscripten:
+        return new EmscriptenTargetInfo<WebAssembly32TargetInfo>(Triple, Opts);
       case llvm::Triple::UnknownOS:
         return new WebAssemblyOSTargetInfo<WebAssembly32TargetInfo>(Triple, Opts);
       default:
@@ -589,6 +591,8 @@ TargetInfo *AllocateTarget(const llvm::Triple &Triple,
     switch (Triple.getOS()) {
       case llvm::Triple::WASI:
         return new WASITargetInfo<WebAssembly64TargetInfo>(Triple, Opts);
+      case llvm::Triple::Emscripten:
+        return new EmscriptenTargetInfo<WebAssembly64TargetInfo>(Triple, Opts);
       case llvm::Triple::UnknownOS:
         return new WebAssemblyOSTargetInfo<WebAssembly64TargetInfo>(Triple, Opts);
       default: