[llvm] 2368f18 - [WebAssembly] Fixed AsmPrinter not emitting .functype for intrinsics

[Wouter van Oortmerssen via llvm-commits]

Author: Wouter van Oortmerssen
Date: 2022-02-22T16:14:26-08:00
New Revision: 2368f18eb305ae9d5a4f2110c048e5daf5007992

URL: https://github.com/llvm/llvm-project/commit/2368f18eb305ae9d5a4f2110c048e5daf5007992
DIFF: https://github.com/llvm/llvm-project/commit/2368f18eb305ae9d5a4f2110c048e5daf5007992.diff

LOG: [WebAssembly] Fixed AsmPrinter not emitting .functype for intrinsics

Intrinsics like `memset` were not emitted as `.functype` because
WebAssemblyAsmPrinter::emitExternalDecls explicitly skips symbols
that are isIntrinsic. Removing that check doesn't work, since the symbol
from the module refers to a 4-argument `llvm.memset.p0i8.i32` rather
than the 3-argument `memset` symbol referenced in the call.
Our `WebAssemblyMCLowerPrePass` however does collect the
`memset` symbol, so the current solution is as simple as emitting
`.functype` for those.

Fixes: https://github.com/llvm/llvm-project/issues/53712

Differential Revision: https://reviews.llvm.org/D120365

Added: 
    llvm/test/MC/WebAssembly/extern-functype-intrinsic.ll

Modified: 
    llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
index 4dc2c4c9e29e2..a518938dd908c 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyAsmPrinter.cpp
@@ -302,7 +302,12 @@ void WebAssemblyAsmPrinter::emitExternalDecls(const Module &M) {
   // not be found here.
   MachineModuleInfoWasm &MMIW = MMI->getObjFileInfo<MachineModuleInfoWasm>();
   for (const auto &Name : MMIW.MachineSymbolsUsed) {
-    getOrCreateWasmSymbol(Name.getKey());
+    auto *WasmSym = cast<MCSymbolWasm>(getOrCreateWasmSymbol(Name.getKey()));
+    if (WasmSym->isFunction()) {
+      // TODO(wvo): is there any case where this overlaps with the call to
+      // emitFunctionType in the loop below?
+      getTargetStreamer()->emitFunctionType(WasmSym);
+    }
   }
 
   for (auto &It : OutContext.getSymbols()) {

diff  --git a/llvm/test/MC/WebAssembly/extern-functype-intrinsic.ll b/llvm/test/MC/WebAssembly/extern-functype-intrinsic.ll
new file mode 100644
index 0000000000000..f2677262e3b96
--- /dev/null
+++ b/llvm/test/MC/WebAssembly/extern-functype-intrinsic.ll
@@ -0,0 +1,30 @@
+; RUN: llc %s -o - | FileCheck %s
+; RUN: llc %s -o - | llvm-mc -triple=wasm32-unknown-unknown | FileCheck %s
+
+; ModuleID = 'test.c'
+source_filename = "test.c"
+target datalayout = "e-m:e-p:32:32-p10:8:8-p20:8:8-i64:64-n32:64-S128-ni:1:10:20"
+target triple = "wasm32-unknown-wasi"
+
+; Function Attrs: nounwind
+define hidden i32 @d() local_unnamed_addr #0 {
+entry:
+  %0 = call i32 bitcast (i32 (...)* @g to i32 ()*)() #3
+  call void @llvm.memset.p0i8.i32(i8* nonnull align 4 inttoptr (i32 4 to i8*), i8 0, i32 %0, i1 false)                                        ; preds = %for.body.preheader, %entry
+  ret i32 undef
+}
+
+declare i32 @g(...) local_unnamed_addr #1
+
+; Function Attrs: argmemonly nofree nounwind willreturn writeonly
+declare void @llvm.memset.p0i8.i32(i8* nocapture writeonly, i8, i32, i1 immarg) #2
+
+attributes #0 = { nounwind "frame-pointer"="none" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" }
+attributes #1 = { "frame-pointer"="none" "no-prototype" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="generic" }
+attributes #2 = { argmemonly nofree nounwind willreturn writeonly }
+attributes #3 = { nounwind }
+
+; CHECK:         .functype       memset (i32, i32, i32) -> (i32)
+; CHECK:         .functype       g () -> (i32)
+; CHECK:         call    g
+; CHECK:         call    memset