[llvm] 539b2e0 - [WebAssembly] Fix catch block type in wasm64 (#124381)

[via llvm-commits]

Author: Heejin Ahn
Date: 2025-01-27T11:01:48-08:00
New Revision: 539b2e06542f7c099885533e4472e6fb3084aa96

URL: https://github.com/llvm/llvm-project/commit/539b2e06542f7c099885533e4472e6fb3084aa96
DIFF: https://github.com/llvm/llvm-project/commit/539b2e06542f7c099885533e4472e6fb3084aa96.diff

LOG: [WebAssembly] Fix catch block type in wasm64 (#124381)

`try_table`'s `catch` or `catch_ref`'s target block's return type should
be `i64` and `(i64, exnref)` in case of wasm64.

Added: 
    

Modified: 
    llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
    llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
    llvm/test/CodeGen/WebAssembly/exception.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
index bdc1cc6d652ac6..277d353d1db100 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
@@ -852,12 +852,19 @@ void WebAssemblyCFGStackify::placeTryTableMarker(MachineBasicBlock &MBB) {
   // Add a CATCH_*** clause to the TRY_TABLE. These are pseudo instructions
   // following the destination END_BLOCK to simulate block return values,
   // because we currently don't support them.
+  const auto &TLI =
+      *MF.getSubtarget<WebAssemblySubtarget>().getTargetLowering();
+  WebAssembly::BlockType PtrTy =
+      TLI.getPointerTy(MF.getDataLayout()) == MVT::i32
+          ? WebAssembly::BlockType::I32
+          : WebAssembly::BlockType::I64;
   auto *Catch = WebAssembly::findCatch(&MBB);
   switch (Catch->getOpcode()) {
   case WebAssembly::CATCH:
     // CATCH's destination block's return type is the extracted value type,
-    // which is currently i32 for all supported tags.
-    BlockMIB.addImm(int64_t(WebAssembly::BlockType::I32));
+    // which is currently the thrown value's pointer type for all supported
+    // tags.
+    BlockMIB.addImm(int64_t(PtrTy));
     TryTableMIB.addImm(wasm::WASM_OPCODE_CATCH);
     for (const auto &Use : Catch->uses()) {
       // The only use operand a CATCH can have is the tag symbol.

diff  --git a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
index f09b29472cb6b2..eed0b42863ee62 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
@@ -169,6 +169,13 @@ void WebAssemblyMCInstLower::lower(const MachineInstr *MI,
 
   const MCInstrDesc &Desc = MI->getDesc();
   unsigned NumVariadicDefs = MI->getNumExplicitDefs() - Desc.getNumDefs();
+  const MachineFunction *MF = MI->getMF();
+  const auto &TLI =
+      *MF->getSubtarget<WebAssemblySubtarget>().getTargetLowering();
+  wasm::ValType PtrTy = TLI.getPointerTy(MF->getDataLayout()) == MVT::i32
+                            ? wasm::ValType::I32
+                            : wasm::ValType::I64;
+
   for (unsigned I = 0, E = MI->getNumOperands(); I != E; ++I) {
     const MachineOperand &MO = MI->getOperand(I);
 
@@ -234,12 +241,12 @@ void WebAssemblyMCInstLower::lower(const MachineInstr *MI,
             //    return type of the parent function.
             // 2. (catch_ref ...) clause in try_table instruction. Currently all
             //    tags we support (cpp_exception and c_longjmp) throws a single
-            //    i32, so the multivalue signature for this case will be (i32,
-            //    exnref). Having MO_CATCH_BLOCK_SIG target flags means this is
-            //    a destination of a catch_ref.
-            if (MO.getTargetFlags() == WebAssemblyII::MO_CATCH_BLOCK_SIG)
-              Returns = {wasm::ValType::I32, wasm::ValType::EXNREF};
-            else
+            //    pointer, so the multivalue signature for this case will be
+            //    (ptr, exnref). Having MO_CATCH_BLOCK_SIG target flags means
+            //    this is a destination of a catch_ref.
+            if (MO.getTargetFlags() == WebAssemblyII::MO_CATCH_BLOCK_SIG) {
+              Returns = {PtrTy, wasm::ValType::EXNREF};
+            } else
               getFunctionReturns(MI, Returns);
             MCOp = lowerTypeIndexOperand(std::move(Returns),
                                          SmallVector<wasm::ValType, 4>());

diff  --git a/llvm/test/CodeGen/WebAssembly/exception.ll b/llvm/test/CodeGen/WebAssembly/exception.ll
index 304664b622e800..febab822a6a9e3 100644
--- a/llvm/test/CodeGen/WebAssembly/exception.ll
+++ b/llvm/test/CodeGen/WebAssembly/exception.ll
@@ -2,6 +2,7 @@
 ; RUN: llc < %s -asm-verbose=false -wasm-enable-eh -wasm-use-legacy-eh=false -exception-model=wasm -mattr=+exception-handling -verify-machineinstrs -O0
 ; RUN: llc < %s -wasm-enable-eh -wasm-use-legacy-eh=false -exception-model=wasm -mattr=+exception-handling
 ; RUN: llc < %s -wasm-enable-eh -wasm-use-legacy-eh=false -exception-model=wasm -mattr=+exception-handling -filetype=obj
+; RUN: llc < %s -mtriple=wasm64-unknown-unknown -wasm-enable-eh -wasm-use-legacy-eh=false -exception-model=wasm -mattr=+exception-handling -verify-machineinstrs | FileCheck --implicit-check-not=ehgcr -allow-deprecated-dag-overlap %s --check-prefix=WASM64
 
 target triple = "wasm32-unknown-unknown"
 
@@ -30,11 +31,13 @@ define void @throw(ptr %p) {
 ; }
 
 ; CHECK-LABEL: catch:
+; WASM64-LABEL: catch:
 ; CHECK: global.get  __stack_pointer
 ; CHECK: local.set  0
 ; CHECK: block
 ; CHECK:   block     () -> (i32, exnref)
 ; CHECK:     try_table    (catch_ref __cpp_exception 0)
+; WASM64:  block     () -> (i64, exnref)
 ; CHECK:       call  foo
 ; CHECK:       br        2
 ; CHECK:     end_try_table
@@ -138,8 +141,10 @@ ehcleanup:                                        ; preds = %entry
 ; }
 
 ; CHECK-LABEL: terminatepad
+; WASM64-LABEL: terminatepad
 ; CHECK: block
 ; CHECK:   block     i32
+; WASM64:  block     i64
 ; CHECK:     try_table    (catch __cpp_exception 0)
 ; CHECK:       call  foo
 ; CHECK:       br        2