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[WebAssembly] Fix catch block type in wasm64 #124381

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Merged
merged 2 commits into from
Jan 27, 2025
Merged

[WebAssembly] Fix catch block type in wasm64 #124381

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b8d02f7
[WebAssembly] Fix catch block type in wasm64
aheejin Jan 25, 2025
4cb862b
clang-format
aheejin Jan 25, 2025
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11 changes: 9 additions & 2 deletions llvm/lib/Target/WebAssembly/WebAssemblyCFGStackify.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -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.
Expand Down
19 changes: 13 additions & 6 deletions llvm/lib/Target/WebAssembly/WebAssemblyMCInstLower.cpp
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Expand Up @@ -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);

Expand Down Expand Up @@ -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>());
Expand Down
5 changes: 5 additions & 0 deletions llvm/test/CodeGen/WebAssembly/exception.ll
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Expand Up @@ -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"

Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down
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