[lld] [llvm] [WebAssembly] Use 64-bit table when targeting wasm64 (PR #92042)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-lld-wasm

Author: Sam Clegg (sbc100)

<details>
<summary>Changes</summary>

See https://github.com/WebAssembly/memory64/issues/51

---
Full diff: https://github.com/llvm/llvm-project/pull/92042.diff


3 Files Affected:

- (modified) lld/test/wasm/shared64.s (+1) 
- (modified) lld/wasm/Writer.cpp (+2) 
- (modified) llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp (-12) 


``````````diff
diff --git a/lld/test/wasm/shared64.s b/lld/test/wasm/shared64.s
index 3401faed8610c..2148d464f4158 100644
--- a/lld/test/wasm/shared64.s
+++ b/lld/test/wasm/shared64.s
@@ -154,6 +154,7 @@ get_local_func_address:
 # CHECK-NEXT:           Index:           0
 # CHECK-NEXT:           ElemType:        FUNCREF
 # CHECK-NEXT:           Limits:
+# CHECK-NEXT:             Flags:         [ IS_64 ]
 # CHECK-NEXT:             Minimum:         0x2
 # CHECK-NEXT:       - Module:          env
 # CHECK-NEXT:         Field:           __stack_pointer
diff --git a/lld/wasm/Writer.cpp b/lld/wasm/Writer.cpp
index 55eff995fb8a1..91d1113df6a3c 100644
--- a/lld/wasm/Writer.cpp
+++ b/lld/wasm/Writer.cpp
@@ -939,6 +939,8 @@ static void finalizeIndirectFunctionTable() {
     limits.Flags |= WASM_LIMITS_FLAG_HAS_MAX;
     limits.Maximum = limits.Minimum;
   }
+  if (config->is64.value_or(false))
+    limits.Flags |= WASM_LIMITS_FLAG_IS_64;
   WasmSym::indirectFunctionTable->setLimits(limits);
 }
 
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
index 1c62290704fe4..26e13948bc9a6 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
@@ -885,18 +885,6 @@ bool WebAssemblyFastISel::selectCall(const Instruction *I) {
       Table->setNoStrip();
       MIB.addImm(0);
     }
-    // See if we must truncate the function pointer.
-    // CALL_INDIRECT takes an i32, but in wasm64 we represent function pointers
-    // as 64-bit for uniformity with other pointer types.
-    // See also: WebAssemblyISelLowering.cpp: LowerCallResults
-    if (Subtarget->hasAddr64()) {
-      auto Wrap = BuildMI(*FuncInfo.MBB, std::prev(FuncInfo.InsertPt), MIMD,
-                          TII.get(WebAssembly::I32_WRAP_I64));
-      Register Reg32 = createResultReg(&WebAssembly::I32RegClass);
-      Wrap.addReg(Reg32, RegState::Define);
-      Wrap.addReg(CalleeReg);
-      CalleeReg = Reg32;
-    }
   }
 
   for (unsigned ArgReg : Args)

``````````

</details>


https://github.com/llvm/llvm-project/pull/92042