[llvm] [WebAssembly] Remove the `wasm-disable-fix-irreducible-control-flow-pass` switch (PR #185072)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-webassembly

Author: Demetrius Kanios (QuantumSegfault)

<details>
<summary>Changes</summary>

This removes the `wasm-disable-fix-irreducible-control-flow-pass` switch.

It was originally added in #<!-- -->67715 as a way to avoid the potentially absurd compile times the pass used to bring. However with the successful merge of #<!-- -->184441, the pass itself has been fixed to avoid this issue.

Given that, it is no longer necessary nor desirable to keep this switch.

---
Full diff: https://github.com/llvm/llvm-project/pull/185072.diff


1 Files Affected:

- (modified) llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp (+1-8) 


``````````diff
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
index ab1b24a4fd9b1..331bd0a360149 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyTargetMachine.cpp
@@ -51,12 +51,6 @@ static cl::opt<bool> WasmDisableExplicitLocals(
              " instruction output for test purposes only."),
     cl::init(false));
 
-static cl::opt<bool> WasmDisableFixIrreducibleControlFlowPass(
-    "wasm-disable-fix-irreducible-control-flow-pass", cl::Hidden,
-    cl::desc("webassembly: disables the fix "
-             " irreducible control flow optimization pass"),
-    cl::init(false));
-
 // Exception handling & setjmp-longjmp handling related options.
 
 // Emscripten's asm.js-style exception handling
@@ -605,8 +599,7 @@ void WebAssemblyPassConfig::addPreEmitPass() {
   addPass(createWebAssemblyNullifyDebugValueLists());
 
   // Eliminate multiple-entry loops.
-  if (!WasmDisableFixIrreducibleControlFlowPass)
-    addPass(createWebAssemblyFixIrreducibleControlFlow());
+  addPass(createWebAssemblyFixIrreducibleControlFlow());
 
   // Do various transformations for exception handling.
   // Every CFG-changing optimizations should come before this.

``````````

</details>


https://github.com/llvm/llvm-project/pull/185072