disable LICM when unmasked mode is set

Loop invariant code motion is known to break unmasked functions, as it
may move code in and out of these unmasked functions. Best one should
just disable LICM whenever unmasked mode is used. LICM is disabled
after unmasked functions are inlined.

Author: itsimbal

IGC/Compiler/CISACodeGen/ShaderCodeGen.cpp

@@ -365,6 +365,12 @@ static void AddLegalizationPasses(CodeGenContext& ctx, IGCPassManager& mpm, PSSi
         IGC_SET_FLAG_VALUE(FastCompileRA, 1);
         IGC_SET_FLAG_VALUE(HybridRAWithSpill, 1);
     }
+    // Disable loop invariant motion after Unmasked functions are inlined
+    // at optimization phase
+    if (IGC_IS_FLAG_ENABLED(EnableUnmaskedFunctions) &&
+        IGC_IS_FLAG_DISABLED(LateInlineUnmaskedFunc)) {
+        IGC_SET_FLAG_VALUE(allowLICM, false);
+    }
 
     if (IGC_IS_FLAG_ENABLED(ForceAllPrivateMemoryToSLM) ||
         IGC_IS_FLAG_ENABLED(ForcePrivateMemoryToSLMOnBuffers))