[Autobackout][FuncReg]Revert of change: 393c54a

 RemoveCodeAssumptions pass

Instruction combining can miss some optimizations if it happens, that the only use of instructions end up in llvm.assume intrinsic. This change removes llvm.assume calls and runs instruction combining before Legalization pass.

Author: PawelJurek

IGC/Compiler/CISACodeGen/ShaderCodeGen.cpp

@@ -126,7 +126,6 @@ SPDX-License-Identifier: MIT
 #include "Compiler/InitializePasses.h"
 #include "Compiler/GenRotate.hpp"
 #include "Compiler/Optimizer/Scalarizer.h"
-#include "Compiler/RemoveCodeAssumptions.hpp"
 #include "common/debug/Debug.hpp"
 #include "common/igc_regkeys.hpp"
 #include "common/debug/Dump.hpp"
@@ -906,9 +905,9 @@ static void AddLegalizationPasses(CodeGenContext& ctx, IGCPassManager& mpm, PSSi
         }
     }
 
-    // Enabling half promotion AIL for compute shaders only at this point.
+    // Enabling half promotion AIL for compute shaders only at this point. 
     // If needed ctx.type check can be removed to apply for all shader types
-    if (IGC_IS_FLAG_ENABLED(ForceHalfPromotion) ||
+    if (IGC_IS_FLAG_ENABLED(ForceHalfPromotion) || 
         (ctx.getModuleMetaData()->compOpt.WaForceHalfPromotion && ctx.type == ShaderType::COMPUTE_SHADER) ||
         (!ctx.platform.supportFP16() && IGC_IS_FLAG_ENABLED(EnableHalfPromotion)))
     {
@@ -941,20 +940,12 @@ static void AddLegalizationPasses(CodeGenContext& ctx, IGCPassManager& mpm, PSSi
         mpm.add(createNanHandlingPass());
     }
 
-    if(!isOptDisabled) {
-        // Removing code assumptions can enable some InstructionCombining optimizations.
-        // Last instruction combining pass needs to be before Legalization pass, as it can produce illegal instructions.
-        mpm.add(new RemoveCodeAssumptions());
-        mpm.add(createIGCInstructionCombiningPass());
-    }
-
     // TODO: move to use instruction flags
     // to figure out if we need to preserve Nan
     bool preserveNan = !ctx.getCompilerOption().NoNaNs;
 
     // Legalizer does not handle constant expressions
     mpm.add(new BreakConstantExpr());
-
     mpm.add(new Legalization(preserveNan));
 
     // Scalarizer in codegen to handle the vector instructions

IGC/Compiler/CMakeLists.txt

@@ -66,7 +66,6 @@ set(IGC_BUILD__SRC__Compiler
     "${CMAKE_CURRENT_SOURCE_DIR}/SampleMultiversioning.cpp"
     "${CMAKE_CURRENT_SOURCE_DIR}/HandleFRemInstructions.cpp"
     "${CMAKE_CURRENT_SOURCE_DIR}/GenRotate.cpp"
-    "${CMAKE_CURRENT_SOURCE_DIR}/RemoveCodeAssumptions.cpp"
     "${IGC_BUILD__GFX_DEV_SRC_DIR}/skuwa/ibdw_wa.c"
     "${IGC_BUILD__GFX_DEV_SRC_DIR}/skuwa/ichv_wa.c"
     "${IGC_BUILD__GFX_DEV_SRC_DIR}/skuwa/ibxt_wa.c"
@@ -158,7 +157,6 @@ set(IGC_BUILD__HDR__Compiler
     "${CMAKE_CURRENT_SOURCE_DIR}/HandleFRemInstructions.hpp"
     "${CMAKE_CURRENT_SOURCE_DIR}/GenRotate.hpp"
     "${CMAKE_CURRENT_SOURCE_DIR}/SamplerPerfOptPass.hpp"
-    "${CMAKE_CURRENT_SOURCE_DIR}/RemoveCodeAssumptions.hpp"
     ${IGC_BUILD__HDR__Compiler_CISACodeGen}
     ${IGC_BUILD__HDR__Compiler_DebugInfo}
     ${IGC_BUILD__HDR__Compiler_Legalizer}

IGC/Compiler/InitializePasses.h

@@ -226,5 +226,3 @@ void initializeCatchAllLineNumberPass(llvm::PassRegistry&);
 void initializePromoteConstantStructsPass(llvm::PassRegistry&);
 void initializeLowerInvokeSIMDPass(llvm::PassRegistry&);
 void initializeImplicitGIDRestoringPass(llvm::PassRegistry&);
-void initializeRemoveCodeAssumptionsPass(llvm::PassRegistry&);
-