Ensure loop sinking of inttoptr instructions

Sink inttoptr and other instructions that should always be sinked into
the loop, also when they don't immediately reduce pressure, to enable
further optimizations.

(cherry picked from commit 8338901)

Author: admitric

IGC/Compiler/CISACodeGen/CodeSinking.cpp

@@ -1233,11 +1233,6 @@ namespace IGC {
 
                 LoopSinkWorthiness Worthiness = LoopSinkWorthiness::Unknown;
 
-                if (isAlwaysSinkInstruction(I))
-                {
-                    Worthiness = LoopSinkWorthiness::Sink;
-                }
-
                 if (AllowOnlySingleUseLoadChainSinking)
                 {
                     if (!isLoadChain(I, LoadChains, true))
@@ -1256,6 +1251,11 @@ namespace IGC {
                         Worthiness = LoopSinkWorthiness::Sink;
                 }
 
+                if (isAlwaysSinkInstruction(I))
+                {
+                    Worthiness = LoopSinkWorthiness::Sink;
+                }
+
                 if (isa<LoadInst>(I))
                 {
                     if (!AllowLoadSinking)

IGC/Compiler/tests/CodeSinking/LoopSinking/loopsink-inttoptr.ll

@@ -0,0 +1,56 @@
+;
+; Copyright (C) 2024 Intel Corporation
+;
+; This software and the related documents are Intel copyrighted materials,
+; and your use of them is governed by the express license under which they were
+; provided to you ("License"). Unless the License provides otherwise,
+; you may not use, modify, copy, publish, distribute, disclose or transmit this
+; software or the related documents without Intel's prior written permission.
+;
+; This software and the related documents are provided as is, with no express or
+; implied warranties, other than those that are expressly stated in the License.
+;
+;============================ end_copyright_notice =============================
+; REQUIRES: regkeys
+; RUN: igc_opt --regkey LoopSinkMinSave=1 --regkey LoopSinkDisableRollback=1 --regkey ForceLoopSink=1 --regkey CodeLoopSinkingMinSize=10 %enable-basic-aa% --igc-code-loop-sinking -S %s | FileCheck %s
+
+; check the inttoptr instructions are sinked
+
+define void @foo(i32 %pointer_int, i32 %count, i32 %offset_load, i32 %offset_store) {
+; CHECK-LABEL: @foo(
+; CHECK:       entry_preheader:
+; CHECK:         [[LOAD_PTR:%.*]] = add i32 [[POINTER_INT:%.*]], [[OFFSET_LOAD:%.*]]
+; CHECK:         [[STORE_PTR:%.*]] = add i32 [[POINTER_INT]], [[OFFSET_STORE:%.*]]
+; CHECK:         br label [[LOOP:%.*]]
+; CHECK:       loop:
+; CHECK:         [[INDEX:%.*]] = phi i32 [ 0, [[ENTRY_PREHEADER:%.*]] ], [ [[INC:%.*]], [[LOOP]] ]
+; CHECK:         [[SINK_LOAD_PTR_CAST:%.*]] = inttoptr i32 [[LOAD_PTR]] to i32 addrspace(3)*
+; CHECK:         [[LOAD:%.*]] = load i32, i32 addrspace(3)* [[SINK_LOAD_PTR_CAST]], align 4
+; CHECK:         [[SINK_STORE_PTR_CAST:%.*]] = inttoptr i32 [[STORE_PTR]] to i32 addrspace(3)*
+; CHECK:         store i32 [[LOAD]], i32 addrspace(3)* [[SINK_STORE_PTR_CAST]], align 4
+; CHECK:         [[CMPTMP:%.*]] = icmp ult i32 [[INDEX]], [[COUNT:%.*]]
+; CHECK:         [[INC]] = add i32 [[INDEX]], 1
+; CHECK:         br i1 [[CMPTMP]], label [[LOOP]], label [[AFTERLOOP:%.*]]
+; CHECK:       afterloop:
+; CHECK:         ret void
+;
+entry_preheader:
+  %load_ptr = add i32 %pointer_int, %offset_load
+  %load_ptr_cast = inttoptr i32 %load_ptr to i32 addrspace(3)*
+  %store_ptr = add i32 %pointer_int, %offset_store
+  %store_ptr_cast = inttoptr i32 %store_ptr to i32 addrspace(3)*
+  br label %loop
+
+loop:                                             ; preds = %loop, %entry_preheader
+  %index = phi i32 [ 0, %entry_preheader ], [ %inc, %loop ]
+  %load = load i32, i32 addrspace(3)* %load_ptr_cast, align 4
+  store i32 %load, i32 addrspace(3)* %store_ptr_cast, align 4
+  %cmptmp = icmp ult i32 %index, %count
+  %inc = add i32 %index, 1
+  br i1 %cmptmp, label %loop, label %afterloop
+
+afterloop:                                        ; preds = %loop
+  ret void
+}
+
+!igc.functions = !{}