[ARM] Move ConstantIsland and LowOverheadLoops Passes.

Move ARM ConstantIsland and LowOverheadLopps passes later in the pipeline
such that they will be run after the upcoming Machine Outlining pass.

Differential Revision: https://reviews.llvm.org/D76065

lib/Target/ARM/ARMTargetMachine.cpp

@@ -362,6 +362,7 @@ public:
   void addPreRegAlloc() override;
   void addPreSched2() override;
   void addPreEmitPass() override;
+  void addPreEmitPass2() override;
 
   std::unique_ptr<CSEConfigBase> getCSEConfig() const override;
 };
@@ -541,7 +542,9 @@ void ARMPassConfig::addPreEmitPass() {
   // Don't optimize barriers at -O0.
   if (getOptLevel() != CodeGenOpt::None)
     addPass(createARMOptimizeBarriersPass());
+}
 
+void ARMPassConfig::addPreEmitPass2() {
   addPass(createARMConstantIslandPass());
   addPass(createARMLowOverheadLoopsPass());
 

test/CodeGen/ARM/O3-pipeline.ll

@@ -161,15 +161,15 @@
 ; CHECK-NEXT:      Thumb2 instruction size reduce pass
 ; CHECK-NEXT:      Unpack machine instruction bundles
 ; CHECK-NEXT:      optimise barriers pass
+; CHECK-NEXT:      Contiguously Lay Out Funclets
+; CHECK-NEXT:      StackMap Liveness Analysis
+; CHECK-NEXT:      Live DEBUG_VALUE analysis
 ; CHECK-NEXT:      MachineDominator Tree Construction
 ; CHECK-NEXT:      ARM constant island placement and branch shortening pass
 ; CHECK-NEXT:      MachineDominator Tree Construction
 ; CHECK-NEXT:      Machine Natural Loop Construction
 ; CHECK-NEXT:      ReachingDefAnalysis
 ; CHECK-NEXT:      ARM Low Overhead Loops pass
-; CHECK-NEXT:      Contiguously Lay Out Funclets
-; CHECK-NEXT:      StackMap Liveness Analysis
-; CHECK-NEXT:      Live DEBUG_VALUE analysis
 ; CHECK-NEXT:      Lazy Machine Block Frequency Analysis
 ; CHECK-NEXT:      Machine Optimization Remark Emitter
 ; CHECK-NEXT:      ARM Assembly Printer

test/DebugInfo/ARM/cfi-eof-prologue.mir

@@ -139,6 +139,7 @@
 ---
 name:            _ZN1BC2Ev
 alignment:       2
+tracksRegLiveness: true
 liveins:         
   - { reg: '$r0' }
 frameInfo:       
@@ -154,6 +155,8 @@ stack:
       callee-saved-register: '$r4' }
 body:             |
   bb.0.entry:
+    liveins: $r0, $r4, $lr
+
     frame-setup tPUSH 14, $noreg, killed $r4, killed $lr, implicit-def $sp, implicit $sp
     frame-setup CFI_INSTRUCTION def_cfa_offset 8
     frame-setup CFI_INSTRUCTION offset $lr, -4
@@ -175,6 +178,7 @@ body:             |
 ---
 name:            _ZN1BC1Ev
 alignment:       2
+tracksRegLiveness: true
 liveins:         
   - { reg: '$r0' }
 frameInfo:       
@@ -190,6 +194,8 @@ stack:
       callee-saved-register: '$r4' }
 body:             |
   bb.0.entry:
+    liveins: $r0, $r4, $lr
+
     frame-setup tPUSH 14, $noreg, killed $r4, killed $lr, implicit-def $sp, implicit $sp
     frame-setup CFI_INSTRUCTION def_cfa_offset 8
     frame-setup CFI_INSTRUCTION offset $lr, -4

test/DebugInfo/MIR/ARM/larger-subregister.mir

@@ -29,8 +29,11 @@
   !13 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !14)
   !14 = !DICompositeType(tag: DW_TAG_structure_type, name: "CGRect", scope: !5, file: !3, line: 46, size: 128, elements: !4, runtimeLang: DW_LANG_Swift, identifier: "$sSo6CGRectVD")
 name:            'f'
+tracksRegLiveness: true
 body:             |
   bb.0:
+    liveins: $r6
+
     DBG_VALUE $s31, $noreg, !12, !DIExpression(DW_OP_LLVM_fragment, 32, 32), debug-location !10
     DBG_VALUE $q8, $noreg, !12, !DIExpression(DW_OP_LLVM_fragment, 0, 32), debug-location !10
     renamable $r0 = t2ADDri $r6, 144, 14, $noreg, $noreg, debug-location !10

test/DebugInfo/MIR/ARM/param-reg-const-mix.mir

@@ -67,9 +67,11 @@
 ...
 ---
 name:            fn1
-tracksRegLiveness: false
+tracksRegLiveness: true
 body:             |
   bb.0.entry:
+    liveins: $r0, $r1, $r4, $lr
+
     $sp = frame-setup STMDB_UPD $sp, 14, $noreg, killed $r4, killed $lr
     $r4 = MOVr $r0, 14, $noreg, $noreg
     DBG_VALUE $r1, $noreg, !17, !DIExpression(DW_OP_LLVM_fragment, 32, 32), debug-location !18

test/DebugInfo/MIR/ARM/subregister-full-piece.mir

@@ -39,8 +39,12 @@
   !9 = !DILocalVariable(name: "q9", scope: !5, file: !4, line: 1, type: !7)
   !20 = !DILocation(line: 0, scope: !5)
 name:            f
+tracksRegLiveness: true
 body:             |
   bb.2.for.body:
+    liveins: $r2
+
+    t2CMPri killed renamable $r2, 5, 14, $noreg, implicit-def $cpsr
     t2Bcc %bb.2.for.body, 0, killed $cpsr, debug-location !20
     DBG_VALUE $q8, $noreg, !8, !DIExpression(DW_OP_LLVM_fragment, 0, 64), debug-location !20
     DBG_VALUE $q9, $noreg, !9, !DIExpression(DW_OP_LLVM_fragment, 0, 56), debug-location !20