[LoongArch] Add tests showing the optimization pipeline

Other targets like ARM, AArch64, RISCV and X86 have similar tests.

`O1`, `O2` and `O3` appear to be the same for now. But in future, some
passes may be disabled at lower levels (e.g. `O1`). Hoping we can use
FileCheck prefixes for differences to avoid repeating the contents 3
times.

Reviewed By: xen0n, MaskRay

Differential Revision: https://reviews.llvm.org/D139499

llvm/test/CodeGen/LoongArch/O0-pipeline.ll

@@ -0,0 +1,71 @@
+;; When EXPENSIVE_CHECKS are enabled, the machine verifier appears between each
+;; pass. Ignore it with 'grep -v'.
+; RUN: llc --mtriple=loongarch32 -O0 --debug-pass=Structure %s -o /dev/null 2>&1 | \
+; RUN:   grep -v "Verify generated machine code" | FileCheck %s
+; RUN: llc --mtriple=loongarch64 -O0 --debug-pass=Structure %s -o /dev/null 2>&1 | \
+; RUN:   grep -v "Verify generated machine code" | FileCheck %s
+
+; REQUIRES: asserts
+
+; CHECK-LABEL: Pass Arguments:
+; CHECK-NEXT: Target Library Information
+; CHECK-NEXT: Target Pass Configuration
+; CHECK-NEXT: Machine Module Information
+; CHECK-NEXT: Target Transform Information
+; CHECK-NEXT: Create Garbage Collector Module Metadata
+; CHECK-NEXT: Assumption Cache Tracker
+; CHECK-NEXT: Profile summary info
+; CHECK-NEXT: Machine Branch Probability Analysis
+; CHECK-NEXT:   ModulePass Manager
+; CHECK-NEXT:     Pre-ISel Intrinsic Lowering
+; CHECK-NEXT:     FunctionPass Manager
+; CHECK-NEXT:       Expand large div/rem
+; CHECK-NEXT:       Expand large fp convert
+; CHECK-NEXT:       Expand Atomic instructions
+; CHECK-NEXT:       Module Verifier
+; CHECK-NEXT:       Lower Garbage Collection Instructions
+; CHECK-NEXT:       Shadow Stack GC Lowering
+; CHECK-NEXT:       Lower constant intrinsics
+; CHECK-NEXT:       Remove unreachable blocks from the CFG
+; CHECK-NEXT:       Expand vector predication intrinsics
+; CHECK-NEXT:       Scalarize Masked Memory Intrinsics
+; CHECK-NEXT:       Expand reduction intrinsics
+; CHECK-NEXT:       Exception handling preparation
+; CHECK-NEXT:       Safe Stack instrumentation pass
+; CHECK-NEXT:       Insert stack protectors
+; CHECK-NEXT:       Module Verifier
+; CHECK-NEXT:       Dominator Tree Construction
+; CHECK-NEXT:       Basic Alias Analysis (stateless AA impl)
+; CHECK-NEXT:       Function Alias Analysis Results
+; CHECK-NEXT:       Natural Loop Information
+; CHECK-NEXT:       Post-Dominator Tree Construction
+; CHECK-NEXT:       Branch Probability Analysis
+; CHECK-NEXT:       Lazy Branch Probability Analysis
+; CHECK-NEXT:       Lazy Block Frequency Analysis
+; CHECK-NEXT:       LoongArch DAG->DAG Pattern Instruction Selection
+; CHECK-NEXT:       Finalize ISel and expand pseudo-instructions
+; CHECK-NEXT:       Local Stack Slot Allocation
+; CHECK-NEXT:       LoongArch Pre-RA pseudo instruction expansion pass
+; CHECK-NEXT:       Eliminate PHI nodes for register allocation
+; CHECK-NEXT:       Two-Address instruction pass
+; CHECK-NEXT:       Fast Register Allocator
+; CHECK-NEXT:       Remove Redundant DEBUG_VALUE analysis
+; CHECK-NEXT:       Fixup Statepoint Caller Saved
+; CHECK-NEXT:       Lazy Machine Block Frequency Analysis
+; CHECK-NEXT:       Machine Optimization Remark Emitter
+; CHECK-NEXT:       Prologue/Epilogue Insertion & Frame Finalization
+; CHECK-NEXT:       Post-RA pseudo instruction expansion pass
+; CHECK-NEXT:       Analyze Machine Code For Garbage Collection
+; CHECK-NEXT:       Insert fentry calls
+; CHECK-NEXT:       Insert XRay ops
+; CHECK-NEXT:       Implement the 'patchable-function' attribute
+; CHECK-NEXT:       Branch relaxation pass
+; CHECK-NEXT:       Contiguously Lay Out Funclets
+; CHECK-NEXT:       StackMap Liveness Analysis
+; CHECK-NEXT:       Live DEBUG_VALUE analysis
+; CHECK-NEXT:       Machine Sanitizer Binary Metadata
+; CHECK-NEXT:       LoongArch atomic pseudo instruction expansion pass
+; CHECK-NEXT:       Lazy Machine Block Frequency Analysis
+; CHECK-NEXT:       Machine Optimization Remark Emitter
+; CHECK-NEXT:       LoongArch Assembly Printer
+; CHECK-NEXT:       Free MachineFunction

llvm/test/CodeGen/LoongArch/opt-pipeline.ll

@@ -0,0 +1,167 @@
+;; When EXPENSIVE_CHECKS are enabled, the machine verifier appears between each
+;; pass. Ignore it with 'grep -v'.
+; RUN: llc --mtriple=loongarch32 -O1 --debug-pass=Structure %s -o /dev/null 2>&1 | \
+; RUN:   grep -v "Verify generated machine code" | FileCheck %s
+; RUN: llc --mtriple=loongarch32 -O2 --debug-pass=Structure %s -o /dev/null 2>&1 | \
+; RUN:   grep -v "Verify generated machine code" | FileCheck %s
+; RUN: llc --mtriple=loongarch32 -O3 --debug-pass=Structure %s -o /dev/null 2>&1 | \
+; RUN:   grep -v "Verify generated machine code" | FileCheck %s
+; RUN: llc --mtriple=loongarch64 -O1 --debug-pass=Structure %s -o /dev/null 2>&1 | \
+; RUN:   grep -v "Verify generated machine code" | FileCheck %s
+; RUN: llc --mtriple=loongarch64 -O2 --debug-pass=Structure %s -o /dev/null 2>&1 | \
+; RUN:   grep -v "Verify generated machine code" | FileCheck %s
+; RUN: llc --mtriple=loongarch64 -O3 --debug-pass=Structure %s -o /dev/null 2>&1 | \
+; RUN:   grep -v "Verify generated machine code" | FileCheck %s
+
+; REQUIRES: asserts
+
+; CHECK-LABEL: Pass Arguments:
+; CHECK-NEXT: Target Library Information
+; CHECK-NEXT: Target Pass Configuration
+; CHECK-NEXT: Machine Module Information
+; CHECK-NEXT: Target Transform Information
+; CHECK-NEXT: Type-Based Alias Analysis
+; CHECK-NEXT: Scoped NoAlias Alias Analysis
+; CHECK-NEXT: Assumption Cache Tracker
+; CHECK-NEXT: Profile summary info
+; CHECK-NEXT: Create Garbage Collector Module Metadata
+; CHECK-NEXT: Machine Branch Probability Analysis
+; CHECK-NEXT: Default Regalloc Eviction Advisor
+; CHECK-NEXT: Default Regalloc Priority Advisor
+; CHECK-NEXT:   ModulePass Manager
+; CHECK-NEXT:     Pre-ISel Intrinsic Lowering
+; CHECK-NEXT:     FunctionPass Manager
+; CHECK-NEXT:       Expand large div/rem
+; CHECK-NEXT:       Expand large fp convert
+; CHECK-NEXT:       Expand Atomic instructions
+; CHECK-NEXT:       Module Verifier
+; CHECK-NEXT:       Dominator Tree Construction
+; CHECK-NEXT:       Basic Alias Analysis (stateless AA impl)
+; CHECK-NEXT:       Natural Loop Information
+; CHECK-NEXT:       Canonicalize natural loops
+; CHECK-NEXT:       Scalar Evolution Analysis
+; CHECK-NEXT:       Loop Pass Manager
+; CHECK-NEXT:         Canonicalize Freeze Instructions in Loops
+; CHECK-NEXT:         Induction Variable Users
+; CHECK-NEXT:         Loop Strength Reduction
+; CHECK-NEXT:       Basic Alias Analysis (stateless AA impl)
+; CHECK-NEXT:       Function Alias Analysis Results
+; CHECK-NEXT:       Merge contiguous icmps into a memcmp
+; CHECK-NEXT:       Natural Loop Information
+; CHECK-NEXT:       Lazy Branch Probability Analysis
+; CHECK-NEXT:       Lazy Block Frequency Analysis
+; CHECK-NEXT:       Expand memcmp() to load/stores
+; CHECK-NEXT:       Lower Garbage Collection Instructions
+; CHECK-NEXT:       Shadow Stack GC Lowering
+; CHECK-NEXT:       Lower constant intrinsics
+; CHECK-NEXT:       Remove unreachable blocks from the CFG
+; CHECK-NEXT:       Natural Loop Information
+; CHECK-NEXT:       Post-Dominator Tree Construction
+; CHECK-NEXT:       Branch Probability Analysis
+; CHECK-NEXT:       Block Frequency Analysis
+; CHECK-NEXT:       Constant Hoisting
+; CHECK-NEXT:       Replace intrinsics with calls to vector library
+; CHECK-NEXT:       Partially inline calls to library functions
+; CHECK-NEXT:       Expand vector predication intrinsics
+; CHECK-NEXT:       Scalarize Masked Memory Intrinsics
+; CHECK-NEXT:       Expand reduction intrinsics
+; CHECK-NEXT:       Natural Loop Information
+; CHECK-NEXT:       TLS Variable Hoist
+; CHECK-NEXT:       CodeGen Prepare
+; CHECK-NEXT:       Dominator Tree Construction
+; CHECK-NEXT:       Exception handling preparation
+; CHECK-NEXT:       Safe Stack instrumentation pass
+; CHECK-NEXT:       Insert stack protectors
+; CHECK-NEXT:       Module Verifier
+; CHECK-NEXT:       Basic Alias Analysis (stateless AA impl)
+; CHECK-NEXT:       Function Alias Analysis Results
+; CHECK-NEXT:       Natural Loop Information
+; CHECK-NEXT:       Post-Dominator Tree Construction
+; CHECK-NEXT:       Branch Probability Analysis
+; CHECK-NEXT:       Lazy Branch Probability Analysis
+; CHECK-NEXT:       Lazy Block Frequency Analysis
+; CHECK-NEXT:       LoongArch DAG->DAG Pattern Instruction Selection
+; CHECK-NEXT:       Finalize ISel and expand pseudo-instructions
+; CHECK-NEXT:       Lazy Machine Block Frequency Analysis
+; CHECK-NEXT:       Early Tail Duplication
+; CHECK-NEXT:       Optimize machine instruction PHIs
+; CHECK-NEXT:       Slot index numbering
+; CHECK-NEXT:       Merge disjoint stack slots
+; CHECK-NEXT:       Local Stack Slot Allocation
+; CHECK-NEXT:       Remove dead machine instructions
+; CHECK-NEXT:       MachineDominator Tree Construction
+; CHECK-NEXT:       Machine Natural Loop Construction
+; CHECK-NEXT:       Machine Block Frequency Analysis
+; CHECK-NEXT:       Early Machine Loop Invariant Code Motion
+; CHECK-NEXT:       MachineDominator Tree Construction
+; CHECK-NEXT:       Machine Block Frequency Analysis
+; CHECK-NEXT:       Machine Common Subexpression Elimination
+; CHECK-NEXT:       MachinePostDominator Tree Construction
+; CHECK-NEXT:       Machine Cycle Info Analysis
+; CHECK-NEXT:       Machine code sinking
+; CHECK-NEXT:       Peephole Optimizations
+; CHECK-NEXT:       Remove dead machine instructions
+; CHECK-NEXT:       LoongArch Pre-RA pseudo instruction expansion pass
+; CHECK-NEXT:       Detect Dead Lanes
+; CHECK-NEXT:       Process Implicit Definitions
+; CHECK-NEXT:       Remove unreachable machine basic blocks
+; CHECK-NEXT:       Live Variable Analysis
+; CHECK-NEXT:       Eliminate PHI nodes for register allocation
+; CHECK-NEXT:       Two-Address instruction pass
+; CHECK-NEXT:       MachineDominator Tree Construction
+; CHECK-NEXT:       Slot index numbering
+; CHECK-NEXT:       Live Interval Analysis
+; CHECK-NEXT:       Simple Register Coalescing
+; CHECK-NEXT:       Rename Disconnected Subregister Components
+; CHECK-NEXT:       Machine Instruction Scheduler
+; CHECK-NEXT:       Machine Block Frequency Analysis
+; CHECK-NEXT:       Debug Variable Analysis
+; CHECK-NEXT:       Live Stack Slot Analysis
+; CHECK-NEXT:       Virtual Register Map
+; CHECK-NEXT:       Live Register Matrix
+; CHECK-NEXT:       Bundle Machine CFG Edges
+; CHECK-NEXT:       Spill Code Placement Analysis
+; CHECK-NEXT:       Lazy Machine Block Frequency Analysis
+; CHECK-NEXT:       Machine Optimization Remark Emitter
+; CHECK-NEXT:       Greedy Register Allocator
+; CHECK-NEXT:       Virtual Register Rewriter
+; CHECK-NEXT:       Register Allocation Pass Scoring
+; CHECK-NEXT:       Stack Slot Coloring
+; CHECK-NEXT:       Machine Copy Propagation Pass
+; CHECK-NEXT:       Machine Loop Invariant Code Motion
+; CHECK-NEXT:       Remove Redundant DEBUG_VALUE analysis
+; CHECK-NEXT:       Fixup Statepoint Caller Saved
+; CHECK-NEXT:       PostRA Machine Sink
+; CHECK-NEXT:       Machine Block Frequency Analysis
+; CHECK-NEXT:       MachineDominator Tree Construction
+; CHECK-NEXT:       MachinePostDominator Tree Construction
+; CHECK-NEXT:       Lazy Machine Block Frequency Analysis
+; CHECK-NEXT:       Machine Optimization Remark Emitter
+; CHECK-NEXT:       Shrink Wrapping analysis
+; CHECK-NEXT:       Prologue/Epilogue Insertion & Frame Finalization
+; CHECK-NEXT:       Machine Late Instructions Cleanup Pass
+; CHECK-NEXT:       Control Flow Optimizer
+; CHECK-NEXT:       Lazy Machine Block Frequency Analysis
+; CHECK-NEXT:       Tail Duplication
+; CHECK-NEXT:       Machine Copy Propagation Pass
+; CHECK-NEXT:       Post-RA pseudo instruction expansion pass
+; CHECK-NEXT:       MachineDominator Tree Construction
+; CHECK-NEXT:       Machine Natural Loop Construction
+; CHECK-NEXT:       Post RA top-down list latency scheduler
+; CHECK-NEXT:       Analyze Machine Code For Garbage Collection
+; CHECK-NEXT:       Machine Block Frequency Analysis
+; CHECK-NEXT:       MachinePostDominator Tree Construction
+; CHECK-NEXT:       Branch Probability Basic Block Placement
+; CHECK-NEXT:       Insert fentry calls
+; CHECK-NEXT:       Insert XRay ops
+; CHECK-NEXT:       Implement the 'patchable-function' attribute
+; CHECK-NEXT:       Branch relaxation pass
+; CHECK-NEXT:       Contiguously Lay Out Funclets
+; CHECK-NEXT:       StackMap Liveness Analysis
+; CHECK-NEXT:       Live DEBUG_VALUE analysis
+; CHECK-NEXT:       Machine Sanitizer Binary Metadata
+; CHECK-NEXT:       LoongArch atomic pseudo instruction expansion pass
+; CHECK-NEXT:       Lazy Machine Block Frequency Analysis
+; CHECK-NEXT:       Machine Optimization Remark Emitter
+; CHECK-NEXT:       LoongArch Assembly Printer
+; CHECK-NEXT:       Free MachineFunction