3d08ade7bd
This patch is part of a set of patches that add an `-fextend-lifetimes` flag to clang, which extends the lifetimes of local variables and parameters for improved debuggability. In addition to that flag, the patch series adds a pragma to selectively disable `-fextend-lifetimes`, and an `-fextend-this-ptr` flag which functions as `-fextend-lifetimes` for this pointers only. All changes and tests in these patches were written by Wolfgang Pieb (@wolfy1961), while Stephen Tozer (@SLTozer) has handled review and merging. The extend lifetimes flag is intended to eventually be set on by `-Og`, as discussed in the RFC here: https://discourse.llvm.org/t/rfc-redefine-og-o1-and-add-a-new-level-of-og/72850 This patch implements a new intrinsic instruction in LLVM, `llvm.fake.use` in IR and `FAKE_USE` in MIR, that takes a single operand and has no effect other than "using" its operand, to ensure that its operand remains live until after the fake use. This patch does not emit fake uses anywhere; the next patch in this sequence causes them to be emitted from the clang frontend, such that for each variable (or this) a fake.use operand is inserted at the end of that variable's scope, using that variable's value. This patch covers everything post-frontend, which is largely just the basic plumbing for a new intrinsic/instruction, along with a few steps to preserve the fake uses through optimizations (such as moving them ahead of a tail call or translating them through SROA). Co-authored-by: Stephen Tozer <stephen.tozer@sony.com>
80 lines
3.6 KiB
LLVM
80 lines
3.6 KiB
LLVM
; RUN: llc --debugify-and-strip-all-safe=0 -mtriple=powerpc64-- -O0 \
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; RUN: -debug-pass=Structure < %s -o /dev/null 2>&1 | \
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; RUN: grep -v "Verify generated machine code" | FileCheck %s
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; REQUIRES: asserts
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; CHECK-LABEL: Pass Arguments:
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; CHECK-NEXT: Target Library Information
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; CHECK-NEXT: Target Pass Configuration
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; CHECK-NEXT: Machine Module Information
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; CHECK-NEXT: Target Transform Information
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; CHECK-NEXT: Create Garbage Collector Module Metadata
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; CHECK-NEXT: Assumption Cache Tracker
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; CHECK-NEXT: Profile summary info
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; CHECK-NEXT: Machine Branch Probability Analysis
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; CHECK-NEXT: ModulePass Manager
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; CHECK-NEXT: Pre-ISel Intrinsic Lowering
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; CHECK-NEXT: FunctionPass Manager
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; CHECK-NEXT: Expand large div/rem
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; CHECK-NEXT: Expand large fp convert
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; CHECK-NEXT: Expand Atomic instructions
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; CHECK-NEXT: PPC Lower MASS Entries
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; CHECK-NEXT: FunctionPass Manager
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; CHECK-NEXT: Module Verifier
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; CHECK-NEXT: Lower Garbage Collection Instructions
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; CHECK-NEXT: Shadow Stack GC Lowering
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; CHECK-NEXT: Remove unreachable blocks from the CFG
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; CHECK-NEXT: Instrument function entry/exit with calls to e.g. mcount() (post inlining)
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; CHECK-NEXT: Scalarize Masked Memory Intrinsics
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; CHECK-NEXT: Expand reduction intrinsics
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; CHECK-NEXT: Exception handling preparation
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; CHECK-NEXT: Prepare callbr
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; CHECK-NEXT: Safe Stack instrumentation pass
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; CHECK-NEXT: Insert stack protectors
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; CHECK-NEXT: Module Verifier
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; CHECK-NEXT: Assignment Tracking Analysis
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; CHECK-NEXT: PowerPC DAG->DAG Pattern Instruction Selection
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; CHECK-NEXT: PowerPC VSX Copy Legalization
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; CHECK-NEXT: Finalize ISel and expand pseudo-instructions
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; CHECK-NEXT: Local Stack Slot Allocation
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; CHECK-NEXT: Remove unreachable machine basic blocks
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; CHECK-NEXT: Live Variable Analysis
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; CHECK-NEXT: MachineDominator Tree Construction
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; CHECK-NEXT: Slot index numbering
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; CHECK-NEXT: Live Interval Analysis
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; CHECK-NEXT: PowerPC TLS Dynamic Call Fixup
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; CHECK-NEXT: PowerPC TOC Register Dependencies
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; CHECK-NEXT: Eliminate PHI nodes for register allocation
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; CHECK-NEXT: Two-Address instruction pass
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; CHECK-NEXT: Fast Register Allocator
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; CHECK-NEXT: Remove Redundant DEBUG_VALUE analysis
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; CHECK-NEXT: Fixup Statepoint Caller Saved
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; CHECK-NEXT: Lazy Machine Block Frequency Analysis
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; CHECK-NEXT: Machine Optimization Remark Emitter
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; CHECK-NEXT: Prologue/Epilogue Insertion & Frame Finalization
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; CHECK-NEXT: Post-RA pseudo instruction expansion pass
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; CHECK-NEXT: Analyze Machine Code For Garbage Collection
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; CHECK-NEXT: Insert fentry calls
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; CHECK-NEXT: Insert XRay ops
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; CHECK-NEXT: Implement the 'patchable-function' attribute
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; CHECK-NEXT: PowerPC Pre-Emit Peephole
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; CHECK-NEXT: Contiguously Lay Out Funclets
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; CHECK-NEXT: Remove Loads Into Fake Uses
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; CHECK-NEXT: StackMap Liveness Analysis
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; CHECK-NEXT: Live DEBUG_VALUE analysis
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; CHECK-NEXT: Machine Sanitizer Binary Metadata
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; CHECK-NEXT: Lazy Machine Block Frequency Analysis
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; CHECK-NEXT: Machine Optimization Remark Emitter
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; CHECK-NEXT: Stack Frame Layout Analysis
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; CHECK-NEXT: PowerPC Expand Atomic
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; CHECK-NEXT: PowerPC Branch Selector
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; CHECK-NEXT: Lazy Machine Block Frequency Analysis
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; CHECK-NEXT: Machine Optimization Remark Emitter
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; CHECK-NEXT: Linux PPC Assembly Printer
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; CHECK-NEXT: Free MachineFunction
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define void @f() {
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ret void
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}
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