[LazyMachineBFI] Add testcase

[anemet]

Summary

This is based on Justin's testcase and checking whether BFI is not populated
in case hotness is off.

This is a patch meant on top of Justin's patch to enable Machine opt-remarks
in the
AsmPrinter (http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20170130/426595.html)

[davidxl]

test/CodeGen/AArch64/arm64-opt-remarks-lazy-bfi.ll

2 ↗

(On Diff #88017)

Do you need -debug-only=block-freq here? Does it work with release build?

[anemet]

test/CodeGen/AArch64/arm64-opt-remarks-lazy-bfi.ll

2 ↗

(On Diff #88017)

Yeah, I need a way to check whether BFI is being computed *here*.

This mirrors the IR test under Other/optimization-remarks-lazy-bfi.ll.

7 ↗

(On Diff #88017)

Does it work with release build?

No it doesn't. This line ensures that we only run this test when asserts are enabled.

[davidxl]

lgtm

[anemet]

Update after D30128

llvm/trunk/test/CodeGen/AArch64/arm64-opt-remarks-lazy-bfi.ll

+; RUN: llc < %s -mtriple=arm64-apple-ios7.0 -pass-remarks-analysis=asm-printer \
+; RUN:       -pass-remarks-with-hotness=1 -asm-verbose=0 \
+; RUN:       -debug-only=lazy-machine-block-freq,block-freq \
+; RUN:       -debug-pass=Executions 2>&1 | FileCheck %s -check-prefix=HOTNESS
+
+; RUN: llc < %s -mtriple=arm64-apple-ios7.0 -pass-remarks-analysis=asm-printer \
+; RUN:       -pass-remarks-with-hotness=0 -asm-verbose=0 \
+; RUN:       -debug-only=lazy-machine-block-freq,block-freq \
+; RUN:       -debug-pass=Executions 2>&1 | FileCheck %s -check-prefix=NO_HOTNESS
+
+; REQUIRES: asserts
+
+
+; Verify that we don't new populate MachineBFI for passes that already use
+; MBFI, e.g. GreedyRegAlloc.  (This hard-codes the previous pass to the
+; GreedyRegAlloc, please adjust accordingly.)
+
+; HOTNESS:      Executing Pass 'Spill Code Placement Analysis'
+; HOTNESS-NEXT: Executing Pass 'Lazy Machine Block Frequency Analysis'
+; HOTNESS-NEXT: Executing Pass 'Machine Optimization Remark Emitter'
+; HOTNESS-NEXT: MachineBlockFrequencyInfo is available
+; HOTNESS-NEXT: Executing Pass 'Greedy Register Allocator'
+
+
+; Verify that we only populate MachineBFI on behalf of ORE when hotness is
+; requested.  (This hard-codes the previous pass to the Assembly Printer,
+; please adjust accordingly.)
+
+; HOTNESS:      Executing Pass 'Implement the 'patchable-function' attribute'
+; HOTNESS-NEXT:  Freeing Pass 'Implement the 'patchable-function' attribute'
+; HOTNESS-NEXT: Executing Pass 'Lazy Machine Block Frequency Analysis'
+; HOTNESS-NEXT: Executing Pass 'Machine Optimization Remark Emitter'
+; HOTNESS-NEXT: Building MachineBlockFrequencyInfo on the fly
+; HOTNESS-NEXT: Building LoopInfo on the fly
+; HOTNESS-NEXT: Building DominatorTree on the fly
+; HOTNESS-NOT: Executing Pass
+; HOTNESS: block-frequency: empty_func
+; HOTNESS-NOT: Executing Pass
+; HOTNESS: Executing Pass 'AArch64 Assembly Printer'
+
+; HOTNESS: arm64-summary-remarks.ll:5:0: 1 instructions in function (hotness: 33)
+
+
+; NO_HOTNESS:      Executing Pass 'Implement the 'patchable-function' attribute'
+; NO_HOTNESS-NEXT:  Freeing Pass 'Implement the 'patchable-function' attribute'
+; NO_HOTNESS-NEXT: Executing Pass 'Lazy Machine Block Frequency Analysis'
+; NO_HOTNESS-NEXT: Executing Pass 'Machine Optimization Remark Emitter'
+; NO_HOTNESS-NEXT: Executing Pass 'AArch64 Assembly Printer'
+
+; NO_HOTNESS: arm64-summary-remarks.ll:5:0: 1 instructions in function{{$}}
+
+define void @empty_func() nounwind ssp !dbg !3 !prof !4 {
+  ret void
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1)
+!1 = !DIFile(filename: "arm64-summary-remarks.ll", directory: "")
+!2 = !{i32 2, !"Debug Info Version", i32 3}
+!3 = distinct !DISubprogram(name: "empty_func", scope: !1, file: !1, line: 5, scopeLine: 5, unit: !0)
+!4 = !{!"function_entry_count", i64 33}