[PATCH] D85408: Let -basic-block-sections=labels emit basicblock metadata in a new .bb_addr_map section, instead of emitting special unary-encoded symbols.

[Rahman Lavaee via Phabricator via llvm-commits]

rahmanl added inline comments.


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Comment at: llvm/lib/CodeGen/MachineBasicBlock.cpp:58
 
+unsigned MachineBasicBlock::getBBAddrMapMetadata() const {
+  const TargetInstrInfo *TII = getParent()->getSubtarget().getInstrInfo();
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snehasish wrote:
> I think this method only relies on already public methods of MachineBasicBlock. It would be cleaner to move this from here to a static helper function in AsmPrinter.cpp. This way we don't add yet another method to the MachineBasicBlock class and keeps the relevant metadata generation logic close to where it is used.
> 
> Feel free to ignore if you plan on calling this method elsewhere apart from AsmPrinter.cpp but I can't think of a reason to do so.
Thanks for the suggestion. It makes the code much more readable since I just place that function above emitBBAddrMapSection.
I can even make it a lambda function within emitBBAddrMapSection. WDYT?


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Comment at: llvm/test/CodeGen/X86/basic-block-sections-labels.ll:5-9
   %2 = alloca i8, align 1
   %3 = zext i1 %0 to i8
   store i8 %3, i8* %2, align 1
   %4 = load i8, i8* %2, align 1
   %5 = trunc i8 %4 to i1
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snehasish wrote:
> I think this can be removed and the branch on L10 can directly use the param like so:
> 
> ```
> define void @_Z3bazb(i1 zeroext %0) personality i32 (...)* @__gxx_personality_v0 {
>   br i1 %0, label %6, label %11
>   ....
> }
> ```
> 
> You will need to adjust the respective virtual register names since %2-%5 is no longer used.
Great suggestion. Thanks. This was copied over from other basic-block-sections tests, so maybe they can be updated too.


Repository:
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  https://reviews.llvm.org/D85408/new/

https://reviews.llvm.org/D85408