[PATCH] D129838: [LoongArch] Optimize the atomic store with amswap_db.[w/d]

[Gong LingQin via Phabricator via llvm-commits]

gonglingqin added inline comments.


================
Comment at: llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp:1741
+    return isa<LoadInst>(I) || isa<StoreInst>(I);
+  } else {
+    unsigned Size = 0;
----------------
SixWeining wrote:
> No need to use `else` after `return`.
Thanks.


================
Comment at: llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp:1742-1744
+    unsigned Size = 0;
+    if (isa<StoreInst>(I))
+      Size = I->getOperand(0)->getType()->getIntegerBitWidth();
----------------
SixWeining wrote:
> SixWeining wrote:
> > Size = isa<StoreInst>(I) ? I->getOperand(0)->getType()->getIntegerBitWidth() : 0;
> How about:
> ```
>   if (isa<LoadInst>(I))
>     return true;
> 
>   // On LA64, atomic store operations with IntegerBitWidth of 32 and 64 do not
>   // require fences beacuse we can use amswap_db.[w/d].
>   if (isa<StoreInst>(I)) {
>     unsigned Size = I->getOperand(0)->getType()->getIntegerBitWidth();
>     return (Size == 8 || Size == 16);
>   }
> 
>   return false;
> ```
Thanks.


================
Comment at: llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp:1742-1748
+    unsigned Size = 0;
+    if (isa<StoreInst>(I))
+      Size = I->getOperand(0)->getType()->getIntegerBitWidth();
+    // On LA64, atomic store operations with IntegerBitWidth of 32 and 64 do not
+    // require fences beacuse we can use amswap_db.[w/d].
+    return isa<LoadInst>(I) || (isa<StoreInst>(I) && (Size == 8 || Size == 16));
+  }
----------------
gonglingqin wrote:
> SixWeining wrote:
> > SixWeining wrote:
> > > Size = isa<StoreInst>(I) ? I->getOperand(0)->getType()->getIntegerBitWidth() : 0;
> > How about:
> > ```
> >   if (isa<LoadInst>(I))
> >     return true;
> > 
> >   // On LA64, atomic store operations with IntegerBitWidth of 32 and 64 do not
> >   // require fences beacuse we can use amswap_db.[w/d].
> >   if (isa<StoreInst>(I)) {
> >     unsigned Size = I->getOperand(0)->getType()->getIntegerBitWidth();
> >     return (Size == 8 || Size == 16);
> >   }
> > 
> >   return false;
> > ```
> Thanks.
Thanks, I will change it.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D129838/new/

https://reviews.llvm.org/D129838