[PATCH] D80943: [X86] Add a flag to guard the wide load

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


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Comment at: llvm/lib/Target/X86/X86InstrInfo.td:1135
     return true;
-  if (ExtType == ISD::EXTLOAD)
+  if (ExtType == ISD::EXTLOAD && Subtarget->enableWideLoad())
     return LD->getAlignment() >= 4 && LD->isSimple();
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Why not do this in loadi16 as well?


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Comment at: llvm/lib/Target/X86/X86Subtarget.cpp:48
 
+static cl::opt<bool> EnableWideLoad("x86-enalbe-wide-load", cl::init(true),
+    cl::desc("If load an 8b or 16b value from 32b aligned address, and any "
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Can we put this in X86ISelDAGToDAG.cpp and access it directly? The .td should generate an include that gets included there.


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Comment at: llvm/lib/Target/X86/X86Subtarget.cpp:48
 
+static cl::opt<bool> EnableWideLoad("x86-enalbe-wide-load", cl::init(true),
+    cl::desc("If load an 8b or 16b value from 32b aligned address, and any "
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craig.topper wrote:
> Can we put this in X86ISelDAGToDAG.cpp and access it directly? The .td should generate an include that gets included there.
enalbe->enable

x86-promote-anyext-load might be a better name? "wide" might get mixed up with vectors since we have WidenVector as a type legalization action.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D80943/new/

https://reviews.llvm.org/D80943