[llvm] r253617 - [WebAssembly] Implement isCheapToSpeculateCtlz and isCheapToSpeculateCttz.

[Dan Gohman via llvm-commits]

Author: djg
Date: Thu Nov 19 17:04:59 2015
New Revision: 253617

URL: http://llvm.org/viewvc/llvm-project?rev=253617&view=rev
Log:
[WebAssembly] Implement isCheapToSpeculateCtlz and isCheapToSpeculateCttz.

This unbreaks test/CodeGen/WebAssembly/i32.ll and
test/CodeGen/WebAssembly/i64.ll after r224899.

Modified:
    llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
    llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.h

Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp?rev=253617&r1=253616&r2=253617&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp Thu Nov 19 17:04:59 2015
@@ -228,6 +228,16 @@ WebAssemblyTargetLowering::getRegForInli
   return TargetLowering::getRegForInlineAsmConstraint(TRI, Constraint, VT);
 }
 
+bool WebAssemblyTargetLowering::isCheapToSpeculateCttz() const {
+  // Assume ctz is a relatively cheap operation.
+  return true;
+}
+
+bool WebAssemblyTargetLowering::isCheapToSpeculateCtlz() const {
+  // Assume clz is a relatively cheap operation.
+  return true;
+}
+
 //===----------------------------------------------------------------------===//
 // WebAssembly Lowering private implementation.
 //===----------------------------------------------------------------------===//

Modified: llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.h?rev=253617&r1=253616&r2=253617&view=diff
==============================================================================
--- llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.h (original)
+++ llvm/trunk/lib/Target/WebAssembly/WebAssemblyISelLowering.h Thu Nov 19 17:04:59 2015
@@ -52,6 +52,8 @@ private:
   std::pair<unsigned, const TargetRegisterClass *>
   getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
                                StringRef Constraint, MVT VT) const override;
+  bool isCheapToSpeculateCttz() const override;
+  bool isCheapToSpeculateCtlz() const override;
 
   SDValue LowerCall(CallLoweringInfo &CLI,
                     SmallVectorImpl<SDValue> &InVals) const override;