From 0426ad40b56741117d00e780b07607f120ee1d01 Mon Sep 17 00:00:00 2001
From: Dan Gohman <dan433584@gmail.com>
Date: Thu, 19 Nov 2015 23:04:59 +0000
Subject: [PATCH] [WebAssembly] Implement isCheapToSpeculateCtlz and
 isCheapToSpeculateCttz.

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


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253617 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/WebAssembly/WebAssemblyISelLowering.cpp | 10 ++++++++++
 lib/Target/WebAssembly/WebAssemblyISelLowering.h   |  2 ++
 2 files changed, 12 insertions(+)

diff --git a/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp b/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
index bae4f526723..dbfe00e95ed 100644
--- a/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
+++ b/lib/Target/WebAssembly/WebAssemblyISelLowering.cpp
@@ -228,6 +228,16 @@ WebAssemblyTargetLowering::getRegForInlineAsmConstraint(
   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.
 //===----------------------------------------------------------------------===//
diff --git a/lib/Target/WebAssembly/WebAssemblyISelLowering.h b/lib/Target/WebAssembly/WebAssemblyISelLowering.h
index c79ffb29c25..3621571151a 100644
--- a/lib/Target/WebAssembly/WebAssemblyISelLowering.h
+++ b/lib/Target/WebAssembly/WebAssemblyISelLowering.h
@@ -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;
-- 
2.34.1