[llvm] r259392 - [InstCombine] simplify masked store intrinsics with all ones or zeros masks

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Mon Feb  1 13:39:52 2016
New Revision: 259392

URL: http://llvm.org/viewvc/llvm-project?rev=259392&view=rev
Log:
[InstCombine] simplify masked store intrinsics with all ones or zeros masks

A masked store with a zero mask means there's no store.
A masked store with an allOnes mask means it's a normal vector store.

This is a continuation of:
http://reviews.llvm.org/rL259369


Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
    llvm/trunk/test/Transforms/InstCombine/masked_intrinsics.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp?rev=259392&r1=259391&r2=259392&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp Mon Feb  1 13:39:52 2016
@@ -773,6 +773,25 @@ static Value *simplifyMaskedLoad(const I
   return nullptr;
 }
 
+static Instruction *simplifyMaskedStore(IntrinsicInst &II, InstCombiner &IC) {
+  auto *ConstMask = dyn_cast<Constant>(II.getArgOperand(3));
+  if (!ConstMask)
+    return nullptr;
+
+  // If the mask is all zeros, this instruction does nothing.
+  if (ConstMask->isNullValue())
+    return IC.EraseInstFromFunction(II);
+
+  // If the mask is all ones, this is a plain vector store of the 1st argument.
+  if (ConstMask->isAllOnesValue()) {
+    Value *StorePtr = II.getArgOperand(1);
+    unsigned Alignment = cast<ConstantInt>(II.getArgOperand(2))->getZExtValue();
+    return new StoreInst(II.getArgOperand(0), StorePtr, false, Alignment);
+  }
+
+  return nullptr;
+}
+
 /// CallInst simplification. This mostly only handles folding of intrinsic
 /// instructions. For normal calls, it allows visitCallSite to do the heavy
 /// lifting.
@@ -901,9 +920,10 @@ Instruction *InstCombiner::visitCallInst
     if (Value *SimplifiedMaskedOp = simplifyMaskedLoad(*II, *Builder))
       return ReplaceInstUsesWith(CI, SimplifiedMaskedOp);
     break;
+  case Intrinsic::masked_store:
+    return simplifyMaskedStore(*II, *this);
 
   // TODO: Handle the other masked ops.
-  // case Intrinsic::masked_store:
   // case Intrinsic::masked_gather:
   // case Intrinsic::masked_scatter:
 

Modified: llvm/trunk/test/Transforms/InstCombine/masked_intrinsics.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/masked_intrinsics.ll?rev=259392&r1=259391&r2=259392&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/masked_intrinsics.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/masked_intrinsics.ll Mon Feb  1 13:39:52 2016
@@ -1,6 +1,7 @@
 ; RUN: opt -instcombine -S < %s | FileCheck %s
 
 declare <2 x double> @llvm.masked.load.v2f64(<2 x double>* %ptrs, i32, <2 x i1> %mask, <2 x double> %src0)
+declare void @llvm.masked.store.v2f64(<2 x double> %val, <2 x double>* %ptrs, i32, <2 x i1> %mask)
 
 
 define <2 x double> @load_zeromask(<2 x double>* %ptr, <2 x double> %passthru)  {
@@ -20,3 +21,20 @@ define <2 x double> @load_onemask(<2 x d
 ; CHECK-NEXT:  ret <2 x double> %unmaskedload
 }
 
+define void @store_zeromask(<2 x double>* %ptr, <2 x double> %val)  {
+  call void @llvm.masked.store.v2f64(<2 x double> %val, <2 x double>* %ptr, i32 3, <2 x i1> zeroinitializer)
+  ret void
+
+; CHECK-LABEL: @store_zeromask(
+; CHECK-NEXT:   ret void
+}
+
+define void @store_onemask(<2 x double>* %ptr, <2 x double> %val)  {
+  call void @llvm.masked.store.v2f64(<2 x double> %val, <2 x double>* %ptr, i32 4, <2 x i1> <i1 1, i1 1>)
+  ret void
+
+; CHECK-LABEL: @store_onemask(
+; CHECK-NEXT:  store <2 x double> %val, <2 x double>* %ptr, align 4
+; CHECK-NEXT:   ret void
+}
+