[llvm] r345030 - [SLSR] use 'match' to simplify code; NFC

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Tue Oct 23 07:07:39 2018
New Revision: 345030

URL: http://llvm.org/viewvc/llvm-project?rev=345030&view=rev
Log:
[SLSR] use 'match' to simplify code; NFC

This pass could probably be modified slightly to allow
vector splat transforms for practically no cost, but
it only works on scalars for now. So the use of the
newer 'match' API should make no functional difference. 

Modified:
    llvm/trunk/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
    llvm/trunk/test/Transforms/StraightLineStrengthReduce/slsr-add.ll

Modified: llvm/trunk/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp?rev=345030&r1=345029&r2=345030&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/StraightLineStrengthReduce.cpp Tue Oct 23 07:07:39 2018
@@ -640,12 +640,12 @@ void StraightLineStrengthReduce::rewrite
   Value *Reduced = nullptr; // equivalent to but weaker than C.Ins
   switch (C.CandidateKind) {
   case Candidate::Add:
-  case Candidate::Mul:
+  case Candidate::Mul: {
     // C = Basis + Bump
-    if (BinaryOperator::isNeg(Bump)) {
+    Value *NegBump;
+    if (match(Bump, m_Neg(m_Value(NegBump)))) {
       // If Bump is a neg instruction, emit C = Basis - (-Bump).
-      Reduced =
-          Builder.CreateSub(Basis.Ins, BinaryOperator::getNegArgument(Bump));
+      Reduced = Builder.CreateSub(Basis.Ins, NegBump);
       // We only use the negative argument of Bump, and Bump itself may be
       // trivially dead.
       RecursivelyDeleteTriviallyDeadInstructions(Bump);
@@ -662,6 +662,7 @@ void StraightLineStrengthReduce::rewrite
       Reduced = Builder.CreateAdd(Basis.Ins, Bump);
     }
     break;
+  }
   case Candidate::GEP:
     {
       Type *IntPtrTy = DL->getIntPtrType(C.Ins->getType());

Modified: llvm/trunk/test/Transforms/StraightLineStrengthReduce/slsr-add.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/StraightLineStrengthReduce/slsr-add.ll?rev=345030&r1=345029&r2=345030&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/StraightLineStrengthReduce/slsr-add.ll (original)
+++ llvm/trunk/test/Transforms/StraightLineStrengthReduce/slsr-add.ll Tue Oct 23 07:07:39 2018
@@ -99,6 +99,34 @@ define void @stride_is_minus_2s(i32 %b,
   ret void
 }
 
+; TODO: This pass is targeted at simple address-calcs, so it is artificially limited to
+; match scalar values. The code could be modified to handle vector types too.
+
+define void @stride_is_minus_2s_vec(<2 x i32> %b, <2 x i32> %s) {
+; CHECK-LABEL: @stride_is_minus_2s_vec(
+; CHECK-NEXT:    [[S6:%.*]] = mul <2 x i32> [[S:%.*]], <i32 6, i32 6>
+; CHECK-NEXT:    [[T1:%.*]] = add <2 x i32> [[B:%.*]], [[S6]]
+; CHECK-NEXT:    call void @voo(<2 x i32> [[T1]])
+; CHECK-NEXT:    [[S4:%.*]] = shl <2 x i32> [[S]], <i32 2, i32 2>
+; CHECK-NEXT:    [[T2:%.*]] = add <2 x i32> [[B]], [[S4]]
+; CHECK-NEXT:    call void @voo(<2 x i32> [[T2]])
+; CHECK-NEXT:    [[S2:%.*]] = shl <2 x i32> [[S]], <i32 1, i32 1>
+; CHECK-NEXT:    [[T3:%.*]] = add <2 x i32> [[B]], [[S2]]
+; CHECK-NEXT:    call void @voo(<2 x i32> [[T3]])
+; CHECK-NEXT:    ret void
+;
+  %s6 = mul <2 x i32> %s, <i32 6, i32 6>
+  %t1 = add <2 x i32> %b, %s6
+  call void @voo(<2 x i32> %t1)
+  %s4 = shl <2 x i32> %s, <i32 2, i32 2>
+  %t2 = add <2 x i32> %b, %s4
+  call void @voo(<2 x i32> %t2)
+  %s2 = shl <2 x i32> %s, <i32 1, i32 1>
+  %t3 = add <2 x i32> %b, %s2
+  call void @voo(<2 x i32> %t3)
+  ret void
+}
+
 ; t = b + (s << 3);
 ; foo(t);
 ; foo(b + s);
@@ -140,4 +168,5 @@ define void @slsr_strided_add_128bit(i12
 }
 
 declare void @foo(i32)
+declare void @voo(<2 x i32>)
 declare void @bar(i128)