Revert "SimplifyCFG: GEPs with just one non-constant index are also cheap."

Yes, there are other types than i8* and GEPs on them can produce an add+multiply.
We don't consider that cheap enough to be speculatively executed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126481 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index 3968d6e8d3bb10e745b95fb641e7e516bdca1fa9..c6708857cb5601255cf26295524e527e004f8d4d 100644 (file)
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -247,13 +247,11 @@ static bool DominatesMergePoint(Value *V, BasicBlock *BB,
     if (PBB->getFirstNonPHIOrDbg() != I)
       return false;
     break;
-  case Instruction::GetElementPtr: {
-    // GEPs are cheap if all indices are constant or if there's only one index.
-    GetElementPtrInst *GEP = cast<GetElementPtrInst>(I);
-    if (!GEP->hasAllConstantIndices() && GEP->getNumIndices() > 1)
+  case Instruction::GetElementPtr:
+    // GEPs are cheap if all indices are constant.
+    if (!cast<GetElementPtrInst>(I)->hasAllConstantIndices())
       return false;
     break;
-  }
   case Instruction::Add:
   case Instruction::Sub:
   case Instruction::And:

diff --git a/test/Transforms/SimplifyCFG/select-gep.ll b/test/Transforms/SimplifyCFG/select-gep.ll
index 98650f0866395502a26d3658f27bcf3dde9059ec..009f05e5574cf1b859afb99c8b430e0024c71550 100644 (file)
--- a/test/Transforms/SimplifyCFG/select-gep.ll
+++ b/test/Transforms/SimplifyCFG/select-gep.ll
@@ -15,7 +15,7 @@ if.end:
   ret i8* %x.addr
 
 ; CHECK: @test1
-; CHECK: %x.addr = select i1 %cmp, i8* %incdec.ptr, i8* %x
+; CHECK-NOT: select
 ; CHECK: ret i8* %x.addr
 }