[llvm] r349693 - [CodeGenPrepare] Fix bad IR created by large offset GEP splitting.

[Eli Friedman via llvm-commits]

Author: efriedma
Date: Wed Dec 19 14:52:04 2018
New Revision: 349693

URL: http://llvm.org/viewvc/llvm-project?rev=349693&view=rev
Log:
[CodeGenPrepare] Fix bad IR created by large offset GEP splitting.

Creating the IR builder, then modifying the CFG, leads to an IRBuilder
where the BB and insertion point are inconsistent, so new instructions
have the wrong parent.

Modified an existing test because the test wasn't covering anything
useful (the "invoke" was not actually an invoke by the time we hit the
code in question).

Differential Revision: https://reviews.llvm.org/D55729


Modified:
    llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
    llvm/trunk/test/Transforms/CodeGenPrepare/AArch64/large-offset-gep.ll

Modified: llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp?rev=349693&r1=349692&r2=349693&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/CodeGenPrepare.cpp Wed Dec 19 14:52:04 2018
@@ -5160,11 +5160,11 @@ bool CodeGenPrepare::splitLargeGEPOffset
       }
 
       // Generate a new GEP to replace the current one.
-      IRBuilder<> Builder(GEP);
+      LLVMContext &Ctx = GEP->getContext();
       Type *IntPtrTy = DL->getIntPtrType(GEP->getType());
       Type *I8PtrTy =
-          Builder.getInt8PtrTy(GEP->getType()->getPointerAddressSpace());
-      Type *I8Ty = Builder.getInt8Ty();
+          Type::getInt8PtrTy(Ctx, GEP->getType()->getPointerAddressSpace());
+      Type *I8Ty = Type::getInt8Ty(Ctx);
 
       if (!NewBaseGEP) {
         // Create a new base if we don't have one yet.  Find the insertion
@@ -5200,6 +5200,7 @@ bool CodeGenPrepare::splitLargeGEPOffset
         NewGEPBases.insert(NewBaseGEP);
       }
 
+      IRBuilder<> Builder(GEP);
       Value *NewGEP = NewBaseGEP;
       if (Offset == BaseOffset) {
         if (GEP->getType() != I8PtrTy)

Modified: llvm/trunk/test/Transforms/CodeGenPrepare/AArch64/large-offset-gep.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/CodeGenPrepare/AArch64/large-offset-gep.ll?rev=349693&r1=349692&r2=349693&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/CodeGenPrepare/AArch64/large-offset-gep.ll (original)
+++ llvm/trunk/test/Transforms/CodeGenPrepare/AArch64/large-offset-gep.ll Wed Dec 19 14:52:04 2018
@@ -88,18 +88,23 @@ while_end:
 }
 
 declare %struct_type* @foo()
+declare void @foo2()
 
 define void @test4(i32 %n) personality i32 (...)* @__FrameHandler {
 ; CHECK-LABEL: test4
 entry:
-  %struct = invoke %struct_type* @foo() to label %while_cond unwind label %cleanup
+  br label %while_cond
 
 while_cond:
   %phi = phi i32 [ 0, %entry ], [ %i, %while_body ]
+  %struct = invoke %struct_type* @foo() to label %while_cond_x unwind label %cleanup
+
+while_cond_x:
 ; CHECK:     mov     w{{[0-9]+}}, #40000
 ; CHECK-NOT: mov     w{{[0-9]+}}, #40004
   %gep0 = getelementptr %struct_type, %struct_type* %struct, i64 0, i32 1
   %gep1 = getelementptr %struct_type, %struct_type* %struct, i64 0, i32 2
+  store i32 0, i32* %gep0
   %cmp = icmp slt i32 %phi, %n
   br i1 %cmp, label %while_body, label %while_end
 
@@ -114,8 +119,10 @@ while_end:
   ret void
 
 cleanup:
-  landingpad { i8*, i32 } cleanup
-  unreachable
+  %x10 = landingpad { i8*, i32 }
+          cleanup
+  call void @foo2()
+  resume { i8*, i32 } %x10
 }
 
 declare i32 @__FrameHandler(...)