[llvm-commits] [llvm] r161654 - in /llvm/trunk: lib/Transforms/Scalar/ScalarReplAggregates.cpp test/Transforms/ScalarRepl/crash.ll

[Pete Cooper]

Author: pete
Date: Thu Aug  9 22:26:36 2012
New Revision: 161654

URL: http://llvm.org/viewvc/llvm-project?rev=161654&view=rev
Log:
Fix crash when when do lto on Bullet.  Dynamic GEPs in SROA were incorrectly being applied to all accesses to an alloca, not just the ones which read from the GEP.  Thanks to Evan for reducing the test.  rdar://11861001

Modified:
    llvm/trunk/lib/Transforms/Scalar/ScalarReplAggregates.cpp
    llvm/trunk/test/Transforms/ScalarRepl/crash.ll

Modified: llvm/trunk/lib/Transforms/Scalar/ScalarReplAggregates.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/ScalarReplAggregates.cpp?rev=161654&r1=161653&r2=161654&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/ScalarReplAggregates.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/ScalarReplAggregates.cpp Thu Aug  9 22:26:36 2012
@@ -612,11 +612,16 @@
     if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(User)) {
       // Compute the offset that this GEP adds to the pointer.
       SmallVector<Value*, 8> Indices(GEP->op_begin()+1, GEP->op_end());
-      if (!GEP->hasAllConstantIndices())
-        NonConstantIdx = Indices.pop_back_val();
+      Value* GEPNonConstantIdx = 0;
+      if (!GEP->hasAllConstantIndices()) {
+        assert(!NonConstantIdx &&
+               "Dynamic GEP reading from dynamic GEP unsupported");
+        GEPNonConstantIdx = Indices.pop_back_val();
+      } else
+        GEPNonConstantIdx = NonConstantIdx;
       uint64_t GEPOffset = TD.getIndexedOffset(GEP->getPointerOperandType(),
                                                Indices);
-      ConvertUsesToScalar(GEP, NewAI, Offset+GEPOffset*8, NonConstantIdx);
+      ConvertUsesToScalar(GEP, NewAI, Offset+GEPOffset*8, GEPNonConstantIdx);
       GEP->eraseFromParent();
       continue;
     }

Modified: llvm/trunk/test/Transforms/ScalarRepl/crash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ScalarRepl/crash.ll?rev=161654&r1=161653&r2=161654&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/ScalarRepl/crash.ll (original)
+++ llvm/trunk/test/Transforms/ScalarRepl/crash.ll Thu Aug  9 22:26:36 2012
@@ -260,5 +260,27 @@
   ret void
 }
 
+; rdar://11861001 - The dynamic GEP here was incorrectly making all accesses
+; to the alloca think they were also dynamic.  Inserts and extracts created to
+; access the vector were all being based from the dynamic access, even in BBs
+; not dominated by the GEP.
+define fastcc void @test() optsize inlinehint ssp align 2 {
+entry:
+  %alloc.0.0 = alloca <4 x float>, align 16
+  %bitcast = bitcast <4 x float>* %alloc.0.0 to [4 x float]*
+  %idx3 = getelementptr inbounds [4 x float]* %bitcast, i32 0, i32 3
+  store float 0.000000e+00, float* %idx3, align 4
+  br label %for.body10
+
+for.body10:                                       ; preds = %for.body10, %entry
+  %loopidx = phi i32 [ 0, %entry ], [ undef, %for.body10 ]
+  %unusedidx = getelementptr inbounds <4 x float>* %alloc.0.0, i32 0, i32 %loopidx
+  br i1 undef, label %for.end, label %for.body10
+
+for.end:                                          ; preds = %for.body10
+  store <4 x float> <float -1.000000e+00, float -1.000000e+00, float -1.000000e+00, float 0.000000e+00>, <4 x float>* %alloc.0.0, align 16
+  ret void
+}
+
 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
 declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind