[llvm-commits] [llvm] r62998 - in /llvm/trunk: lib/Transforms/Scalar/InstructionCombining.cpp test/Transforms/InstCombine/vec_shuffle2.ll

[Mon P Wang]

Author: wangmp
Date: Sun Jan 25 22:39:00 2009
New Revision: 62998

URL: http://llvm.org/viewvc/llvm-project?rev=62998&view=rev
Log:
Fixed optimization of combining two shuffles where the first shuffle inputs
has a different number of elements than the output.

Added:
    llvm/trunk/test/Transforms/InstCombine/vec_shuffle2.ll
Modified:
    llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=62998&r1=62997&r2=62998&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Sun Jan 25 22:39:00 2009
@@ -12179,9 +12179,11 @@
       // If the result mask is equal to the src shuffle or this shuffle mask, do
       // the replacement.
       if (NewMask == LHSMask || NewMask == Mask) {
+        unsigned LHSInNElts =
+          cast<VectorType>(LHSSVI->getOperand(0)->getType())->getNumElements();
         std::vector<Constant*> Elts;
         for (unsigned i = 0, e = NewMask.size(); i != e; ++i) {
-          if (NewMask[i] >= e*2) {
+          if (NewMask[i] >= LHSInNElts*2) {
             Elts.push_back(UndefValue::get(Type::Int32Ty));
           } else {
             Elts.push_back(ConstantInt::get(Type::Int32Ty, NewMask[i]));

Added: llvm/trunk/test/Transforms/InstCombine/vec_shuffle2.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/vec_shuffle2.ll?rev=62998&view=auto

==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/vec_shuffle2.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/vec_shuffle2.ll Sun Jan 25 22:39:00 2009
@@ -0,0 +1,19 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep undef | count 1
+; END.
+
+; Test fold of two shuffles where the first shuffle vectors inputs are a
+; different length then the second.
+
+define void @test_cl(<4 x i8> addrspace(1)* %dest, <16 x i8> addrspace(1)* %old) nounwind {
+entry:
+	%arrayidx = getelementptr <4 x i8> addrspace(1)* %dest, i32 0		; <<4 x i8> addrspace(1)*> [#uses=1]
+	%arrayidx5 = getelementptr <16 x i8> addrspace(1)* %old, i32 0		; <<16 x i8> addrspace(1)*> [#uses=1]
+	%tmp6 = load <16 x i8> addrspace(1)* %arrayidx5		; <<16 x i8>> [#uses=1]
+	%tmp7 = shufflevector <16 x i8> %tmp6, <16 x i8> undef, <4 x i32> < i32 13, i32 9, i32 4, i32 13 >		; <<4 x i8>> [#uses=1]
+	%tmp9 = shufflevector <4 x i8> %tmp7, <4 x i8> undef, <4 x i32> < i32 3, i32 1, i32 2, i32 0 >		; <<4 x i8>> [#uses=1]
+	store <4 x i8> %tmp9, <4 x i8> addrspace(1)* %arrayidx
+	ret void
+
+return:		; preds = %entry
+	ret void
+}
\ No newline at end of file