diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp | 8 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/vec_demanded_elts.ll | 13 |
2 files changed, 20 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp index a1fbda7f7e6..743d51483ea 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp @@ -1057,7 +1057,13 @@ Value *InstCombiner::SimplifyDemandedVectorElts(Value *V, APInt DemandedElts, APInt LeftDemanded(DemandedElts), RightDemanded(DemandedElts); if (ConstantVector* CV = dyn_cast<ConstantVector>(I->getOperand(0))) { for (unsigned i = 0; i < VWidth; i++) { - if (CV->getAggregateElement(i)->isNullValue()) + Constant *CElt = CV->getAggregateElement(i); + // Method isNullValue always returns false when called on a + // ConstantExpr. If CElt is a ConstantExpr then skip it in order to + // to avoid propagating incorrect information. + if (isa<ConstantExpr>(CElt)) + continue; + if (CElt->isNullValue()) LeftDemanded.clearBit(i); else RightDemanded.clearBit(i); diff --git a/llvm/test/Transforms/InstCombine/vec_demanded_elts.ll b/llvm/test/Transforms/InstCombine/vec_demanded_elts.ll index 5a2825ebfc3..0b9663300c3 100644 --- a/llvm/test/Transforms/InstCombine/vec_demanded_elts.ll +++ b/llvm/test/Transforms/InstCombine/vec_demanded_elts.ll @@ -253,3 +253,16 @@ define <4 x double> @test_vpermilvar_pd_256_zero(<4 x double> %v) { %a = tail call <4 x double> @llvm.x86.avx.vpermilvar.pd.256(<4 x double> %v, <4 x i64> zeroinitializer) ret <4 x double> %a } + +define <2 x i64> @PR24922(<2 x i64> %v) { +; CHECK-LABEL: @PR24922 +; CHECK: select <2 x i1> +; +; Check that instcombine doesn't wrongly fold the select statement into a +; ret <2 x i64> %v +; +; FIXME: We should be able to simplify the ConstantExpr in the select mask. +entry: + %result = select <2 x i1> <i1 icmp eq (i64 extractelement (<2 x i64> bitcast (<4 x i32> <i32 15, i32 15, i32 15, i32 15> to <2 x i64>), i64 0), i64 0), i1 true>, <2 x i64> %v, <2 x i64> zeroinitializer + ret <2 x i64> %result +} |
